Compositions and methods for inducing meiosis

Abstract

Provided are compositions and methods for increasing the amount of pro-meiotic proteins in a cell, wherein the proteins are selected from: STRA8, MEIOSIN, DAZL, DMRT1, NANOS3, DDX4, CTCFL, DEK, YY2, SMC1B, or a combination thereof. In some embodiments, the pro-meiotic proteins are useful for inducing meiosis in cells (e.g., non-meiotic cells).

Description

COMPOSITIONS AND METHODS FOR INDUCING MEIOSISCROSS-REFERENCE

[0001] This application claims the benefit of U.S. Patent Application No. 63 / 610,779, filed December 15, 2023, which is entirely incorporated herein by reference.BACKGROUND

[0002] Meiosis is a feature of sexual reproduction characterized by one round of DNA replication followed by two rounds of cell division, resulting in haploid germ cells. The initiation of meiosis requires both intrinsic and extrinsic signals. Effective induction of meiosis cells remains a challenge.SUMMARY

[0003] In some embodiments, provided and described herein are cells comprising one or more engineered polynucleotides encoding one or more proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof.

[0004] In some embodiments, provided and described herein are cells comprising one or more exogenous nucleic acid sequences encoding one or more proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof.

[0005] In some embodiments, provided and described herein are cells comprising one or more CRISPR-dCas activation systems comprising an enzymatically inactive Cas protein and a gRNA comprising a spacer sequence that hybridizes to a gene region (e.g., upstream or downstream of the TSS) selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof.

[0006] In some embodiments, provided and described herein are compositions comprising one or more engineered mRNA polynucleotides encoding one or more proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof.

[0007] In some embodiments, provided and described herein are CRISPR-dCas activation systems comprising an enzymatically inactive Cas protein and a gRNAcomprising a spacer sequence that hybridizes to a gene region selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof. In certain embodiments, the spacer sequence hybridizes upstream or downstream of a transcription start site for a sequence encoding a protein selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof.

[0008] In some embodiments, provided and described herein are methods of inducing and / or promoting meiosis, the methods comprising: increasing the cellular amount of one or more proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof, thereby inducing meiosis of the cell.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Various features of the disclosure set forth herein are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present disclosure can be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings of which:

[0010] FIG. 1 shows CRISPRa data for DAZL in HEK293T cells. CRISPRa having a gRNA targeting DAZL showed increased DAZL expression across multiple targets.

[0011] FIG. 2 shows CRISPRa data for DMRT1 in HEK293T cells. CRISPRa having a gRNA targeting DMRT1 showed increased DMRT1 expression across multiple targets.

[0012] FIG. 3 shows CRISPRa data for MEIOSIN in HEK293T cells. CRISPRa having a gRNA targeting MEIOSIN showed increased MEIOSIN expression across multiple targets.

[0013] FIG. 4 shows CRISPRa data for SMC1 B in HEK293T cells. CRISPRa having a gRNA targeting SMC1 B showed increased SMC1 B expression across multiple targets.

[0014] FIG. 5 shows CRISPRa data for STRA8 in HEK293T cells. CRISPRa having a gRNA targeting STRA8 showed increased STRA8 expression across multiple targets.

[0015] FIG. 6 shows mRNA activation data for SYCP3 in HEK293T cells. mRNA transfection showed increased SYCP3.

[0016] FIG. 7 shows qRT-PCR data illustrating the effect that combinations of meiosis inducing genes have on the expression levels of meiosis markers in iPSC's.

[0017] FIG. 8 shows immunofluorescence data depicting the co-localization of Hoechst nuclear staining with nuclear-localized meiosis markers after induction treatment.

[0018] FIG. 9 shows time course qRT-PCR data illustrating the effect that combinations of meiosis inducing genes have on the expression levels of meiosis markers over time.

[0019] FIG. 10 shows time course bulk RNA seq data depicting the gene activation profile of cells treated with induction media and transfection, versus untreated controls.

[0020] FIG. 11 shows qRT-PCR data showing dose response of downstream meiosis genes from activated effector genes, via CRISPRa experiments.

[0021] FIG. 12 shows qRT-PCR data comparing conditions lacking effector genes versus conditions with effector genes transfected in equivalent medium conditions.

[0022] FIG. 13 shows bulk RNA-seq data quantifying the relative increase in meiosis genes from CRISPRa targeting STRA8, MEIOSIN, and DAZL relative to an un-transfected condition.DETAILED DESCRIPTION

[0023] While various embodiments of the invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions may occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed.Pro-meiotic proteins

[0024] Provided are compositions and methods useful for increasing the amount of pro-meiotic proteins in a cell, wherein the proteins comprise one or more (e.g., at least or at most about 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10) members from: STRA8,MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof. In some embodiments, the pro-meiotic proteins are useful for inducing meiosis in cells.

[0025] Meiosis generally refers to and includes the two-stage process of nuclear division that reduces the somatic chromosome number (2n) to half (n) and is generally followed by gamete formation. Generally, the chromosome number is reduced in the first stage of meiosis and in the second stage of meiosis, there is an equational division of the chromosome resulting in four daughter nuclei, each carrying one chromatid. Meiosis is split into meiosis I and meiosis II, and both meiotic divisions have multiple phases. Meiosis I, the initial stage of meiotic division, commences with prophase I. In this phase, chromatin, the complex of DNA and proteins, condenses into chromosomes. These chromosomes consist of pairs called sister chromatids, connected at a central point known as the centromere. Concurrently, a meiotic spindle forms from microtubules on opposite sides of the cell. Between prophase I and metaphase I, homologous chromosome pairs arrange into tetrads, where chromatid arms can undergo crossing-over or recombination, a process breaking, recombining, and rejoining DNA sections to generate novel gene combinations. In metaphase I, homologous chromosome pairs align on the equatorial plate, and in anaphase I, spindle fibers pull them, each with two chromatids, apart towards opposite poles. Telophase I encases chromosomes in nuclei, followed by cytokinesis, dividing the cell's cytoplasm into two haploid daughter cells, each with half the original chromosome count. Meiosis II represents a mitotic division of the haploid cells from meiosis I. In prophase II, chromosomes condense, and a new set of spindle fibers emerges. Chromosomes migrate toward the cell's equator. Metaphase II sees centromeres of paired chromatids align along the equatorial plate in both cells. In anaphase II, chromosomes separate at the centromeres, and spindle fibers guide them to opposite poles. Telophase II encapsulates chromosomes in nuclear membranes, followed by cytokinesis dividing the cytoplasm. Ultimately, meiosis concludes with four haploid daughter cells, destined to develop into sperm or egg cells.

[0026] Pro-meiotic proteins generally refers to and includes proteins capable of inducing and / or promoting meiosis. In some embodiments, inducing and / or promoting meiosis comprises generating a haploid cell. In some embodiments, inducing and / or promoting meiosis comprises inducing and / or promoting Meiosis IIin a cell (e.g., characterized by a cell being in one of the stages selected from: prophase II, pro-metaphase II, metaphase II, anaphase II, or telophase II). In some embodiments, inducing and / or promoting meiosis comprises inducing and / or promoting Meiosis I in a cell (e.g., characterized by a cell being in one of the stages selected from: prophase I, pro-metaphase I, metaphase I, anaphase I, telophase I, or cytokinesis II). In some embodiments, inducing and / or promoting meiosis comprises inducing and / or promoting leptotene in a cell (e.g., characterized by a cell being in the leptotene stage of prophase I). In some embodiments, inducing and / or promoting meiosis comprises inducing and / or promoting zygotene in a cell (e.g., characterized by a cell being in the zygotene stage of prophase I). In some embodiments, inducing and / or promoting meiosis comprises inducing and / or promoting pachytene in a cell (e.g., characterized by a cell being in the pachytene stage of prophase I). In some embodiments, inducing and / or promoting meiosis comprises inducing and / or promoting diplotene in a cell (e.g., characterized by a cell being in the diplotene stage of prophase I). In some embodiments, inducing and / or promoting meiosis comprises inducing and / or promoting diakinesis in a cell (e.g., characterized by a cell being in the diakinesis stage of prophase I). In some embodiments, inducing and / or promoting meiosis comprises increasing homologous recombination (also referred to as meiotic recombination and / or crossing over). In certain embodiments, recombination is determined by: measuring linkage disequilibrium analysis, whole genome sequencing, cytologically counting chiasmata or recombination nodules, and / or fluorescent tetrad analysis.

[0027] In some embodiments, provided are compositions for increasing DMRT1 in a cell. DMRT1 (doublesex and mab-3 related transcription factor 1 ) generally refers to and includes the protein encoded by the DMRT1 gene (also known as DMT1 or CT154). DMRT1 is considered to be a transcription factor having a DNA- binding domain that is similar to a zine finger (DM domain), and in certain instances, is considered to be involved in sex determination and gonadal development across a broad range of species. In certain embodiments, the DMRT1 gene refers to NCBI GenelD 1761 and / or HGNC ID: HGNC:2934. In certain embodiments, a DMRT1 protein refers to and includes the protein(s) of UniProt ID: H3BN61 , B2R913, Q6T1 H8, Q6T1 H9, Q8IW77, or Q9Y5R6, and / or Consensus CDS: CCDS6442.1 or CCDS87636.1. In certain instances, DMRT1 comprises a protein comprising the amino acid sequence of SEQ ID NO: 1 or an isoform or a homologue or anorthologue or variant thereof (e.g., as referenced in NCBI GenelD 1761 and / or HGNC ID: HGNC:2934). In certain instances, DMRT1 comprises a protein comprising an amino acid sequence having at least or at most about 80, 85, 90, 95, 97, 98, or 99% sequence identity to SEQ ID NO: 1 or an isoform or a homologue or an orthologue or variant thereof (e.g., as referenced in NCBI GenelD 1761 and / or HGNC ID: HGNC:2934). In certain instances, DMRT1 comprises a protein comprising the amino acid sequence of any one of UniProt ID: H3BN61 , B2R913, Q6T1 H8, Q6T1 H9, Q8IW77, or Q9Y5R6, or Consensus CDS: CCDS6442.1 or CCDS87636.1.

[0028] In some embodiments, provided are compositions for increasing YY2 in a cell. YY2 (YY2 transcription factor) generally refers to and includes the protein encoded by the YY2 gene (also known as ZNF631 ). YY2 is considered to be a multifunctional transcription factor, and in certain instances, exhibits a positive or negative control on a large number of genes. In certain embodiments, the YY2 gene refers to NCBI GenelD 404281 and / or HGNC ID: HGNC:31684. In certain embodiments, a YY2 protein refers to and includes the protein(s) of UniProt ID: B2RP10, 015391 , and / or Q6Q1 S4, and / or Consensus CDS: CCDS14202.1. In certain instances, YY2 comprises a protein comprising the amino acid sequence of SEQ ID NO: 2 or an isoform or a homologue or an orthologue or variant thereof (e.g., as referenced in NCBI GenelD 404281 and / or HGNC ID: HGNC:31684). In certain instances, YY2 comprises a protein comprising an amino acid sequence having at least or at most about 80, 85, 90, 95, 97, 98, or 99% sequence identity to of SEQ ID NO: 2 or an isoform or a homologue or an orthologue or variant thereof (e.g., as referenced in NCBI GenelD 404281 and / or HGNC ID: HGNC:31684). In certain instances, YY2 comprises a protein comprising the amino acid sequence of any one of UniProt ID: B2RP10, 015391 , and / or Q6Q1 S4, and / or Consensus CDS: CCDS14202.1.

[0029] In some embodiments, provided are compositions for increasing CTCFL in a cell. CTCFL (CCCTC-binding factor like) generally refers to and includes the protein encoded by the CTCFL (also known as T27, BORIS, CTCF-T, HMGB1 L1 , and dJ579F20.2). CTCFL is considered to be 11 -zinc-finger factor, and in certain instances, is considered to be involved in gene regulation. In certain embodiments, the CTCFL gene refers to NCBI GenelD 140690 and / or HGNC ID: HGNC: 16234. In certain embodiments, a CTCFL protein refers to and includes the protein(s) ofConsensus CDS: CCDS13459.1 , CCDS58780.1 , CCDS58781.1 , CCDS68164.1 , CCDS58779.1 , and / or CCDS68163.1 , and / or UniProt ID: A0S6W1 , A1 L4C6, A6XGL8, A6XGM2, A6XGM3, A6XGM8, A6XGM9, A6XGN0, A6XGN1 , A6XGN2, A6XGN3, A6XGN4, E7EQ27, E7EUE3, E9PBA9, Q5JUG4, Q8NI51 , Q9BZ30, Q9NQJ3, B2RA05. In certain instances, CTCFL comprises a protein comprising the amino acid sequence of SEQ ID NO: 3. In certain instances, CTCFL comprises a protein comprising an amino acid sequence having at least or at most about 80, 85, 90, 95, 97, 98, or 99% sequence identity to of SEQ ID NO: 3. In certain instances, CTCFL comprises a protein comprising the amino acid sequence of any one of CDS: CCDS13459.1 , CCDS58780.1 , CCDS58781.1 , CCDS68164.1 ,CCDS58779.1 , and / or CCDS68163.1 , and / or UniProt ID: A0S6W1 , A1 L4C6, A6XGL8, A6XGM2, A6XGM3, A6XGM8, A6XGM9, A6XGN0, A6XGN1 , A6XGN2, A6XGN3, A6XGN4, E7EQ27, E7EUE3, E9PBA9, Q5JUG4, Q8NI51 , Q9BZ30, Q9NQJ3, B2RA05.

[0030] In some embodiments, provided are compositions for increasing STRA8 in a cell. STRA8 (stimulated by retinoic acid 8) generally refers to and includes the protein encoded by the STRA8 gene. STRA8 is considered to be a retinoic acid- responsive protein, and in certain instances, is considered to play a role in the regulation of meiotic initiation in both spermatogenesis and oogenesis. In certain embodiments, the STRA8 gene refers to NCBI GenelD 346673 and / or HGNC ID: 30653. In certain embodiments, a STRA8 protein refers to and includes the protein(s) of UniProt ID: Q7Z7C7 and / or Consensus CDS: CCDS94209.1 and / or CCDS5839.2. In certain instances, STRA8 comprises a protein comprising the amino acid sequence of SEQ ID NO: 4-6 or an isoform or a homologue or an orthologue or variant thereof (e.g., as referenced in NCBI GenelD 346673 and / or HGNC ID: 30653). In certain instances, STRA8 comprises a protein comprising an amino acid sequence having at least or at most about 80, 85, 90, 95, 97, 98, or 99% sequence identity to of SEQ ID NO: 4-6 or an isoform or a homologue or an orthologue or variant thereof (e.g., as referenced in NCBI GenelD 346673 and / or HGNC ID: 30653). In certain instances, STRA8 comprises a protein comprising the amino acid sequence of any one of UniProt ID: Q7Z7C7 and / or Consensus CDS: CCDS94209.1 and / or CCDS5839.2.

[0031] In some embodiments, provided are compositions for increasing MEIOSIN in a cell. MEIOSIN (meiosis initiator) generally refers to and includes theprotein encoded by the MEIOSIN gene (also referred to as BHMG1 and HMGDC). MEIOSIN is considered to be a retinoic acid-responsive protein, and in certain instances, is considered to play a role in the regulation of meiotic initiation in both spermatogenesis and oogenesis. In certain embodiments, the MEIOSIN gene refers to NCBI GenelD 388553 and / or HGNC ID: 44318. In certain embodiments, a MEIOSIN protein refers to and includes the protein(s) of UniProt ID: C9JSJ3 and / or Consensus CDS: CCDS82368.1. In certain instances, MEIOSIN comprises a protein comprising the amino acid sequence of SEQ ID NO: 7 or an isoform or a homologue or an orthologue or variant thereof (e.g., as referenced in NCBI GenelD 388553 and / or HGNC ID: 44318). In certain instances, MEIOSIN comprises a protein comprising an amino acid sequence having at least or at most about 80, 85, 90, 95, 97, 98, or 99% sequence identity to of SEQ ID NO: 7 or an isoform or a homologue or an orthologue or variant thereof (e.g., as referenced in NCBI GenelD 388553 and / or HGNC ID: 44318). In certain instances, MEIOSIN comprises a protein comprising the amino acid sequence of any one of UniProt ID: C9JSJ3 and / or Consensus CDS: CCDS82368.1 .

[0032] In some embodiments, provided are compositions for increasing DEK in a cell. DEK (DEK proto-oncogene) generally refers to and includes the protein encoded by the DEK gene (also referred to as D6S231 E). DEK is considered to be a multifunctional transcription factor, and in certain instances, exhibits a positive or negative control on a large number of genes. In certain embodiments, the DEK gene refers to NCBI GenelD 7913 and / or HGNC ID: HGNC:2768. In certain embodiments, a DEK protein refers to and includes the protein(s) of UniProt ID: P35659-1 and / or P35659-2 , and / or Consensus CDS: CCDS47382.1 and / or CCDS34344.1 . In certain instances, DEK comprises a protein comprising the amino acid sequence of SEQ ID NO: 8 or an isoform or a homologue or an orthologue or variant thereof (e.g., as referenced in NCBI GenelD 7913 and / or HGNC ID: HGNC:2768). In certain instances, DEK comprises a protein comprising an amino acid sequence having at least or at most about 80, 85, 90, 95, 97, 98, or 99% sequence identity to of SEQ ID NO: 8 or an isoform or a homologue or an orthologue or variant thereof (e.g., as referenced in NCBI GenelD 7913 and / or HGNC ID: HGNC:2768). In certain instances, DEK comprises a protein comprising the amino acid sequence of any one UniProt ID: P35659-1 and / or P35659-2 , and / or Consensus CDS: CCDS47382.1 and / or CCDS34344.1 .

[0033] In some embodiments, provided are compositions for increasing DAZL in a cell. DAZL (deleted in azoospermia like) generally refers to and includes the protein encoded by the DAZL gene (also known as DAZH, DAZL1 , DAZLA, and SPGYLA). DAZL is considered to RNA-binding protein, and in certain instances, is considered to function in gametogenesis in both males and females. In certain embodiments, the DAZL gene refers to NCBI GenelD 1618 and / or HGNC ID: HGNC:2685. In certain embodiments, a DAZL protein refers to and includes the protein(s) of UniProt ID: Q92904 (-1 and / or -2), and / or Consensus CDS: CCDS54556.1 and / or CCDS43059.1. In certain instances, DAZL comprises a protein comprising the amino acid sequence of SEQ ID NO: 9 or an isoform or a homologue or an orthologue or variant thereof (e.g., as referenced in NCBI GenelD 1618 and / or HGNC ID: HGNC:2685). In certain instances, DAZL comprises a protein comprising an amino acid sequence having at least or at most about 80, 85, 90, 95, 97, 98, or 99% sequence identity to of SEQ ID NO: 9 or an isoform or a homologue or an orthologue or variant thereof (e.g., as referenced in NCBI GenelD 1618 and / or HGNC ID: HGNC:2685). In certain instances, DAZL comprises a protein comprising the amino acid sequence of any one of UniProt ID: Q92904 (-1 and / or -2), and / or Consensus CDS: CCDS54556.1 and / or CCDS43059.1 .

[0034] In some embodiments, provided are compositions for increasing NANOS3 in a cell. NANOS3 (nanos C2HC-type zinc finger 3) generally refers to and includes the protein encoded by the NANOS3 gene (also known as NOS3, NANOS1 L, and ZC2HC12C). NANOS3 is considered to function in the maintenance of the undifferentiated state of germ cells regulating the spermatogonia cell cycle and inducing a prolonged transit in G1 phase. In certain embodiments, the NANOS3 gene refers to NCBI GenelD 342977 and / or HGNC ID: HGNC:224048. In certain embodiments, a NANOS3 protein refers to and includes the protein(s) of UniProt ID: P60323 (-1 and / or -2), and / or Consensus CDS: CCDS4251 1.1. In certain instances, NANOS3 comprises a protein comprising the amino acid sequence of SEQ ID NO: 10 or an isoform or a homologue or an orthologue or variant thereof (e.g., as referenced in NCBI GenelD 342977 and / or HGNC ID: HGNC:224048). In certain instances, NANOS3 comprises a protein comprising an amino acid sequence having at least or at most about 80, 85, 90, 95, 97, 98, or 99% sequence identity to of SEQ ID NO: 10 or an isoform or a homologue or an orthologue or variant thereof (e.g., as referenced in NCBI GenelD 342977 and / or HGNC ID:HGNC:224048). In certain instances, NANOS3 comprises a protein comprising the amino acid sequence of any one of UniProt ID: P60323 (-1 and / or -2), and / or Consensus CDS: CCDS4251 1.1.

[0035] In some embodiments, provided are compositions for increasing DDX4 in a cell. DDX4 (DEAD-box helicase 4) generally refers to and includes the protein encoded by the DDX4 gene. DDX4 is considered a putative helicase having a conserved motif Asp-Glu-Ala-Asp (DEAD), and in certain instances, is considered to function in a number of cellular processes involving alteration of RNA secondary structure such as translation initiation, nuclear and mitochondrial splicing, and ribosome and spliceosome assembly. In certain embodiments, the DDX4 gene refers to NCBI GenelD 54514 and / or HGNC ID: HGNC: 18700. In certain embodiments, a DDX4 protein refers to and includes the protein(s) of UniProt ID: Q9NQI0 (-1 , -2, -3, and / or -4), and / or Consensus CDS: CCDS3969.1 , CCDS47208.1 , CCDS54854.1 , and / or CCDS54855.1. In certain instances, DDX4 comprises a protein comprising the amino acid sequence of SEQ ID NO: 1 1 or an isoform or a homologue or an orthologue or variant thereof (e.g., as referenced in NCBI GenelD 54514 and / or HGNC ID: HGNC: 18700). In certain instances, DDX4 comprises a protein comprising an amino acid sequence having at least or at most about 80, 85, 90, 95, 97, 98, or 99% sequence identity to of SEQ ID NO: 11 or an isoform or a homologue or an orthologue or variant thereof (e.g., as referenced in NCBI GenelD 54514 and / or HGNC ID: HGNC: 18700). In certain instances, DDX4 comprises a protein comprising the amino acid sequence of any one of UniProt ID: Q9NQI0 (-1 , -2, -3, and / or -4), and / or Consensus CDS: CCDS3969.1 , CCDS47208.1 , CCDS54854.1 , and / or CCDS54855.1 .

[0036] In some embodiments, provided are compositions for increasing SMC1 B in a cell. SMC1 B (structural maintenance of chromosomes 1 B) generally refers to and includes the protein encoded by the SMC1 B gene (also known as SMC1 L2; SMC1 BETA). SMC1 B is considered to belong to a family of proteins required for chromatid cohesion and DNA recombination during meiosis and mitosis. In certain embodiments, the SMC1 B gene refers to NCBI GenelD 27127 and / or HGNC ID: HGNC: 1 11 12. In certain embodiments, a SMC1 B protein refers to and includes the protein(s) of UniProt ID: Q8NDV3 (-2 and / or -3), and / or Consensus CDS: CCDS43027.1 and / or CCDS74876.1. In certain instances, SMC1 B comprises a protein comprising the amino acid sequence of SEQ ID NO: 12 or an isoform or ahomologue or an orthologue or variant thereof (e.g., as referenced in NCBI GenelD 27127 and / or HGNC ID: HGNC: 1 11 12). In certain instances, SMC1 B comprises a protein comprising an amino acid sequence having at least or at most about 80, 85, 90, 95, 97, 98, or 99% sequence identity to of SEQ ID NO: 12 or an isoform or a homologue or an orthologue or variant thereof (e.g., as referenced in NCBI GenelD 27127 and / or HGNC ID: HGNC: 1 11 12). In certain instances, SMC1 B comprises a protein comprising the amino acid sequence of any one of UniProt ID: Q8NDV3 (- 2 and / or -3), and / or Consensus CDS: CCDS43027.1 and / or CCDS74876.1.Engineered Polynucleotides

[0037] In some embodiments, provided are engineered polynucleotides (e.g., non-naturally occurring polynucleotides) encoding one or more (e.g., at least or at most about 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10) pro-meiotic proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof. In certain embodiments, the engineered polynucleotides are non-naturally occurring polynucleotides. In certain embodiments, the engineered polynucleotides are synthetic polynucleotides (e.g., made by chemical synthesis, not within or by a cell). In certain embodiments, the engineered polynucleotide is an exogenous polynucleotide (e.g., originating from outside a cell / organism). In some embodiments, the engineered polynucleotide is a deoxyribonucleic nucleic acid (DNA) molecule that is capable of being transcribed to produce a messenger ribonucleic acid (mRNA) molecule encoding a pro-meiotic protein in vitro, in vivo, in situ or ex vivo. In some embodiments, the engineered polynucleotide is a messenger ribonucleic nucleic acid (mRNA) molecule that is capable of being translated to produce a messenger ribonucleic acid (mRNA) molecule encoding a pro-meiotic protein in vitro, in vivo, in situ or ex vivo. In certain embodiments, the mRNA molecule comprises, from 5' to 3', a CAP structure, a 5' untranslated region (UTR), the sequence encoding the pro-meiotic protein, a 3' UTR, and a poly-A tail structure / region.

[0038] In some embodiments, provided are engineered polynucleotides encoding a DMRT1 protein. In certain embodiments, the engineered polynucleotide is an mRNA molecule (e.g., an exogenous mRNA molecule). In certain embodiments, the encoding sequence is a CDS (e.g., a codon optimized coding sequence). In certain embodiments, the encoding sequence consists of a CDS. Incertain embodiments, the mRNA molecule is translatable to produce a messenger ribonucleic acid (mRNA) molecule encoding a DMRT1 protein in vitro, in vivo, in situ, or ex vivo. In certain embodiments, the mRNA molecule comprises, from 5' to 3', a CAP structure, a 5' untranslated region (UTR), the sequence encoding the DMRT1 protein, a 3' UTR, and a poly-A tail structure / region. In certain embodiments, the engineered polynucleotide is a DNA molecule. In certain embodiments, the DNA molecule is transcribable to produce a messenger ribonucleic acid (mRNA) molecule encoding the DMRT1 protein in vitro, in vivo, in situ, or ex vivo.

[0039] In some embodiments, provided are engineered polynucleotides encoding a YY2 protein. In certain embodiments, the engineered polynucleotide is an mRNA molecule (e.g., an exogenous mRNA molecule). In certain embodiments, the encoding sequence is a CDS (e.g., a codon optimized coding sequence). In certain embodiments, the encoding sequence consists of a CDS. In certain embodiments, the mRNA molecule is translatable to produce a messenger ribonucleic acid (mRNA) molecule encoding a YY2 protein in vitro, in vivo, in situ, or ex vivo. In certain embodiments, the mRNA molecule comprises, from 5' to 3', a CAP structure, a 5' untranslated region (UTR), the sequence encoding the YY2 protein, a 3' UTR, and a poly-A tail structure / region. In certain embodiments, the engineered polynucleotide is a DNA molecule. In certain embodiments, the DNA molecule is transcribable to produce a messenger ribonucleic acid (mRNA) molecule encoding the YY2 protein in vitro, in vivo, in situ, or ex vivo.

[0040] In some embodiments, provided are engineered polynucleotides encoding a DAZL protein. In certain embodiments, the engineered polynucleotide is an mRNA molecule (e.g., an exogenous mRNA molecule). In certain embodiments, the encoding sequence is a CDS (e.g., a codon optimized coding sequence). In certain embodiments, the encoding sequence consists of a CDS. In certain embodiments, the mRNA molecule is translatable to produce a messenger ribonucleic acid (mRNA) molecule encoding a DAZL protein in vitro, in vivo, in situ, or ex vivo. In certain embodiments, the mRNA molecule comprises, from 5' to 3', a CAP structure, a 5' untranslated region (UTR), the sequence encoding the DAZL protein, a 3' UTR, and a poly-A tail structure / region. In certain embodiments, the engineered polynucleotide is a DNA molecule. In certain embodiments, the DNAmolecule is transcribable to produce a messenger ribonucleic acid (mRNA) molecule encoding the DAZL protein in vitro, in vivo, in situ, or ex vivo.

[0041] In some embodiments, provided are engineered polynucleotides encoding a MEIOSIN protein. In certain embodiments, the engineered polynucleotide is an mRNA molecule (e.g., an exogenous mRNA molecule). In certain embodiments, the encoding sequence is a CDS (e.g., a codon optimized coding sequence). In certain embodiments, the encoding sequence consists of a CDS. In certain embodiments, the mRNA molecule is translatable to produce a messenger ribonucleic acid (mRNA) molecule encoding a MEIOSIN protein in vitro, in vivo, in situ, or ex vivo. In certain embodiments, the mRNA molecule comprises, from 5' to 3', a CAP structure, a 5' untranslated region (UTR), the sequence encoding the MEIOSIN protein, a 3' UTR, and a poly-A tail structure / region. In certain embodiments, the engineered polynucleotide is a DNA molecule. In certain embodiments, the DNA molecule is transcribable to produce a messenger ribonucleic acid (mRNA) molecule encoding the MEIOSIN protein in vitro, in vivo, in situ, or ex vivo.

[0042] In some embodiments, provided are engineered polynucleotides encoding a STRA8 protein. In certain embodiments, the engineered polynucleotide is an mRNA molecule (e.g., an exogenous mRNA molecule). In certain embodiments, the encoding sequence is a CDS (e.g., a codon optimized coding sequence). In certain embodiments, the encoding sequence consists of a CDS. In certain embodiments, the mRNA molecule is translatable to produce a messenger ribonucleic acid (mRNA) molecule encoding a STRA8 protein in vitro, in vivo, in situ, or ex vivo. In certain embodiments, the mRNA molecule comprises, from 5' to 3', a CAP structure, a 5' untranslated region (UTR), the sequence encoding the STRA8 protein, a 3' UTR, and a poly-A tail structure / region. In certain embodiments, the engineered polynucleotide is a DNA molecule. In certain embodiments, the DNA molecule is transcribable to produce a messenger ribonucleic acid (mRNA) molecule encoding the STRA8 protein in vitro, in vivo, in situ, or ex vivo.

[0043] In some embodiments, provided are engineered polynucleotides encoding a NANOS3 protein. In certain embodiments, the engineered polynucleotide is an mRNA molecule (e.g., an exogenous mRNA molecule). In certain embodiments, the encoding sequence is a CDS (e.g., a codon optimizedcoding sequence). In certain embodiments, the encoding sequence consists of a CDS. In certain embodiments, the mRNA molecule is translatable to produce a messenger ribonucleic acid (mRNA) molecule encoding a NANOS3 protein in vitro, in vivo, in situ, or ex vivo. In certain embodiments, the mRNA molecule comprises, from 5' to 3', a CAP structure, a 5' untranslated region (UTR), the sequence encoding the NANOS3 protein, a 3' UTR, and a poly-A tail structure / region. In certain embodiments, the engineered polynucleotide is a DNA molecule. In certain embodiments, the DNA molecule is transcribable to produce a messenger ribonucleic acid (mRNA) molecule encoding the NANOS3 protein in vitro, in vivo, in situ, or ex vivo.

[0044] In some embodiments, provided are engineered polynucleotides encoding a DDX4 protein. In certain embodiments, the engineered polynucleotide is an mRNA molecule (e.g., an exogenous mRNA molecule). In certain embodiments, the encoding sequence is a CDS (e.g., a codon optimized coding sequence). In certain embodiments, the encoding sequence consists of a CDS. In certain embodiments, the mRNA molecule is translatable to produce a messenger ribonucleic acid (mRNA) molecule encoding a DDX4 protein in vitro, in vivo, in situ, or ex vivo. In certain embodiments, the mRNA molecule comprises, from 5' to 3', a CAP structure, a 5' untranslated region (UTR), the sequence encoding the DDX4 protein, a 3' UTR, and a poly-A tail structure / region. In certain embodiments, the engineered polynucleotide is a DNA molecule. In certain embodiments, the DNA molecule is transcribable to produce a messenger ribonucleic acid (mRNA) molecule encoding the DDX4 protein in vitro, in vivo, in situ, or ex vivo.

[0045] In some embodiments, provided are engineered polynucleotides encoding a CTCFL protein. In certain embodiments, the engineered polynucleotide is an mRNA molecule (e.g., an exogenous mRNA molecule). In certain embodiments, the encoding sequence is a CDS (e.g., a codon optimized coding sequence). In certain embodiments, the encoding sequence consists of a CDS. In certain embodiments, the mRNA molecule is translatable to produce a messenger ribonucleic acid (mRNA) molecule encoding a CTCFL protein in vitro, in vivo, in situ, or ex vivo. In certain embodiments, the mRNA molecule comprises, from 5' to 3', a CAP structure, a 5' untranslated region (UTR), the sequence encoding the CTCFL protein, a 3' UTR, and a poly-A tail structure / region. In certain embodiments, the engineered polynucleotide is a DNA molecule. In certainembodiments, the DNA molecule is transcribable to produce a messenger ribonucleic acid (mRNA) molecule encoding the CTCFL protein in vitro, in vivo, in situ, or ex vivo.

[0046] In some embodiments, provided are engineered polynucleotides encoding a DEK protein. In certain embodiments, the engineered polynucleotide is an mRNA molecule (e.g., an exogenous mRNA molecule). In certain embodiments, the encoding sequence is a CDS (e.g., a codon optimized coding sequence). In certain embodiments, the encoding sequence consists of a CDS. In certain embodiments, the mRNA molecule is translatable to produce a messenger ribonucleic acid (mRNA) molecule encoding a DEK protein in vitro, in vivo, in situ, or ex vivo. In certain embodiments, the mRNA molecule comprises, from 5' to 3', a CAP structure, a 5' untranslated region (UTR), the sequence encoding the DEK protein, a 3' UTR, and a poly-A tail structure / region. In certain embodiments, the engineered polynucleotide is a DNA molecule. In certain embodiments, the DNA molecule is transcribable to produce a messenger ribonucleic acid (mRNA) molecule encoding the DEK protein in vitro, in vivo, in situ, or ex vivo.

[0047] In some embodiments, provided are engineered polynucleotides encoding a SMC1 B protein. In certain embodiments, the engineered polynucleotide is an mRNA molecule (e.g., an exogenous mRNA molecule). In certain embodiments, the encoding sequence is a CDS (e.g., a codon optimized coding sequence). In certain embodiments, the encoding sequence consists of a CDS. In certain embodiments, the mRNA molecule is translatable to produce a messenger ribonucleic acid (mRNA) molecule encoding a SMC1 B protein in vitro, in vivo, in situ, or ex vivo. In certain embodiments, the mRNA molecule comprises, from 5' to 3', a CAP structure, a 5' untranslated region (UTR), the sequence encoding the SMC1 B protein, a 3' UTR, and a poly-A tail structure / region. In certain embodiments, the engineered polynucleotide is a DNA molecule. In certain embodiments, the DNA molecule is transcribable to produce a messenger ribonucleic acid (mRNA) molecule encoding the SMC1 B protein in vitro, in vivo, in situ, or ex vivo.

[0048] In some embodiments, provided are compositions comprising one or more engineered polynucleotides encoding one or more (e.g., at least or at most about 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10) proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, and / or SMC1 B, wherein eachengineered polynucleotide of the one or more engineered polynucleotides encodes a different protein. In certain embodiments, the compositions comprises two or more engineered polynucleotides encoding one or more proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, and / or SMC1 B, wherein each engineered polynucleotide of the two or more engineered polynucleotides encodes a different protein. In certain embodiments, the compositions comprises three or more engineered polynucleotides encoding one or more proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, and / or SMC1 B, wherein each engineered polynucleotide of the three or more engineered polynucleotides encodes a different protein. In certain embodiments, the compositions comprises four or more engineered polynucleotides encoding one or more proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, and / or SMC1 B, wherein each engineered polynucleotide of the four or more engineered polynucleotides encodes a different protein.

[0049] In some embodiments, provided are compositions comprising: an engineered polynucleotide encoding a DMRT1 protein; and an engineered polynucleotide encoding a YY2 protein.

[0050] In some embodiments, provided are compositions comprising one or more engineered polynucleotides encoding one or more proteins selected from: STRA8, MEIOSIN, DAZL, NANOS3, DDX4, CTCFL, DEK, and / or SMC1 B, wherein each engineered polynucleotide of the one or more engineered polynucleotides encodes a different protein. In some embodiments, provided are compositions comprising one or more engineered polynucleotides encoding one or more proteins selected from: CTCFL, STRA8, MEIOSIN, DEK, SMC1 B, and / or DAZL. In some embodiments, provided are compositions comprising: an engineered polynucleotide encoding a STRA8 protein, an engineered polynucleotide is designed to encode a MEIOSIN protein; an engineered polynucleotide is designed to encode a DAZL protein; an engineered polynucleotide is designed to encode a NANOS3 protein; an engineered polynucleotide is designed to encode a DDX4 protein; an engineered polynucleotide is designed to encode a CTCFL protein; an engineered polynucleotide is designed to encode a DEK protein; and an engineered polynucleotide is designed to encode a SMC1 B protein. In some embodiments, provided are compositions comprising: an engineered polynucleotide encoding aSTRA8 protein, an engineered polynucleotide is designed to encode a MEIOSIN protein; an engineered polynucleotide is designed to encode a DAZL protein; an engineered polynucleotide is designed to encode a DDX4 protein; an engineered polynucleotide is designed to encode a CTCFL protein; and an engineered polynucleotide is designed to encode a DEK protein.

[0051] In some embodiments, provided are compositions comprising one or more engineered polynucleotides encoding one or more (e.g., at least or at most about 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10) proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, and / or SMC1 B, wherein each engineered polynucleotide of the one or more engineered polynucleotides encodes a different protein. In certain embodiments, the compositions comprises two or more engineered polynucleotides encoding one or more proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, and / or SMC1 B, wherein each engineered polynucleotide of the two or more engineered polynucleotides encodes a different protein. In certain embodiments, the compositions comprises three or more engineered polynucleotides encoding one or more proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, and / or SMC1 B, wherein each engineered polynucleotide of the three or more engineered polynucleotides encodes a different protein. In certain embodiments, the compositions comprises four or more engineered polynucleotides encoding one or more proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, and / or SMC1 B, wherein each engineered polynucleotide of the four or more engineered polynucleotides encodes a different protein.

[0052] In some embodiments, provided are compositions comprising: an engineered mRNA polynucleotide encoding a DMRT1 protein; and an engineered mRNA polynucleotide encoding a YY2 protein.

[0053] In some embodiments, provided are compositions comprising one or more engineered polynucleotides encoding one or more proteins selected from: STRA8, MEIOSIN, DAZL, NANOS3, DDX4, CTCFL, DEK, and / or SMC1 B, wherein each engineered mRNA polynucleotide of the one or more engineered polynucleotides encodes a different protein. In some embodiments, provided are compositions comprising one or more engineered polynucleotides encoding one or more proteins selected from: CTCFL, STRA8, MEIOSIN, DEK, SMC1 B, and / or DAZL. In someembodiments, provided are compositions comprising: an engineered mRNA polynucleotide encoding a STRA8 protein, an engineered mRNA polynucleotide encoding a MEIOSIN protein; an engineered mRNA polynucleotide encoding a DAZL protein; an engineered mRNA polynucleotide encoding a NANOS3 protein; an engineered mRNA polynucleotide encoding a DDX4 protein; an engineered mRNA polynucleotide encoding a CTCFL protein; an engineered mRNA polynucleotide encoding a DEK protein; and an engineered mRNA polynucleotide encoding a SMC1 B protein. In some embodiments, provided are compositions comprising: an engineered mRNA polynucleotide encoding a STRA8 protein, an engineered mRNA polynucleotide encoding a MEIOSIN protein; an engineered mRNA polynucleotide encoding a DAZL protein; an engineered mRNA polynucleotide encoding a DDX4 protein; an engineered mRNA polynucleotide encoding a CTCFL protein; and / or an engineered mRNA polynucleotide encoding a DEK protein.

[0054] In some embodiments, the engineered polynucleotide(s) as provided herein (e.g., the one or more mRNA polynucleotides) encode the STRA8 protein, the MEIOSIN protein, the DAZL protein, the DMRT1 protein, or the CTCFL protein. In some embodiments, the engineered polynucleotide(s) encode two or more (e.g., at least or at most about 2, at least or at most about 3, at least or at most about 4, or at least or at most about 5) members selected from the group consisting of: the STRA8 protein, the MEIOSIN protein, the DAZL protein, the DMRT1 protein, and the CTCFL protein. The two or more members can be selected from the group consisting of the STRA8 protein, the DAZL protein, and the MEIOSIN protein. The two or more members can comprise at least the STRA8 protein and the DAZL protein, at least the STRA8 protein and the MEIOSIN protein, and / or at least the DAZL protein and the MEIOSIN protein.CRISPR-dCas activation systems

[0055] Provided are CRISPR-dCas activation (also referred to as CRISPRa) systems and methods useful for increasing the amount of pro-meiotic proteins in a cell, wherein the pro-meiotic proteins comprise one or more (e.g., at least or at most about 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10) members from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof. In some embodiments, the pro-meiotic proteins are useful for inducing meiosis in a cell.

[0056] CRISPR-dCAS activation systems generally refer to and include CRISPR- Cas systems having (i) an enzymatically inactive (dead) Cas endonucleases (dCas) fused to a partner protein (activating fusion partner) that activates or increases expression of a target nucleic acid (e.g., a target gene) and (ii) a guide RNA (e.g., gRNA or sgRNA) that targets the dCas to a target nucleic acid sequence (e.g., gene or gene region) . In some embodiments, such activating fusion partners include, but are not limited to, a protein (e.g., a transcription activator or a fragment thereof, a protein or fragment thereof that recruits a transcription activator, a small molecule / drug-responsive transcription and / or translation regulator, a translationregulating protein, etc.) that directly and / or indirectly provides for increased transcription and / or translation of a target nucleic acid. In certain embodiments, the activating fusion partner increases expression of the target nucleic acid relative to its expression (e.g., transcription) in the absence of the activating fusion partner. In certain instances, relative expression, including transcription and RNA levels, can be assessed, quantified, and compared, e.g., by RT-qPCR or amounts of a target protein. In some embodiments, activating fusion partners comprise a transcriptional activator. In certain instances, transcriptional activators promote transcription via: recruitment of other transcription factor proteins; modification of target DNA such as demethylation; recruitment of a DNA modifier; modulation of histones associated with target DNA; recruitment of a histone modifier such as those that modify acetylation and / or methylation of histones; or a combination thereof. In some embodiments, the activating fusion partner that activates or increases transcription include, but are not limited to: transcriptional activators such as VP16, VP64, VP48, VP160, p65 subdomain (e.g., from NFkB), an activation domain of EDLL and / or TAL activation domain (e.g., for activity in plants); histone lysine methyltransferases such as SET1A, SET1 B, MLL1 to 5, ASH1 , SYMD2, NSD1 ; histone lysine demethylases such as JHDM2a / b, UTX, JMJD3; histone acetyltransferases such as GCN5, PCAF, CBP, p300, TAF1 , TIP60 / PLIP, MOZ / MYST3, MORF / MYST4, SRC1 , ACTR, P160, CLOCK; and DNA demethylases such as Ten-Eleven Translocation (TET) dioxygenase 1 (TET1 CD), TET1 , DME, DML1 , DML2, and ROS1 ; and functional domains thereof. In some embodiments, the CRISPR-dCAS activation systems comprise a gRNA having a spacer sequence that targets (e.g., hybridizes) to a target sequence upstream or downstream of a transcription start site (TSS) of a pro-meiotic gene or gene regions(e g., STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof)

[0057] CRISPR-dCas systems include Type I CRISPR-dCas systems, Type II CRISPR-dCas systems, Type III CRISPR-dCas systems, and derivatives thereof. CRISPR-dCas systems include engineered and / or programmable nuclease systems derived from naturally accruing CRISPR-Cas systems, having an inactive Cas endonuclease. In some embodiments, the CRISPR-dCas system used herein can be a type I, a type II, or a type III system. Non-limiting examples of suitable CRISPR-dCas proteins include Cas3, Cas4, Cas5, Cas5e (or CasD), Cas6, Cas6e, Cas6f, Cas7, Cas8a1 , Cas8a2, Cas8b, Cas8c, Cas9, Casi o, Cas10d, CasF, CasG, CasH, CasX, Cas<t>, Csy1 , Csy2, Csy3, Cse1 (or CasA), Cse2 (or CasB), Cse3 (or CasE), Cse4 (or CasC), Csc1 , Csc2, Csa5, Csn2, Csm2, Csm3, Csm4, Csm5, Csm6, Cmr1 , Cmr3, Cmr4, Cmr5, Cmr6, Csb1 , Csb2, Csb3, Csx17, Csx14, Csx10, Csx16, CasX, Csx3, Csz1 , Csx15, Csf1 , Csf2, Csf3, Csf4, and Cu1966. In certain embodiments, the CRISPR-Cas protein or endonuclease is dCas9. In some embodiments, the dCas9 protein can be from or derived from: Staphylococcus aureus, Streptococcus pyogenes, Streptococcus thermophilus, Streptococcus sp., Nocardiopsis dassonvillei, Streptomyces pristinaespiral is, Streptomyces viridochromogenes, Streptomyces viridochromogenes, Streptosporangium roseum, Alicyclobacillus acidocaldarius, Bacillus pseudomycoides, Bacillus selenitireducens, Exiguobacterium sibiricum, Lactobacillus delbrueckii, Lactobacillus salivarius, Microscilla marina, Burkholderiales bacterium, Polaromonas naphthalenivorans, Polaromonas sp., Crocosphaera watsonii, Cyanothece sp., Microcystis aeruginosa, Synechococcus sp., Acetohalobium arabaticum, Ammonifex degensii, Caldicelulosiruptor becscii, Candidatus Desulforudis, Clostridium botulinum, Clostridium difficile, Fine goldia magna, Natranaerobius thermophilus, Pelotomaculum the rmopropionicum, Acidithiobacillus caldus, Acidithiobacillus ferrooxidans, Allochromatium vinosum, Marinobacter sp., Nitrosococcus halophilus, Nitrosococcus watsoni, Pseudoalteromonas haloplanktis, Ktedonobacter racemifer, Methanohalobium evestigatum, Anabaena variabilis, Nodularia spumigena, Nostoc sp., Arthrospira maxima, Arthrospira platensis, Arthrospira sp., Lyngbya sp., Microcoleus chthonoplastes, Oscillatoria sp., Petrotoga mobilis, Thermosipho africanus, or Acaryochloris marina.

[0058] gRNA generally refers to and encompassed a short synthetic RNA composed of a scaffold sequence necessary for Cas-binding and targeting a targeting sequence (also referred to as a spacer sequence) that defines the genomic target (also referred to as a protospacer sequence). The gRNA functions, in part, by hybridizing to a template nucleic acid molecule (e.g., at a targeted site). Hybridization generally refers to and includes the capacity and / or ability of a first nucleic acid molecule to non-covalently bind (e.g., form Watson-Crick-base pairs and / or G / U base pairs), anneal, and / or hybridize to a second nucleic acid molecule under the appropriate or certain in vitro and / or in vivo conditions of temperature, pH, and / or solution ionic strength. Generally, standard Watson-Crick base pairing includes: adenine (A) pairing with thymidine (T); adenine (A) pairing with uracil (U); and guanine (G) pairing with cytosine (C). In some embodiments, hybridization comprises at least two nucleic acids comprising complementary sequences (e.g., fully complementary, substantially complementary, or partially complementary). In certain embodiments, hybridization comprises at least two nucleic acids comprising fully complementary sequences. In certain embodiments, hybridization comprises at least two nucleic acids comprising substantially complementary sequences (e.g., greater than about 75%, greater than about 80%, greater than about 85%, greater than about 90%, or greater than about 95% complementary). In certain embodiments, hybridization comprises at least two nucleic acids comprising partially complementary sequences (e.g., greater than about 40%, greater than about 50%, greater than about 60%, or greater than about 70% complementary). In certain embodiments, partially complementary sequences comprises one or more regions of fully or substantially complementary sequences. In certain embodiments, partially complementary sequences comprises one or more regions of fully or substantially complementary sequences, even if an overall complementarity is low (e.g., a total complementarity lower than about 50%, lower than about 40%, lower than about 30%, or lower than about 20%). The conditions appropriate for hybridization between two nucleic acids depend on the length of the nucleic acids and the degree of complementation, variables well known in the art. For example, the greater the degree of complementation between two nucleotide sequences, the greater the value of the melting temperature (Tm) for hybrids of nucleic acids having those sequences.

[0059] Complementary or complementarity generally refers to a polynucleotide that includes a nucleotide sequence capable of selectively annealing to an identifying region of a target polynucleotide under certain conditions. As used herein, the term substantially complementary and grammatical equivalents is intended to mean a polynucleotide that includes a nucleotide sequence capable of specifically annealing to an identifying region of a target polynucleotide under certain conditions. Annealing refers to the nucleotide base-pairing interaction of one nucleic acid with another nucleic acid that results in the formation of a duplex, triplex, or other higher-ordered structure. The primary interaction is typically nucleotide base specific, e.g., A:T, A: U, and G:C, by Watson-Crick and Hoogsteen- type hydrogen bonding. In certain embodiments, base-stacking and hydrophobic interactions can also contribute to duplex stability. Conditions under which a polynucleotide anneals to complementary or substantially complementary regions of target nucleic acids are well known in the art, e.g., as described in Nucleic Acid Hybridization, A Practical Approach, Hames and Higgins, eds., IRL Press, Washington, D.C. (1985) and Wetmur and Davidson, Mol. Biol. 31 :349 (1968). Annealing conditions will depend upon the particular application and can be routinely determined by persons skilled in the art, without undue experimentation. Hybridization generally refers to process in which two single-stranded polynucleotides bind non-covalently to form a stable double-stranded polynucleotide.

[0060] Target specificity can be used in reference to a gRNA specific to a target polynucleotide sequence (protospacer) or region and further includes a sequence of nucleotides (spacer) capable of selectively annealing / hybridizing to a target (protospacer) of a target polynucleotide, e.g., a target DNA.

[0061] gRNAs are generally supported by a scaffold, wherein a scaffold refers to the portions of gRNA or crRNA molecules comprising sequences which are substantially identical or are highly conserved across natural biological species (e.g., not conferring target specificity). Scaffolds include the tracrRNA segment and the portion of the crRNA segment other than the polynucleotide-targeting guide sequence at or near the 5' end of the crRNA segment, excluding any unnatural portions comprising sequences not conserved in native crRNAs and tracrRNAs. In some embodiments, the gRNA comprises a CRISPR RNA (crRNA):trans activating cRNA (tracrRNA) duplex. In some embodiments, the gRNA comprises a stem-loopthat mimics the natural duplex between the crRNA and tracrRNA. In some embodiments, the stem-loop comprises a nucleotide sequence comprising non- naturally occurring sequence. For example, in some embodiments, the composition comprises a synthetic or chimeric guide RNA comprising a crRNA, stem, and tracrRNA.

[0062] In some embodiments, the gRNA spacer sequence comprises about 15 nucleotides to about 28 nucleotides. In some embodiments, the gRNA comprises at least about 15 nucleotides. In some embodiments, the gRNA spacer sequence comprises at most about 28 nucleotides. In some embodiments, the gRNA spacer sequence comprises about 15 nucleotides to about 16 nucleotides, about 15 nucleotides to about 17 nucleotides, about 15 nucleotides to about 18 nucleotides, about 15 nucleotides to about 19 nucleotides, about 15 nucleotides to about 20 nucleotides, about 15 nucleotides to about 21 nucleotides, about 15 nucleotides to about 22 nucleotides, about 15 nucleotides to about 23 nucleotides, about 15 nucleotides to about 24 nucleotides, about 15 nucleotides to about 25 nucleotides, about 15 nucleotides to about 28 nucleotides, about 16 nucleotides to about 17 nucleotides, about 16 nucleotides to about 18 nucleotides, about 16 nucleotides to about 19 nucleotides, about 16 nucleotides to about 20 nucleotides, about 16 nucleotides to about 21 nucleotides, about 16 nucleotides to about 22 nucleotides, about 16 nucleotides to about 23 nucleotides, about 16 nucleotides to about 24 nucleotides, about 16 nucleotides to about 25 nucleotides, about 16 nucleotides to about 28 nucleotides, about 17 nucleotides to about 18 nucleotides, about 17 nucleotides to about 19 nucleotides, about 17 nucleotides to about 20 nucleotides, about 17 nucleotides to about 21 nucleotides, about 17 nucleotides to about 22 nucleotides, about 17 nucleotides to about 23 nucleotides, about 17 nucleotides to about 24 nucleotides, about 17 nucleotides to about 25 nucleotides, about 17 nucleotides to about 28 nucleotides, about 18 nucleotides to about 19 nucleotides, about 18 nucleotides to about 20 nucleotides, about 18 nucleotides to about 21 nucleotides, about 18 nucleotides to about 22 nucleotides, about 18 nucleotides to about 23 nucleotides, about 18 nucleotides to about 24 nucleotides, about 18 nucleotides to about 25 nucleotides, about 18 nucleotides to about 28 nucleotides, about 19 nucleotides to about 20 nucleotides, about 19 nucleotides to about 21 nucleotides, about 19 nucleotides to about 22 nucleotides, about 19 nucleotides to about 23 nucleotides, about 19 nucleotides to about 24 nucleotides, about 19nucleotides to about 25 nucleotides, about 19 nucleotides to about 28 nucleotides, about 20 nucleotides to about 21 nucleotides, about 20 nucleotides to about 22 nucleotides, about 20 nucleotides to about 23 nucleotides, about 20 nucleotides to about 24 nucleotides, about 20 nucleotides to about 25 nucleotides, about 20 nucleotides to about 28 nucleotides, about 21 nucleotides to about 22 nucleotides, about 21 nucleotides to about 23 nucleotides, about 21 nucleotides to about 24 nucleotides, about 21 nucleotides to about 25 nucleotides, about 21 nucleotides to about 28 nucleotides, about 22 nucleotides to about 23 nucleotides, about 22 nucleotides to about 24 nucleotides, about 22 nucleotides to about 25 nucleotides, about 22 nucleotides to about 28 nucleotides, about 23 nucleotides to about 24 nucleotides, about 23 nucleotides to about 25 nucleotides, about 23 nucleotides to about 28 nucleotides, about 24 nucleotides to about 25 nucleotides, about 24 nucleotides to about 28 nucleotides, or about 25 nucleotides to about 28 nucleotides. In some embodiments, the gRNA spacer sequence comprises about 15 nucleotides, about 16 nucleotides, about 17 nucleotides, about 18 nucleotides, about 19 nucleotides, about 20 nucleotides, about 21 nucleotides, about 22 nucleotides, about 23 nucleotides, about 24 nucleotides, about 25 nucleotides, or about 28 nucleotides.

[0063] In some embodiments, the CRISPR-dCAS activation systems comprise a gRNA having a spacer sequence that targets (e.g., hybridizes) to a target sequence (protospacer) upstream or downstream of a transcription start site (TSS) of a pro- meiotic gene or gene regions (e.g., STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof). In certain embodiments, the gRNA comprises a spacer sequence targets (e.g., hybridizes) to a target sequence (protospacer) between -10 and -500 base pairs upstream or downstream of a transcription start site (TSS). In certain embodiments, the gRNA comprises a spacer sequence targets (e.g., hybridizes) to a target sequence (protospacer) between -25 and -500 base pairs upstream or downstream of a transcription start site (TSS). In certain embodiments, the gRNA comprises a spacer sequence targets (e.g., hybridizes) to a target sequence (protospacer) between -50 and -500 base pairs upstream or downstream of a transcription start site (TSS). In certain embodiments, the gRNA comprises a spacer sequence targets (e.g., hybridizes) to a target sequence (protospacer) between -50 and -400 base pairs upstream or downstream of a transcription start site (TSS). In certainembodiments, the gRNA comprises a spacer sequence targets (e.g., hybridizes) to a target sequence (protospacer) between -50 and -250 base pairs upstream or downstream of a transcription start site (TSS).

[0064] In some embodiments, provided are CRISPR-dCas activation systems comprising an enzymatically inactive Cas protein and a gRNA comprising a spacer sequence that hybridizes to a gene region (e.g., upstream or downstream or downstream of the TSS) selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, or SMC1 B. In certain embodiments, the gRNA hybridizes to a target upstream or downstream of the TSS for a gene region encoding a protein selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, or SMC1 B. In certain embodiments, the gRNA is complementary to a target upstream or downstream of the TSS for a gene region encoding a protein selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, or SMCI B.

[0065] In some embodiments, provided are CRISPR-dCas activation systems comprising an enzymatically inactive Cas protein and a gRNA comprising a spacer sequence that hybridizes to a X gene region (e.g., upstream or downstream of the TSS). In certain embodiments, the gRNA hybridizes to a target upstream or downstream of the TSS for a gene region encoding a X protein. In certain embodiments, the gRNA is complementary to a target upstream or downstream of the TSS for a gene region encoding a X protein.

[0066] In some embodiments, provided are CRISPR-dCas activation systems comprising an enzymatically inactive Cas protein and a gRNA comprising a spacer sequence that hybridizes to a STRA8 gene region (e.g., upstream or downstream of the TSS). In certain embodiments, the gRNA hybridizes to a target upstream or downstream of the TSS for a gene region encoding a STRA8 protein. In certain embodiments, the gRNA is complementary to a target upstream or downstream of the TSS for a gene region encoding a STRA8 protein.

[0067] In some embodiments, provided are CRISPR-dCas activation systems comprising an enzymatically inactive Cas protein and a gRNA comprising a spacer sequence that hybridizes to a MEIOSIN gene region (e.g., upstream or downstream of the TSS). In certain embodiments, the gRNA hybridizes to a target upstream or downstream of the TSS for a gene region encoding a MEIOSIN protein. In certainembodiments, the gRNA is complementary to a target upstream or downstream of the TSS for a gene region encoding a MEIOSIN protein.

[0068] In some embodiments, provided are CRISPR-dCas activation systems comprising an enzymatically inactive Cas protein and a gRNA comprising a spacer sequence that hybridizes to a DAZL gene region (e.g., upstream or downstream of the TSS). In certain embodiments, the gRNA hybridizes to a target upstream or downstream of the TSS for a gene region encoding a DAZL protein. In certain embodiments, the gRNA is complementary to a target upstream or downstream of the TSS for a gene region encoding a DAZL protein.

[0069] In some embodiments, provided are CRISPR-dCas activation systems comprising an enzymatically inactive Cas protein and a gRNA comprising a spacer sequence that hybridizes to a DMRT1 gene region (e.g., upstream or downstream of the TSS). In certain embodiments, the gRNA hybridizes to a target upstream or downstream of the TSS for a gene region encoding a DMRT1 protein. In certain embodiments, the gRNA is complementary to a target upstream or downstream of the TSS for a gene region encoding a DMRT1 protein.

[0070] In some embodiments, provided are CRISPR-dCas activation systems comprising an enzymatically inactive Cas protein and a gRNA comprising a spacer sequence that hybridizes to a NANOS3 gene region (e.g., upstream or downstream of the TSS). In certain embodiments, the gRNA hybridizes to a target upstream or downstream of the TSS for a gene region encoding a NANOS3 protein. In certain embodiments, the gRNA is complementary to a target upstream or downstream of the TSS for a gene region encoding a NANOS3 protein.

[0071] In some embodiments, provided are CRISPR-dCas activation systems comprising an enzymatically inactive Cas protein and a gRNA comprising a spacer sequence that hybridizes to a DDX4 gene region (e.g., upstream or downstream of the TSS). In certain embodiments, the gRNA hybridizes to a target upstream or downstream of the TSS for a gene region encoding a DDX4 protein. In certain embodiments, the gRNA is complementary to a target upstream or downstream of the TSS for a gene region encoding a DDX4 protein.

[0072] In some embodiments, provided are CRISPR-dCas activation systems comprising an enzymatically inactive Cas protein and a gRNA comprising a spacer sequence that hybridizes to a CTCFL gene region (e.g., upstream or downstream of the TSS). In certain embodiments, the gRNA hybridizes to a target upstream ordownstream of the TSS for a gene region encoding a CTCFL protein. In certain embodiments, the gRNA is complementary to a target upstream or downstream of the TSS for a gene region encoding a CTCFL protein.

[0073] In some embodiments, provided are CRISPR-dCas activation systems comprising an enzymatically inactive Cas protein and a gRNA comprising a spacer sequence that hybridizes to a DEK gene region (e.g., upstream or downstream of the TSS). In certain embodiments, the gRNA hybridizes to a target upstream or downstream of the TSS for a gene region encoding a DEK protein. In certain embodiments, the gRNA is complementary to a target upstream or downstream of the TSS for a gene region encoding a DEK protein.

[0074] In some embodiments, provided are CRISPR-dCas activation systems comprising an enzymatically inactive Cas protein and a gRNA comprising a spacer sequence that hybridizes to a YY2 gene region (e.g., upstream or downstream of the TSS). In certain embodiments, the gRNA hybridizes to a target upstream or downstream of the TSS for a gene region encoding a YY2 protein. In certain embodiments, the gRNA is complementary to a target upstream or downstream of the TSS for a gene region encoding a YY2 protein.

[0075] In some embodiments, provided are CRISPR-dCas activation systems comprising an enzymatically inactive Cas protein and a gRNA comprising a spacer sequence that hybridizes to a SMC1 B gene region (e.g., upstream or downstream of the TSS). In certain embodiments, the gRNA hybridizes to a target upstream or downstream of the TSS for a gene region encoding a SMC1 B protein. In certain embodiments, the gRNA is complementary to a target upstream or downstream of the TSS for a gene region encoding a SMC1 B protein.

[0076] In some embodiments, the CRISPR-dCas activation (also referred to as CRISPRa) systems described herein include one or more nucleic acid molecules encoding the CRISPR-dCas activation (also referred to as CRISPRa) system(s).

[0077] In some embodiments, the CRISPR-dCas activation system as provided herein comprises a spacer sequence that hybridizes upstream or downstream of a transcription start site for a sequence encoding a protein selected from: STRA8, MEIOSIN, DAZL, DMRT1 , or CTCFL. In some embodiments, the CRISPR-dCas activation system comprises a spacer sequence that hybridizes upstream or downstream of a transcription start site for a sequence encoding two or more (e.g., at least or at most about 2, at least or at most about 3, at least or at most about 4,or at least or at most about 5) members selected from the group consisting of: STRA8, MEIOSIN, DAZL DMRT1 , and CTCFL. The two or more members can be selected from the group consisting of STRA8, DAZL, and MEIOSIN. The two or more members can comprise at least STRA8 and DAZL, at least STRA8 and MEIOSIN, and / or at least DAZL and MEIOSIN.

[0078] Representative gRNA targets are shown in TABLE 1. In some embodiments, the gRNA has a spacer (e.g., having U substituted for T in RNA) comprising any one of the sequences in TABLE 1 (or reverse complement thereof).

[0079] In some embodiments, the gRNA as provided herein can exhibit at least or at most about 80, 85, 90, 95, 97, 98, or 99% sequence identity to one or more members selected from the group consisting of SEQ ID NOs: 13-27 (DAZL). In some embodiments, the gRNA as provided herein can exhibit at least or at most about 80, 85, 90, 95, 97, 98, or 99% sequence identity to one or more members selected from the group consisting of SEQ ID NOs: 28-69 (DMRT1 ). In some embodiments, the gRNA as provided herein can exhibit at least or at most about 80, 85, 90, 95, 97, 98, or 99% sequence identity to one or more members selected from the group consisting of SEQ ID NOs: 70-103 (MEIOSIN). In some embodiments, the gRNA as provided herein can exhibit at least or at most about 80, 85, 90, 95, 97, 98, or 99% sequence identity to one or more members selected from the group consisting of SEQ ID NOs: 104-11 1 (SMC1 B). In some embodiments, the gRNA as provided herein can exhibit at least or at most about 80, 85, 90, 95, 97, 98, or 99% sequence identity to one or more members selected from the group consisting of SEQ ID NOs: 1 12-149 (STRA8).

[0080] In some embodiments, the gRNA has a spacer (e.g., having U substituted for T in RNA) exhibiting at least or at most about 80, 85, 90, 95, 97, 98, or 99% sequence identity to one or more members selected from the group consisting of SEQ ID NOs: 13-27 or reverse complement thereof (DAZL). In some embodiments, the gRNA has a spacer (e.g., having U substituted for T in RNA) exhibiting at least or at most about 80, 85, 90, 95, 97, 98, or 99% sequence identity to one or more members selected from the group consisting of SEQ ID NOs: 28-69 or reverse complement thereof (DMRT1 ). In some embodiments, the gRNA has a spacer (e.g., having U substituted for T in RNA) exhibiting at least or at most about 80, 85, 90, 95, 97, 98, or 99% sequence identity to one or more members selected from the group consisting of SEQ ID NOs: 70-103 or reverse complement thereof(MEIOSIN). In some embodiments, the gRNA has a spacer (e.g., having U substituted for T in RNA) exhibiting at least or at most about 80, 85, 90, 95, 97, 98, or 99% sequence identity to one or more members selected from the group consisting of SEQ ID NOs: 104-11 1 or reverse complement thereof (SMC1 B). In some embodiments, the gRNA has a spacer (e.g., having U substituted for T in RNA) exhibiting at least or at most about 80, 85, 90, 95, 97, 98, or 99% sequence identity to one or more members selected from the group consisting of SEQ ID NOs: 112-149 or reverse complement thereof (STRA8).Table 1Cells

[0081] Also provided herein are engineered cells having an increased amount (e.g., transcription and / or translation) of one or more (e.g., at least or at most about 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10) proteins (e.g., pro-meiotic proteins) selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof. In some embodiments, the engineered cells comprise one or more engineered polynucleotides (e.g., exogenous polynucleotides) encoding one or more proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof. In some embodiments, the engineered cells comprise one or more engineered CRISPR- dCas activation systems comprising an enzymatically inactive Cas protein and a gRNA comprising a spacer sequence that hybridizes to a gene region (e.g., upstream or downstream of the TSS) selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof.

[0082] In some embodiments, the cells are stem cells. Stems cells generally refer to and include undifferentiated cells (1 ) capable of long-term self-renewal, or the ability to generate at least one identical copy of the original cell, (2) capable of differentiation at the single cell level into multiple, and in some instances only one, specialized cell type, and / or (3) capable of in vivo functional regeneration of tissues. Stem cells can generally be subclassified according to their developmental potential as totipotent, pluripotent, multipotent and oligo / unipotent.

[0083] In some embodiments, the cells are pluripotent stem cells. In certain embodiments, the cells are induced pluripotent stem cells (also known as iPS cells or iPSCs). iPSCs generally refer to and include a type of pluripotent stem cell that can be generated directly from adult cells. For example, by the introduction of products of specific sets of pluripotency-associated genes, non-pluripotent cells can be converted into pluripotent stem cells. Additionally, embryonic stem cells can generally be produced from a single blastomere or by culturing an inner cell mass obtained without the destruction of the embryo.

[0084] In some embodiments, the cells are primordial germ cells (PGCs). Primordial germ cells (PGCs) generally refer to and include embryonic precursors of sperm and egg that pass on genetic and epigenetic information from one generation to the next are embryonic precursors of sperm and egg that pass on genetic and epigenetic information from one generation to the next.

[0085] In some embodiments, the cell is a mesenchymal stem cell or fibroblast. In some embodiments, the cells are somatic cells.

[0086] In some embodiments, provided are cells comprising one or more engineered polynucleotides encoding one or more (e.g., at least or at most about 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10) proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof. In some embodiments, the cell comprises: an engineered polynucleotide encoding a STRA8 protein. In some embodiments, the cell comprises: an engineered polynucleotide encoding a MEIOSIN protein. In some embodiments, the cell comprises: an engineered polynucleotide encoding a DAZL protein. In some embodiments, the cell comprises: an engineered polynucleotide encoding a DMRT1 protein. In some embodiments, the cell comprises: an engineered polynucleotide encoding a NANOS3 protein. In some embodiments, the cell comprises: an engineered polynucleotide encoding a DDX4 protein. In some embodiments, the cell comprises: an engineered polynucleotide encoding a CTCFL protein. In some embodiments, the cell comprises: an engineered polynucleotide encoding a DEK protein. In some embodiments, the cell comprises: an engineered polynucleotide encoding a YY2 protein. In some embodiments, the cell comprises: an engineered polynucleotide encoding a SMC1 B protein.

[0087] In some embodiments, the cell comprises: an engineered polynucleotide encoding a DMRT1 protein; and an engineered polynucleotide encoding YY2 protein. In some embodiments, provided are cells comprising one or more engineered polynucleotides encoding one or more proteins selected from: STRA8, MEIOSIN, DAZL, NANOS3, DDX4, CTCFL, DEK, AMC1 B, or a combination thereof. In some embodiments, the cell comprises: an engineered polynucleotide encoding a STRA8 protein; an engineered polynucleotide encoding a MEIOSIN protein; an engineered polynucleotide encoding a DAZL protein; an engineered polynucleotide encoding a NANOS3 protein; an engineered polynucleotide encoding a DDX4 protein; an engineered polynucleotide encoding a CTCFL protein; an engineeredpolynucleotide encoding a DEK protein; and / or an engineered polynucleotide encoding a SMC1 B protein.

[0088] In some embodiments, the engineered polynucleotide(s) of the cell as provided herein (e.g., the one or more mRNA polynucleotides) encode the STRA8 protein, the MEIOSIN protein, the DAZL protein, the DMRT1 protein, or the CTCFL protein. In some embodiments, the engineered polynucleotide(s) encode two or more (e.g., at least or at most about 2, at least or at most about 3, at least or at most about 4, or at least or at most about 5) members selected from the group consisting of: the STRA8 protein, the MEIOSIN protein, the DAZL protein, the DMRT 1 protein, and the CTCFL protein. The two or more members can be selected from the group consisting of the STRA8 protein, the DAZL protein, and the MEIOSIN protein. The two or more members can comprise at least the STRA8 protein and the DAZL protein, at least the STRA8 protein and the MEIOSIN protein, and / or at least the DAZL protein and the MEIOSIN protein.

[0089] In some embodiments, provided are cells comprising one or more exogenous nucleic acid sequences encoding one or more (e.g., at least or at most about 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10) proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B or a combination thereof. In some embodiments, the cell comprises: an exogenous nucleic acid sequence encoding a STRA8 protein. In some embodiments, the cell comprises: an exogenous nucleic acid sequence encoding a MEIOSIN protein. In some embodiments, the cell comprises: an engineered polynucleotide encoding a DAZL protein. In some embodiments, the cell comprises: an exogenous nucleic acid sequence encoding a DMRT1 protein. In some embodiments, the cell comprises: an exogenous nucleic acid sequence encoding a NANOS3 protein. In some embodiments, the cell comprises: an exogenous nucleic acid sequence encoding a DDX4 protein. In some embodiments, the cell comprises: an exogenous nucleic acid sequence encoding a CTCFL protein. In some embodiments, the cell comprises: an exogenous nucleic acid sequence encoding a DEK protein. In some embodiments, the cell comprises: an exogenous nucleic acid sequence encoding a YY2 protein. In some embodiments, the cell comprises: an exogenous nucleic acid sequence encoding a SMC1 B protein.

[0090] In some embodiments, the cell comprises: an exogenous nucleic acid sequence encoding a DMRT1 protein; and an exogenous nucleic acid sequenceencoding YY2 protein. In some embodiments, provided are cells comprising one or more exogenous nucleic acid sequences encoding one or more proteins selected from: STRA8, MEIOSIN, DAZL, NANOS3, DDX4, CTCFL, DEK, SMC1 B, or a combination thereof. In some embodiments, the cell comprises: an exogenous nucleic acid sequence encoding a STRA8 protein; an exogenous nucleic acid sequence encoding a MEIOSIN protein; an exogenous nucleic acid sequence encoding a DAZL protein; an exogenous nucleic acid sequence encoding a NANOS3 protein; an exogenous nucleic acid sequence encoding a DDX4 protein; an exogenous nucleic acid sequence encoding a CTCFL protein; an exogenous nucleic acid sequence encoding a DEK protein; and / or an exogenous nucleic acid sequence encoding a SMC1 B protein.

[0091] In some embodiments, the exogenous nucleic acid sequence(s) of the cell as provided herein (e.g., the one or more mRNA polynucleotides) encode the STRA8 protein, the MEIOSIN protein, the DAZL protein, the DMRT1 protein, or the CTCFL protein. In some embodiments, the exogenous nucleic acid sequence(s) encode two or more (e.g., at least or at most about 2, at least or at most about 3, at least or at most about 4, or at least or at most about 5) members selected from the group consisting of: the STRA8 protein, the MEIOSIN protein, the DAZL protein, the DMRT1 protein, and the CTCFL protein. The two or more members can be selected from the group consisting of the STRA8 protein, the DAZL protein, and the MEIOSIN protein. The two or more members can comprise at least the STRA8 protein and the DAZL protein, at least the STRA8 protein and the MEIOSIN protein, and / or at least the DAZL protein and the MEIOSIN protein.

[0092] In some embodiments, the cell is from a vertebrate. In some embodiments, the cell is a mammalian cell. In some embodiments, the cell is a human cell.

[0093] In some embodiments, the cell comprises increased expression or activation of at least or at most about one member, at least or at most about two members, at least or at most about three members, at least or at most about four members at least or at most about five members selected from the group consisting of: STRA8, MEIOSIN, DAZL, DMRT1 and CTCFL.Methods

[0094] Provided herein are methods advantageous for inducing and / or promoting meiosis. In some embodiments, provided are methods of inducing meiosis of a cell,comprising: increasing (e.g., via transfection or transduction with an engineered polynucleotide or exogenous nucleic acid molecule; via CRISPR activation of one or more endogenous genes, etc.) the cellular amount of one or more proteins (e.g., at least or at most about 1 , 2, 3, 4, 5, 6, 7, 8, 9, or 10) selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof, thereby inducing meiosis of the cell. In some embodiments, inducing and / or promoting meiosis comprises generating a haploid cell. In some embodiments, inducing and / or promoting meiosis comprises inducing and / or promoting Meiosis Il in a cell (e.g., characterized by a cell being in one of the stages selected from: prophase II, prometaphase II, metaphase II, anaphase II, or telophase II). In some embodiments, inducing and / or promoting meiosis comprises inducing and / or promoting Meiosis I in a cell (e.g., characterized by a cell being in one of the stages selected from: prophase I, prometaphase I, metaphase I, anaphase I, telophase I, or cytokinesis II). In some embodiments, inducing and / or promoting meiosis comprises inducing and / or promoting leptotene in a cell (e.g., characterized by a cell being in the leptotene stage of prophase I). In some embodiments, inducing and / or promoting meiosis comprises inducing and / or promoting zygotene in a cell (e.g., characterized by a cell being in the zygotene stage of prophase I). In some embodiments, inducing and / or promoting meiosis comprises inducing and / or promoting pachytene in a cell (e.g., characterized by a cell being in the pachytene stage of prophase I). In some embodiments, inducing and / or promoting meiosis comprises inducing and / or promoting diplotene in a cell (e.g., characterized by a cell being in the diplotene stage of prophase I). In some embodiments, inducing and / or promoting meiosis comprises inducing and / or promoting diakinesis in a cell (e.g., characterized by a cell being in the diakinesis stage of prophase I). In some embodiments, inducing and / or promoting meiosis comprises increasing homologous recombination (also referred to as meiotic recombination and / or crossing over) In certain embodiments, recombination is determined by: measuring linkage disequilibrium analysis, whole genome sequencing, cytologically counting chiasmata or recombination nodules, and / or fluorescent tetrad analysis.

[0095] In some embodiments, provided are methods of inducing meiosis of a cell, comprising: increasing the cellular amount of STRA8 protein. In some embodiments, provided are methods of inducing meiosis of a cell, comprising:increasing the cellular amount of MEIOSIN protein. In some embodiments, provided are methods of inducing meiosis of a cell, comprising: increasing the cellular amount of DAZL protein. In some embodiments, provided are methods of inducing meiosis of a cell, comprising: increasing the cellular amount of DMRT1 protein. In some embodiments, provided are methods of inducing meiosis of a cell, comprising: increasing the cellular amount of NANOS3 protein. In some embodiments, provided are methods of inducing meiosis of a cell, comprising: increasing the cellular amount of DDX4 protein. In some embodiments, provided are methods of inducing meiosis of a cell, comprising: increasing the cellular amount of CTCFL protein. In some embodiments, provided are methods of inducing meiosis of a cell, comprising: increasing the cellular amount of DEK protein. In some embodiments, provided are methods of inducing meiosis of a cell, comprising: increasing the cellular amount of YY2 protein. In some embodiments, provided are methods of inducing meiosis of a cell, comprising: increasing the cellular amount of SMC1 B protein.

[0096] In some embodiments, provided herein method of inducing and / or promoting meiosis, comprising: (a) increasing the cellular amount of a DMRT1 protein and a YY2 protein; and increasing the cellular amounts of one or more proteins selected from: a CTCFL protein, a STRA8 protein, a MEIOSIN protein, a DAZL protein, a SMC1 B protein, or a combination thereof. In some embodiments, (b) is performed two or more days after (a) (e.g., 7, 10, or 14 days). In certain embodiments, (b) is performed two days after (a). In certain embodiments, (b) is performed two days after (a). In certain embodiments, (b) is performed one day after (a). In certain embodiments, (b) is performed two days after (a). In certain embodiments, (b) is performed three days after (a). In certain embodiments, (b) is performed four days after (a). In certain embodiments, (b) is performed five days after (a). In certain embodiments, (b) is performed six days after (a). In certain embodiments, (b) is performed seven days after (a). In certain embodiments, (b) is performed eight days after (a). In certain embodiments, (b) is performed nine days after (a). In certain embodiments, (b) is performed ten days after (a). In certain embodiments, (b) is performed eleven days after (a). In certain embodiments, (b) is performed twelve days after (a). In certain embodiments, (b) is performed thirteen days after (a). In certain embodiments, (b) is performed fourteen days after (a). In some embodiments, (b) is performed 2-14 days after (a). In some embodiments, (b) is performed 2-10 days after (a). In some embodiments, (b) is performed 2-7days after (a). In some embodiments, (b) is performed 2-5 days after (a). In some embodiments, (b) is performed 5-14 days after (a). In some embodiments, (b) is performed 7-14 days after (a). In some embodiments, (b) is performed 10-14 days after (a).

[0097] In some embodiments, the methods as provided herein can comprise increasing the cellular amount of STRA8, MEIOSIN, DAZL, DMRT1 , or CTCFL, thereby inducing meiosis of the cell. In some embodiments, the methods can comprise increasing the cellular amount of two or more (e.g., at least or at most about 2, at least or at most about 3, at least or at most about 4, or at least or at most about 5) members selected from the group consisting of: STRA8, MEIOSIN, DAZL, DMRT1 , or CTCFL thereby inducing meiosis of the cell. The two or more members can be selected from the group consisting of STRA8, DAZL, and MEIOSIN. The two or more members can comprise at least STRA8 and DAZL, at least STRA8 and MEIOSIN, and / or at least DAZL and MEIOSIN.

[0098] In some embodiments of any of the methods as provided herein, increased expression or amount of two or more proteins (e.g. , two or more different members from STRA8, MEIOSIN, DAZL, DMRT1 , or CTCFL) can be performed or induced simultaneously or in a sequential order, e.g. separated by at least or at most about 1 hour, at least or at most about 2 hours, at least or at most about 4 hours, at least or at most about 6 hours, at least or at most about 12 hours, at least or at most about 18 hours, at least or at most about 1 day, at least or at most about 2 days, at least or at most about 3 days, at least or at most about 4 days, at least or at most about 5 days, at least or at most about 6 days, at least or at most about 7 days, at least or at most about 8 days, at least or at most about 9 days, at least or at most about 10 days, at least or at most about 1 1 days, at least or at most about 12 days, at least or at most about 13 days, at least or at most about 14 days, or at least or at most about 21 days.

[0099] In some embodiments, increasing the cellular amount protein comprises: transfecting or transducing the cell with one or more engineered polynucleotides encoding the one or more proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof. In certain embodiments, the engineered polynucleotide is a DNA molecule. In certain embodiments, the engineered polynucleotide is an mRNA molecule.

[0100] In some embodiments, increasing the cellular amount protein comprises: transfecting or transducing the cell with one or more engineered polynucleotides encoding one or more CRISPR-dCas activation systems targeting a gene region (e.g., a location upstream or downstream of a TSS) encoding a protein selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof.

[0101] In some embodiments, provided herein are methods of increasing and / or promoting meiosis, comprising: transducing or transfecting a cell with one or more engineered polynucleotides encoding one or more proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof. In certain embodiments, the engineered polynucleotide is an mRNA molecule. In certain embodiments, the engineered polynucleotide is an DNA molecule. In some embodiments, provided are methods of inducing meiosis of a cell, comprising: transducing or transfecting a cell with an engineered polynucleotide encoding a STRA8 protein. In some embodiments, provided are methods of inducing meiosis of a cell, comprising: transducing or transfecting a cell with an engineered polynucleotide encoding a MEIOSIN protein. In some embodiments, provided are methods of inducing meiosis of a cell, comprising: transducing or transfecting a cell with an engineered polynucleotide encoding a DAZL protein. In some embodiments, provided are methods of inducing meiosis of a cell, comprising: transducing or transfecting a cell with an engineered polynucleotide encoding a DMRT1 protein. In some embodiments, provided are methods of inducing meiosis of a cell, comprising: transducing or transfecting a cell with an engineered polynucleotide encoding a NANOS3 protein. In some embodiments, provided are methods of inducing meiosis of a cell, comprising: transducing or transfecting a cell with an engineered polynucleotide encoding a DDX4 protein. In some embodiments, provided are methods of inducing meiosis of a cell, comprising: transducing or transfecting a cell with an engineered polynucleotide encoding a CTCFL protein. In some embodiments, provided are methods of inducing meiosis of a cell, comprising: transducing or transfecting a cell with an engineered polynucleotide encoding a DEK protein. In some embodiments, provided are methods of inducing meiosis of a cell, comprising: transducing or transfecting a cell with an engineered polynucleotide encoding a YY2 protein. In some embodiments, provided are methods of inducing meiosis of a cell, comprising:transducing or transfecting a cell with an engineered polynucleotide encoding a SMC1 B protein.

[0102] In some embodiments, provided are methods of cell nuclear transfer, comprising: (a) increasing the cellular amount of one or more proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof, thereby inducing meiosis of the cell; (b) isolating the nucleus from the cell; and (c) transferring nucleus into a denucleated oocyte. In certain embodiments, transferring the nucleus into the cell activates the oocyte (e.g., enabling successful 2, 4, 8 cell cleavage and / or blastocyst formation). In some embodiment, the methods further comprises: (d) fertilizing the oocyte generated in (c)

[0103] In some embodiments, provided are methods of cell nuclear transfer, comprising: (a) increasing the cellular amount of one or more proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof, thereby inducing meiosis of the cell; (b) isolating the genome from the cell; and (c) transferring genome into an oocyte. In certain embodiments, the genome into the oocyte results in fertilization of the oocyte. In certain embodiments, transferring the genome into the oocyte and the fertilization activates the oocyte comprises successful 2, 4, or 8 cell cleavage, and / or blastocyst formation.

[0104] In some embodiments, increasing the cellular amount protein comprises, transfecting or transducing the cell with one or more engineered polynucleotides encoding the one or more proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof. In certain embodiments, the engineered polynucleotide is a DNA molecule. In certain embodiments, the engineered polynucleotide is an mRNA molecule. In some embodiments, increasing the cellular amount protein comprises, transfecting or transducing the cell with one or more engineered polynucleotides encoding one or more CRISPR-dCas activation systems targeting a gene region (e.g., a location upstream or downstream of a TSS) encoding a protein selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof.

[0105] In some embodiments, provided herein method of inducing and / or promoting meiosis, comprising: (a) increasing the cellular amount of a DMRT1protein and a YY2 protein; and increasing the cellular amounts of one or more proteins selected from: a CTCFL protein, a STRA8 protein, a MEIOSIN protein, a DAZL protein, a SMC1 B protein, or a combination thereof.

[0106] In some embodiments, the cell is a stem cell. In some embodiments, the cell is a pluripotent stem cell. In certain embodiments, the cell is an induced pluripotent stem cell. In some embodiments, the cell is a primordial germ cell (PGCs). In some embodiments, the cell is a somatic cell. In some embodiments, the cell is a mesenchymal stem cell or fibroblast.

[0107] In some embodiments, the cell and / or oocyte is from a vertebrate. In some embodiments, the cell and / or oocyte is a mammalian cell and / or mammalian oocyte. In some embodiments, the cell and / or oocyte is a human cell and / or human oocyte.

[0108] In some embodiments, the methods further comprise treating the cell with one or more co-factors. In some embodiments, one or more co-factors can comprise a small molecule, a nucleotide, a polynucleotide, an amino acid, a peptide, a protein, or a combination thereof. In some embodiments, the one or more co-factors can be exogenous to cells treated with such co-factors. In some embodiments, the one or more co-factors can comprise at least or at most about one co-factor, at least or at most about two co-factors, at least or at most about three co-factors, at least or at most about four co-factors, at least or at most about five co-factors, at least or at most about six co-factors, at least or at most about seven co-factors, at least or at most about eight co-factors, at least or at most about nine co-factors, or at least or at most about 10 co-factors.

[0109] In some embodiments, the one or more co-factors are selected from: antiviral response factors (B18R, E3, K3), activin-A, retinoic acid, and / or CCNA1. In some embodiments, the one or more co-factors may be a small molecule. In some embodiments, the one or more cofactors comprise one or more members selected from the group consisting of: GSK3484862, Z-DEVD-FMK, valproic acid, MC3343, AM580, and BMP2.

[0110] In some embodiments, one or more cells can be exposed to (or can be contacted by) the one or more co-factors prior to, simultaneously with, and / or subsequent to increasing expression (e.g. via CRISPRa, or introduction of an engineered polynucleotide) of one or more target genes as provided herein. In some embodiments, the exposure of the cells to the one or more co-factors and theincreasing of the expression of the one or more target genes / proteins (in either order) can be separated by at least or at most about 1 hour, at least or at most about 2 hours, at least or at most about 4 hours, at least or at most about 6 hours, at least or at most about 12 hours, at least or at most about 18 hours, at least or at most about 1 day, at least or at most about 2 days, at least or at most about 3 days, at least or at most about 4 days, at least or at most about 5 days, at least or at most about 6 days, at least or at most about 7 days, at least or at most about 8 days, at least or at most about 9 days, at least or at most about 10 days, at least or at most about 11 days, at least or at most about 12 days, at least or at most about 13 days, at least or at most about 14 days, or at least or at most about 21 days.

[0111] In some embodiments, inducing cellular meiosis as provided herein may not comprise increasing expression (e.g. via CRISPRa, or introduction of an engineered polynucleotide) of one or more (e.g., at least or at most about 1 , at least or at most about 2, at least or at most about 3, at least or at most about 4, at least or at most about 5) members selected from the group consisting of BOLL, MEIOC, myr-AKT, BCL2 and HOXB5. In some embodiments, the inducing of the cellular meiosis may not comprise increasing expression (e.g. via CRISPRa, or introduction of an engineered polynucleotide) of all members selected from the group consisting of STRA8, MEIOSIN, BOLL, MEIOC, myr-AKT, BCL2 and HOXB5.

[0112] As described herein, the term “percent (%) sequence identity,” and terms related thereto, in the context of amino acid sequences or nucleic acid sequences, is the percentage of amino acid residues or nucleic acid residues in a candidate sequence that are identical with the amino acid residues or nucleic acid residues, respectively, in a selected sequence, after aligning the sequences and introducing gaps, if necessary, to achieve the maximum percent sequence identity, and not considering any conservative substitutions as part of the sequence identity. Alignment for purposes of determining percent amino acid sequence identity or percent nucleic acid identity can be achieved in various ways that are within the skill in the art, for instance, using publicly available computer software such as Clustal Omega, BLAST, BLAST-2, ALIGN, ALIGN-2 or Megalign (DNASTAR) software, with BLAST being the alignment algorithm of preference. Those skilled in the art can determine appropriate parameters for measuring alignment, including any algorithms needed to achieve maximal alignment over the full-length of thesequences being compared, although for simplicity it maybe preferred to use default parameters.

[0113] The term “gene” or “gene region”, as used interchangeably herein, generally refers to a nucleic acid (e.g., DNA such as genomic DNA and cDNA) and its corresponding nucleotide sequence that is involved in encoding an RNA transcript. The term as used herein with reference to genomic DNA includes intervening, non-coding regions as well as regulatory regions and can include 5' and 3' ends. In some uses, the term encompasses the transcribed sequences, including 5' and 3' untranslated regions (5'-UTR and 3'-UTR), exons and introns. In some genes, the transcribed region will contain “open reading frames” that encode polypeptides. In some uses of the term, a “gene” comprises only the coding sequences (e.g., an “open reading frame” or “coding region”) necessary for encoding a polypeptide. In some cases, genes do not encode a polypeptide, for example, ribosomal RNA genes (rRNA) and transfer RNA (tRNA) genes. In some cases, the term “gene” includes not only the transcribed sequences, but in addition, also includes non-transcribed regions including upstream and downstream regulatory regions, enhancers and promoters. For example, a gene can refer to a portion of the gene that is near or adjacent to (e.g., upstream or downstream) a transcription start site (TSS) of the gene. The gene (e.g., that is targeted as disclosed herein) can be at least or up to about 2,000 nucleobases, at least or up to about 1 ,800 nucleobases, at least or up to about 1 ,600 nucleobases, at least or up to about 1 ,500 nucleobases, at least or up to about 1 ,400 nucleobases, at least or up to about 1 ,200 nucleobases, at least or up to about 1 ,000 nucleobases, at least or up to about 900 nucleobases, at least or up to about 800 nucleobases, at least or up to about 700 nucleobases, at least or up to about 600 nucleobases, at least or up to about 500 nucleobases, at least or up to about 400 nucleobases, at least or up to about 300 nucleobases, at least or up to about 200 nucleobases, at least or up to about 100 nucleobases, or at least or up to about 50 nucleobases away from the TSS of the gene.

[0114] As used herein, the term “individual” is synonymous with patient and / or subject and includes and / or refers to a human and may be a human that has been diagnosed as needing to treat a disease or condition as disclosed herein. However, examples are not limited to humans and include, chimpanzees, marmosets, cows, horses, sheep, goats, pigs, rabbits, dogs, cats, rats, mice, guinea pigs, and the like.The term individual includes vertebrates. The individual is typically a human and may be a human that has been diagnosed as needing to treat a disease or condition as disclosed herein.

[0115] As used herein, treating or treatment of includes and / or refers to ameliorating the disease or disorder or symptoms thereof (e.g., slowing or arresting or reducing the development of the disease or at least one of the clinical symptoms thereof). In certain embodiments, treating or treatment also includes and / or refers to alleviating or ameliorating at least one physical and / or biological parameters including those which may not be discernible by the patient. In certain embodiments, treating or treatment includes and / or refers to modulating a disease, disorder, or biological process either physically, (e.g., stabilization of a discernible symptom), physiologically, (e.g. , stabilization of a physical and / or biological parameter), or both. In certain embodiments, treating or treatment includes and / or refers to preventing or delaying the onset or development or progression of the disease or disorder. In certain embodiments, treating or treatment includes and / or refers to preventing or delaying or inhibiting the deterioration of (i) a healthy physiological state or (ii) a baseline physiological state (e.g., the progression of a disease or disorder).

[0116] As used herein, in any instance or embodiment described herein, “comprising” may be replaced with “consisting essentially of” and / or “consisting of,” unless context clearly connotes otherwise. Similarly, as used herein, in any instance or embodiment described herein, “comprises” may be replaced with “consists essentially of” and / or “consists of,” unless context clearly connotes otherwise.

[0117] As used herein, the term “about,” in the context of a given value or range, includes and / or refers to a value or range that is within 10% of the given value or range.

[0118] As used herein, the term “and / or” is to be taken as specific disclosure of each of the two specified features or components with or without the other. For example, “A and / or B” is to be taken as specific disclosure of each of (i) A, (ii) B and (iii) A and B, just as if each were set out individually herein.

[0119] Whenever the term “at least,” “greater than,” or “greater than or equal to” precedes the first numerical value in a series of two or more numerical values, the term “at least,” “greater than” or “greater than or equal to” applies to each of thenumerical values in that series of numerical values. For example, greater than or equal to 1 , 2, or 3 is equivalent to greater than or equal to 1 , greater than or equal to 2, or greater than or equal to 3.

[0120] Whenever the term “no more than,” “less than,” or “less than or equal to” precedes the first numerical value in a series of two or more numerical values, the term “no more than,” “less than,” or “less than or equal to” applies to each of the numerical values in that series of numerical values. For example, less than or equal to 3, 2, or 1 is equivalent to less than or equal to 3, less than or equal to 2, or less than or equal to 1 .EXAMPLESExample 1 : Identifying and targeting one or more genes of interest to induce meiosis in non-germ cellsTarget Identification

[0121] Target identification for meiosis induction broadly entails the combination of various multimodal datasets, most of which are derived from existing public resources. Differentially regulated genes from RNAseq and scRNAseq in germline related datasets are used to determine genes that are likely to play a role in meiosis induction. This is then combined with a variety of techniques with other transcriptomic data such as CHIPseq, ATACseq and RIP-ChIP (or RIP-ChiP similar) to determine a causal network of potential driver genes.

[0122] Public scRNAseq from Mammalian spermatogenesis and oogenesis was collated from GEO and Array-express. FASTQC was used to obtain quality metrics. Trimmomatic was used to trim sequencing adapters and remove low quality bases. Trimmed sequencing reads were pseudo-aligned against their respective genomes from NCBI datasets using alevin-fry. And gene counts were loaded into the scanpy package. Doublets, low read count cells were filtered from the datasets. Read counts or normalized and logl p transformed. Non-germline cells were filtered based on a geneset based scoring. A common manifold projection between sexes and species was derived using latent variable methods from scVI-tools. Cells were then clustered into different sets using the leiden algorithm. Differentially expressed genes (DEGs) were determined using the pyDeseq2 package were assessed between the different leiden groups and in particular the leidendetermined groups around meiosis initiation. Using a known list of transcription factors, their expression in this dataset is used to predict the expression of the remaining non-transcription factor genes using the catboost gradient boosting regressor with total read counts as an additional covariate. Transcription factors were then ranked on their importance in prediction and serve as the first unfiltered source of potential targets.

[0123] Public ATAC-seq / CHIP-seq (for the various factors if available) were used to narrow down to determine the factors involved in driving the core factors sufficient to initiate meiosis and derive potential gene regulatory networks (GRN). ATAC-seq reads were obtained from SRA. FASTQC was used to obtain quality metrics and filter low-quality samples. Trimmomatic was used to trim Nextera sequencing adapters and remove low quality bases. Reads were aligned to GRCh38p14 using bwa using the default parameters. Duplicate PCR reads were removed using PICARDtools. The alignmentsieve function from deeptools were used to shift sequencing reads for motif analysis due to the shift introduced by the ATAC transposase. Peaks were called using MACSv3. FIMO was used to scan the human genome for predicted transcription factor binding sites from the combined Jasper Core and HOCOMOCOv1 1 . DAStk was used to calculate MD- statistics, a measure of predicted peak enrichment central to ATAC-seq peaks. CHIP-seq reads were trimmed for base quality scores and aligned to NCBI’s GRCh38p14 using bwa and peaks called with MACSv3. Called peaks and predicted binding sites were then compared against the unfiltered list via multiple methods and manually selected for the most likely to drive meiosis.

[0124] RNA-sequencing reads were aligned using salmon. Counts were scaled and normalized together in aggregate and differential testing was done in pyDeseq2.

[0125] The following targets were identified: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, and SMC1 B.Transfection

[0126] For CRISPRa in HEK293T cells, a line with doxycycline-inducible dCas9- VPR stably integrated was generated via PiggyBac-mediated genomic insertion. These cells were plated into 24-well plates and transfected with 500 ng sgRNA plasmid target bearing a puromycin-resistance marker (puroR). 1 day post-transfection, cells were induced with 2 pg / mL doxycycline and selected with 2 pg I mL puromycin for 2 days. Cells were extracted for RNA using the Omega Biotek Magbead RNA Extraction kit.

[0127] For iPSCs, CRISPRa was achieved by plating wild-type cells into 24- wells and co-transfecting 1.5 pg of dCas9-VPR (with P2A-GFP or P2A-puroR) mRNA (Horizon) along with 12.5 pmol synthetic sgRNA (Synthego). If cells were transfected with puroR construct, they were selected with 0.1 -0.5 pg I mL puromycin. After 2 days, RNA extraction was carried out, as above.

[0128] For direct factor expression, mRNA constructs coding genes of interest (with P2A-GFP or P2A-puror) were transfected, as above, using 500 ng - 1.5 pg of mRNA constructs. Extraction was performed, as normal.

[0129] For time-course experiments, multiple transfections were carried out, with cells being replated every 3-4 days and being transfected the following day. Time-points were collected at each replating and at the end of the experiments.Protocol 1 (simultaneous transfection):

[0130] A combination of factors from the following genes (some or all) will be simultaneously transfected or activated via CRISPRa (as previously described above): DMRT1 , CTCFL, STRA8, MEIOSIN, YY2, DEK, SMC1 B, NANOS3, SYCP3 and DAZL. Successfully transfected cells will be selected for using antibiotic selection or FACS, as appropriate. These transfections will be performed sequentially over the course of up to 4 weeks. The targeted cell types will be iPSCs, PGCLCs, and primary cells such as MSCs and fibroblasts.Protocol 2 (simultaneous transfection, circRNA):

[0131] As protocol 1 , but the cells will be transfected only once with circRNA constructs bearing the genes of interest.Protocol 3 (sequential transfection):

[0132] As protocol 1 or 2, but the genes will be transfected I activated sequentially. The order of the genes we would be activating is as follows, DMRT 1 , and YY2 followed by a second treatment with CTCFL, STRA8, MEIOSIN, DEK, SMC1 B, NANOS3, SYCP3 and / or DAZL. The spacing between the treatments will range from 2-14 days.Protocol 4 (combined transfections + co-factors):

[0133] As protocols 1 -3, but the cells will be incubated in a combination of the following factors or conditions in addition to being transfected: valproic acid (1 -20 mM), hypoxic conditions (5 % 02), antiviral response factors (B18R, E3, K3).Protocol 5 (combined transfections + co-factors and meiosis / mitosis resolution factors):

[0134] As with protocols 1 -4 but with additional treatment of co-factors (e.g., antiviral response factors (B18R, E3, K3), activin-A, retinoic acid, and / or CCNA1 ) within 2-14 days after the last treatment specified in protocol 3 to initiate the second cell division in meiosis and induce the separation of sister chromatids.Example 2: Protocols for the initiation of meiosis (e.g., in non-germ cells)HEK293T cell culture and transfection protocol

[0135] 500-1 OOOng of total plasmids was added into a solution of Opti-MEM and mixed with TransIT-LT transfection reagent. After a brief incubation of 15-30 minutes at room temperature, the transfection complex was added to the cell culture media (2% L-glutamine and 10% FBS in DMEM). Cells were induced and selected in a medium containing 2 pg / mL doxycycline and 2 pg / mL puromycin. iPSCs cells were grown in mTESR plus medium on vitronectin coated plates. To detach cells from wells, cells were first washed with DPBS, and Accutase added and incubated for 5-7 minutes until the cells were detached and counted using a cell counter. iPSC cell culture and transfection protocol

[0136] iPSCs cells were grown in mTESR plus medium on vitronectin coated plates. To detach cells from wells, cells were first washed with DPBS, and Accutase added and incubated for 5-7 minutes until the cells were detached and counted using a cell counter. Cells were harvested from confluent cultures and cell counts were performed to prepare aliquots of 200,000-600,000 cells per experimental condition. For mRNA transfection experiments, mRNA mixtures containing a pool of the genes STRA8, MEIOSIN, DMRT1 , CTCFL and DAZL (5-pool) and STRA8, MEIOSIN, DMRT1 (3-pool) were prepared at concentrations ranging from 1.5 to 3 pg total. For some experiments, linear mRNA was transfected while others ascircRNA when noted using roughly the same gene sequences. For CRISPR activation experiments, appropriate RNA for the dCas9-VPR-P2A-sfGFP experiments and gRNA mixtures targeting the genes, STRA8, MEIOSIN and DAZL were prepared at 2pg and 25 pmol concentrations, respectively.

[0137] iPSC cells were nucleofected using Lonza’s 4D nucleofector according to the manufacturer's instructions using the CA-137 program, with cells and nucleic acids combined in P3 nucleofection solution. Immediately following nucleofection, cells were transferred to pre-warmed culture medium supplemented with B18R protein (for mRNA transfections), ROCKi, and other supplements if noted. Cells were then plated in vitronectin-coated 24-well plates at 100K-250K density. For selected conditions, GSK3484862 was added to the culture medium at 0.5-1 mM concentration. Cells were maintained under standard iPSC culture conditions (37°C, 5% CO2). For GFP-containing constructs, expression was monitored from one day post transfection to 4-weeks post-nucleofection using fluorescence microscopy. Samples were collected for RT-qPCR analysis at various timepoints. Throughout the experiment, cell confluency was monitored using microscopy.

[0138] iPSCs were transfected with the following: 500-2500 ng of mRNA encoding one or more of STRA8, MEIOSIN, DAZL, DMRT1 , CTCFL; or 500-2000 ng of circRNA encoding one or more of STRA8, MEIOSIN, DAZL; or 2000-2500 ng of mRNA encoding dCas9-VPR plus sgRNA pools allowing targeted activation of one or more of STRA8, MEIOSIN, DAZL; or were left untreated.Initiation of meiosis culturing conditions:

[0139] Post-transfection, cells were subsequently plated in tissue culture plates and cultured in one of the following media conditions:(A) (i.) mTeSR + 5 pM GSK3484862 (+G); or (ii.) mTeSR + 5 pM GSK3484862 + 1 pM retinoic acid (+GR); or (iii.) mTeSR +5 pM GSK3484862 + 1 pM retinoic acid + 100 pM Z-DEVD- FMK (+GRZ); or (iv.) mTeSR +5 pM GSK3484862 + 1 mM valproic acid (+GV); or (v.) mTeSR +5 pM GSK3484862 + 1 pM retinoic acid + 1 mM valproic acid (+GRV); or (vi.) mTeSR +2 pM MC3343, 1 pM AM580, 100 ng / pL BMP2; or (B) (APEL2 + 5 pM GSK3484862 + 1 pM retinoic acid (+GR); or a mixture (A) and (B). Cells were maintained in media and regularly taken for readouts for meiosis on the transcriptional and protein expression level.RNA extraction

[0140] RNA extraction was performed using the QIAcube automated system with the RNeasy Mini kit, incorporating QIAshredder homogenization and DNase I digestion. Cells were lysed in Buffer RLT containing [3-mercaptoethanol. The QIAcube was set up with appropriate reagents, including Buffer RPE (with added ethanol), DNase I mixture, and RNase-free water. Samples were processed using the "RNeasy Mini > Animal Cells > QIAshredder DNase Digest" protocol. RNA was eluted in 100 pL of RNase-free water. Concentration of the purified RNA was measured using Nanodrop spectrophotometry. qRT-PCR Quantification

[0141] For qRT-PCR quantification, RNA samples were processed using the Luna® Universal One-Step RT-qPCR Kit. The reaction setup was automated using an Opentrons robot, following a custom python script. Samples and reagents were arranged according to the generated plate configuration. The qPCR plate was prepared with mastermixes containing specific Taqman primer and probes for target genes and multiplexed with a housekeeping background gene. The prepared plate was then run on a QuantStudio 6 Flex machine using a pre-defined template. Cq values were determined using QuantStudio Software v1.7.2, with results exported for further statistical evaluation and interpretation of gene expression levels.IVT transcription

[0142] In vitro transcription (IVT) was performed using the HiScribe® T7 mRNA Kit with CleanCap® Reagent AG. This kit utilizes a modified T7 promoter to specifically cap mRNA beginning with AG bases. The amount of template DNA added was adjusted to account for additional plasmid sequences upstream of the T7 promoter, ensuring 1 pg of effective template DNA was used. The reaction was carried out following the manufacturer's standard synthesis protocol. After transcription, the resulting mRNA was purified and analyzed for quality and quantity.Immunofluorescence imaging

[0143] To stain for SYCP3 and STRA8, cells were first permeabilized with 0.2% Triton X-100 for 10 minutes. After washing with PBS, the wells were blocked using different solutions: 5% BSA for SYCP3 staining and 3% BSA with 3% goat serum for STRA8 staining, both for 30 minutes. Primary antibodies were incubated for variable times. STRA8 staining a primary antibody AB217380 (1 :250) was used and AB15093 (1 :250). An anti-rabbit goat TxRed antibody (ab6719) was used as a secondary antibody.Example 3: Quantifying induced meiosis gene markers in iPSCs

[0144] Exposing iPSCs to a combination of meiosis induction media (IM), relevant co-factors and polynucleotides can induce meiosis in what were once non- meiotic cells. Such induction will result in the increase expression, or activation, of various meiosis pathway genes. Some genes, such as REC8, are known as early meiosis markers, while others such as SYCP3 are known as late meiosis markers. Observing an increase in the expression, or activation, of markers spanning the early-late timeframe signifies successful meiosis induction, which can be recorded and quantified via techniques like qRT-PCR.

[0145] As provided herein, cells (e.g., HEK293T cells iPSCs) were treated to various IM conditions and control conditions and characterized for meiosis induction, as described in Example 3.

[0146] Figs. 7A-C show graphs depicting qRT-PCR data measuring the impact of: the expression of various combinations of STRA8, DMRT1 , MEIOSIN, CTCFL, and DAZL on the expression levels of key meiosis markers. These genes, identified in earlier experiments in Example 1 , were either expressed via from CRISPRa or delivery of polynucleic acids. Common among treatment groups receiving mRNA delivery (see Fig. 7A), activation by CRISPRa (see Fig. 7B) or circRNA delivery (see Fig. 7C, was the resulting, robust gene expression upon induction. These treatments were additionally paired with various combinations of meiosis-inducing co-factors: GSK3484862 (G), retinoic acid (R), valproic acid (V), Z-DEVD-FMK (Z) to assess their possible synergistic effects. The meiotic genes queried (listed at the top of the graph, exhibited a mosaic of expression changes with the addition of particularly effective combinations polynucleic acid delivery, CRISPRa, and / or cofactor exposure.

[0147] The effect of IM treatments on the expression of meiosis genes can also be observed and quantified by eye. Fig. 8 depicts the results of immunostainingexperiments on plates of iPSC cells having undergone IM treatment. Expression of STRA8 (top) and SYCP3 (bottom) are visualized, along with a Hoechst nuclear stain to pair with it. Increased expression of STRA8 and SYCP3 was visually robust in each culture, as numerous nuclei that are present in the Hoechst images demonstrate co-expression of a respective meiosis gene of interest.

[0148] Fig. 9 shows an additional set of qRT-PCR results presented as a time course study. The expression of four meiosis genes, SMC1 B, SYCE1 , SYCP1 , and SYCP3 were quantified and tracked over time in response to the IM treatments outlined previously. Although there were variable magnitudes of the impact of IM treatment on each gene, expression elevation appeared to reach a maximum value after day 6 in all cases.

[0149] In some embodiments, as shown in Fig. 10, cells treated with meiosis induction media (IM) can induce enhanced expression of one or more meiosis driver or related genes (e.g., HORMAD1 , STRA8, MEIS1 , SYCP3, SYCE1 , etc.) in comparison to untreated controls (e.g., mTeSR media alone without small molecules added). Specific media and co-factor treatment groups are listed at the top. Timepoints were taken over multiple days. Cells treated with IM with CRISPR activation of endogenous STRA8, MEIOSIN, and DAZL (n=1 ) also showed enhanced expression of the one or more meiosis driver or related genes.

[0150] The relationships between each purported meiosis-inducing gene, like STRA8, DAZL, and MEIOSIN, and a known meiosis marker, are demonstrated in Fig. 11. HEK293T cells were treated with CRISPRa to activate the indicated meiosis inducing gene (x-axis) and their expression in log fold change was charted against the expression of the meiosis marker of interest (y-axis). In all cases, an increase or activation of the meiosis inducing genes by CRISPRa is closely associated with an increase in the expression or activation of meiosis markers ranging from early to late.

[0151] Fig. 12 depicts further qRT-PCR data from iPSC cells, where the effect of mTeSR media alone on the expression or activation ofparticular meiosis marker (SYCE1 , left. SMCB1 , right) is compared to mTeSR media and co-transfection with STRA8 and MEIOSIN circRNAs. In both cases, induction media on its own had some activating / upregulating effect on those markers. However, co-transfection with the media treatment resulted in > 15-fold increase in the expression of the indicated meiosis markers.

[0152] Fig 13 also illustrates the effect of induction media alone, versus induction media plus co-transfection. Expression levels of meiosis markers of interest, SMC1 B (left) and SYCE1 (right), were analyzed between cells receiving induction media alone or media combined with co-transfection with a combination of: STRA8, DAZL,MEIOSIN, DMRT1 , or CTCFL mRNA. Like Figure 12, there was some basal meiosis gene expression when exposed to induction media alone. But in all cases, transfection combined with induction media resulted in multi-log increases in the levels of meiosis marker expression. The importance of co- transfection with media treatment was thusly illustrated.SEQUENCESEMBODIMENTS

[0154] The following non-limiting embodiments provide illustrative examples of the invention, but do not limit the scope of the invention.

[0155] Embodiment 1 . A cell comprising one or more engineered polynucleotides encoding one or more proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof, optionally wherein:(i) the cell comprises: an engineered polynucleotide encoding a STRA8 protein; an engineered polynucleotide encoding a MEIOSIN protein; an engineered polynucleotide encoding a DAZL protein; an engineered polynucleotide encoding a DMRT1 protein; or an engineered polynucleotide encoding a CTCFL protein; and / or(ii) the cell comprises two or more members selected from the group consisting of: the engineered polynucleotide encoding the STRA8 protein; the engineered polynucleotide encoding the MEIOSIN protein; the engineered polynucleotide encoding the DAZL protein;the engineered polynucleotide encoding the DMRT1 protein; and the engineered polynucleotide encoding the CTCFL protein; and / or(iii) the cell comprises two or more members selected from the group consisting of: the engineered polynucleotide encoding the STRA8 protein; the engineered polynucleotide encoding the DAZL protein; and the engineered polynucleotide encoding the MEIOSIN protein; and / or (iv.) the cell comprises: the engineered polynucleotide encoding the STRA8 protein; the engineered polynucleotide encoding the DAZL protein; and the engineered polynucleotide encoding the MEIOSIN protein; and / or (v.) the cell comprises: an engineered polynucleotide encoding a DMRT1 protein; and an engineered polynucleotide encoding a YY2 protein; and / or (vi.) the cell comprises: an engineered polynucleotide encoding a STRA8 protein; an engineered polynucleotide encoding a MEIOSIN protein; an engineered polynucleotide encoding a DAZL protein; an engineered polynucleotide encoding a NANOS3 protein; an engineered polynucleotide encoding a DDX4 protein; an engineered polynucleotide encoding a CTCFL protein; an engineered polynucleotide encoding a DEK protein; an engineered polynucleotide encoding a SMC1 B protein; or a combination thereof; and / or(vii.) the engineered polynucleotide is a deoxyribonucleic acid (DNA) molecule; and / or(viii.) the engineered polynucleotide is a messenger ribonucleic acid (mRNA) molecule; and / or(ix.) the mRNA molecule is a circular mRNA molecule.

[0156] Embodiment 2. A cell comprising one or more exogenous nucleic acid sequences encoding one or more proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof, optionally wherein: (i) the cell comprises:an exogenous nucleic acid sequence encoding a STRA8 protein; an exogenous nucleic acid sequence encoding a MEIOSIN protein; an exogenous nucleic acid sequence encoding a DAZL protein; an exogenous nucleic acid sequence encoding a DMRT1 protein; or an exogenous nucleic acid sequence encoding a CTCFL protein; and / or(ii) the cell comprises: two or more members selected from the group consisting of: the exogenous nucleic acid sequence encoding the STRA8 protein; the exogenous nucleic acid sequence encoding the MEIOSIN protein; the exogenous nucleic acid sequence encoding the DAZL protein; the exogenous nucleic acid sequence encoding the DMRT1 protein; or the exogenous nucleic acid sequence encoding the CTCFL protein; and / or(iii.) the cell comprises two or more members selected from the group consisting of: the exogenous nucleic acid sequence encoding the STRA8 protein; the exogenous nucleic acid sequence encoding the DAZL protein; and the exogenous nucleic acid sequence encoding the MEIOSIN protein; and / or(iv.) the cell comprises: the exogenous nucleic acid sequence encoding the STRA8 protein; the exogenous nucleic acid sequence encoding the DAZL protein, and the exogenous nucleic acid sequence encoding the MEIOSIN protein; and / or(v.) the cell comprises: an exogenous nucleic acid sequence encoding a DMRT1 protein; and an exogenous nucleic acid sequence encoding a YY2 protein; and / or (vi.) the cell comprises: an exogenous nucleic acid sequence encoding a STRA8 protein; an exogenous nucleic acid sequence encoding a MEIOSIN protein; an exogenous nucleic acid sequence encoding a DAZL protein; an exogenous nucleic acid sequence encoding a NANOS3 protein; an exogenous nucleic acid sequence encoding a DDX4 protein; an exogenous nucleic acid sequence encoding a CTCFL protein;an exogenous nucleic acid sequence encoding a DEK protein; an exogenous nucleic acid sequence encoding a SMC1 B protein; or a combination thereof; and / or(vii.) the engineered polynucleotide is a deoxyribonucleic acid (DNA) molecule; and / or(viii.) the engineered polynucleotide is a messenger ribonucleic acid (mRNA) molecule; and / or(ix.) the mRNA molecule is a circular mRNA molecule.

[0157] Embodiment 3. A cell comprising one or more CRISPR-dCas activation systems comprising an enzymatically inactive Cas protein and a gRNA comprising a spacer sequence that hybridizes to a gene region (e.g., upstream or downstream of the TSS) selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof, optionally, wherein:(i.) the gene region comprises STRA8, MEIOSIN, DAZL, DMRT1 , or CTCFL; and / or(ii.) the gene region comprises two or more members selected from the group consisting of: STRA8, MEIOSIN, DAZL DMRT1 , and CTCF; and / or.(iii.) the gene region comprises two or more members selected from the group consisting of: STRA8, DAZL and MEIOSIN; and / or(iv.) the gene region comprises STRA8, DAZL and MEIOSIN; and / or(v.) the engineered CRISPR-dCas activation system comprises one or more nucleic acid molecules encoding the enzymatically inactive Cas protein and / or the gRNA.

[0158] Embodiment 4. The cell of any one of Embodiments 1 -3, further optionally wherein:(i) the cell is a stem cell; and / or(ii.) the cell is a pluripotent stem cell; and / or(iii.) the cell is an iPSC; and / or(iv.) the cell is a PGCLC; and / or(v.) the cell is a fibroblast; and / or(vi.) the cell is a mesenchymal stem cell; and / or(vii.) the cell is a somatic cell.

[0159] Embodiment 5. A nucleus isolated from the cell of any one of Embodiments 1 -4.

[0160] Embodiment 6. An oocyte isolated from the cell of any one of Embodiments 1 -4.

[0161] Embodiment 7. A composition comprising one or more engineered mRNA polynucleotides encoding one or more proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof, optionally, wherein:(i.) the composition comprises: an engineered mRNA polynucleotide encoding a STRA8 protein; an engineered mRNA polynucleotide encoding a MEIOSIN protein; an engineered mRNA polynucleotide encoding a DAZL protein; an engineered mRNA polynucleotide encoding a DMRT1 protein; or an engineered mRNA polynucleotide encoding a CTCFL protein; and / or(ii.) the composition comprises two or more members selected from the group consisting of: the engineered mRNA polynucleotide encoding the STRA8 protein; the engineered mRNA polynucleotide encoding the MEIOSIN protein; the engineered mRNA polynucleotide encoding the DAZL protein; the engineered mRNA polynucleotide encoding the DMRT1 protein; and the engineered mRNA polynucleotide encoding the CTCFL protein; and / or (iii.) the composition comprises two or more members selected from the group consisting of: the engineered mRNA polynucleotide encoding the STRA8 protein; the engineered mRNA polynucleotide encoding the DAZL protein; and the engineered mRNA polynucleotide encoding the MEIOSIN protein; and / or(iv.) the composition comprises: the engineered mRNA polynucleotide encoding the STRA8 protein; the engineered mRNA polynucleotide encoding the DAZL protein; and the engineered mRNA polynucleotide encoding the MEIOSIN protein; and / or(v.) the composition comprises:an engineered mRNA polynucleotide encoding a DMRT1 protein; and an engineered mRNA polynucleotide encoding a YY2 protein; and / or (vi.) the composition comprises: an engineered mRNA polynucleotide encoding a STRA8 protein; an engineered mRNA polynucleotide encoding a MEIOSIN protein; an engineered mRNA polynucleotide encoding a DAZL protein; an engineered mRNA polynucleotide encoding a NANOS3 protein; an engineered mRNA polynucleotide encoding a DDX4 protein; an engineered mRNA polynucleotide encoding a CTCFL protein; an engineered mRNA polynucleotide encoding a DEK protein; an engineered mRNA polynucleotide encoding a SMC1 B protein; or a combination thereof.

[0162] Embodiment 8. A CRISPR-dCas activation system comprising an enzymatically inactive Cas protein and a gRNA comprising a spacer sequence that hybridizes to a gene region selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof, optionally, wherein:(i.) the spacer sequence hybridizes upstream or downstream of a transcription start site for a sequence encoding a protein selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof.; and / or(ii.) the spacer sequence hybridizes upstream or downstream of a transcription start site for a sequence encoding a protein selected from: STRA8, MEIOSIN, DAZL, DMRT1 , or CTCFL; and / or(iii.) the spacer sequence hybridizes upstream or downstream of a transcription start site for two or more sequences respectively encoding two or more members selected from the group consisting of: STRA8, MEIOSIN, DAZL DMRT1 , and CTCFL; and / or(iv.) the spacer sequence hybridizes upstream or downstream of a transcription start site for two or more sequences respectively encoding two or more members selected from the group consisting of: STRA8, DAZL and MEIOSIN; and / or(v.) the spacer sequence hybridizes upstream or downstream of a transcription start site for sequences respectively encoding STRA8, DAZL and MEIOSIN.

[0163] Embodiment 9. A composition comprising the cell of any one of Embodiments 1 -4 or the CRISPR-dCas activation system of Embodiment 8.

[0164] Embodiment 10. The composition of any one of Embodiments 7 and Embodiment 9, further comprising one or more co-factors.

[0165] Embodiment 11. The composition of Embodiment 10, wherein the one or more co-factors are selected from the group consisting of: GSK3484862, Z-DEVD- FMK, valproic acid, MC3343, AM580, and BMP2.

[0166] Embodiment 12. A method of inducing and / or promoting meiosis in a cell, the method comprising: increasing the cellular amount of one or more proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof, thereby inducing meiosis of the cell, optionally, wherein:(i.) the inducing and / or promoting meiosis comprises generating a haploid nucleus; and / or(ii.) the inducing and / or promoting meiosis comprises inducing and / or promoting Meiosis Il in a cell (e.g., characterized by a cell being in one of the stages selected from: prophase II, pro-metaphase II, metaphase II, anaphase II, or telophase II); and / or(iii.) the inducing and / or promoting meiosis comprises inducing and / or promoting Meiosis I in a cell (e.g., characterized by a cell being in one of the stages selected from: prophase I, pro-metaphase I, metaphase I, anaphase I, telophase I, or cytokinesis II); and / or(iv.) the inducing and / or promoting meiosis comprises inducing and / or promoting leptotene in a cell (e.g., characterized by a cell being in the leptotene stage of prophase I); and / or(v.) the inducing and / or promoting meiosis comprises inducing and / or promoting zygotene in a cell (e.g., characterized by a cell being in the zygotene stage of prophase I); and / or(vi.) the inducing and / or promoting meiosis comprises inducing and / or promoting pachytene in a cell (e.g., characterized by a cell being in the pachytene stage of prophase I); and / or(vii..) the inducing and / or promoting meiosis comprises inducing and / or promoting diplotene in a cell (e.g., characterized by a cell being in the diplotene stage of prophase I); and / or(viii.) wherein the inducing and / or promoting meiosis comprises inducing and / or promoting diakinesis in a cell (e.g., characterized by a cell being in the diakinesis stage of prophase I); and / or(ix.) wherein the inducing and / or promoting meiosis comprises increasing homologous recombination.

[0167] Embodiment 13. The method of Embodiment 12, wherein the inducing and / or promoting meiosis is compared to a cell not having an increased cellular amount of one or more proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof, thereby inducing meiosis of the cell.

[0168] Embodiment 14. The method of Embodiment 12, wherein the method comprises:(a) increasing the cellular amount of a DMRT1 protein and a YY2 protein; and(b) increasing the cellular amounts of one or more proteins selected from: a CTCFL protein, a STRA8 protein, a MEIOSIN protein, a DAZL protein, a SMC1 B protein, or a combination thereof.

[0169] Embodiment 15. The method of any one of Embodiments 12-14, wherein increasing the cellular amount protein comprises transfecting or transducing the cell with one or more engineered polynucleotides encoding the one or more proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof.

[0170] Embodiment 16. The method of any one of Embodiments 12-15, wherein increasing the cellular amount protein comprises: transfecting or transducing the cell with one or more engineered mRNA polynucleotides encoding the one or more proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof.

[0171] Embodiment 17. The method of any one of Embodiments 12-14, wherein increasing the cellular amount protein comprises transfecting or transducing the cell with one or more engineered polynucleotides encoding one or more CRISPR- dCas activation systems targeting a gene region (e.g., a location upstream ordownstream of a TSS) encoding a protein selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof.

[0172] Embodiment 18. The method of any one of Embodiments 12-17 wherein the one or more proteins comprise STRA8, MEIOSIN, DAZL, DMRT1 , or CTCFL.

[0173] Embodiment 19. The method of Embodiment 18 wherein the one or more proteins comprise two or more members selected from the group consisting of: STRA8, MEIOSIN, DAZL DMRT1 , and CTCFL.

[0174] Embodiment 20. The method of Embodiment 19 wherein the one or more proteins comprise two or more members selected from the group consisting of STRA8, DAZL, and MEIOSIN.

[0175] Embodiment 21 . The method of Embodiment 20 wherein the one or more proteins comprise STRA8, DAZL, and MEIOSIN.

[0176] Embodiment 22. The method of any one of Embodiments 12-21 further comprising treating the cell with one or more co-factors.

[0177] Embodiment 23. The method of Embodiment 22, wherein the one or more co-factors are selected from: antiviral response factors (B18R, E3, K3), activin-A, retinoic acid, and / or CCNA1 .

[0178] Embodiment 24. The method of Embodiment 22, wherein the one or more co-factors are selected from the group consisting of: GSK3484862, Z-DEVD-FMK, valproic acid, MC3343, AM580, and BMP2.

[0179] Embodiment 25. The method of any one of Embodiments 22-24, wherein the one or more co-factors are selected from the group consisting of: GSK3484862, Z-DEVD-FMK, valproic acid, MC3343, AM580, and BMP2.

[0180] Embodiment 26. The method of any one of Embodiments 12-25, further comprising:(i) isolating the nucleus from the cell; and(ii) transferring the nucleus into a denucleated oocyte

[0181] Embodiment 27. The method of Embodiment 26, wherein the transferring of the nucleus into the denucleated oocyte further activates the oocyte comprises successful 2, 4, or 8 cell cleavage, and / or blastocyst formation.

[0182] Embodiment 28. The method of Embodiment 26 or 27, wherein the method further comprises: fertilizing the oocyte.

[0183] Embodiment 29: The method of any one of Embodiments 12-25, further comprising:(i) isolating the genome from the cell; and(ii) transferring the genome into an oocyte

[0184] Embodiment 30: The method of Embodiment 29, wherein the transferring of the genome into the oocyte results in fertilization of the oocyte.

[0185] Embodiment 31 : The method of Embodiment 30, wherein the transferring of the genome into the oocyte and the fertilization activates the oocyte comprises successful 2, 4, or 8 cell cleavage, and / or blastocyst formation

[0186] Embodiment 32: The method of any one of Embodiments 12-31 , wherein the cell is a stem cell

[0187] Embodiment 33: The method of any one of Embodiments 12-31 , wherein the cell is a pluripotent stem cell.

[0188] Embodiment 34: The method of any one of Embodiments 12-31 , wherein the cell is an iPSC.

[0189] Embodiment 35: The method of any one of Embodiments 12-31 , wherein the cell is a PGCLC.

[0190] Embodiment 36: The method of any one of Embodiments 12-31 , wherein the cell is a fibroblast.

[0191] Embodiment 37: The method of any one of Embodiments 12-31 , wherein the cell is a mesenchymal stem cell.

[0192] Embodiment 38: The method of any one of Embodiments 12-31 , wherein the cell is a somatic cell.

[0193] Embodiment 39: The method of any one of Embodiments 12-38, wherein the cell is a somatic cell.

[0194] Embodiment 40: The method of any one of Embodiments 12-38, wherein the cell and / or oocyte is a vertebrate cell and / or oocyte.

[0195] Embodiment 41 : The method of any one of Embodiments 12-38, wherein the cell and / or egg is a mammalian cell and / or oocyte.

[0196] Embodiment 42: The method of any one of Embodiments 12-38, wherein the cell and / or egg is a human cell and / or oocyte.

Claims

CLAIMSWHAT IS CLAIMED IS:1 . A cell comprising one or more engineered polynucleotides encoding one or more proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof.

2. The cell of claim 1 , wherein the cell comprises: an engineered polynucleotide encoding a STRA8 protein; an engineered polynucleotide encoding a MEIOSIN protein; an engineered polynucleotide encoding a DAZL protein; an engineered polynucleotide encoding a DMRT1 protein; or an engineered polynucleotide encoding a CTCFL protein.

3. The cell of claim 2, wherein the cell comprises two or more members selected from the group consisting of: the engineered polynucleotide encoding the STRA8 protein; the engineered polynucleotide encoding the MEIOSIN protein; the engineered polynucleotide encoding the DAZL protein; the engineered polynucleotide encoding the DMRT1 protein; and the engineered polynucleotide encoding the CTCFL protein.

4. The cell of any one of claims 1 -3, wherein the cell comprises two or more members selected from the group consisting of: the engineered polynucleotide encoding the STRA8 protein; the engineered polynucleotide encoding the DAZL protein; and the engineered polynucleotide encoding the MEIOSIN protein.

5. The cell of any one of claims 1 -4, wherein the cell comprises: the engineered polynucleotide encoding the STRA8 protein; the engineered polynucleotide encoding the DAZL protein; and the engineered polynucleotide encoding the MEIOSIN protein.

6. The cell of claim 1 , wherein the cell comprises: an engineered polynucleotide encoding a DMRT1 protein; and an engineered polynucleotide encoding a YY2 protein.

7. The cell of any one of claims 1 -6, wherein the cell comprises: an engineered polynucleotide encoding a STRA8 protein; an engineered polynucleotide encoding a MEIOSIN protein; an engineered polynucleotide encoding a DAZL protein;an engineered polynucleotide encoding a NANOS3 protein; an engineered polynucleotide encoding a DDX4 protein; an engineered polynucleotide encoding a CTCFL protein; an engineered polynucleotide encoding a DEK protein; an engineered polynucleotide encoding a SMC1 B protein; or a combination thereof.

8. The cell of any one of claims 1 -7, wherein the engineered polynucleotide is a deoxyribonucleic acid (DNA) molecule.

9. The cell of any one of claims 1 -8, wherein the engineered polynucleotide is a messenger ribonucleic acid (mRNA) molecule.

10. The cell of claim 9, wherein the mRNA molecule is a circular mRNA molecule.11 .A cell comprising one or more exogenous nucleic acid sequences encoding one or more proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof.

12. The cell of claim 1 1 , wherein the cell comprises: an exogenous nucleic acid sequence encoding a STRA8 protein; an exogenous nucleic acid sequence encoding a MEIOSIN protein; an exogenous nucleic acid sequence encoding a DAZL protein; an exogenous nucleic acid sequence encoding a DMRT1 protein; or an exogenous nucleic acid sequence encoding a CTCFL protein.

13. The cell of claim 12, wherein the cell comprises two or more members selected from the group consisting of: the exogenous nucleic acid sequence encoding the STRA8 protein; the exogenous nucleic acid sequence encoding the MEIOSIN protein; the exogenous nucleic acid sequence encoding the DAZL protein; the exogenous nucleic acid sequence encoding the DMRT1 protein; or the exogenous nucleic acid sequence encoding the CTCFL protein.

14. The cell of any one of claims 11 -13, wherein the cell comprises two or more members selected from the group consisting of: the exogenous nucleic acid sequence encoding the STRA8 protein; the exogenous nucleic acid sequence encoding the DAZL protein; and the exogenous nucleic acid sequence encoding the MEIOSIN protein.

15. The cell of any one of claims 1 1 -14, wherein the cell comprises: the exogenous nucleic acid sequence encoding the STRA8 protein;the exogenous nucleic acid sequence encoding the DAZL protein; and the exogenous nucleic acid sequence encoding the MEIOSIN protein.

16. The cell of claim 1 1 , wherein the cell comprises: an exogenous nucleic acid sequence encoding a DMRT1 protein; and an exogenous nucleic acid sequence encoding a YY2 protein.

17. The cell of any one of claims 1 1 -15, wherein the cell comprises: an exogenous nucleic acid sequence encoding a STRA8 protein; an exogenous nucleic acid sequence encoding a MEIOSIN protein; an exogenous nucleic acid sequence encoding a DAZL protein; an exogenous nucleic acid sequence encoding a NANOS3 protein; an exogenous nucleic acid sequence encoding a DDX4 protein; an exogenous nucleic acid sequence encoding a CTCFL protein; an exogenous nucleic acid sequence encoding a DEK protein; an exogenous nucleic acid sequence encoding a SMC1 B protein; or a combination thereof.

18. The cell of any one of claims 1 1 -17, wherein the exogenous nucleic acid is a deoxyribonucleic acid (DNA) sequence.

19. The cell of any one of claims 11 -17, wherein the exogenous nucleic acid sequence is a ribonucleic acid (RNA) sequence.

20. A cell comprising one or more CRISPR-dCas activation systems comprising an enzymatically inactive Cas protein and a gRNA comprising a spacer sequence that hybridizes to a gene region (e.g., upstream or downstream of the TSS) selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof.

21. The cell of claim 20, wherein the gene region comprises STRA8, MEIOSIN, DAZL, DMRT1 , or CTCFL.

22. The cell of claim 21 wherein the gene region comprises two or more members selected from the group consisting of: STRA8, MEIOSIN, DAZL DMRT1 , and CTCFL.

23. The cell of claim 20-22, wherein the gene region comprises two or more members selected from the group consisting of: STRA8, DAZL and MEIOSIN.

24. The cell of claim 20-23, wherein the gene region comprises STRA8, DAZL and MEIOSIN.

25. The cell of claim 20, wherein the engineered CRISPR-dCas activation system comprises one or more nucleic acid molecules encoding the enzymatically inactive Cas protein and / or the gRNA.

26. The cell of any one of claims 1 -25, wherein the cell is a stem cell.

27. The cell of any one of claims 1 -25, wherein the cell is a pluripotent stem cell.

28. The cell of any one of claims 1 -25, wherein the cell is an iPSC.

29. The cell of any one of claims 1 -25, wherein the cell is a PGCLC.

30. The cell of any one of claims 1 -25, wherein the cell is a fibroblast.31 .The cell of any one of claims 1 -25, wherein the cell is a mesenchymal stem cell.

32. The cell of any one of claims 1 -25, wherein the cell is a somatic cell.

33. A nucleus isolated from the cell of any one of claims 1 -32.

34. An oocyte comprising a nucleus isolated from the cell of any one of claims 1 -32.

35. A composition comprising one or more engineered mRNA polynucleotides encoding one or more proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof.

36. The composition of claim 35, wherein the composition comprises: an engineered mRNA polynucleotide encoding a STRA8 protein; an engineered mRNA polynucleotide encoding a MEIOSIN protein; an engineered mRNA polynucleotide encoding a DAZL protein; an engineered mRNA polynucleotide encoding a DMRT1 protein; or an engineered mRNA polynucleotide encoding a CTCFL protein.

37. The composition of 36, wherein the composition comprises two or more members selected from the group consisting of: the engineered mRNA polynucleotide encoding the STRA8 protein; the engineered mRNA polynucleotide encoding the MEIOSIN protein; the engineered mRNA polynucleotide encoding the DAZL protein; the engineered mRNA polynucleotide encoding the DMRT1 protein; and the engineered mRNA polynucleotide encoding the CTCFL protein.

38. The composition of any one of claims 35-37, wherein the composition comprises two or more members selected from the group consisting of: the engineered mRNA polynucleotide encoding the STRA8 protein; the engineered mRNA polynucleotide encoding the DAZL protein; and the engineered mRNA polynucleotide encoding the MEIOSIN protein.

39. The composition of any one of claims 35-38, wherein the composition comprises: the engineered mRNA polynucleotide encoding the STRA8 protein; the engineered mRNA polynucleotide encoding the DAZL protein; and the engineered mRNA polynucleotide encoding the MEIOSIN protein.

40. The composition of claim 35, wherein the composition comprises: an engineered mRNA polynucleotide encoding a DMRT1 protein; and an engineered mRNA polynucleotide encoding a YY2 protein.

41. The composition of any one of claims 35-40, wherein the composition comprises: an engineered mRNA polynucleotide encoding a STRA8 protein; an engineered mRNA polynucleotide encoding a MEIOSIN protein; an engineered mRNA polynucleotide encoding a DAZL protein; an engineered mRNA polynucleotide encoding a NANOS3 protein; an engineered mRNA polynucleotide encoding a DDX4 protein; an engineered mRNA polynucleotide encoding a CTCFL protein; an engineered mRNA polynucleotide encoding a DEK protein; an engineered mRNA polynucleotide encoding a SMC1 B protein; or a combination thereof.

42. A CRISPR-dCas activation system comprising an enzymatically inactive Cas protein and a gRNA comprising a spacer sequence that hybridizes to a gene region selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof.

43. The CRISPR-dCas activation system of claim 42, wherein the spacer sequence hybridizes upstream or downstream of a transcription start site for a sequence encoding a protein selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof.

44. The CRISPR-dCas activation system of claim 43, wherein the spacer sequence hybridizes upstream or downstream of a transcription start site for a sequence encoding a protein selected from: STRA8, MEIOSIN, DAZL, DMRT1 , or CTCFL.

45. The CRISPR-dCas activation system of claim 44, wherein the spacer sequence hybridizes upstream or downstream of a transcription start site for two or more sequences respectively encoding two or more members selected from the group consisting of: STRA8, MEIOSIN, DAZL DMRT1 , and CTCFL.

46. The CRISPR-dCas activation system of any one of claims 42-45, wherein the spacer sequence hybridizes upstream or downstream of a transcription start site for two or more sequences respectively encoding two or more members selected from the group consisting of: STRA8, DAZL and MEIOSIN.

47. The CRISPR-dCas activation system of any one of claims 42-46, wherein the spacer sequence hybridizes upstream or downstream of a transcription start site for sequences respectively encoding STRA8, DAZL and MEIOSIN.

48. A composition comprising the cell of any one of claims 1 -32 or the CRISPR- dCas activation system of any one of claims 42-47.

49. The composition of any one of claims 35-41 and 48, further comprising one or more co-factors.

50. The composition of claim 49, wherein the one or more co-factors are selected from the group consisting of: GSK3484862, Z-DEVD-FMK, valproic acid, MC3343, AM580, and BMP2.51 .A method of inducing and / or promoting meiosis in a cell, the method comprising: increasing the cellular amount of one or more proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof, thereby inducing meiosis of the cell.

52. The method of claim 51 , wherein the inducing and / or promoting meiosis comprises generating a haploid nucleus.

53. The method of claim 51 , wherein the inducing and / or promoting meiosis comprises inducing and / or promoting Meiosis II in a cell (e.g., characterized by a cell being in one of the stages selected from: prophase II, pro-metaphase II, metaphase II, anaphase II, or telophase II).

54. The method of claim 51 , wherein the inducing and / or promoting meiosis comprises inducing and / or promoting Meiosis I in a cell (e.g., characterized by a cell being in one of the stages selected from: prophase I, pro-metaphase I, metaphase I, anaphase I, telophase I, or cytokinesis II).

55. The method of claim 51 , wherein the inducing and / or promoting meiosis comprises inducing and / or promoting leptotene in a cell (e.g., characterized by a cell being in the leptotene stage of prophase I).

56. The method of claim 51 , wherein the inducing and / or promoting meiosis comprises inducing and / or promoting zygotene in a cell (e.g., characterized by a cell being in the zygotene stage of prophase I).

57. The method of claim 51 , wherein the inducing and / or promoting meiosis comprises inducing and / or promoting pachytene in a cell (e.g., characterized by a cell being in the pachytene stage of prophase I).

58. The method of claim 51 , wherein the inducing and / or promoting meiosis comprises inducing and / or promoting diplotene in a cell (e.g., characterized by a cell being in the diplotene stage of prophase I).

59. The method of claim 51 , wherein the inducing and / or promoting meiosis comprises inducing and / or promoting diakinesis in a cell (e.g., characterized by a cell being in the diakinesis stage of prophase I).

60. The method of claim 51 , wherein the inducing and / or promoting meiosis comprises increasing homologous recombination.61 .The method of any one of claims 51 -60, wherein the inducing and / or promoting meiosis is compared to a cell not having an increased cellular amount of one or more proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof, thereby inducing meiosis of the cell.

62. The method of any one of claims 51 -60, wherein the method comprises:(a) increasing the cellular amount of a DMRT1 protein and a YY2 protein; and(b) increasing the cellular amounts of one or more proteins selected from: a CTCFL protein, a STRA8 protein, a MEIOSIN protein, a DAZL protein, a SMC1 B protein, or a combination thereof.

63. The method of any one of claims 51 -62, wherein increasing the cellular amount protein comprises transfecting or transducing the cell with one or more engineered polynucleotides encoding the one or more proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof.

64. The method of any one of claims 51 -63, wherein increasing the cellular amount protein comprises: transfecting or transducing the cell with one or more engineered mRNA polynucleotides encoding the one or more proteins selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof.

65. The method of any one of claims 51 -62, wherein increasing the cellular amount protein comprises: transfecting or transducing the cell with one or moreengineered polynucleotides encoding one or more CRISPR-dCas activation systems targeting a gene region (e.g., a location upstream or downstream of a TSS) encoding a protein selected from: STRA8, MEIOSIN, DAZL, DMRT1 , NANOS3, DDX4, CTCFL, DEK, YY2, SMC1 B, or a combination thereof.

66. The method of any one of claims 51 -65, wherein the one or more proteins comprise STRA8, MEIOSIN, DAZL, DMRT1 , or CTCFL.

67. The method of claim 66, wherein the one or more proteins comprise two or more members selected from the group consisting of: STRA8, MEIOSIN, DAZL DMRT1 , and CTCFL.

68. The method of claim 67, wherein the one or more proteins comprise two or more members selected from the group consisting of STRA8, DAZL, and MEIOSIN.

69. The method of claim 68, wherein the one or more proteins comprise STRA8, DAZL, and MEIOSIN.

70. The method of any one of claims 51 -69, further comprising treating the cell with one or more co-factors.

71. The method of claim 70, wherein the one or more co-factors are selected from: antiviral response factors (B18R, E3, K3), activin-A, retinoic acid, and / or CCNA172. The method of claim 70, wherein the one or more co-factors are selected from the group consisting of: GSK3484862, Z-DEVD-FMK, valproic acid, MC3343, AM580, and BMP2.

73. The method of any one of claims 70-72, wherein the cell is contacted by the one or more co-factors prior to, simultaneously with, or subsequent to the increasing of the cellular amount of the one or more proteins.

74. The method of any one of claims 51 -73, further comprising:(i) isolating the nucleus from the cell; and(ii) transferring the nucleus into a denucleated oocyte.

75. The method of claim 74, wherein the transferring of the nucleus into the denucleated oocyte further activates the oocyte comprises successful 2, 4, or 8 cell cleavage, and / or blastocyst formation.

76. The method of claim 74 or 75, wherein the method further comprises: fertilizing the oocyte.

77. The method of any one of claims 51 -73, further comprising:(i) isolating the genome from the cell; and(ii) transferring the genome into an oocyte.

78. The method of claim 77, wherein the transferring of the genome into the oocyte results in fertilization of the oocyte.

79. The method of claim 78, wherein the transferring of the genome into the oocyte and the fertilization activates the oocyte comprises successful 2, 4, or 8 cell cleavage, and / or blastocyst formation.

80. The method of any one of claims 51 -79, wherein the cell is a stem cell.

81. The method of any one of claims 51 -79, wherein the cell is a pluripotent stem cell.

82. The method of any one of claims 51 -79, wherein the cell is an iPSC.

83. The method of any one of claims 51 -79, wherein the cell is a PGCLC.

84. The method of any one of claims 51 -79, wherein the cell is a fibroblast.

85. The method of any one of claims 51 -79, wherein the cell is a mesenchymal stem cell.

86. The method of any one of claims 51 -79, wherein the cell is a somatic cell.

87. The method of any one of claims 51 -86, wherein the cell and / or oocyte is a vertebrate cell and / or oocyte.

88. The method of any one of claims 51 -86, wherein the cell and / or egg is a mammalian cell and / or oocyte.

89. The method of any one of claims 51 -86, wherein the cell and / or egg is a human cell and / or oocyte.

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