11 results about "Totipotent" patented technology

The invention discloses a vector system and method capable of converting mouse embryonic stem cells into embryonic-like cells in a 2-cell period, the vector system comprises a mouse Zfp352 gene sequence, and the nucleotide sequence of the mouse Zfp352 gene is shown as SEQ ID No.1. The invention also discloses a method for converting the mouse embryonic stem cells into embryonic-like cells in a 2-cell period. The invention creatively discovers that through overexpression of the Zfp352 in the mouse embryonic stem cells, the efficiency of converting the mouse pluripotent embryonic stem cells into the totipotent embryonic-like cells in the 2-cell period can be remarkably improved.

The invention discloses a PPR (pentatricopeptide repeats) high-salt-resistant all-potent nuclease mutant and application thereof. The invention firstly discloses an amino acid sequence of the PPR high-salt-resistant all-potent nuclease mutant as shown in SEQ ID NO. 1. The invention further discloses application of the PPR high-salt-resistant all-potent nuclease mutant to removal of nucleic acid. According to the PPR high-salt-resistant totipotent nuclease mutant, alanine at the 165 site of wild PPR high-salt-resistant totipotent nuclease which does not contain signal peptide is replaced with aspartic acid, overexpression can be carried out in a prokaryotic host, and a large number of proteins can be obtained through purification. The PPR high-salt-resistant all-purpose nuclease mutant disclosed by the invention maintains high activity in a wide salt concentration range, a temperature range, a pH range and a Mg < 2 + > range, and can be compatible with most additives used in a biological process. In addition, the activity of the PPR high-salt-resistant all-purpose nuclease mutant is superior to that of other domestic competitive products, and the competitive product level with the best commercial effect at present can be achieved.

The invention relates to the technical field of enzyme engineering, and particularly provides an all-round nuclease variant, the variant can tolerate a wider salt concentration range compared with wild type all-round nuclease, good enzyme activity is still kept under the increased salt concentration, and the application of all-round nuclease under different salt concentrations is widened.

The invention provides a culture method for promoting conversion of mouse embryonic stem cells into totipotent stem cells. The cells can be kept in a brand new form and subcultured under the condition. According to the method adopted by the invention, an inhibitor WM-3825 of 2 mu M H4K16ac is added into a DMEM (Dulbecco Modified Eagle Medium) with a culture medium composition of 10% fetal calf serum according to a proportion of 1: 1000, the mouse embryonic stem cells can be normally cultured and passaged, the change of the totipotent gene is detected through real-time fluorescent quantitative PCR (Polymerase Chain Reaction), the expression of the totipotent related gene Dux is found to be obviously increased, and the expression of the mouse embryonic stem cells is obviously improved. Flow cytometry detection shows that the proportion of the totipotent stem cells is remarkably increased, and AP dyeing shows that the pluripotency of the mouse embryonic stem cells is reduced. The method starts from cell culture, and the method is possibly suitable for research on conversion from pluripotency to totipotency of embryonic stem cells of other mammals including human. By adding a small-molecule inhibitor WM-3825 of H4K16ac, a brand-new method for promoting conversion from the mouse pluripotent stem cells to the totipotent stem cells is established, and the 2-cell period of mouse embryonic development can be simulated in vitro through the culture system. The invention provides a new method for the generation of the totipotent stem cells, deepens the understanding of people on different states of the stem cells, and provides a new perspective for understanding an epigenetics mechanism between the conversion of the totipotent stem cells and the conversion of the pluripotent stem cells.

The present application provides a method for preparing human ovarian somatic cell-like cells. The present application establishes a method for preparing human ovarian somatic cell-like cells in vitro, which comprises stage-based culture based on human stem cells (including human pluripotent stem cells and human totipotent stem cells). The method of the present application can efficiently obtain functional human ovarian somatic cell-like cells, promote the differentiation ability of female germ stem cells (FGSC) cultured in vitro, and provide a new approach for assisted reproduction and treatment of infertility.

The present invention relates to a method for producing hematopoietic stem cells derived from totipotent stem cells, and a method for producing a humanized mouse model using the produced hematopoietic stem cells. According to one aspect, the method for producing hematopoietic stem cells can highly efficiently differentiate hematopoietic stem cells from totipotent stem cells without gene insertion, and optimal differentiation conditions have been confirmed by combining low molecular weight compounds and protein growth factors.

The invention provides a method for promoting induction of human totipotent stem cells, belongs to the technical field of biology, and particularly relates to a method for promoting induction of the human totipotent stem cells to the totipotent stem cells through OTX2 knockout or knockdown, the method comprises the following steps: S1, constructing an OTX2 knockout or knockout plasmid vector; s2, establishing a human pluripotent stem cell line with OTX2 knocked down or knocked out; and S3, inducing the human pluripotent stem cells of which the OTX2 is knocked down or knocked out into totipotent stem cells, which are also called 8-cell-like cells (8CLCs). According to the invention, the efficiency of inducing the human pluripotent stem cells into the totipotent stem cells can be improved, and the application of the totipotent stem cells in in-vitro blastocyst-like induction, in-vivo chimeric embryo formation and the like is provided.

The present invention relates to methods of determining a potency state of an embryonic stem cell (ESC) in culture, comprising detecting the expression level of Negative Elongation Factor Complex Member A (Nelfa) in the ESC, and correlating the expression level of Nelfa with that of a reference sample to determine the potency state of the ESC. The present invention also provides methods of selecting totipotent-like ESCs from a population of ESCs in culture using an anti-Nelfa antigen binding protein, methods of inducing totipotency in an ESC in culture, methods of improving the reprogramming efficiency of a somatic cell into an induced pluripotent stem cell and methods of reprogramming a somatic cell into a totipotent stem cell by inducing Nelfa expression. Cells comprising an expression vector encoding Nelfa and kits for use in the methods of the invention are also provided.

This invention discloses a method for inducing mouse embryonic stem cells to transition to a pluripotent state using H2BC21 and its application, belonging to the fields of molecular biology and stem cell engineering technology. By constructing an interference vector targeting the H2BC21 gene, packaging it with lentivirus, and infecting mouse embryonic stem cells, the expression of the H2BC21 gene is knocked down, and embryonic stem cell lines with stable low expression of H2BC21 are obtained through screening. This invention is the first to discover that H2BC21 is a core negative regulator of mammalian embryonic stem cell pluripotency. After knocking down H2BC21, the expression of pluripotency core genes Nanog, Oct4, and Sox2 is downregulated, while the expression of pluripotency core genes Zscan4b, Usp17la, and Tmem92 is upregulated. The cells exhibit molecular characteristics similar to 2-cell phase cells, successfully achieving the transition from pluripotency to a pluripotent state.

This invention discloses a method for preparing inclusion bodies based on dual-promoter expression plasmids and its application, belonging to the field of biotechnology. The invention includes screening of totipotent nucleases, purification of totipotent nucleases, verification of the degradation activity of the totipotent nuclease DNS on nucleic acids, construction of dual-promoter recombinant strains, fermenter culture, cell recovery, and cell disruption to obtain crude inclusion bodies. This invention achieves high-efficiency expression of the recombinant human growth hormone gene induced by the T7 promoter and high-activity expression of the totipotent nuclease gene DNS induced by the cspA promoter, demonstrating significant effects in the application of recombinant human growth hormone. During the preparation process, the cell viscosity is low, the homogenization and disruption effect is improved, the BL21(DE3) / DGH cell disruption rate is high, the inclusion body content harvested by centrifugation per unit volume of fermentation broth is high, and the residual amount of HCD (host DNA residue) in the target protein per unit mass is reduced, effectively reducing energy consumption.

The invention discloses construction and application of a vector for expressing totipotent nuclease and a host cell, and discloses a fusion signal peptide of which the nucleotide sequence is shown as SEQ ID NO.1. The transformed signal peptide pelb guides totipotent nuclease to be converted into periplasmic space of escherichia coli Rosetta (DE3) host cells for efficient secretory expression, and a matched purification process is suitable for scenes of vaccine production, host nucleic acid residue removal in biological pharmacy and the like.