208 results about "Site-specific recombination" patented technology

The present invention is a cell-free subcloning system utilizing three elements: (1) a donor vector that contains a nucleic acid sequence to be transferred to another vector flanked by a site-specific recombination sequence and one or more optional additional nucleic acid sequences, (2) an acceptor vector that contains a site-specific recombination sequence and one or more optional additional nucleic acid sequences, and (3) a site-specific recombinase that recognizes the site-specific recombination sequences in the donor and acceptor vectors so as to transfer the transfer sequence from the donor to the acceptor vector upon contact of the three elements of the system. Also disclosed are rapid subcloning methods employing the vectors and enzymes disclosed herein and kits for use in such methods.

A process for assembling a series of DNA fragments generated by PCR into an ordered circular arrangement for replication and genetic work in cells. The PCR fragments are made with a modified nucleotide in the primers that can be removed with a DNA excision repair enzyme to generate a 3′ overhang. The 3′ overhangs are designed to allow directional annealing and thus sequential PCR fragments can be assembled by annealing the overhangs and subsequent ligation. Sequential addition of PCR fragments is facilitated by growing the chain on a solid support, and the assembled chain can be removed with a site specific recombinase if the first and last primers contain the recombinase site. The circularized assembled fragment can be directly used for cell transformation if the appropriate sequences are included, such as an origin of replication and a selectable marker.

Site-specific recombinases provide a means of efficiently manipulating chromosomal sequences in mammalian cells in culture and in animals. Embryonic stem cells containing recombinase nucleic acid constructs that were expressed in the male germline simplify current protocols for producing mice bearing homologously recombined alleles that have been secondarily rearranged by a site-specific recombinase. In different ProCre strains, between 80% and 100% of the progeny that inherited a Cre target nucleic acid construct from males that were also heterozygous for a ProCre nucleic acid construct inherited the Cre-recombined target. ProCre nucleic acid constructs and recombined targets segregated in the first generation. When ES cells prepared from one ProCre line were transfected with vectors containing a loxP-flanked neomycin cassette, G418 resistant, homologously recombined clones, in which the loxP sites remained functional, were readily isolated.

The invention relates to methods and compositions for site-specific recombinase-mediated mobilization of viral replicons and associated DNAs of interest from T-DNA. The methods of the invention comprise Agrobacterium-mediated transfer of T-DNA to a plant cell, wherein the T-DNA contains a viral replicon flanked by directly repeated target sites for a site-specific recombinase and optionally a DNA of interest linked to the viral replicon. The DNA of interest may also contain a non-identical target site for the recombinase. An expression cassette for the site-specific recombinase is present on the T-DNA or the plant genome, or is transiently introduced into the plant cell. Expression of the site-specific recombinase in the plant cell results in excision of the viral replicon and the associated DNA of interest. The viral replicon and DNA of interest are then replicated to high copy number in the host plant cell. The compositions of the invention comprise nucleic acids, such as T-DNAs containing a viral DNA flanked by directly repeated target sites for a site-specific recombinase. The nucleic acids of the invention may additionally contain expression cassettes encoding the cognate site-specific recombinase for the target sites flanking the viral genome. The compositions of the invention further comprise Agrobacterium containing the nucleic acids of the invention. The compositions and methods of the invention have use in increasing the efficiency of agroinfection, providing high copy numbers of a DNA of interest for transient expression or for integration into a plant chromosome, and in simplifying the construction and stable maintenance of vectors for agroinfection and transformation.

This invention relates to methods of controlling gene silencing using site-specific recombination. A variety of constructs are provided which are useful for conditional or regulated gene silencing in plants, comprising a suite of constitutive, inducible, tissue-specific or developmental stage-specific promoters operably linked to target sequences (TS). Recombinase inversion or excision yields double-stranded TS RNA, which thereby functions to trigger endogenous gene silencing mechanisms. By matching promoters, responsive to various inducers, plant tissues or plant developmental states with the recombinase systems, transcriptional stop fragments or introns and target sequences, gene silencing of virtually any target sequence may be modulated at any plant development stage or in any plant generation. This is especially useful, when genes responsible for gene silencing are down-regulated to permit expression of particular transgenes at levels greater than permitted when gene silencing is activated.

Site-specific recombinase based methods for making a recombinant adenoviral genome, as well as kits for practicing the same and the recombinant adenovirus vectors produced thereby, are provided. In the subject methods, the subject genomes are prepared from donor and acceptor vectors that each include at least one site recombinase recognition site, where in certain preferred embodiments, one of the donor and acceptor vectors includes a single recombinase recognition site while the other includes two recombinase recognition sites. The acceptor vector includes an adenoviral genome having an E region deletion. The donor vector includes an insertion nucleic acid. In the subject methods, the donor and acceptor vectors are combined in the presence of a recombinase to produce an adenoviral genome that includes the insertion nucleic acid. The subject adenoviral genomes find use in a variety of applications, including as vectors for use in a variety of applications.