1878 results about "Homologous recombination" patented technology

A method for engineering and utilizing large DNA vectors to target, via homologous recombination, and modify, in any desirable fashion, endogenous genes and chromosomal loci in eukaryotic cells. These large DNA targeting vectors for eukaryotic cells, termed LTVECs, are derived from fragments of cloned genomic DNA larger than those typically used by other approaches intended to perform homologous targeting in eukaryotic cells. Also provided is a rapid and convenient method of detecting eukaryotic cells in which the LTVEC has correctly targeted and modified the desired endogenous gene(s) or chromosomal locus (loci) as well as the use of these cells to generate organisms bearing the genetic modification.

A method for achieving site specific integration of a desired DNA at a target site in a mammalian cell via homologous recombination is described. This method provides for the reproducible selection of cell lines wherein a desired DNA is integrated at a predetermined transcriptionally active site previously marked with a marker plasmid. The method is particularly suitable for the production of mammalian cell lines which secrete mammalian proteins at high levels, in particular immunoglobulins. Novel vectors and vector combinations for use in the subject cloning method are also provided.

A method for engineering and utilizing large DNA vectors to target, via homologous recombination, and modify, in any desirable fashion, endogenous genes and chromosomal loci in eukaryotic cells. These large DNA targeting vectors for eukaryotic cells, termed LTVECs, are derived from fragments of cloned genomic DNA larger than those typically used by other approaches intended to perform homologous targeting in eukaryotic cells. Also provided is a rapid and convenient method of detecting eukaryotic cells in which the LTVEC has correctly targeted and modified the desired endogenous genes(s) or chromosomal locus (loci) as well as the use of these cells to generate organisms bearing the genetic modification.

The present invention provides compositions and methods for targeted cleavage of cellular chromatin in a region of interest and / or homologous recombination at a predetermined site in cells. Compositions include fusion polypeptides comprising a TAL effector binding domain and a cleavage domain. The cleavage domain can be from any endonuclease. In certain embodiments, the endonuclease is a Type IIS restriction endonuclease. In further embodiments, the Type IIS restriction endonuclease is FokI.

A method to produce a cell expressing an antibody from a genomic sequence of the cell comprising a modified immunoglobulin locus using Cre-mediated site-specific recombination is disclosed. The method involves first transfecting an antibody-producing cell with a homology-targeting vector comprising a lox site and a targeting sequence homologous to a first DNA sequence adjacent to the region of the immunoglobulin loci of the genomic sequence which is to be converted to a modified region, so the first lox site is inserted into the genomic sequence via site-specific homologous recombination. Then the cell is transfected with a lox-targeting vector comprising a second lox site suitable for Cre-mediated recombination with the integrated lox site and a modifying sequence to convert the region of the immunoglobulin loci to the modified region. This conversion is performed by interacting the lox sites with Cre in vivo, so that the modifying sequence inserts into the genomic sequence via Cre-mediated site-specific recombination of the lox sites. Also disclosed are a form of the method used to produce a cell expressing a modified antibody molecule using Cre-mediated site-specific recombination, and antibody-producing cells obtainable by the disclosed methods. Class-switching modifications of human antibodies produced in murine hybridoma cells are exemplified.

The invention provides a method of cloning a reproductive and respiratory syndrome resisting pig. The method comprises the following steps: transferring CRISPR / Cas9 targeting vectors and CD163 gene homologous recombination modification vectors into fibroblasts of a pig to obtain positive clone cells, wherein the seventh exon of the endogenous CD163 gene in the positive clone cells of the pig is replaced by the tenth exon of the CD163-L1 gene of human, so that the positive clone cells are incapable of mediating PRRSV invading; obtaining a clone embryo by adopting a somatic cell nucleus transfer technology by taking positive cells as nucleus transfer donor cells and oocytes as nucleus transfer recipient cells; and transferring the clone embryo into the uterus of the pig, and impregnating to obtain a cloned pig. The method provided by the invention is low in cost, the time of obtaining the homozygous pig is shortened greatly, the expression of the CD163 gene is not affected by gene editing, and a foundation is laid for the research into the gene function of large animals and the establishment of disease models on the basis of CRISPR / Cas9 mediated homologous recombination.

A single chain homing endonuclease, comprising a first variant of I-CreI having the amino acid sequence of accession number pdb 1g9y (SEQ ID NO: 23 is residues 1-153 of pdb Ig9y) and a second variant of I-CreI variant having the amino acid sequence of accession number pdb 1g9y (SEQ ID NO: 23 is residues 1-153 of pdb Ig9y) in a single polypeptide.

The present invention relates to guide RNAs comprising adaptor segments having one or more modifications, and their use in homologous recombination by CRISPR:Cas systems. The modified adaptor segments are resistant to degradation by RNaseH. The present invention also relates to a dual guide RNA strategy in which a first guide RNA directs a Cas enzyme to make a double-strand break at a first target sequence, and a second guide RNA comprises an adaptor segment attached to a donor polynucleotide, and binds a second target sequence that is offset from the first target sequence.

The present invention provides for a method or methods of targeted genetic recombination or mutagenesis in a host cell or organism, and compositions useful for carrying out the method. The targeting method of the present invention exploits endogenous cellular mechanisms for homologous recombination and repair of double stranded breaks in genetic material. The present invention provides numerous improvements over previous mutagenesis methods, such advantages include that the method is generally applicable to a wide variety of organisms, the method is targeted so that the disadvantages associated with random insertion of DNA in-to host genetic material are eliminated, and certain embodiments require relatively little manipulation of the host genetic material for success. Additionally, it provides a method that produces organisms with specific gene modifications in a short period of time.

Described herein are methods of generating a genetically modified cell by providing a zinc finger endonuclease (ZFE) that includes an endonuclease domain that cuts DNA, and a zinc finger domain that includes a plurality of zinc fingers that bind to a specific nucleotide sequence within the endogenous chromosomal target DNA in the primary cell. Further, the methods can include contacting the endogenous chromosomal target DNA sequence with the zinc finger endonuclease in the primary cell such that the zinc finger endonuclease cuts both strands of a nucleotide sequence within the endogenous chromosomal target DNA sequence in the primary cell, thereby enhancing the frequency of homologous recombination in the endogenous chromosomal target DNA sequence.

Mutant thermophilic organisms that consume a variety of biomass derived substrates are disclosed herein. Strains of Thermoanaerobacterium saccharolyticum with acetate kinase and phosphotransacetylase expression eliminated are disclosed herein. Further, strain ALK1 has been engineered by site directed homologous recombination to knockout both acetic acid and lactic acid production. Continuous culture involving a substrate concentration challenge lead to evolution of ALK1, and formation of a more robust strain designated ALK2. The organisms may be utilized for example in thermophilic SSF and SSCF reactions performed at temperatures that are optimal for cellulase activity to produce near theoretical ethanol yields without expressing pyruvate decarboxylase.