Abstract: The present disclosure provides compositions and methods for enhanced expression of exogenous genes in eukaryotic cells. Also provided are chromosomal loci, sequences for enhanced and stable expression of exogenous genes.

Abstract: Provided is a genetically modified non-human mammal that comprises an anchor DNA sequence inserted at an endogenous locus of a secretory milk protein gene, wherein the anchor DNA sequence comprises a site-specific recombinase recognition site. Also provided is a genetically modified non-human mammal that comprises a transgene inserted at an endogenous locus of a secretory milk protein gene, wherein the transgene encodes a secretory protein and is operably linked to the endogenous promoter of said secretory milk protein gene, and wherein the transgene is flanked by a pair of site-specific recombinase resulting sites. The genetically modified non-human mammals provided can be used for producing the secreted recombinant protein encoded by the transgene from the milk produced by the genetically modified non-human mammals.

Abstract: Provided is a method for knocking in a gene of interest to a cell. The genome of the cell contains a negative selectable marker, e.g., a thymidine kinase gene flanked by a pair of recombinase recognition sites (RRS), e.g., attP. The method involves introducing into the cell a targeting construct that contains a gene of interest flanked by a second pair of RRS, e.g., attB. The targeting construct also contains in the vector backbone a negative selectable marker, e.g., thymidine kinase gene. When a recombinase recognizing the RRS is expressed, the recombination events between the two pairs of RRS result in the site-specific integration of the gene of interest in the genome of the cell. Upon selection based on the negative selectable marker, the parental cells, cells with undesired integration, e.g., random integration, or the integration of the vector backbone are removed.

Abstract: The present disclosure provides a composition comprising a site-specific nuclease domain capable of cleaving a target DNA sequence; and a sequence-specific DNA binding domain capable of specifically binding to a recognition DNA sequence, wherein the site-specific nuclease domain operably links to the sequence-specific DNA binding domain.

Abstract: Methods for inserting a polynucleotide sequence into the genome of a human cell are provided. The present methods result in insertion of a polynucleotide sequence of interest into the H11 locus in the genome of a human cell. Also provided are nucleic acids that include sequences for integrating a polynucleotide sequence of interest into the H11 locus in the genome of a human cell. A transgenic human cell including site specific recombination sites at the H11 locus is also disclosed.

Abstract: Disclosed herein are targeted chimeric polypeptides, compositions thereof, expression vectors, and methods of use thereof, for the generation of transgenic cells, tissues, plants, and animals. The compositions, vectors, and methods of the present invention are also useful in gene therapy and cell therapy techniques. The chimeric polypeptide includes a CRISPR-Cas domain and a recombinase domain.

Abstract: The present disclosure provides a method of making a mammal (e.g., a rodent, such as a mouse) by integrating an intact polynucleotide sequence into a specific genomic locus of the mammal to result in a transgenic mammal. A transgenic mammal made by the methods of the present disclosure would contain a known copy number (e.g., one) of the inserted polynucleotide sequence at a predetermined location. The method involves introducing a site-specific recombinase and a targeting construct, containing a first recombination site and the polynucleotide sequence of interest, into the mammalian cell. The genome of the cell contains a second recombination site and recombination between the first and second recombination sites is facilitated by the site-specific, uni-directional recombinase. The result of the recombination is site-specific integration of the polynucleotide sequence of interest in the genome of the mammal. This inserted sequence is then also transmitted to the progeny of the mammal.

Abstract: Methods for inserting a polynucleotide sequence into the genome of a human cell are provided. The present methods result in insertion of a polynucleotide sequence of interest into the H11 locus in the genome of a human cell. Also provided are nucleic acids that include sequences for integrating a polynucleotide sequence of interest into the H11 locus in the genome of a human cell. A transgenic human cell including site specific recombination sites at the H11 locus is also disclosed.

Abstract: The present disclosure provides a method of making a mammal (e.g., a rodent, such as a mouse) by integrating an intact polynucleotide sequence into a specific genomic locus of the mammal to result in a transgenic mammal. A transgenic mammal made by the methods of the present disclosure would contain a known copy number (e.g., one) of the inserted polynucleotide sequence at a predetermined location. The method involves introducing a site-specific recombinase and a targeting construct, containing a first recombination site and the polynucleotide sequence of interest, into the mammalian cell. The genome of the cell contains a second recombination site and recombination between the first and second recombination sites is facilitated by the site-specific, uni-directional recombinase. The result of the recombination is site-specific integration of the polynucleotide sequence of interest in the genome of the mammal. This inserted sequence is then also transmitted to the progeny of the mammal.