Abstract: Transgenes encoding exogenous proteins are stably integrated into embryonic stem cells and are present in the somatic tissue of transgenic or chimeric birds. The transgenes encode exogenous proteins and are expressed in any of endodermal, ectodermal, mesodermal, or extra embryonic tissue. Tissue specificity is provided by selecting the content of the transgene accordingly. Transgenic birds whose genome is comprised of trangene derived exogenous DNA express exogenous proteins with tissue specificity, and specifically express exogenous proteins in the tubular gland cells of the oviduct to concentrate exogenous proteins in egg white.

Abstract: Sustained cultures of avian embryonic stem cells are provided. Injection of avian embryonic stem cells into recipient embryos yields chimeras with a significant contribution from the embryonic stem cell phenotype. Transgene encoding exogenous proteins are stably integrated in the embryonic stem cells and are present in the somatic tissue of the resulting chimeras. The transgenes may encode exogenous proteins expressed in endodermal, ectodermal, mesodermal, or extra embryonic tissue. Breeding the resulting chimera yields transgenic birds whose genome is comprised of exogenous DNA.

Abstract: Human antibodies are produced in transgenic chickens having functional genetic components of the human immune system stably integrated in the genome. Techniques are described to integrate unrearranged human heavy and light chain immunoglobulin loci into the genome of the transgenic chicken. The functional description of the endogenous immunoglobulin loci yields an animal whose antibody repertoire in response to antigen is fully human. In the preferred embodiment, the human immunoglobulin locus is at least as large as the native human locus and exhibits functional class switching to yield IgG isotype antibodies. In addition to monoclonal antibodies secreted from immortalized B cell populations, polyclonal antibodies may be obtained from eggs laid by the transgenic chickens of the invention.

Abstract: Methods for preparing recombinant proteins, such as antibodies, in eggs are described. The method offers advantages over existing systems for preparing recombinant proteins including high yield, low cost and compatibility with animal protection regulations. In addition, since eggs are edible food sources the recombinant protein does not have to be isolated from the egg.

Abstract: A transgenic chicken is disclosed having disrupted endogenous immunoglobulin production. In one embodiment, a targeting construct is stably integrated into the genome of the chicken by homologous recombination in embryonic stem cells, and injection of the engineered embryonic stem cells into recipient embryos, thereby knocking out the endogenous immunoglobulin gene locus in resulting animals. The targeted disruption of the locus in embryonic stem cells is particularly useful in combination with the insertion of genetic elements encoding exogenous immunoglobulin molecules. After these chickens are cross-bred, a line of chickens is produced that has a reduction of endogenous immunoglobulin molecule production.

Abstract: Sustained cultures of avian embryonic stem cells are provided. Injection of avian embryonic stem cells into recipient embryos yields chimeras with a significant contribution from the embryonic stem cell phenotype. Transgene encoding exogenous proteins are stably integrated in the embryonic stem cells and are present in the somatic tissue of the resulting chimeras. The transgenes may encode exogenous proteins expressed in endodermal, ectodermal, mesodermal, or extra embryonic tissue. Breeding the resulting chimera yields transgenic birds whose genome is comprised of exogenous DNA.

Abstract: Transgenes encoding exogenous proteins are stably integrated into embryonic stem cells and are present in the somatic tissue of transgenic or chimeric birds. The transgenes encode exogenous proteins and are expressed in any of endodermal, ectodermal, mesodermal, or extra embryonic tissue. Tissue specificity is provided by selecting the content of the transgene accordingly. Transgenic birds whose genome is comprised of trangene derived exogenous DNA express exogenous proteins with tissue specificity, and specifically express exogenous proteins in the tubular gland cells of the oviduct to concentrate exogenous proteins in egg white..