Abstract: A method of producing a cloned or genetically modified non-human mammalian embryo comprising: (a) providing a cell culture comprising a plurality of in vitro matured oocytes; (b) preferentially selecting from the cell culture a rapidly matured oocyte or developmentally competent oocyte; (c) transferring DNA from a donor cell derived from non-human mammalian tissue to the matured oocyte to form a nuclear transfer unit; and (d) culturing said nuclear transfer unit to form an embryo. At the initiation of maturation, oocytes are preferably beyond the GV-II stage of prophase I. Porcine oocytes most preferably mature in about 20-28 hours.

Abstract: A culture system for producing PGCs or EG cells by culturing PGCs for long periods in tissue culture is provided. This culture system uses LIF, bFGF, IGF and SCF. The resultant EG cells are useful for the production of transgenic and chimeric avians, in particular, chickens and turkeys, and also for cloning purposes.

Abstract: An improved method of nuclear transfer involving the transplantation of donor cell nuclei into enucleated oocytes of a species different from the donor cell is provided. The resultant nuclear transfer units are useful for the production of isogenic embryonic stem cells, in particular human isogenic embryonic or stem cells. These embryonic or stem-like cells are useful for producing desired differentiated cells and for introduction, removal or modification, of desired genes, e.g., at specific sites of the genome of such cells by homologous recombination. These cells, which may contain a heterologous gene, are especially useful in cell transplantation therapies and for in vitro study of cell differentiation.

Abstract: Methods and cell lines for cloning ungulate embryos and offspring, in particular bovines and porcines, are provided. The resultant fetuses, embryos or offspring are especially useful for the expression of desired heterologous DNAs, and may be used as a source of cells or tissue for transplantation therapy for the treatment of diseases such as Parkinson's disease.

Abstract: An improved method of nuclear transfer involving the transplantation of donor differentiated pig cell nuclei into enucleated pig oocytes is provided. The resultant nuclear transfer units are useful for multiplication of genotypes and transgenic genotypes by the production of fetuses and offspring. Production of genetically engineered or transgenic pig embryos, fetuses and offspring is facilitated by the present method since the differentiated cell source of the donor nuclei can be genetically modified and clonally propagated.

Abstract: Methods and cell lines for cloning ungulate embryos and offspring, in particular bovines and porcines, are provided. The resultant fetuses, embryos or offspring are especially useful for the expression of desired heterologous DNAs, and may be used as a source of cells or tissue for transplantation therapy for the treatment of diseases such as Parkinson's disease.

Abstract: An improved method of nuclear transfer involving the transplantation of donor differentiated cell nuclei into enucleated oocytes of the same species as the donor cell is provided. The resultant nuclear transfer units are useful for multiplication of genotypes and transgenic genotypes by the production of fetuses and offspring, and for production of isogenic CICM cells, including human isogenic embryonic or stem cells. Production of genetically engineered or transgenic mammalian embryos, fetuses and offspring is facilitated by the present method since the differentiated cell source of the donor nuclei can be genetically modified and clonally propagated.

Abstract: A process of parthenogenic activation of mammalian oocytes which includes increasing intercellular levels of divalent cations in the oocyte; and reducing phosphorylation of cellular proteins in the oocyte. One method of accomplishing this is by introducing Ca2+ free cation, such as inomycin, to the oocyte and then preventing phosphorylation of the cellular proteins within the oocyte by adding a serine-threonine kinase inhibitor, such as 6-dimethylaminopurine (DMAP).

Abstract: Methods and cell lines for cloning ungulate embryos and offspring, in particular bovines and porcines, are provided. The resultant fetuses, embryos or offspring are especially useful for the expression of desired heterologous DNAs, and may be used as a source of cells or tissue for transplantation therapy for the treatment of diseases such as Parkinson's disease.

Abstract: An improved method of nuclear transfer involving the transplantation of donor cell nuclei into enucleated oocytes of a species different from the donor cell is provided. The resultant nuclear transfer units are useful for the production of isogenic embryonic stem cells, in particular human isogenic embryonic or stem cells. These embryonic or stem-like cells are useful for producing desired differentiated cells and for introduction, removal or modification, of desired genes, e.g., at specific sites of the genome of such cells by homologous recombination. These cells, which may contain a heterologous gene, are especially useful in cell transplantation therapies and for in vitro study of cell differentiation.

Abstract: An improved method of nuclear transfer involving the transplantation of donor differentiated pig cell nuclei into enucleated pig oocytes is provided. The resultant nuclear transfer units are useful for multiplication of genotypes and transgenic genotypes by the production of fetuses and offspring. Production of genetically engineered or transgenic pig embryos, fetuses and offspring is facilitated by the present method since the differentiated cell source of the donor nuclei can be genetically modified and clonally propagated.

Abstract: An improved method of nuclear transfer involving the transplantation of donor differentiated cell nuclei into enucleated oocytes of the same species as the donor cell is provided. The resultant nuclear transfer units are useful for multiplication of genotypes and transgenic genotypes by the production of fetuses and offspring, and for production of isogenic CICM cells, including human isogenic embryonic or stem cells. Production of genetically engineered or transgenic mammalian embryos, fetuses and offspring is facilitated by the present method since the differentiated cell source of the donor nuclei can be genetically modified and clonally propagated.

Abstract: Methods and cell lines for cloning bovine embryos and offspring are provided. The resultant embryos or offspring are especially useful for the expression of desired heterologous DNAs.

Abstract: A process of parthenogenic activation of mammalian oocytes which includes increasing intracellular levels of divalent cations in the oocyte; and reducing phosphorylation of cellular proteins in the oocyte. One method of accomplishing this is by introducing Ca2+ free cation, such as ionomycin, to the oocyte and then preventing phosphorylation of the cellular proteins within the oocyte by adding a serine-threonine kinase inhibitor, such as 6-dimethylaminopurine (DMAP).

Abstract: A culture system for maintaining avian PGCs for long periods in tissue culture is provided. This culture system uses LIF, bFGF, IGF and SCF. The resultant PGCs are useful for the production of transgenic and chimeric avians, in particular, chickens or turkeys.

Abstract: A process of parthenogenic activation of mammalian oocytes which includes increasing intracellular levels of divalent cations in the oocyte; and reducing phosphorylation of cellular proteins in the oocyte. One method of accomplishing this is by introducing Ca.sup.2+ free cation, such as ionomycin, to the oocyte and then preventing phosphorylation of the cellular proteins within the oocyte by adding a serine-threonine kinase inhibitor, such as 6-dimethylaminopurine (DMAP).

Abstract: Novel cultured inner cell mass (CICM) cells, and cell lines, derived from ungulates, in particular, pigs and cows, and methods for their preparation are provided. The subject CICMs possess similar morphology and express cell markers identically or substantially similarly to ICMs of undifferentiated developing embryos for prolonged culturing periods. Heterologous DNA is inserted into the subject CICM cells and cell lines so as produce transgenic CICM cell which are introduced into non-human fertilized embryos to produce transgenic chimeric embryos. The transgenic chimeric embryos are transferred into recipient females where they are permitted to develop into transgenic chimeric fetuses. Recipient females give birth to transgenic chimeric animals which are capable of transmitting the heterologous DNA to their progeny. Transgenic CICM cells are also used to produce cloned transgenic embryos, fetuses and offspring.

Abstract: An improved method of nuclear transfer involving the transplantation of donor differentiated cell nuclei into enucleated oocytes of the same species as the donor cell is provided. The resultant nuclear transfer units are useful for multiplication of genotypes and transgenic genotypes by the production of fetuses and offspring, and for production of isogenic CICM cells, including human isogenic embryonic or stem cells. Production of genetically engineered or transgenic mammalian embryos, fetuses and offspring is facilitated by the present method since the differentiated cell source of the donor nuclei can be genetically modified and clonally propagated.

Abstract: Novel cultured inner cell mass (CICM) cells, and cell lines, derived from ungulates, in particular, pigs and cows, and methods for their preparation are provided. The subject CICMs possess similar morphology and express cell markers identically or substantially similarly to ICMs of undifferentiated developing embryos for prolonged culturing periods. Heterologous DNAs may be introduced into the subject CICM cells and cell lines to produce transgenic cells useful for the production of transgenic embryos, fetuses and/or offspring, e.g., by nuclear transfer procedures.

Abstract: A process of parthenogenic activation of mammalian oocytes which includes increasing intercellular levels of divalent cations in the oocyte; and reducing phosphorylation of cellular proteins in the oocyte. One method of accomplishing this is by introducing Ca.sup.2+ free cation, such as ionomycin, to the oocyte and then preventing phosphorylation of the cellular proteins within the oocyte by adding a serine-threonine kinase inhibitor, such as 6-dimethylaminopurine (DMAP).