Abstract: A nuclear transfer method is provided wherein nuclear DNA in whole or part is injected into enucleated oocytes. The method is suitable for different donor cells, and preferably ES cells.

Abstract: A nuclear transfer method is provided wherein nuclear DNA in whole or part is injected into enucleated oocytes. The method is suitable for different donor cells, and preferably ES cells.

Abstract: The present invention provides methods of preparing mammalian cells and tissues for therapeutic and diagnostic purposes that are derived from ntES cells. The present invention further provides the mammalian cells and tissues themselves. In addition, methods of using the mammalian cells and tissues as a therapeutic agent or as a diagnostic are provided.

Abstract: Immunodeficient animals are generated by introducing a mutation in RAG-1 into the germline of the animals via gene targeting in embryonic stem cells. The production of mutant RAG-1 deficient mice is detailed. RAG-1 deficient mice have no mature B and T lymphocytes. The arrest of B and T cell differentiation occurs at an early stage and correlates with the inability to perform V(D)J recombination. To date, these mice do not have mature B and T lymphocytes, nor do they express immunoglobulin or T cell receptors. The same strategy can be applied to the generation of other RAG-1 deficient animals, such as rabbits, rats, and pigs, using known techniques. These animals are all useful for the same general purposes as the scid mice, for example, cultivation of human lymphocytes for expression of human immunoglobulin.