PRODUCTION OF RECOMBINANT POLYPEPTIDES BY BOVINE SPECIES ANDTRANSGENIC METHODS

摘要

A transgene for producing recombinant polypeptides in the milk of transgenic bovine species comprises at least one ex- pression regulation sequence, a secretory DNA sequence encoding a secretory signal which is functional in mammary secretory cells of the bovine species and a recombinant DNA sequence encoding the recombinant polypeptides. A method for producing transgenic bovine species comprises introducing the above transgene into an embryonal target cell of a bovine species, transplan- ting the transgenic embryonic target cell formed thereby into a recipient bovine parent and identifying at least one female off, spring which is capable of producing the recombinant polypeptide in its milk . The invention also includes transgenic bovine spe- cies capable of producing recombinant polypeptides in transgenic milk as wel l as the milk from such transgenic bovine species and food formulations containing one or more recombinant polypeptide. A meth od for producing transgenic non-human mam- mals having a desirable phenotype comprises first methylating a transgene followed by introduction into fertilized oocytes. The oocytes are then cultured to form preimplantation embryos. Thereafter, at least one cell is removed from each of the pre-implan- tation embryos and the DNA digested with restriction endonuclease capable of cleaving the methylated transgene but incapable cleaving the unmethylated form of the transgene.