Sperm-mediated DNA transfer in bovine and swine species

Ejaculated sperm cells from both bovine and swine animals depleted of the seminal fluid were used as vectors for transferring different plasmid DNAs into eggs during the fertilization process. PCR screening of about 2000 blastocysts showed that transformed embryos were obtained in both animal species with varying efficiencies, and that the rate of transformation depended on the plasmid used. The most efficient rate was obtained in both species with the pSV2CAT construct, yielding 22% positive blastocysts in bovine and 5.7% in swine respectively. Artificial insemination of ten sows with boar sperm cells that had been preincubated with pSV2CAT DNA produced 82 offspring. Southern blot analysis of the DNAs extracted from the animal tails showed that five animals were transgenic and contained sequences complementary to pSV2CAT DNA that appeared to be rearranged compared to the original plasmid, These results indicate that sperm-mediated DNA transfer protocols can be successfully adapted for the generation of genetically transformed livestock.