Nature Genetics pp775 - 780

In a paper from the July issue of the journal Nature Genetics, to be published online on June 6th, the research groups of James Robl and Isao Ishida report a new technique for producing cows where two copies of a gene can be knocked out within a year.

This is the first report of targeted removal of both copies of a gene in cattle without having to wait many years to breed the cattle. The researchers deleted the genes in cultured cells, called primary fibroblasts, then produced cloned embryos from the cell nuclei. With this technique, they produced cattle lacking the antibody immunoglobulin-mu and fetal cattle lacking the bovine prion protein. The first feat extends the technology to permanent removal of genes in cells where the genes aren't currently active. Whether or not the second feat will result in cattle that do not transmit the prion disease, Bovine Spongiform Encephalopathy (BSE) remains to be seen.