INDUCING PLURIPOTENCY IN RUMINANTS

Abstract

The generation of ES cell lines in ruminants, including cattle and sheep, has been inefficient with putative ESCs undergoing rapid spontaneous differentiation. Recently direct reprogramming of rodent and primate somatic cells to induced Pluripotent Stem Cells (iPSC) is possible simply by forcing expression of a handful of transcription factors, typically OCT3/4, SOX2, KLF4 and cMYC (OSKM). Using a similar approach we have identified that addition of NANOG to the reprogramming cocktail was essential for the generation of stable bovine induced pluripotent stem cells (biPSC). Conversely, generation of reprogrammed sheep iPS (siPSC) cells was achieved by transduction of four factors (OSKM) alone. Significantly, at passage 17 the siPS cells showed silencing of the OSKM transgenes with concomitant reactivation of endogenous pluripotent genes, including OCT4, SOX2 and NANOG. The generation of stable ruminant pluripotent cell lines paves the way for the use of these cells for both biomedical research and agricultural outcomes.