Keefer Lab

In studies exploring the acquisition and maintenance of pluripotency, the bovine promoter controlling expression of one of the pluripotency transcription factors, NANOG, was linked to GFP and transfected into mouse ESC and bovine fibroblasts.  The transgene was incorporated into the genome as demonstrated by FISH (photo above). The bovine promoter turned on the GFP in mouse ESC (see Tools) and was down-regulated with differentiation. Following Somatic Cell Nuclear Transfer (SCNT) of the transgenic bovine fibroblasts into oocytes, the SCNT derived embryos appropriately expressed the NANOG promoter driven GFP (see Lei et al. (2013) Monitoring bovine fetal fibroblast reprogramming utilizing a bovine NANOG promoter-driven EGFP reporter system. Molecular Reproduction and Development. 80(3):193-203.).

In other studies we are exploring alternative approaches, which do not involve genetic modifications, to induce pluripotency in somatic cells for animal species conservation. These include the reprogramming of cat somatic cells using cell membrane permeable complexes containing pluripotency-inducing transcription factors and small molecules.  We seek methods which will allow safe and reliable ways to produce and use stem cells for conservation applications.