Expression of putative markers of pluripotency in equine embryonic and adult tissues

Expression of several putative markers of pluripotency (OCT4, SOX2, NANOG, LIN28A, REX1, DNMT3B and TERT) was examined in a range of equine tissues, including early embryos, induced pluripotent stem cells (iPSCs), testis, adipose- and bone marrow-derived mesenchymal stromal cells (MSCs), and keratinocytes. Transcript levels of all markers were highest in embryos and iPSCs and, except for SOX2, were very low or undetectable in keratinocytes. Mean expression levels of all markers were lower in testis than in embryos or iPSCs and, except for DNMT3B, were higher in testis than in MSCs. Expression of OCT4, NANOG and DNMT3B, but not the other markers, was detected in MSCs. Of all markers analysed, only LIN28A, REX1 and TERT were associated exclusively with pluripotent cells in the horse.