Sox as a Functionally Conserved Link Between Unicellular Ancestors and Human Stem Cell Control

Stem cells are key to human tissue maintenance. Because tissue maintenance allows us to live and reproduce, stem cell control is fundamental for animal life and evolution. A team of researchers set out to explore the origins of transcription factors at the core of the induction and the maintenance of stemnss. They focus on the conservation of the Sry-related box 2 (Sox2) and the octamer-binding transcriptor factor 4 (Oct4) in the Pit-Oct-Unc (POU) family. While these have been thought as animal-specific, the authors identified SOX and POU in pre-animal organisms. In particular, the SOX protein from a very simple unicellular organism was functionally conserved enough to reprogram somatic mouse cells to induce pluripotent stem cells. To ponder on the importance of their findings, we first need to step back a couple of hundred million years.