Co-option of the PRDM14–CBFA2T complex from motor neurons to pluripotent cells during vertebrate evolution

Abstract

Gene regulatory networks underlying cellular pluripotency are controlled by a core circuitry of transcription factors in mammals, including POU5F1. However, the evolutionary origin and transformation of pluripotency-related transcriptional networks have not been elucidated in deuterostomes. PR domain-containing protein 14 (PRDM14) is specifically expressed in pluripotent cells and germ cells, and required for establishing embryonic stem cells (ESCs) and primordial germ cells in mice. Here, we compared the functions and expression patterns of PRDM14 orthologues within deuterostomes. Amphioxus PRDM14 and zebrafish PRDM14, but not sea urchin PRDM14, compensated for mouse PRDM14 function in maintaining mouse ESC pluripotency. Interestingly, sea urchin PRDM14 together with sea urchin CBFA2T, an essential partner of PRDM14 in mouse ESCs, complemented the self-renewal defect in mouse Prdm14 KO ESCs. Contrary to the Prdm14-expression pattern in mouse embryos, Prdm14 was expressed in motor neurons of amphioxus embryos as observed in zebrafish embryos. Thus, Prdm14 expression in motor neurons was conserved in non-tetrapod deuterostomes and the co-option of the PRDM14-CBFA2T complex from motor neurons into pluripotent cells may have maintained the transcriptional network for pluripotency during vertebrate evolution.