Induced Pluripotency in Chicken Embryonic Fibroblast Results in a Germ Cell Fate

Germ cells (GCs) are critically important as the vehicle that passes genetic information from one generation to the next. Correct development of these cells is essential and perturbation in their development often leads to reproductive failure and disease. Despite the importance of GCs, little is known about the mechanisms underlying the acquisition and maintenance of the GC character. Using a reprogramming strategy, we demonstrate that overexpression of ectopic transcription factors in embryonic fibroblasts can lead to the generation of chicken induced primordial germ cells (ciPGCs). These ciPGCs express pluripotent markers POU5F1, SSEA1, and the GC defining proteins, CVH and DAZL, closely resembling in vivo sourced PGCs instead of embryonic stem cells. Moreover, CXCR4 expressing ciPGCs were capable of migrating to the embryonic gonad after injection into the vasculature of stage 15 embryos, indicating the acquisition of a GC fate in these cells. Direct availability of ciPGCs in vitro would facilitate the study of GC development as well as provide a potential strategy for the conservation of important genetics of agricultural and endangered birds using somatic cells.