Reproductive challenges in both human and livestock populations are of significant concern and are often a direct result of abnormal germ cell (oocyte and sperm) development. Aberrant germ cell development significantly affects human fertility, is the leading cause of early pregnancy loss, and results in birth defects such as Down’s syndrome and Klinefelter’s. Failed gametogenesis in livestock has significantly increased because of intense selection for commercial traits and decreased emphasis on reproductive success. Livestock sub-fertility and sterility, spontaneous fetal abortion, decrease litter size and abnormal offspring have all been linked to errors in germ cell development and are a significant source of lost potential income. To address aberrant germ cell development, my lab has developed novel technologies enabling the systematic study of gametogenesis in humans and livestock including 1) A robust in vitro pluripotent stem cell to germ cell differentiation culture system capable of generating large numbers of germ like-cells and 2) the development of the only known chimera competent porcine induced pluripotent stem cell line. Utilizing stem cells and advanced molecular and genetic tools, we can address our long-term goal of identifying and understanding germ cell regulatory signaling in humans and domestic livestock species that could provide invaluable insight into the mechanistic causes of abnormal gametogenesis. Studying important germ cell signaling in human and livestock stem cell-derived germ cells may one day lead to the discovery of new targets for drug and toxicology screens, a better understanding of the etiology of diseases caused by errors in germ cell differentiation or even assisted reproductive technologies in domestic livestock species.