Research progress on primordial germ cell development and reproductive manipulation techniques of fish

Primordial germ cells (PGCs) are the earliest germline stem cells established during embryonic development. The survival of species is dependent upon PGCs in sexually reproducing organisms. The specification of fish PGCs follows the pattern of “preformation” mode. In this mode, PGCs are specified by inheritance of maternal cytoplasm (germ plasm) during early embryogenesis. Specialized PGCs need to maintain their cell fates and migrate over long distances to reach the gonadal primordium. The biological processes of fish PGC specification, migration and fate maintenance are regulated by a variety of genes and signaling pathways. The study of fish PGC development is helpful for understanding the molecular mechanism of vertebrate cell specification, migration, and fate maintenance, and it is also important for developing new reproductive containment and germline stem cell transplantation techniques in farmed fish. Here, we review the research progress in fish PGC development and reproductive manipulation techniques, and look into rospect of their future development, hoping to provide theoretical and technical supports for the development of new techniques applicable to creating new germplasm of important farmed fish.