Current Progress of the Long-Term Preservation for Fish Embryos, Female Reproductive Cells, and Tissues

Abstract

Cryopreservation is an effective technique to preserve biomaterials for a very long time period. The long-term preservation techniques benefit the rapid development of the aquaculture industry, such as optimizing the breeding schemes. Currently, many cryopreservation attempts have been conducted on fish embryos and gametes. The cryopreservation of fish sperms is the most successful among these studies due to the simple structure of sperms. However, the cryopreservation of female gametes is developing at a much slower pace. In this work, the techniques and progress related to the cryopreservation of fish embryos, blastomeres, oocytes, testicular tissue, ovarian tissues, and primordial germ cells (PGCs) are introduced. This review first discusses the cryoprotective agents (CPAs) used in the cryopreservation or vitrification of fish embryos and gametes. Then we summarize advanced techniques including the pretreatment, rewarming methods, removal of CPAs, and assessment methods, followed by introducing the preservation results. In the end, some suggestions are raised for the future development of fish embryos, germ cells, and gonadal tissues.