Fish Germline Stem Cells: Biological Traits, Culture Techniques, Germplasm Repositories and Application Prospects

Fish germline stem cells (GSCs) are pivotal mediators in the transmission of genetic information across generations, possessing irreplaceable significance in aquatic germplasm protection and genetic breeding. Stable in vitro culture serves as an essential prerequisite for construction of standardized fish GSC germplasm repositories. Only by developing a robust culture system to sustain long-term proliferation and stemness of GSCs can large-scale cell reserves be established and long-term safe preservation be realized, and relevant applications including germ cell transplantation (GCT), in vitro differentiation and gene editing be further supported. However, most existing studies focus merely on individual techniques or partial research modules, while few integrate GSC biological mechanisms, in vitro culture systems, and germplasm repository construction with downstream industrial applications. This review elaborates the biological characteristics and classification of fish GSCs, summarizes the regulatory mechanisms of GSC fate determination, and comprehensively updates the research progress of in vitro culture technology and germplasm repository development. Multiple application scenarios based on cell bank resources are holistically illustrated, and prevailing technical and industrial challenges are analyzed. The study aims to provide theoretical reference for promoting technological innovation and practical utilization of fish germ stem cell research.