Establishment of Sertoli Cell Lines from Giant Pandas (Ailuropoda melanoleuca).

Giant pandas (Ailuropoda melanoleuca) are a critically protected endangered species in China, but current understanding of their testicular physiology and regulatory mechanisms for spermatogenesis remains limited. Sertoli cells (SCs), the sole somatic cell type within seminiferous tubules, play essential roles in nutritional support, blood-testis barrier (BTB) formation, and hormonal regulation, indispensable for germ cell development in testes. However, primary cultured SCs are prone to undergo replicative senescence, which severely impedes their in-depth studies in vitro. In this study, we introduced the SV40 large T antigen into giant panda primary testicular somatic cells via lentiviral transduction and then performed monoclonal isolation, eventually successfully establishing two immortalized cell lines (PD-SCs-1 and PD-SCs-2). These two cell lines exhibited long-term proliferative capacity and have been cultured for more than eight months and passaged over 70 times. They also stably expressed typical SC markers and retained intercellular junction-like structures and molecular responses to hormonal stimulation, supporting the preservation of several important SC characteristics. Yet, immortalization was accompanied by alterations in cellular properties, including reduced androgen receptor expression and chromosomal abnormalities. Together, the established PD-SCs-1 and PD-SCs-2 cell lines provide a valuable in vitro platform for in-depth investigation of the testicular niche, the mechanisms for spermatogenesis, and the pathology of reproductive disorders in giant pandas, and also lay the experimental groundwork for development of novel breeding technology and conservation of this endangered species.