Long-term culture and analysis of cashmere goat Sertoli cells

Sertoli cells have important functions in the testis for spermatogenesis. Thus, Sertoli cell culture systems have been established in many animals, such as rat, mouse, human, dog, cow, and pig, but a goat culture has not been reported. This study describes the isolation and culture of Sertoli cells from 3- to 4-month-old cashmere goat (Capra hircus) testes. These proliferative cells were expanded for 20 passages and repeatedly cryopreserved in vitro, in contrast to previous study in human, of which maintain steady growth for up to seven passages and only passages 1 to 5 could be refrozen. The microstructure and ultrastructure of the culture were typical of Sertoli cells, bearing irregular nuclei and a cytoplasm that was rich in smooth and rough endoplasmic reticulum, mitochondria, Golgi, lysosomes, lipid drops, and glycogenosomes. By immunofluorescence analysis, the all cells expressed SRY-related HMG box gene 9 (Sox9). Growth curves and 5-bromo-2'-deoxyuridine (BrdU) incorporation were used to analyze the proliferation of the cultured cells. With increasing passage times, the proliferation of the Sertoli cells declined, but the transcription of glial cell-derived neurotrophic factor (GDNF), stem cell factor (SCF), and β1-integrin was constant. By flow cytometry, the cells retained the ability to proliferate after 5 yr of cryopreservation. Thus, cashmere goat Sertoli cells have significant proliferative potential in vitro, expressing germ cell regulatory factors and have important applications in studying Sertoli cell-germ cell interactions, spermatogenesis, reproductive toxicology, and male infertility.