Effect of testosterone on of ovine spermatogonial colony formation in-vitro
Spermatogonial stem cells (SSCs) are able to establish balance between self-renewal and differentiation, thereby maintain the spermatogenesis. The aim of this study was to investigate effects of different doses of Testosterone on SSCs colony formation. Materials and Methods: The cells were isolated from testes of prepubertal lambs by two-step enzymatic digestion and then purified by differential platting. The cells were cultured for 13 days in 4 groups: Control [DMEM containing antibiotic (1%)
... ng antibiotic (1%) and FBS (5%)]; and Treatment groups 1, 2 and 3 (DMEM+Testosterone 60, 120 and 240 µg/ml, respectively). The culture media was changed every 72 h. Identification of SSCs was performed by immunocytochemistry staining against PGP9.5. Finally, following the evaluation of percentage for viability rate of SSCs immediately after isolation and also the number and surface areas of the colonies on days 5, 9 and 13 after the beginning of culturing by invert microscopy, the analyses were made using statistical tests. Results: The percentage for viability rate of SSCs after isolation was 86.77±3.63%. The decrease in the number and surface areas of spermatogonial colonies in Treatment groups 2 and 3 were significant compared to Control and Treatment group1 (P<0.05). Furthermore, colony number and surface area were significantly increased at day 13 compared to those of the days 5 and 9 (P<0.05). Conclusion: The results of this study showed that Testosterone has no effect on colony induction of SSCs in vitro. Increasing the Testosterone dose decreases the colony number and surface area of SSCs.