Effect of different concentrations of GDNF on proliferation and differentiation of goat spermatogonia

چکیده مقاله

Introduction: The access to sufficient number of undifferentiated spermatogonia in vitro is a prerequisite for the study of their regulation and further biomanipulations. In spite of the biologic significance of undifferentiated type A spermatogonia, little is known about their behavior, properties and growth requirements. The present study was aimed to investigate the effect of different concentrations of GDNF on colony characteristics and purification rate of goat undifferentiated type A spermatogonia. Materials and Methods: One month goat testes were transported to the lab in transition media at 37oC. Donor cells were isolated through two-step digestion method and purified by discontinuous percoll density with different gradients. The purified cells were propagated in culture media supplemented with different concentrations of GDNF (0, 20 and 40 ng/ml) for 2 weeks. At the end of each week, the morphological characteristics of colonies and purification rate of undifferentiated type A spermatogonia were evaluated by immunocytochemical staining. Results: The number and size of colonies in group containing 40ng GDNF were significantly (p<0.01) higher than corresponding values in the other groups (0 and 20 ng/ml). Higher concentration of GDNF induced logarithmically self-renewing divisions of type A spermatogonia and decreased the number and chain length of colonies into 4-5 clumps. In immunocytochemical evaluation, the proportion of c-kit and PGP9.5 positive cells were significantly (p<0.001) higher in groups containing 0 and 40 ng/ml GDNF, respectively. Conclusion: The medium including 40 ng/ml GDNF was superior with respect to the population of undifferentiated type A spermatogonia, self-renewal of goat spermatogonia, and its propagation in culture system