Abstract
Background:
Reports on the effects of glial cell-derived neurotrophic factor (GDNF) on spermatogonial stem cells (SSCs) of Zebu or crossbred bovine are lacking. Proliferative effects were reported in ovine and caprine, whereas non-proliferative effects were only observed in Bos taurus.
Aim:
Understanding the roles of GDNF in maintaining germ cell proliferation may be crucial for reducing the high rate of reproductive failure in crossbred (Bos indicus X Bos taurus) bovine.
Methods:
In the present study, the in vitro culture effects of GDNF on SSCsof crossbred bovine were assessed. In the treatment groups, SSCs were cultured in a medium supplemented with two different doses of GDNF (T1-10ng/mL, T2-40ng/mL) and co-cultured with the Sertoli cell layer (T3). In the control group, SSCs were grown without GDNF or without co-culture (C). The proliferative effects in terms of the number of cells and colonies were determined on days 4, 7, 10, and 13 of in vitro culture.
Results:
There was a significant (p<0.05) increase in the number of cells in the T2and T3 groups compared with the control group on days 4, 7, 10, and 13 of culture. There was no significant (p<0.05) difference was observed in the number of colonies between the control and GDNF (T1 and T2)-supplemented groups. However, the number of colonies was significantly (p<0.05) higher in the T3 group than in theT1, T2, and control groups on days10 and 13. Supplementation of GDNF (T2) and co-culture of SSCs with Sertoli cells significantly increased the surface area of SSCs colony during the entire period of in vitro culture compared with the control and T1 groups. However, on day 7, a significant difference (p<0.05) in the surface area of the colonies was observed between the T2 and T3groups.
Conclusion:
The supplementation of GDNF at 40 ng/mL and co-culture of SSCs with Sertoli cells enhanced both the multiplication and growth of SSCs during in vitro culture, indicating their possible role in SSC proliferation and self-renewal in crossbred bovine.
Key words: Bovine; GDNF; Sertoli cells; Spermatogonial stem cells.
