The access to sufficient numbers of spermatogonial stem cells (SSCs) is a prerequisite for the study of their regulation and further biomanipulation. Rho kinase (ROCK) belongs to a family of serine/threonine kinases and involves in a wide range of fundamental cellular functions. The aim of the present study was to study the effect of ROCK inhibitor, Y-27632 (0.1-40 µM), during the primary culture of ovine SSCs. SSCs were collected from 3-5-month-old's lamb testes. The viability of SSCs, the apoptosis assay of SSCs, the intracellular reactive oxygen species (ROS) analysis, and the SSCs markers and apoptosis-related gene expressions were detected by MTT reduction assay, Annexin V-FITC/ Propidium Iodide (PI) dual staining, flow cytometry and real-time-PCR studies, respectively. Morphological analyses indicated that the 5-10 µM Y-27632 had an optimal effect on the number of presumptive SSCs colonies and the area covered by them after a 10 days culture. The cell viability, apoptosis and necrosis of SSCs after 10 days' culture were not affected in comparison with the control group, and the 20 µM of Y-27632 resulted in significantly decreased cell viability (P<0.05) and an increased necrosis of cells. On day 10 after culture, the expression of P53 was decreased with an increase from 0 to 10 µM in the Y-27632 dose. In the 20 µM Y-27632 group, the expressions of P53 and Bax were higher and the Bcl-2 was lower than other groups and these values were significantly different from 5 and 10 µM Y-27632 groups (P<0.05). The level of intracellular ROS was decreased with an increase in the Y-27632 dose from 5 to 20 µM in comparison with the control group. In conclusion, the present study demonstrated that Y-27632 at a concentration of 5-10 µM provided optimal culture conditions for the primary culture of ovine SSCs.

The aim of the present study was to examine the effect of quercetin on the survival and primary culture of ovine spermatogonial stem cells (SSCs). The two-time enzymatic digestion process was employed to obtain SSCs from lamb testes. In the next step, the use of filtration and differential plating methods caused an increase in the number of SSCs in the cell suspension resulting from enzymatic and mechanical digestions. Mitomycin-C-treated Sertoli cells were used to prepare the feeder layer. The stem cells were then cultured on the Sertoli cell feeder layer. The identification of the colonies was done through alkaline phosphatase staining methods and specific gene expression of ram’s SSCs (nanog and Plzf). The results of methylthiazolyldiphenyl-tetrazolium bromide assay on SSCs 72 h after culture with different treatments of quercetin demonstrated that the highest percentage of survival was for 5 μM and 10 μM concentrations, respectively; however, compared to the control, no significant difference was observed. In comparison with the control, the concentration equal to and greater than 20 μM quercetin caused a significant decrease in the survival of SSCs (P &lt; 0.05). Seven days after culture, 40 μM quercetin caused a substantial reduction in the mean number of colonies, compared to the control (P &lt; 0.05). The results demonstrated that compared to the control, 5 μM to 40 μM of quercetin significantly reduced Plzf gene expression. Furthermore, the concentration equal to and higher than 10 μM quercetin significantly decreased bcl-2 gene expression in the cells under study (P &lt; 0.05). Based on the findings of the present study, the use of quercetin for the primary culture of ovine SSCs is not recommended. It is suggested that the function of this antioxidant should be investigated on the differentiation of SSCs.