Expression of Ets Transcription Factors Etv4, Etv1 in Mouse Testis.

Spermatogonial stem cells (SSCs) are primordial spermatogonia being capable of self-renewal and differentiation throughout the life of the male. The recent blizzard of researches implied that SSCs self-renewal is modulated by the integration of SSCs intrinsic factors with their microenvironment niches. Signaling from Sertoli cells, the primary component of SSCs niches, determine the fate of SSCs by either supporting self-renewal or initiating differentiation leading to meiotic entry and production of spermatozoa. However, the detailed mechanisms of SSCs self-renewal and differentiation still remains unclear. Recently, Ets related molecule (ERM, Etv5) was reported as an essential molecule for the maintenance of SSCs niches in mouse testis. Since Etv5, Etv4 and Etv1 belong to the same subfamily of Ets transcription factors and they have highly conserved homologous domain, this research focused on whether Etv4 and Etv1 are expressed in mouse seminiferous epithelium and what roles they play on SSCs behavior. To this end, Specific primers for Etv4, Etv1, Etv5 and internal control beta-actin were designed and synthesized to investigate the mRNA expression level of the interested gene in mouse testicular tissue at different developmental stages by employing Real-time RT-PCR analysis. Four time points including 5-day, 7-week, 16-week and 10-month were selected as the representative developmental stages for puberty, sexual maturity, adulthood and old age, respectively. The ANOVA test of the data was carried out by using SPSS. The results showed that the expression of Etv5 mRNA was lower at 5-day, extremely increased at 7-week (P<0.001), then significantly decreased at 16-week and 10-month (P<0.01). The expression of Etv1 mRNA was at the same level with that of Etv5 at 5-day, increased significantly at 7-week (P<0.05), decreased slightly at 16-week and then increased evidently at 10-month. The expression of Etv4 was very lower at all four time points compared with that of Etv5 and Etv1. However, it also increased significantly at 7-week and decreased afterwards. The present results indicate that expression of Etv5 and Etv1 in testis reaches peak along with the sexual maturity, and then decreases and maintains at a relatively high level during the spermatogenesis, which putatively suggests Etv1 may has functions in mouse spermatognesis. However, the exact roles of Etv1 on SSCs self-renewal and differentiation still need to be addressed in next step. This research was supported by the National Natural Science Foundation of China (No. 30771555, No.30200195, No.30471246).