Expressions of Transcription Factors Ets1 and Ets2 in Mouse Testis Tissue.

Abstract

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. We previously demonstrated that the expression of the subfamily member Etv4 and Etv1 of Etv5 subfamily in testis reaches peak along with the sexual maturity, decreases and maintains at a relatively high level during the spermatogenesis. However, it is still unknown that whether other Ets subfamily factors are expressed in mouse seminiferous epithelium and what roles they play on SSCs behavior. To investigate the regulation of Ets subfamily factors Ets1 and Ets2 on the development of mouse testis, and elucidate the effects of Ets1 and Ets2 in mouse testis on self-renewal and differentiation of spermatogonial stem cells, mouse testis tissues were collected from specific developmental stages including postnatal days 1, 5, 10, 15, 20, 25, 30, 35, 40, 50 and 70. Busulfan peritoneal injection was performed and mouse testis tissues were collected on the 0th, 3rd, 5th, 8th, 10th, 18th days after injection respectively. The mRNA expression levels of Ets1 and Ets2 in samples were analyzed by semi-quantitative RT-PCR with β-actin as the internal control. The expression of Ets1 was significantly higher during the period of postnatal 1~30 day than that at postnatal day 35 (P < 0.05 or 0.01), while decreased evidently and maintained at a stable level afterwards. Ets2 expressed significantly higher during the period of postnatal 1~25 day than that at postnatal day 35 (P < 0.05 or 0.01), while decreased significantly and maintained at a stable level afterwards similarly. After busulfan treatment, the expression of Ets1 declined and reached the lowest level at day 5, then increased gradually and reached the level of day 0 and maintained steadily around day 9. Notably, the expressions of Ets1 at day 5 and day 8 were significantly higher than that of day 0 after busulfan treatment (P < 0.05 or 0.01). No obvious changes was observed for the expression of Ets2 during 1~9 day after busulfan treatment, while it decreased dramatically at day 10, which was significantly lower than that of day 0 and day 18 (P < 0.05 or 0.01). The expression of Ets2 gradually increased after day 10 and reached its normal level around day 18. Taken together, Ets1 and Ets2 may affect the early development of mouse testis, adult spermatogenesis, as well as the proliferation and differentiation of spermatogonia. This research was supported by the National Natural Science Foundation of China (No. 30771555, No.30200195, No.30471246) and the Functional Expenses of Basic Scientific Research of Jilin University (200903333). (poster)