Abstract
Spermatogonial stem cell (SSC) niche are specific regions of the testes which regulate stem cell properties, such as, self-renewal, differentiation, apoptosis, quiescence and pluripotency. The regulation of the SSC niche is essential to avoid accumulation of SSC (seminoma), when self-renewal is favored, or spermatogenesis depletion when differentiation is predominant over self-renewal. Characterization of SSC niche and its regulation have been drawn attention of several studies, including those with teleost fish, in particular with zebrafish. Zebrafish SSC niche is formed by Sertoli cells surrounding SSC, and adjacent interstitial cells, such as Leydig cells and blood vessels. Follicle-stimulating hormone (Fsh), and growth factors, as Amh (Anti-Müllerian hormone) and Igf3 (Insulin growth factor-like) have an important role on zebrafish SSC nice. While Amh inhibits spermatogonial differentiation and maintains SSC in their undifferentiated state, being down-regulated by Fsh, Igf3, induced by Fsh, promotes differentiation and spermatogonial proliferation towards meiosis. However, it remains unclear how Amh and Igf3 interact among each other, and the molecular changes induced by them on the SSC niche. The project aims to study the interaction (direct or indirect) between Fsh, estrogens and androgens with Igf3 and Amh evaluating the overall gene expression in order to determine the potential candidates (mRNAs or microRNAs) that would be involved in the proliferation and spermatogonial differentiation.
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