Expression of Activin β-Subunit and Type II Receptor Genes During Newt Spermatogenesis
Spermatogenesis consists of a series of complicated processes that involve mitotic proliferation of spermatogonia, meiotic division of spermatocytes, and morphological changes of spermatids into mature sperm. In mammals, pituitary follicle-stimulating hormone (FSH) and androgens secreted by Leydig cells are the main hormones regulating spermatogenesis. These hormones act on Sertoli cells, which are considered to be activated to produce paracrine factors that stimulate proliferation and differentiation of germ cells. Inhibin and activin, members of the transforming growth factor-β (TGF-β) superfamily, have been suggested to play an important role in paracrine regulation of testicular function. It was reported that activin A stimulates the spermatogenesis in the rat testis (1) and inhibin suppresses the number of differentiated spermatogonia in mouse testis (2).
KeywordsSertoli Cell Paracrine Factor Primary Spermatocyte Subunit mRNA Activin Receptor
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