Cloning and expression pattern of gsdf during the first maleness reproductive phase in the protandrous Acanthopagrus...

Gonadal soma-derived factor (Gsdf) is a new member of the transforming growth factor beta superfamily. As a teleost- and gonad-specific growth factor, several studies indicate that Gsdf plays an important role in early germ cell development. In the present study, for the first time, a 1700-bp long gsdf gene was cloned from a protandrous species, Acanthopagrus latus. We further analyzed the cellular localization and the expression patterns of gsdf in respective testicular and ovarian zones during the first maleness reproductive phase. The results showed that gsdf transcripts were highly expressed in the ovotestis during sex differentiation, and the somatic cells of the testicular zone expressed many more gsdf transcripts than those of the ovarian zone. At the onset of puberty, the gsdf expression levels decreased gradually during spermatogenesis. Conversely, the ovarian zone exhibited a stable increase pattern which was similar to the plasma 17β-estradiol (E2) levels. These results suggested that Gsdf may participates in early germ cell development, e.g. proliferation and differentiation of spermatogonia and oogonia in A. latus.