1. Two genes coding for gonadal soma-derived factors act in early gametogenesis in European sea bass
- Author
-
Mascoli, Alessia, Zapater, Cinta, Pizarro, J., Espigares, F., Zanuy, Silvia, Gómez Peris, A., Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), and Generalitat Valenciana
- Abstract
Trabajo presentado en 30th CECE & 9th ISFE Joint Conference of the European Society for Comparative Endocrinology and of the 9 International Society for Fish Endocrinology, celebrado en Faro (Portugal) del 04 al 08 de septiembre de 2022., Puberty is the developmental period during which an individual becomes sexually mature for the first time and its regulation is not completely known in teleosts. The gonadal soma-derived factor (Gsdf) gene was found to be downregulated in precocious testis of male European sea bass and proposed as an early gonadal marker of puberty. Gsdf is a member of the TGFbeta superfamily, it is found in tetrapods, excluding mammals, and it is apparently involved in the proliferation of type A spermatogonia. The genome of sea bass contains two gsdf duplicates, gsdf1 and gsdf2, whose encoded proteins share 87% identity and have gonad-specific expression.In the present study we aimed at characterizing the Gsdf genes of European sea bass. First, we have confirmed that expression of gsdf1 and gsdf2 decreases in testis of sea bass males that enter precocious puberty compared with their siblings that remain immature. To achieve this, prepuberal one-year -old male European sea bass of two different sizes (Small or Large) were sampled during the months corresponding to onset of gametogenesis in adults (August to November). The males from the Small groupdid not arrive to full spermiation and showed higher gsdf1 expression than the ones of the Large group during all the experiment, with significant differences in August and October. Most of the animals of the Large group spermiated the next winter. In adult males, gsdf1 showed maximum expression levels in premeiotic (immature) testis, that decreased as spermatogenesis progressed. The expression of gsdf2 followed the same trend but was 5-fold lower. This expression profile matched with the presence of Gsdf protein in testis extracts, and with its location in Sertoli cells surrounding type A spermatogonia, as revealed by IHC with a species-specific antibody.In adult female ovaries, mRNAs from gsdf1 and gsdf2 are present to a much lower level than in testis, and the highest levels correspond to gsdf2 in post-ovulatory ovaries and also in isolated follicular cells. In fact, Gsdf1/2 was located in follicular cells surrounding previtellogenic oocytes. The sea bass gsdf1 and gsdf2 genes are located in the same chromosome, and their coding sequences are placed in different strands and transcription directions. The functional data obtained so far point to common regulatory elements for both genes, but also to a sex-specific regulation for gsdf1 and gsdf2 connected to males and females respectively., Funded by Spanish MCIN/AEI/10.13039/501100011033 and EU-FEDER through grant RTI2018-094667-B-C22. A.M. is supported by a PhD contract from GV (GRISOLIAP/2020/129).
- Published
- 2022