Gonadal soma-derived factor (gsdf), a TGF-beta superfamily gene, induces testis differentiation in the teleost fish Oreochromis niloticus

Abstract

Highlights･ Gsdf is expressed predominantly in XY gonads in the Nile tilapia.･ Gsdf expression pattern shows sexual dimorphism before morphological differentiation.･ Gsdf expression is the earliest gene expression detected in testis differentiation.･ Overexpression of gsdf is sufficient to induce testis differentiation in XX tilapia.Abbreviations: transforming growth factor-beta (TGF-beta), gonadal soma-derived factor (gsdf), doublesex/mab-3-related transcription factor-1 (Dmrt1), days post-hatching (dph), quantitative one-step RT-PCR (qRT-PCR), in situ hybridization (ISH) 2 ABSTRACTThe Nile tilapia, Oreochromis niloticus, is a gonochoristic teleost fish with an XX/XY genetic system and is an excellent model for gonadal sex differentiation. In the present study, we screened novel genes that were expressed predominantly in either XY or XX undifferentiated gonads during the critical period for differentiation of gonads into ovaries or testes using 5 microarray screening. We focused on one of the isolated 12 candidate genes, #9475, which was an ortholog of gsdf (gonadal soma-derived factor), a member of the transforming growth factor-beta superfamily. #9475/gsdf showed sexual dimorphism in expression in XY gonads before any other testis differentiation-related genes identified in this species thus far. We also overexpressed the #9475/gsdf gene in XX tilapia, and XX tilapia bearing the #9475/gsdf gene 10 showed normal testis development, which suggests that #9475/gsdf plays an important role in male determination and/or differentiation in tilapia.

Gonadal soma controls ovarian follicle proliferation through Gsdf in zebrafish

“…In phylogenies, GDF9 and BMP15 generally group as sister clades variably related to gsdf (Sawatari et al, ; Shibata et al, ; Gautier et al, ; Myosho et al, ; Forconi et al, ; Horiguchi et al, ; Kaneko et al, ). Our comparative genomic investigations found that GDF9 , BMP15 , and gsdf ; are all near Aff family genes, which occupy paralogous chromosome segments in the human genome (Fig.…”

“…Because phylogenetic analyses of TGFB family genes disagree on the affinities of gsdf (Sawatari et al, 2007;Shibata et al, 2010;Gautier et al, 2011a;Myosho et al, 2012;Forconi et al, 2013;Horiguchi et al, 2013;Kaneko et al, 2015), we analyzed conserved syntenies to learn which tetrapod TGFB genes are most closely related to those of fishes. Results showed that zebrafish gsdf shares conserved syntenies with gsdf of spotted gar (Fig.…”

The Reversible Sex of Gonochoristic Fish: Insights and Consequences

“…Complete femaleto-male sex reversal of the medaka O. sakaizumii but not of O. latipes stimulated gsdf and subsequently dmrt1 [Horie et al, 2016]. In tilapia, upregulation of gsdf transcripts were initially suggested to be at 8 dpf prior to dmrt1 and localized also in the somatic cells surrounding germ cells [Kaneko et al, 2015]. However, CRISPR/Cas9 knockouts revealed that gsdf is in fact expressed after dmrt1 and an aromatase inhibitor treatment rescued the testicular phenotype of XY gsdf -/-gonads .…”

A Review of Genetic Advances Related to Sex Control and Manipulation in Tilapia

“…The best way to obtain monosex populations is through genetic control. Recently, researchers found that gsdf transgenic XX tilapia showed normal testis development (Kaneko et al ). In addition, our group found that the XX fish with amhy transgene displayed female‐to‐male sex reversal with functional testis (Li et al ).…”