Transcription of the Sox30 Gene Is Positively Regulated by Dmrt1 in Nile Tilapia

Abstract

The Sox family member Sox30 is highly expressed in the testis of several vertebrate species and has been shown to play key roles in spermiogenesis. However, its transcription regulation remains unclear. Here, we analyzed the Sox30 promoter from the teleost fish Nile tilapia (Oreochromis niloticus) and predicted a putative cis-regulatory element (CRE) for doublesex and mab-3 related transcription factor 1 (Dmrt1), a male-specific transcription factor involved in male sex differentiation. Transcriptional profiling revealed that Sox30 and Dmrt1 similarly exhibited a high expression in tilapia testes from 90 days after hatching (dah) to 300 dah, and the transcription of the Sox30 gene was reduced about one-fold in the testes of male tilapia with Dmrt1 knockdown. Further dual-luciferase reporter assay confirmed that Dmrt1 overexpression significantly promoted transcriptional activity of the Sox30 promoter and this promotion was decreased following the mutation of putative CRE for Dmrt1 within the Sox30 promoter. Chromatin immunoprecipitation-based PCR (ChIP-PCR) and electrophoretic mobility shift assay (EMSA) demonstrated that Dmrt1 directly binds to putative CRE within the Sox30 promoter. These results together indicate that Dmrt1 positively regulates the transcription of the tilapia Sox30 gene by directly binding to specific CRE within the Sox30 promoter.

High‐quality chromosome‐level genomes of two tilapia species reveal their evolution of repeat sequences and sex chromosomes

“…Among them, knockouts in ONJp of conserved teleost male‐determining genes Amhy , Gsdf or Dmrt1 , or those of female‐determining genes Foxl2 or Cyp19a1a all leads to sex reversal (Jiang et al., 2016; Li et al., 2013; Zhang et al., 2017). The temporal expression patterns of these genes are consistent with their known hierarchical positions in the SD pathway of ONJp : for example, Dmrt1 has robust male‐specific expression and steady upregulation since 5 dah, before its validated downstream target genes Gsdf (Jiang et al., 2016), Sox9b (Wei et al., 2019) and Sox30 (Tang et al., 2019) reaching their peak expression levels specifically in males. This is similar in the female determining pathway between the upstream gene Foxl2 versus its downstream target Cyp19a1a (Li et al., 2013; Figure S19 ) .…”

High-quality chromosome-level genomes of two tilapia species reveal their evolution of repeat sequences and sex chromosomes

“…Among them, knockouts in ONJp of conserved teleost male-determining genes Amhy, Gsdf or Dmrt1 , or those of female-determining genes Foxl2 or Cyp19a1a all leads to sex reversal [27, 51, 52]. The temporal expression patterns of these genes are consistent with their known hierarchical positions in the SD pathway of ONJp : for example, Dmrt1 has robust male-specific expression and steady upregulation since 5dah, before its validated downstream target genes Gsdf [52], Sox9b [53] and Sox30 [54] reaching their peak expression levels specifically in males. This is similar in the female determining pathway between the upstream gene Foxl2 vs. its downstream target Cyp19a1a [27].…”

A review on sox genes in fish

“…The p62 gene of O. mykiss can associate with sox23 in vivo to modulate the function of sox23, and interaction between sox23 and p62 may affect ovary (Yamashita et al 1998). Over-expression of dmrt1 in O. niloticus can promote significantly transcriptional activity of the sox30 promoter in testis, which decreases following the mutation of putative cis-regulatory element for dmrt1, suggesting that dmrt1 positively regulates the transcription of O. niloticus sox30 by binding to specific cis-regulatory element within the sox30 promoter directly (Tang et al 2019). Med12, a regulatory subunit of the transcriptional mediator complex in D. rerio, modulates the ability of casanova/sox32 to induce expression of sox17 (Shin et al 2008).…”