Differential Dmrt1 transcripts in gonads of the protandrous black porgy, <i>Acanthopagrus schlegeli</i>

Abstract

Black porgy, Acanthopagrus schlegeli Bleeker, is a marine protandrous hermaphrodite fish. A Dmrt1 cDNA was cloned and characterized and in order to study the process of sex change in this species, mRNA transcripts of Dmrt1 were monitored. Dmrt1 was specifically transcribed in testis and seminal vesicle in 2-year-old black porgy according to RT-PCR and Southern analysis. A real-time quantification PCR analysis was further developed for the measurement of Dmrt1 transcripts. Dmrt1 transcripts were at significantly higher levels in bisexual testis than bisexual ovary in 1+ and 2+ year-old fish. Dmrt1 transcripts decreased in the functional and bisexual testis of 3-year-old fish. Much higher levels of Dmrt1 transcripts in the bisexual ovary were detected in 1+ year-old fish than in 2+ and 3-year-old fish. No differences in Dmrt1 transcripts were found in bisexual ovaries of 2+ and 3-year-old fish and female ovaries of 3-year-old fish. The data suggest there is relationship of Dmrt1 to the sex change of protandrous black porgy.

Sexual dimorphic expression of DMRT1 and Sox9a during gonadal differentiation and hormone‐induced sex reversal in the teleost fish Nile tilapia (Oreochromis niloticus)

“…Evidence of the male-specific expression of DMRT1 was also obtained in humans, a reptile species and a frog species (Raymond et al, 1999;Smith et al, 1999;Kettlewell et al, 2000;Moniot et al, 2000;Shibata et al, 2002). In teleost fish, several reports indicate that DMRT1 expression is related to the development of the testes (Guan et al, 2000;Marchand et al, 2000;He et al, 2003). The present study indicates clearly, for the first time in fish, that tDMRT1 is expressed in the germcell-surrounding cells and medullarycell-mass cells, which differentiate into the efferent duct during testicular differentiation, irrespective of the genetic sex.…”

“…In chickens, aromatase inhibitor-treated ZW embryos showed sex reversal, accompanied by DMRT1 expression (Smith et al, 2003). In teleost fish also, DMRT1 has been linked to both natural sex change from female to male, and to sex hormone-dependent sex reversal (He et al, 2003;Guan et al, 2000;Marchand et al, 2000). These findings strongly suggest that DMRT1 homologs are involved in testicular differentiation in the process of normal sex development and sex reversal in nonmammalian vertebrates.…”

Governing Sex Determination in Fish: Regulatory Putsches and Ephemeral Dictators

“…For example, the expression pattern of the transcription factor Dmrt1, which is involved in the development of the male phenotype in tetrapods, is consistent with a similar role in sex determination and/or testis differentiation in both hermaphrodite and gonochoristic fish [Marchand et al, 2000;Brunner et al, 2001;He et al, 2003;Veith et al, 2003Veith et al, , 2006Kobayashi et al, 2004;Winkler et al, 2004;Guo et al, 2005]. Hence, diversity of sex determination in fish might be associated with a turnover of master regulators governing a more conserved part of the sex-determining cascade.…”

Histological observation of doublesex-mab 3-related transcription factor 1 (DMRT1) localization in the adult testis of three-spot wrasse

“…In contrast, suppression of DMRT1 transcripts in the gonads was observed in estrogen (E2)-treated male embryos of zebrafish (Schulz et al 2007) and tilapia ). In addition, changes were noticed in DMRT1 expression in concordance with the phases of testicular differentiation in several fishes that change their sexes naturally (Alam et al 2008;He et al 2003;Liarte et al 2007). These findings suggest that DMRT1 is involved not only in early testicular differentiation, but also in gonadal sex reversal/change in teleosts.…”