Sex differentiation in teleost fishes occurs in response to sex determination signals, which induce the gonad to develop as either an ovary or testis. However, sex differentiation mechanisms in fishes are diverse, and information on gonad differentiation in sex changing fishes remains limited. The orange-spotted grouper Epinephelus coioides is a protogynous hermaphroditic fish that provides an ideal model for investigating gonad differentiation in vertebrates. In this study, Transcriptome data showed that expression levels of amh and amhrII in gonads were increased during sex differentiation. Overexpression of Amh was also promoted the spermatogonia proliferation and induced the development of male gonads in undifferentiated orange-spotted groupers, but that this male tendency was preceded by female differentiation.
Genetic architecture of sex determination in fish: applications to sex ratio control in aquaculture
Roles of estrogens in fish sexual plasticity and sex differentiation.
Electronic address: wdeshou swu. Fish sex could be reversed at the undifferentiated stage of gonad by administration of exogenous estrogen E2 or blockade of endogenous estrogen synthesis with aromatase inhibitors, which is designated as primary sex reversal PSR. The differentiated ovary could be transdifferentiated into functional testis, and vice versa, the differentiated testis could be transdifferentiated into ovary. By analyzing these two secondary sex reversal SSR models, it was found that induction of male-to-female sex reversal initiates from dorsal near the blood vessel to the ventral, while induction of female-to-male sex reversal initiates from the ventral to dorsal.
Metrics details. The molecular mechanisms that underlie sex determination and differentiation are conserved and diversified. In fish species, temperature-dependent sex determination and differentiation seem to be ubiquitous and molecular players involved in these mechanisms may be conserved. Although how the ambient temperature transduces signals to the undifferentiated gonads remains to be elucidated, the genes downstream in the sex differentiation pathway are shared between sex-determining mechanisms. In this paper, we review recent advances on the molecular players that participate in the sex determination and differentiation in fish species, by putting emphasis on temperature-dependent sex determination and differentiation, which include temperature-dependent sex determination and genetic sex determination plus temperature effects.
The chapter is devoted to the consideration of sex determination in vertebrate groups of nonmammalians: fish, amphibians, reptiles, and birds. Attention is drawn to the fact that all these groups of animals, unlike mammals, are implemented hormonal control options for primary sex determination, and there is a possibility of sex reversion. Determination of gonadal development in vertebrates like testis or ovary was initially controlled mainly by sex hormones fish and amphibians. Later, various sex determining genes were involved in this process.