Knowledge of both sex and maturity stage without killing fish is important from many aspects. The establishment of accurate sex and maturity determination without external sexual dimorphism or when external characters are not developed has usually involved the use of either hormone radioimmunoassay or biopsy techniques. These methods are time and labor consuming as well as harmful to fish. Ther...

Knowledge of both sex and maturity stage without killing fish is important from many aspects. The establishment of accurate sex and maturity determination without external sexual dimorphism or when external characters are not developed has usually involved the use of either hormone radioimmunoassay or biopsy techniques. These methods are time and labor consuming as well as harmful to fish. Ther...

Four pairs of XX and XY gonads from Nile tilapia were sequenced at four developmental stages, 5, 30, 90, and 180 days after hatching (dah) using Illumina Hiseq(TM) technology. This produced 28 Gb sequences, which were mapped to 21,334 genes. Of these, 259 genes were found to be specifically expressed in XY gonads, and 69 were found to be specific to XX gonads. Totally, 187 XX- and 1,358 XY-enha...

The chicken embryo represents a suitable model for studying vertebrate sex determination and gonadal sex differentiation. While the basic mechanism of sex determination in birds is still unknown, gonadal morphogenesis is very similar to that in mammals, and most of the genes implicated in mammalian sex determination have avian homologues. However, in the chicken embryo, these genes show some in...

Most amphibians lack morphologically distinguishable sex chromosomes, but a number of experimental techniques have shown that amphibian sex determination is controlled genetically. The few studies suggesting that environment influences sex determination in amphibians have all been conducted at temperatures outside of the range normally experienced by the species under study, and these effects p...

27 Fish can be threatened by distorted sex ratios that arise during sex differentiation. It is 28 therefore important to understand sex determination and differentiation, especially in river29 dwelling fish that are often exposed to environmental factors that may interfere with sex 30 differentiation. However, sex differentiation is not sufficiently understood in keystone taxa 31 such as the Th...

27 Fish can be threatened by distorted sex ratios that arise during sex differentiation. It is 28 therefore important to understand sex determination and differentiation, especially in river29 dwelling fish that are often exposed to environmental factors that may interfere with sex 30 differentiation. However, sex differentiation is not sufficiently understood in keystone taxa 31 such as the Th...

BACKGROUND Investigating gonadal gene expression is important in attempting to elucidate the molecular mechanism of sex determination and differentiation in the model species zebrafish. However, the small size of juvenile zebrafish and correspondingly their gonads complicates this type of investigation. Furthermore, the lack of a genetic sex marker in juvenile zebrafish prevents pooling gonads ...

In many species of oviparous reptiles, the first steps of gonadal sex differentiation depend on the incubation temperature of the eggs. Feminization of gonads by exogenous oestrogens at a male-producing temperature and masculinization of gonads by antioestrogens and aromatase inhibitors at a female-producing temperature have irrefutably demonstrated the involvement of oestrogens in ovarian diff...

In mammals, sex is determined by the Y chromosome, which encodes a testis-determining factor (TDF). This factor causes the undifferentiated embryonic gonads to develop as testes rather than ovaries. The testes subsequently produce the male sex hormones that are responsible for all male sexual characteristics. In 1990, the sex-determining gene, TDF, was identified and termed SRY in humans (Sry i...