Background: Mammals utilise an XX/XY system of sex determination in which the Y-linked gene SRY (Sexdetermining region Y) exerts a dominant masculinising influence on sexual development. Sex chromosome homology and comparative sequence studies suggest that SRY evolved from the related SOX3 gene on the X chromosome, although there is no direct functional evidence to support this hypothesis. The ...

Gonadal sex in the red-eared slider turtle, Trachemys scripta, is determined by incubation temperature during embryonic development. Evidence suggests that temperature determines sex by influencing steroid hormone metabolism and/or sensitivity: steroidogenic enzyme inhibitors or exogenous sex steroid hormones and their man-made analogs override (or enhance) temperature effects on sex determinat...

doublesex (dsx) is unusual among the known sex-determination genes of Drosophila melanogaster in that functional homologs are found in distantly related species. In flies, dsx occupies a position near the bottom of the sex determination hierarchy. It is expressed in male- and female-specific forms and these proteins function as sex-specific transcription factors. In the studies reported here, w...

Willow minnow, Gnathopogon caerulescens, is a commercially important freshwater fish species in Japan. In particular, female fish with eggs are more expensive than male fish. Many methods have been tested to achieve 100% willow minnow female production; however, none of them were successful because of the temperature-dependent sex determination mechanism. To date, the molecular mechanism underl...

Mechanisms and evolutionary dynamics of sex-determination systems are of particular interest in insect vectors of human pathogens like mosquitoes because novel control strategies aim to convert pathogen-transmitting females into nonbiting males, or rely on accurate sexing for the release of sterile males. In Aedes aegypti, the main vector of dengue and Zika viruses, sex determination is governe...

Genetic control of female sex differentiation from a bipotential gonad in mammals is poorly understood. We find that mouse XX gonads lacking the forkhead transcription factor Foxl2 form meiotic prophase oocytes, but then activate the genetic program for somatic testis determination. Pivotal Foxl2 action thus represses the male gene pathway at several stages of female gonadal differentiation. 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...

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...

The immense value of sex differentiation as a means of enriching and evolving the genome has been proven by the vast variety of sex determining mechanisms to which organisms of all kinds resort. From single gene switching pathways found in lower level organisms to haplodiploid reproduction in hymenoptera, temperature-determined sex in reptiles and sex chromosomes in mammals and avians, nature a...