Sex determination in mammals is controlled by various transcription factors. Following the identification of SRY on the Y chromosome, several other factors have been identified. They can normally be identified as being involved in sex determination by the identification of sex reversal mutations or deletions, functional studies, and also by male-specific expression patterns in embryos. Here, it...

Van Valen (1973) characterized evolution as the control of development by ecology. Sex determination in fishes provides some clear examples of this “control” in operation. Teleost fishes show a remarkable variety of sex determination and differentiation patterns. These range from systems in which sex is determined by sex chromosomes, as in birds and mammals, to simultaneous hermaphrodites that ...

In mammals, sex differentiation depends on gonad development, which is controlled by two groups of sex-determining genes that promote one gonadal sex and antagonize the opposite one. SOX9 plays a key role during testis development in all studied vertebrates, whereas it is kept inactive in the XX gonad at the critical time of sex determination, otherwise, ovary-to-testis gonadal sex reversal occ...

Determination of sex from the femur measurements has been attempted in several populations and various studies have demonstrated the importance of population specific standards in the metric assessment of sex. The present study attempts to establish metric standards for sex determination by using femur measurements for ancient Japanese populations. Osteometric data were obtained from 151 adult ...

Sex determination of Daphnia pulex is decided by environmental conditions. We established a suitable experimental system for this study using D. pulex WTN6 strain, in which the sex of the offspring can be controlled by photoperiod. Long-day conditions induced females and short-day conditions induced males. Using this system, we previously found that methy farnesoate (MF), which is a putative in...

Sex determination in Drosophila is commonly thought to be a cell-autonomous process, where each cell decides its own sexual fate based on its sex chromosome constitution (XX versus XY). This is in contrast to sex determination in mammals, which largely acts nonautonomously through cell-cell signaling. Here we examine how sexual dimorphism is created in the Drosophila gonad by investigating the ...