SYNOPSIS. Research on the sexual differentiation of mating behavior has impeded progress in our understanding of the proximate bases of individual differences in two ways. First, by viewing variation as categorical rather than continuous, and second, by not placing sufficient emphasis on the fact that males and females differ genetically in many vertebrates, environmental contributions to indiv...

Key conceptual issues about speciation go unanswered without consideration of non-mutually exclusive factors. With tests based on speciation theory, we exploit the island distribution and habitat differences exhibited by the Caribbean cricket Amphiacusta sanctaecrucis, and with an analysis of divergent ecological selection, sexually selected differentiation and geographical isolation, address h...

Sexual shape dimorphism is the differentiation of male and female organisms based on their shape variation; this definition was proposed for the use of geometric morphometrics analysis where the geometric features of the shape are analyzed without the influence of the size. Macaria mirthae (Lepidoptera: Geometridae) is a moth that inhabits different valleys in the north of Chile principally ass...

Complete sex reversal of fish is accomplished routinely in aquaculture practices by exposing fish to exogenous sex steroids during gonadal differentiation. A variety of environmental chemicals are also active at sex steroid receptors and theoretically possess the potential to alter normal sexual differentiation in fish. However, in controlled environmental chemical exposures to date, only parti...

In humans and rodents, exposure to antiandrogenic chemicals during sexual differentiation can produce malformations of the reproductive tract. Perinatal administration of 100 or 200 mg vinclozolin (V) kg-1 day-1 during sexual differentiation in rats induces female-like anogenital distance (AGD), retained nipples, cleft phallus with hypospadias, suprainguinal ectopic scrota/testes, a vaginal pou...

Prenatal androgen shapes genital differentiation. In humans, genital anatomy determines sex of rearing and subsequent behavioral development. Rhesus monkey genital anatomy and neuroendocrine function are sexually differentiated, and behavioral development occurs in a complex social environment. We investigated prenatal hormonal influences on sexual differentiation by suppressing or increasing a...

Over the past 40 years, gonadal sex differentiation in teleost fish has been studied from histological and physiological viewpoints, for its application in fisheries. The morphological characteristics of gonadal sex differentiation in teleost fish were discussed in Section 2, and a summary of sexual processes, such as gonadal sex differentiation and sexual maturation in triploid salmonid fishes...

Differentiation and secondary metabolism are correlated processes in fungi that respond to light. In Aspergillus nidulans, light inhibits sexual reproduction as well as secondary metabolism. We identified the heterotrimeric velvet complex VelB/VeA/LaeA connecting light-responding developmental regulation and control of secondary metabolism. VeA, which is primarily expressed in the dark, physica...

Sexual dimorphism is a phenotypic differentiation between males and females of the same species. Thrips display a wide variety of sexual dimorphism between taxa including size, ornamentation and coloration (Crespi 1986, Mound 2005, Tyagi et al. 2008). During recent surveys on the thrips fauna in subtropical China, Aroidothrips longistylus Ananthakrishnan, an interesting and little known sexuall...

In contrast to females adult male rats excrete a variety of low molecular weight sex dependent urinary proteins (SDP). Electrophoretic separation of these proteins yields at least 8 protein bands which are arranged in typical patterns. The present study was performed to investigate the effect of sexual differentiation, which can be influenced by neonatal hormone treatment, on production and exc...