mined? In high school biology class you probably learned a basic rule for mammals: Individuals with one X and one Y chromosome develop into males. Those with two X’s develop into females. Distinguishing between the resulting males and females should be straightforward. Unfortunately for those who like simple rules, the story is far more complex. X and Y chromosomes are only the beginning of sex...

We review the hypothesized and observed effects of two of the major forms of genomic conflicts, genomic imprinting and sexual antagonism, on human health. We focus on phenotypes mediated by peptide and steroid hormones (especially oxytocin and testosterone) because such hormones centrally mediate patterns of physical and behavioral resource allocation that underlie both forms of conflict. In ea...

The classic view of brain and behavioral sexual differentiation holds that the neural mechanisms controlling sexual behavior in female rodents develop in the absence of ovarian sex hormone actions. However, in a previous study, female aromatase knock-out (ArKO) mice, which cannot convert testosterone to estradiol, showed deficient male-oriented partner preference and lordosis behaviors in respo...

The immunocompetence handicap hypothesis postulates that secondary sexual traits are honest signals of mate quality because the hormones (e.g. testosterone) needed to develop secondary sexual traits have immunosuppressive effects. The best support for predictions arising from the immunocompetence handicap hypothesis so far comes from studies of insects, although they lack male-specific hormones...

This article is part of a Special Issue "Energy Balance". The prevalence of adult obesity has risen markedly in the last quarter of the 20th century and has not been reversed in this century. Less well known is the fact that obesity prevalence has risen in domestic, laboratory, and feral animals, suggesting that all of these species have been exposed to obesogenic factors present in the environ...

GH and sex hormones are critical regulators of body growth and composition, somatic development, intermediate metabolism, and sexual dimorphism. Deficiencies in GH- or sex hormone-dependent signaling and the influence of sex hormones on GH biology may have a dramatic impact on liver physiology during somatic development and in adulthood. Effects of sex hormones on the liver may be direct, throu...

OBJECTIVES Genetic factors are extensively studied in respect to drug response in psychiatric disorders. Recent evidence suggests that action of reproductive steroid hormones in brain may also have a role. METHODS Sex-specific differences in terms of illness onset, duration, severity of symptoms and treatment response are well documented. It is believed they result from different brain morpho...

High HIV prevalence and incidence rates and high-risk sexual activity have been documented in certain subgroups of the transgender community; however, less is known about the sexual experiences and risks shared by these subgroups. To identify contextual features influencing the sexual risk-taking of transgender adults, semi-structured interviews conducted with 41 self-identified transgender adu...