Gonadal dysgenesis If a single or combination of these genes are mutated or deleted, downstream signalling is disrupted, leading to malformation of male external genitalia. SRY acts on gene SOX9 which drives Sertoli cell formation and testis differentiation. An absence in SRY causes SOX9 to not be expressed at the appropriate time or concentration, leading to a deficiency in testosterone and Anti-Müllerian hormone production. Inadequate levels of testosterone and Anti-Müllerian hormone disrupts the development of Wolffian ducts and internal genitalia that are key to male reproductive tract development. The lack of the male associated steroid hormones drives Müllerian duct development and perusal
Human male sexuality Human male sexuality Human male sexuality covers physiological, psychological, social, cultural, and political aspects of the human male sexual response and related phenomena. It encompasses a broad range of topics involving male sexual desires and behavior that have also been addressed by ethics, morality, and religion. There are a number of factors that influence male sexuality and sexual behaviour, including expected parental investment, and paternal presence during development. Elizabeth Cashdan proposed that mate strategies among both genders differ depending on how much parental investment is expected of the male, and provided research support for her hypotheses. When men expect to