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
Sexual Preference (book) Sexual Preference (book) Sexual Preference: Its Development in Men and Women (1981) is a book about the development of sexual orientation by the psychologist Alan P. Bell and the sociologists Martin S. Weinberg and Sue Kiefer Hammersmith, in which the authors reevaluate what were at the time of its publication widely held ideas about the origins of heterosexuality and homosexuality, sometimes rejecting entirely the factors proposed as causes, and in other cases concluding that their importance had been exaggerated. Produced with the help of the American National Institute of Mental Health, the study was a publication of the Institute for