Simon Silver | Jan 20, 1991 | 2 min read
SIMON SILVER Department of Microbiology & Immunology University of Illinois Chicago It is not the absence of two X chromosomes that makes for a man rather than a woman. The Y chromosome contains a sex-determining gene (or genes), which functions during testis differentiation. Missense and frame-shift mutations result in XY females. P. Berta, J.R. Hawkins, A.H. Sinclair, A. Taylor, et al., "Genetic evidence equating SRY and the testis-determining factor," Nature, 348, 448-50, 29 November 199