How Organs of Male and Female Mammals Differ

Researchers from Heidelberg and London decode genetic programmes that underlie the development of sex-specific characteristics of mammalian organs. The development of sex-specific characteristics is frequently seen in mammals. These characteristics stem from the activation of corresponding genetic programmes that until now have been largely undescribed by the scientific community. An international research team from the Center for Molecular Biology of Heidelberg University and The Francis Crick Institute in London has, for the first time, decoded the programmes that control the sex-specific development of major organs in selected mammals - humans, mice, rats, rabbits, and opossums. By comparing these programmes, the researchers were also able to trace the evolution of sex-specific organ characteristics. Sexual dimorphism describes the development of secondary sex characteristics and in biology refers to the differences in the appearance of sexually mature males and females of the same species that are unrelated to the reproductive organs. Such sex-specific characteristics include clearly identifiable differences in the size and coloration of the body, or the development of different organs, such as antlers in male deer.