A joint team of geneticists from the University of Geneva (UNIGE) and the Swiss Federal Institute of Technology in Lausanne (EPFL), Switzerland, demonstrated that the emergence of mammary glands in placental mammals and marsupials results from recycling certain ‘architect’ genes. The latter, known as Hox genes, are responsible for coordinating the formation of the organs and limbs during the embryonic stage. Such genes are controlled by complex regulatory networks. In the course of evolution, parts of these networks were reused to produce different functions. Architect genes were thus requisitioned to form the mammary bud and, later, for gestation.
This team’s work has been published in the journal PNAS.