One gene controls sex preference in mate choice
Peg13 regulates genes for behavioral control
The Peg13 gene plays an essential role in the development of social brain functions and in mate choice. Maryam Keshavarz and Diethard Tautz of the Max Planck Institute for Evolutionary Biology have shown this with the help of behavioral experiments in mice. The gene is also found in humans.
Normally, both gene copies inherited from the mother and father are active in the offspring. However, the mammalian genome contains about a hundred genes in which only one of the parental copies is active. This phenomenon is called "genomic imprinting" and occurs primarily in mammals. The gene Peg13 (paternally expressed gene 13) is active only on the paternal chromosome and has a key role in the regulation of brain development. Animals carrying a mutation of this gene prefer same-sex mates, show higher levels of anxiety, decreased activity and curiosity, and a lack of maternal care.
Peg13 is required for the regulation of genes with basic synapse and receptor functions, as well as for the regulation of a number of other genes that show genomic imprinting and control of behavioral responses. When Peg13 is absent, the differences between male and female brains become greater, meaning the normal role of the gene is to make the brains of the sexes more similar to each other. Peg13 is expressed only as RNA and does not code for a protein. The gene sequence evolves very rapidly in evolutionary terms and it is therefore possible that it is also involved in speciation processes via the control of mate preference.