Sexual maturation in female mammals is controlled by specific changes to the chemical groups attached to DNA — a type of 'epigenetic' change — which results in the coordinated action of multiple genes.

Puberty begins with a rise in the secretion of gonadotropin-releasing hormone (GnRH) by a region of the brain called the hypothalamus, but the mechanism that coordinates the genes involved has been unclear. Alejandro Lomniczi and Sergio Ojeda at Oregon Health & Science University in Portland and their colleagues report that decreasing levels of a gene-silencing molecule called EED may control the process in rats. EED regulates the expression of a gene called Kiss1, which encodes a protein that helps to stimulate GnRH production. The addition of methyl groups to the regulatory region of the EED gene lowers EED expression just before the onset of puberty, resulting in a rise in Kiss1 activity and more frequent pulses of GnRH from the hypothalamus.

Nature Neurosci. (2013)