Epigenetic Regulation of the GnRH and Kiss1 Genes

This chapter focuses on epigenetic regulation of the GnRH and Kiss1 genes in the context of neuronal development, puberty onset, and reproductive function. Diverse epigenetic phenomena including the formation of chromatin loops, activation of bivalent domains, maintenance of “stable” histone modifications, and DNA methylation, active demethylation, and hydroxymethylation dynamics are covered. When possible, particular effort is made to focus on how these phenomena may be related to each other and which enzymes or binding factors are involved in these processes. In highlighting similar epigenetic mechanisms between these distinct peptidergic neuronal populations, we hope to impress upon the reader the potential relationships between those mechanisms and the development of hypothalamic peptidergic neurons in general. While this chapter does not cover relationships between peptidergic systems and psychiatric conditions, it does cover epigenetic mechanisms related to puberty. Because puberty represents a developmental period when neuropsychiatric diseases commonly present, understanding the epigenetic processes operating in the hypothalamus during that window could be instrumental to deciphering the onset, exacerbation, or resolution of neuropsychiatric diseases.