Imprinting, inactivation and the behavioural genetics of the X chromosome

Abstract

The X chromosome presents some unique features in the context of DNA modifications including methylation and histone deposition. In some ways, the patterns of epigenetic changes during the life cycle of the X chromosome resemble those affecting autosomal loci in parent-of-origin effects. Similarly, chromatin changes to the X chromosome of somatic cells may occur in response to the impact of external environmental factors. In addition to any imprinting, the X chromosome of placental mammals has the distinction of random inactivation in diploid females. The focus of this chapter is to examine what consequences these X-chromosomal modifications may have for human phenotypes and in particular that of behaviour. It is of particular interest in this context that, of the few loci escaping inactivation and expressed at higher levels in females, several are notable for their involvement in chromatin remodelling. © Springer-Verlag Berlin Heidelberg 2011.