Genomic Imprinting in the Adult and Developing Brain

Abstract

Genomic imprinting results in the preferential expression of the paternally or maternally inherited allele of certain genes. Although originally studied in the context of early embryonic development, imprinted genes are also highly expressed in the adult and developing brain and have been implicated in key steps of brain development, cortical plasticity, and social and motivated behavior. Furthermore, defects in imprinted loci have been associated with various mental illnesses, including autism, psychosis, and mental retardation, generating an enormous interest in this mode of epigenetic regulation. We recently developed a genome-wide experimental strategy that led to the identification of over 1,000 new imprinted loci and large numbers of imprinted clusters in the adult and developing brain. Strikingly, the repertoires of imprinted genes in the developing brain and adult male and female cortex differ, suggesting a complex regulation of imprinting that has direct implications for the understanding of male and female brain development and function, and of impairment leading to mental illnesses.