How Imprinted Genes Shape Nurturing Behaviours and Neural Circuits

Genomic imprinting is an epigenetic phenomenon that, in animals, is found only in placental mammals and, to a lesser extent, marsupials. Broadly, differential epigenetic marking of the genomes during gametogenesis leads to parent-of-origin specific silencing of imprinted genes, with some solely expressed from the maternally inherited allele, and others solely expressed from the paternally inherited allele. From an evolutionary perspective, genomic imprinting is fascinating, as it appears to negate the benefits of diploidy and yet correct expression of imprinted genes essential for normal development and function. Genomic imprinting influences a number of key mammalian physiologies, including brain and behaviour. Imprinted gene expression is particularly enriched in the hypothalamus and the wider defined parental care circuitry. We provide an overview of this here and detail the role imprinted genes play shaping nurturing and parental behaviours.