Imprinted genes and mother-offspring interactions.

A subset of mammalian genes is subject to genomic imprinting. These imprinted genes show parent of origin specific monoallelic or parental allele-biased expression, such that for some genes, it is mainly the maternally inherited allele that is expressed, whereas for others, expression occurs mainly from the paternal copy. Evolutionary theory predicts that these genes will have a role in the mother-offspring interaction in mammals, and indeed many imprinted genes have a role in growth and placental function, and consequently influence prenatal development. In addition to the developing foetus, there is increasing evidence to suggest that imprinted genes influence the pre-weaning mother-offspring relationship, and consequently the development of the offspring into adulthood. In this review, we present an overview of the role imprinted genes play in the mother-offspring relationship using examples from the human and animal literature.