6 - Imprinted genes and placental growth

Summary

Imprinted genes are regulated by parent-of-origin-specific epigenetic marks, notably DNA methylation, leading to monoallelic expression of these genes in the offspring. All of these genes are conserved in mice and humans, although there are a few differences in imprinting status in the two species, with a slightly greater number of genes imprinted in mice than in humans. Given the frequent function as growth rheostats, imprinted genes are interesting candidates for a role in intrauterine growth restriction (IUGR). IUGR is a common medical condition that often leads to expensive neonatal hospitalization and predisposes to serious postnatal complications. Owing to their action in the placenta, there are a number of genetic models involving imprinted genes that already seem promising for investigating DOHAD. Very few genes are expressed only in the placenta, and even some legendary placenta specific genes are, in fact, expressed in the adult animal, an example being Ascl2.