High-Resolution Analysis of Parent-of-Origin Allelic Expression in the Mouse Brain

Abstract

Parental Influences Genomic imprinting results in the preferential expression of either the paternally or the maternally inherited allele of certain genes. Two papers by Gregg et al. (p. 643 , published online 8 July; and p. 682 , published online 8 July; see the Perspective by Wilkinson ) use a genome-wide approach to characterize the repertoire of genes with parent-of-origin allelic effects in the mouse embryonic and adult brain. The studies uncovered over 1300 loci with maternal or paternal allelic bias. Comparison of the parent-of-origin allelic expression bias in the adult hypothalamus and cortex, and in the developing brain, revealed spatiotemporal, sex-specific, and isoform-specific regulation. Parent-of-origin effects thus represent a major and dynamic mode of epigenetic regulation of gene expression in the brain.