GENOMIC IMPRINTING - CONTROL OF GENE-EXPRESSION BY EPIGENETIC INHERITANCE

One parental copy of an imprinted gene is invariably expressed during development. The characteristic of the heritable epigenetic germline i mprint remains elusive, but recent evidence stresses the necessity for additional post-zygotic epigenetic modifications to account for this temporal and tissue-specific mono-allelic expression. Preliminary insi ght into a diversity of post-zygotic control mechanisms is beginning t o emerge.