Chromatin mechanisms in genomic imprinting

Mamm Genome. 2009 Sep-Oct;20(9-10):544-56. doi: 10.1007/s00335-009-9223-4. Epub 2009 Sep 17.

Abstract

Mammalian imprinted genes are clustered in chromosomal domains. Their mono-allelic, parent-of-origin-specific expression is regulated by imprinting control regions (ICRs), which are essential sequence elements marked by DNA methylation on one of the two parental alleles. These methylation "imprints" are established during gametogenesis and, after fertilization, are somatically maintained throughout development. Nonhistone proteins and histone modifications contribute to this epigenetic process. The way ICRs mediate imprinted gene expression differs between domains. At some domains, for instance, ICRs produce long noncoding RNAs that mediate chromatin silencing. Lysine methylation on histone H3 is involved in this developmental process and is particularly important for imprinting in the placenta and brain. Together, the newly discovered chromatin mechanisms provide further clues for addressing imprinting-related pathologies in humans.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Chromatin / genetics
  • Chromatin / metabolism*
  • DNA Methylation
  • Embryo, Mammalian
  • Gene Expression Regulation, Developmental*
  • Genomic Imprinting*
  • Histones / genetics
  • Histones / metabolism
  • Humans

Substances

  • Chromatin
  • Histones