Dynamics of the two heterochromatin types during imprinted X chromosome inactivation in vole Microtus levis

PLoS One. 2014 Feb 4;9(2):e88256. doi: 10.1371/journal.pone.0088256. eCollection 2014.

Abstract

In rodent female mammals, there are two forms of X-inactivation - imprinted and random which take place in extraembryonic and embryonic tissues, respectively. The inactive X-chromosome during random X-inactivation was shown to contain two types of facultative heterochromatin that alternate and do not overlap. However, chromatin structure of the inactive X-chromosome during imprinted X-inactivation, especially at early stages, is still not well understood. In this work, we studied chromatin modifications associated with the inactive X-chromosome at different stages of imprinted X-inactivation in a rodent, Microtus levis. It has been found that imprinted X-inactivation in vole occurs in a species-specific manner in two steps. The inactive X-chromosome at early stages of imprinted X-inactivation is characterized by accumulation of H3K9me3, HP1, H4K20me3, and uH2A, resembling to some extent the pattern of repressive chromatin modifications of meiotic sex chromatin. Later, the inactive X-chromosome recruits trimethylated H3K27 and acquires the two types of heterochromatin associated with random X-inactivation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Arvicolinae / genetics*
  • Embryonic Development / genetics
  • Female
  • Genomic Imprinting / genetics*
  • Heterochromatin / genetics*
  • Histones / genetics
  • Histones / metabolism
  • Meiosis / genetics
  • Sex Chromatin / genetics
  • Stem Cells / metabolism
  • Trophoblasts / metabolism
  • X Chromosome / genetics*
  • X Chromosome Inactivation / genetics*
  • Y Chromosome / genetics

Substances

  • Heterochromatin
  • Histones

Grants and funding

This work was supported by the Russian Foundation for Basic Research (grants no.12-04-31704, 11-04-00799), The Ministry of Education and Science of Russian Federation, project 8264, and The Program of Russian Academy of Sciences, Molecular and Cellular Biology (http://www.rfbr.ru/rffi/ru/) (https://kias.rfbr.ru/) (http://www.fcpk.ru/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.