Genome-wide nucleosome positioning is orchestrated by genomic regions associated with DNase I hypersensitivity in rice

PLoS Genet. 2014 May 22;10(5):e1004378. doi: 10.1371/journal.pgen.1004378. eCollection 2014 May.

Abstract

Nucleosome positioning dictates the DNA accessibility for regulatory proteins, and thus is critical for gene expression and regulation. It has been well documented that only a subset of nucleosomes are reproducibly positioned in eukaryotic genomes. The most prominent example of phased nucleosomes is the context of genes, where phased nucleosomes flank the transcriptional starts sites (TSSs). It is unclear, however, what factors determine nucleosome positioning in regions that are not close to genes. We mapped both nucleosome positioning and DNase I hypersensitive site (DHS) datasets across the rice genome. We discovered that DHSs located in a variety of contexts, both genic and intergenic, were flanked by strongly phased nucleosome arrays. Phased nucleosomes were also found to flank DHSs in the human genome. Our results suggest the barrier model may represent a general feature of nucleosome organization in eukaryote genomes. Specifically, regions bound with regulatory proteins, including intergenic regions, can serve as barriers that organize phased nucleosome arrays on both sides. Our results also suggest that rice DHSs often span a single, phased nucleosome, similar to the H2A.Z-containing nucleosomes observed in DHSs in the human genome.

Publication types

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

MeSH terms

  • Binding Sites
  • Deoxyribonuclease I / metabolism*
  • Genome, Plant*
  • Nucleosomes / metabolism*
  • Oryza / genetics*
  • Promoter Regions, Genetic
  • Transcription, Genetic

Substances

  • Nucleosomes
  • Deoxyribonuclease I

Associated data

  • GEO/GSE53027

Grants and funding

This research was supported by grants DBI-0603927 and DBI-0923640 from the National Science Foundation. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.