Differential patterns of intronic and exonic DNA regions with respect to RNA polymerase II occupancy, nucleosome density and H3K36me3 marking in fission yeast.
Author(s)
Type
Journal Article
Abstract
BACKGROUND: The generation of mature mRNAs involves interconnected processes, including transcription by RNA polymerase II (Pol II), modification of histones, and processing of pre-mRNAs through capping, intron splicing, and polyadenylation. These processes are thought to be integrated, both spatially and temporally, but it is unclear how these connections manifest at a global level with respect to chromatin patterns and transcription kinetics. We sought to clarify the relationships between chromatin, transcription and splicing using multiple genome-wide approaches in fission yeast. RESULTS: To investigate these functional interdependencies, we determined Pol II occupancy across all genes using high-density tiling arrays. We also performed ChIP-chip on the same array platform to globally map histone H3 and its H3K36me3 modification, complemented by formaldehyde-assisted isolation of regulatory elements (FAIRE). Surprisingly, Pol II occupancy was higher in introns than in exons, and this difference was inversely correlated with gene expression levels at a global level. Moreover, introns showed distinct distributions of histone H3, H3K36me3 and FAIRE signals, similar to those at promoters and terminators. These distinct transcription and chromatin patterns of intronic regions were most pronounced in poorly expressed genes. CONCLUSIONS: Our findings suggest that Pol II accumulates at the 3' ends of introns, leading to substantial transcriptional delays in weakly transcribed genes. We propose that the global relationship between transcription, chromatin remodeling, and splicing may reflect differences in local nuclear environments, with highly expressed genes being associated with abundant processing factors that promote effective intron splicing and transcriptional elongation.
Date Issued
2011-08-22
Date Acceptance
2011-08-22
Citation
Genome Biology, 2011, 12, pp.R82-R82
ISSN
1474-760X
Publisher
BioMed Central
Start Page
R82
End Page
R82
Journal / Book Title
Genome Biology
Volume
12
Copyright Statement
© 2011 Wilhelm et al.; licensee BioMed Central Ltd.
This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
License URL
Identifier
PII: gb-2011-12-8-r82
Subjects
Chromatin
Chromatin Assembly and Disassembly
DNA, Fungal
Exons
Histones
Introns
Nucleosomes
Oligonucleotide Array Sequence Analysis
Polyadenylation
RNA Polymerase II
RNA Precursors
RNA Splicing
RNA, Messenger
Regulatory Sequences, Nucleic Acid
Schizosaccharomyces
Signal Transduction
Transcription, Genetic
Publication Status
Published
Article Number
r82