Rapid genome-scale mapping of chromatin accessibility in tissue

<p>Abstract</p> <p>Background</p> <p>The challenge in extracting genome-wide chromatin features from limiting clinical samples poses a significant hurdle in identification of regulatory marks that impact the physiological or pathological state. Current methods that iden...

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Main Authors: Grøntved Lars, Bandle Russell, John Sam, Baek Songjoon, Chung Hye-Jung, Liu Ying, Aguilera Greti, Oberholtzer Carl, Hager Gordon L, Levens David
Format: Article
Language:English
Published: BMC 2012-06-01
Series:Epigenetics & Chromatin
Subjects:
Online Access:http://www.epigeneticsandchromatin.com/content/5/1/10
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author Grøntved Lars
Bandle Russell
John Sam
Baek Songjoon
Chung Hye-Jung
Liu Ying
Aguilera Greti
Oberholtzer Carl
Hager Gordon L
Levens David
author_facet Grøntved Lars
Bandle Russell
John Sam
Baek Songjoon
Chung Hye-Jung
Liu Ying
Aguilera Greti
Oberholtzer Carl
Hager Gordon L
Levens David
author_sort Grøntved Lars
collection DOAJ
description <p>Abstract</p> <p>Background</p> <p>The challenge in extracting genome-wide chromatin features from limiting clinical samples poses a significant hurdle in identification of regulatory marks that impact the physiological or pathological state. Current methods that identify nuclease accessible chromatin are reliant on large amounts of purified nuclei as starting material. This complicates analysis of trace clinical tissue samples that are often stored frozen. We have developed an alternative nuclease based procedure to bypass nuclear preparation to interrogate nuclease accessible regions in frozen tissue samples.</p> <p>Results</p> <p>Here we introduce a novel technique that specifically identifies Tissue Accessible Chromatin (TACh). The TACh method uses pulverized frozen tissue as starting material and employs one of the two robust endonucleases, Benzonase or Cyansase, which are fully active under a range of stringent conditions such as high levels of detergent and DTT. As a proof of principle we applied TACh to frozen mouse liver tissue. Combined with massive parallel sequencing TACh identifies accessible regions that are associated with euchromatic features and accessibility at transcriptional start sites correlates positively with levels of gene transcription. Accessible chromatin identified by TACh overlaps to a large extend with accessible chromatin identified by DNase I using nuclei purified from freshly isolated liver tissue as starting material. The similarities are most pronounced at highly accessible regions, whereas identification of less accessible regions tends to be more divergence between nucleases. Interestingly, we show that some of the differences between DNase I and Benzonase relate to their intrinsic sequence biases and accordingly accessibility of CpG islands is probed more efficiently using TACh.</p> <p>Conclusion</p> <p>The TACh methodology identifies accessible chromatin derived from frozen tissue samples. We propose that this simple, robust approach can be applied across a broad range of clinically relevant samples to allow demarcation of regulatory elements of considerable prognostic significance.</p>
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spelling doaj.art-ebbd8bf7908f4c11a6fc51b4e272ba082022-12-22T01:12:56ZengBMCEpigenetics & Chromatin1756-89352012-06-01511010.1186/1756-8935-5-10Rapid genome-scale mapping of chromatin accessibility in tissueGrøntved LarsBandle RussellJohn SamBaek SongjoonChung Hye-JungLiu YingAguilera GretiOberholtzer CarlHager Gordon LLevens David<p>Abstract</p> <p>Background</p> <p>The challenge in extracting genome-wide chromatin features from limiting clinical samples poses a significant hurdle in identification of regulatory marks that impact the physiological or pathological state. Current methods that identify nuclease accessible chromatin are reliant on large amounts of purified nuclei as starting material. This complicates analysis of trace clinical tissue samples that are often stored frozen. We have developed an alternative nuclease based procedure to bypass nuclear preparation to interrogate nuclease accessible regions in frozen tissue samples.</p> <p>Results</p> <p>Here we introduce a novel technique that specifically identifies Tissue Accessible Chromatin (TACh). The TACh method uses pulverized frozen tissue as starting material and employs one of the two robust endonucleases, Benzonase or Cyansase, which are fully active under a range of stringent conditions such as high levels of detergent and DTT. As a proof of principle we applied TACh to frozen mouse liver tissue. Combined with massive parallel sequencing TACh identifies accessible regions that are associated with euchromatic features and accessibility at transcriptional start sites correlates positively with levels of gene transcription. Accessible chromatin identified by TACh overlaps to a large extend with accessible chromatin identified by DNase I using nuclei purified from freshly isolated liver tissue as starting material. The similarities are most pronounced at highly accessible regions, whereas identification of less accessible regions tends to be more divergence between nucleases. Interestingly, we show that some of the differences between DNase I and Benzonase relate to their intrinsic sequence biases and accordingly accessibility of CpG islands is probed more efficiently using TACh.</p> <p>Conclusion</p> <p>The TACh methodology identifies accessible chromatin derived from frozen tissue samples. We propose that this simple, robust approach can be applied across a broad range of clinically relevant samples to allow demarcation of regulatory elements of considerable prognostic significance.</p>http://www.epigeneticsandchromatin.com/content/5/1/10Chromatin accessibilityTissueTAChBenzonaseCyanaseDNase I
spellingShingle Grøntved Lars
Bandle Russell
John Sam
Baek Songjoon
Chung Hye-Jung
Liu Ying
Aguilera Greti
Oberholtzer Carl
Hager Gordon L
Levens David
Rapid genome-scale mapping of chromatin accessibility in tissue
Epigenetics & Chromatin
Chromatin accessibility
Tissue
TACh
Benzonase
Cyanase
DNase I
title Rapid genome-scale mapping of chromatin accessibility in tissue
title_full Rapid genome-scale mapping of chromatin accessibility in tissue
title_fullStr Rapid genome-scale mapping of chromatin accessibility in tissue
title_full_unstemmed Rapid genome-scale mapping of chromatin accessibility in tissue
title_short Rapid genome-scale mapping of chromatin accessibility in tissue
title_sort rapid genome scale mapping of chromatin accessibility in tissue
topic Chromatin accessibility
Tissue
TACh
Benzonase
Cyanase
DNase I
url http://www.epigeneticsandchromatin.com/content/5/1/10
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