NucTools: analysis of chromatin feature occupancy profiles from high-throughput sequencing data

BMC Genomics

Software

Yevhen Vainshtein¹  Karsten Rippe²  Vladimir B. Teif³ 

[1] Functional Genomics Group, Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, Nobelstraße 12, 70569, Stuttgart, Germany;Research Group Genome Organization & Function, German Cancer Research Center (DKFZ) and Bioquant, Im Neuenheimer Feld 280, 69120, Heidelberg, Germany;School of Biological Sciences, University of Essex, Wivenhoe Park, CO4 3SQ, Colchester, UK;

关键词: MNase-seq;    ChIP-seq;    Nucleosome positioning;    Chromatin;    Next-generation sequencing (NGS);   

DOI  :  10.1186/s12864-017-3580-2

 received in 2016-07-26, accepted in 2017-02-10,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundBiomedical applications of high-throughput sequencing methods generate a vast amount of data in which numerous chromatin features are mapped along the genome. The results are frequently analysed by creating binary data sets that link the presence/absence of a given feature to specific genomic loci. However, the nucleosome occupancy or chromatin accessibility landscape is essentially continuous. It is currently a challenge in the field to cope with continuous distributions of deep sequencing chromatin readouts and to integrate the different types of discrete chromatin features to reveal linkages between them.ResultsHere we introduce the NucTools suite of Perl scripts as well as MATLAB- and R-based visualization programs for a nucleosome-centred downstream analysis of deep sequencing data. NucTools accounts for the continuous distribution of nucleosome occupancy. It allows calculations of nucleosome occupancy profiles averaged over several replicates, comparisons of nucleosome occupancy landscapes between different experimental conditions, and the estimation of the changes of integral chromatin properties such as the nucleosome repeat length. Furthermore, NucTools facilitates the annotation of nucleosome occupancy with other chromatin features like binding of transcription factors or architectural proteins, and epigenetic marks like histone modifications or DNA methylation. The applications of NucTools are demonstrated for the comparison of several datasets for nucleosome occupancy in mouse embryonic stem cells (ESCs) and mouse embryonic fibroblasts (MEFs).ConclusionsThe typical workflows of data processing and integrative analysis with NucTools reveal information on the interplay of nucleosome positioning with other features such as for example binding of a transcription factor CTCF, regions with stable and unstable nucleosomes, and domains of large organized chromatin K9me2 modifications (LOCKs). As potential limitations and problems we discuss how inter-replicate variability of MNase-seq experiments can be addressed.

【 授权许可】

CC BY   
© The Author(s). 2017