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Mitochondrial heteroplasmy in vertebrates using ChIP-sequencing data.

Published version
Peer-reviewed

Type

Article

Change log

Authors

Rensch, Thomas 
Villar, Diego 
Horvath, Julie 
Odom, Duncan T 
Flicek, Paul 

Abstract

BACKGROUND: Mitochondrial heteroplasmy, the presence of more than one mitochondrial DNA (mtDNA) variant in a cell or individual, is not as uncommon as previously thought. It is mostly due to the high mutation rate of the mtDNA and limited repair mechanisms present in the mitochondrion. Motivated by mitochondrial diseases, much focus has been placed into studying this phenomenon in human samples and in medical contexts. To place these results in an evolutionary context and to explore general principles of heteroplasmy, we describe an integrated cross-species evaluation of heteroplasmy in mammals that exploits previously reported NGS data. Focusing on ChIP-seq experiments, we developed a novel approach to detect heteroplasmy from the concomitant mitochondrial DNA fraction sequenced in these experiments. RESULTS: We first demonstrate that the sequencing coverage of mtDNA in ChIP-seq experiments is sufficient for heteroplasmy detection. We then describe a novel detection method for accurate detection of heteroplasmies, which also accounts for the error rate of NGS technology. Applying this method to 79 individuals from 16 species resulted in 107 heteroplasmic positions present in a total of 45 individuals. Further analysis revealed that the majority of detected heteroplasmies occur in intergenic regions. CONCLUSION: In addition to documenting the prevalence of mtDNA in ChIP-seq data, the results of our mitochondrial heteroplasmy detection method suggest that mitochondrial heteroplasmies identified across vertebrates share similar characteristics as found for human heteroplasmies. Although largely consistent with previous studies in individual vertebrates, our integrated cross-species analysis provides valuable insights into the evolutionary dynamics of mitochondrial heteroplasmy.

Description

Keywords

Chromatin immunoprecipitation sequencing (ChIP-seq), Heteroplasmy, Mitochondrion, Vertebrates, mitochondrial DNA (mtDNA), Animals, Chromatin Immunoprecipitation, DNA, Mitochondrial, Evolution, Molecular, High-Throughput Nucleotide Sequencing, Humans, Mitochondria, Mitochondrial Diseases, Sequence Analysis, DNA, Vertebrates

Journal Title

Genome Biol

Conference Name

Journal ISSN

1474-7596
1474-760X

Volume Title

17

Publisher

Springer Science and Business Media LLC
Sponsorship
Cancer Research UK (20412)