The Most Redundant Sequences in Human CpG Island Library Are Derived from Mitochondrial Genome
10.1016/S1672-0229(10)60009-5
- Author:
He XIMIAO
1
,
2
;
Tao SHU
;
Jin JING
;
Hu SONGNIAN
;
Yu JUN
Author Information
1. CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100029, China
2. Graduate University of Chinese Academy of Sciences, Beijing 100049, China
- Keywords:
human;
DNA methylation;
CpG islands;
nuclear mitochondrial DNA;
molecular phylogeny
- From:
Genomics, Proteomics & Bioinformatics
2010;08(2):81-91
- CountryChina
- Language:Chinese
-
Abstract:
An altered pattern of epigenetic modifications, such as DNA methylation and histone modification, is critical to many common human diseases, including cancer. Recently, mitochondrial DNA (mtDNA) was reported to be associated with tumorigenesis through epigenetic regulation of methylation patterns. One of the promising approaches to study DNA methylation and CpG islands (CGIs) is sequencing and analysis of clones derived from the physical library generated by methyl-CpG-binding domain proteins and restriction enzyme MseI. In this study, we observed that the most redundant sequences of 349 clones in a human CGI library were all generated from the human mitochondrial genome. Further analysis indicated that there was a 5,845-bp DNA transfer from mtDNA to chromosome 1, and all the clones should be the products of a 510-hp MseI fragment, which contained a putative CGI of 270 bp. The 510-bp fragment was annotated as part of cytochrome c oxidase subunit Ⅱ (COXⅡ), and phylogenetic analysis of homologous sequences containing COXII showed three DNA transfer events from mtDNA to nuclear genome, one of which underwent secondary transfer events between different chromosomes. These results may further our understanding of how the mtDNA regulates DNA methylation in the nucleus.
