Global, comparative analysis of tissue-specific promoter CpG methylation

Genomics. 2007 Sep;90(3):314-23. doi: 10.1016/j.ygeno.2007.04.011. Epub 2007 Jun 20.

Abstract

Understanding cell-type-specific epigenetic codes on a global level is a major challenge after the sequencing of the human genome has been completed. Here we applied methyl-CpG immunoprecipitation (MCIp) to obtain comparative methylation profiles of coding and noncoding genes in three human tissues, testis, brain, and monocytes. Forty-four mainly testis-specific promoters were independently validated using bisulfite sequencing or single-gene MCIp, confirming the results obtained by the MCIp microarray approach. We demonstrate the previously unknown somatic hypermethylation at many CpG-rich, testis-specific gene promoters, in particular in ampliconic areas of the Y chromosome. We also identify a number of miRNA genes showing tissue-specific methylation patterns. The comparison of the obtained tissue methylation profiles with corresponding gene expression data indicates a significant association between tissue-specific promoter methylation and gene expression, not only in CpG-rich promoters. In summary, our study highlights the exceptional epigenetic status of germ-line cells in testis and provides a global insight into tissue-specific DNA methylation patterns.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Brain / metabolism
  • CpG Islands*
  • DNA Methylation*
  • Epigenesis, Genetic*
  • Genome, Human*
  • Humans
  • Immunoprecipitation
  • Male
  • MicroRNAs / metabolism
  • Models, Genetic
  • Monocytes / metabolism
  • Oligonucleotide Array Sequence Analysis / methods*
  • Promoter Regions, Genetic
  • Reproducibility of Results
  • Testis / metabolism

Substances

  • MicroRNAs

Associated data

  • GEO/GSE5548