Transcriptional repression and DNA hypermethylation of a small set of ES cell marker genes in male germline stem cells

BMC Dev Biol. 2006 Jul 21;6:34. doi: 10.1186/1471-213X-6-34.


Background: We previously identified a set of genes called ECATs (ES cell-associated transcripts) that are expressed at high levels in mouse ES cells. Here, we examine the expression and DNA methylation of ECATs in somatic cells and germ cells.

Results: In all ECATs examined, the promoter region had low methylation levels in ES cells, but higher levels in somatic cells. In contrast, in spite of their lack of pluripotency, male germline stem (GS) cells expressed most ECATs and exhibited hypomethylation of ECAT promoter regions. We observed a similar hypomethylation of ECAT loci in adult testis and isolated sperm. Some ECATs were even less methylated in male germ cells than in ES cells. However, a few ECATs were not expressed in GS cells, and most of them targets of Oct3/4 and Sox2. The Octamer/Sox regulatory elements were hypermethylated in these genes. In addition, we found that GS cells express little Sox2 protein and low Oct3/4 protein despite abundant expression of their transcripts.

Conclusion: Our results suggest that DNA hypermethylation and transcriptional repression of a small set of ECATs, together with post-transcriptional repression of Oct3/4 and Sox2, contribute to the loss of pluripotency in male germ cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cells, Cultured
  • Chromatin Immunoprecipitation
  • Chromosomes, Mammalian / genetics
  • DNA / genetics
  • DNA / metabolism
  • DNA Methylation*
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • Fibroblast Growth Factor 4 / genetics
  • Fibroblast Growth Factor 4 / metabolism
  • Gene Expression Regulation, Developmental / genetics
  • Genetic Markers / genetics*
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / metabolism
  • Male
  • Mice
  • Nanog Homeobox Protein
  • Octamer Transcription Factor-3 / genetics
  • Octamer Transcription Factor-3 / metabolism
  • Organic Cation Transport Proteins / genetics
  • Organic Cation Transport Proteins / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction / methods
  • SOXB1 Transcription Factors
  • Spermatozoa / cytology
  • Spermatozoa / metabolism*
  • Stem Cells / cytology
  • Stem Cells / metabolism*
  • Trans-Activators / genetics
  • Trans-Activators / metabolism
  • Transcription, Genetic / genetics*


  • DNA-Binding Proteins
  • Fgf4 protein, mouse
  • Fibroblast Growth Factor 4
  • Genetic Markers
  • Homeodomain Proteins
  • Nanog Homeobox Protein
  • Nanog protein, mouse
  • Octamer Transcription Factor-3
  • Organic Cation Transport Proteins
  • Pou5f1 protein, mouse
  • SOXB1 Transcription Factors
  • Sox2 protein, mouse
  • Trans-Activators
  • solute carrier family 22 (organic cation transporter), member 3
  • DNA