Heterogeneous DNA methylation status of the regulatory element of the mouse Oct4 gene in adult somatic cell population.
The transcription factor Oct4 is specifically expressed in the germ line and pluripotent stem cells, and is indispensable for normal mouse development. To understand the epigenetic control of Oct4 expression, we examined the DNA methylation pattern of the Oct4 regulatory element in various types of cells. Bisulfite analysis showed that the regulatory element was unmethylated in P19 embryonal carcinoma cells, which robustly express Oct4. By contrast, the regulatory element was distinctly methylated in somatic cells, including cell lines, such as NIH3T3 embryonic fibroblast and Hepa1-6 hepatoma, as well as tissues from the adult body, such as liver, spleen, and cumulus cells. However, we found that the extent of methylation was considerably heterogeneous among the alleles in the adult somatic cells. Using a luciferase reporter construct, we demonstrated that the extent of methylation directly affects the efficiency of gene expression driven by the Oct4 regulatory element in P19 cells. These results raise the possibility that the epigenetic status of Oct4 is heterogeneous among a population of somatic cells, which may affect the efficiency of Oct4 reactivation after somatic cell nuclear transfer.
Marikawa
Yusuke
Y
Institute for Biogenesis Research, Department of Anatomy and Reproductive Biology, University of Hawaii School of Medicine, 1960 East-West Road, Honolulu, HI 96822, USA. marikawa@hawaii.edu
Fujita
Toko C
TC
Alarcón
Vernadeth B
VB
D000483:Alleles; D000818:Animals; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism; D003001:Cloning, Molecular / Q000379:methods*; D018899:CpG Islands; D019175:DNA Methylation; D004268:DNA-Binding Proteins / Q000235:genetics*; D005260:Female; D005347:Fibroblasts / Q000378:metabolism; D005809:Genes, Regulator; D017930:Genes, Reporter; D006801:Humans; D008156:Luciferases / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D008957:Models, Genetic; D041681:NIH 3T3 Cells; D050814:Octamer Transcription Factor-3; D010957:Plasmids / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013447:Sulfites / Q000494:pharmacology; D014018:Tissue Distribution; D014157:Transcription Factors / Q000235:genetics*
D004268:DNA-Binding Proteins; D050814:Octamer Transcription Factor-3; C494173:POU5F1 protein, human; C494174:Pou5f1 protein, mouse; D013447:Sulfites; D014157:Transcription Factors; D008156:Luciferases