title: Enrichment of short interspersed transposable elements to embryonic stem cell-specific hypomethylated gene regions.
abstract: Embryonic stem cells (ESCs) have a distinctive epigenome, which includes their genome-wide DNA methylation modification status, as represented by the ESC-specific hypomethylation of tissue-dependent and differentially methylated regions (T-DMRs) of Pou5f1 and Nanog. Here, we conducted a genome-wide investigation of sequence characteristics associated with T-DMRs that were differentially methylated between ESCs and somatic cells, by focusing on transposable elements including short interspersed elements (SINEs), long interspersed elements (LINEs) and long terminal repeats (LTRs). We found that hypomethylated T-DMRs were predominantly present in SINE-rich/LINE-poor genomic loci. The enrichment for SINEs spread over 300 kb in cis and there existed SINE-rich genomic domains spreading continuously over 1 Mb, which contained multiple hypomethylated T-DMRs. The characterization of sequence information showed that the enriched SINEs were relatively CpG rich and belonged to specific subfamilies. A subset of the enriched SINEs were hypomethylated T-DMRs in ESCs at Dppa3 gene locus, although SINEs are overall methylated in both ESCs and the liver. In conclusion, we propose that SINE enrichment is the genomic property of regions harboring hypomethylated T-DMRs in ESCs, which is a novel aspect of the ESC-specific epigenomic information.
authors.affiliation: Laboratory of Cellular Biochemistry, Department of Animal Resource Sciences/Veterinary Medical Sciences, The University of Tokyo, Tokyo 113-8657, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Muramoto
authors.forename: Shintaro
authors.initials: S
authors.lastname: Yagi
authors.forename: Keiji
authors.initials: K
authors.lastname: Hirabayashi
authors.forename: Shinya
authors.initials: S
authors.lastname: Sato
authors.forename: Jun
authors.initials: J
authors.lastname: Ohgane
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tanaka
authors.forename: Kunio
authors.initials: K
authors.lastname: Shiota
mesh_terms: D000818:Animals; D019175:DNA Methylation / Q000235:genetics*; D053595:Embryonic Stem Cells / Q000378:metabolism*; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D000071317:Nanog Homeobox Protein; D050814:Octamer Transcription Factor-3 / Q000235:genetics* / Q000378:metabolism; D020086:Short Interspersed Nucleotide Elements / Q000235:genetics*
chemical_list: D018398:Homeodomain Proteins; D000071317:Nanog Homeobox Protein; C475540:Nanog protein, mouse; D050814:Octamer Transcription Factor-3; C494174:Pou5f1 protein, mouse