title: Epigenetic marks by DNA methylation specific to stem, germ and somatic cells in mice.
abstract: BACKGROUND
  DNA methylation is involved in many gene functions such as gene-silencing, X-inactivation, imprinting and stability of the gene. We recently found that some CpG islands had a tissue-dependent and differentially methylated region (T-DMR) in normal tissues, raising the possibility that there may be more CpG islands capable of differential methylation.
  
  
  RESULTS
  We investigated the genome-wide DNA methylation pattern of CpG islands by restriction landmark genomic scanning (RLGS) in mouse stem cells (ES, EG and trophoblast stem) before and after differentiation, and sperm as well as somatic tissues. A total of 247 spots out of 1500 (16%) showed differences in the appearance of their RLGS profiles, indicating that CpG islands having T-DMR were numerous and widespread. The methylation pattern was specific, and varied in a precise manner according to cell lineage, tissue type and during cell differentiation.
  
  
  CONCLUSIONS
  Genomic loci with altered methylation status seem to be more common than has hitherto been realized. The formation of DNA methylation patterns at CpG islands is one of the epigenetic events which underlies the production of various cell types in the body. These findings should have implications for the use of embryonic stem cells and cells derived from them therapeutically, and also for the cloning of animals by the transfer of somatic cell nuclei.
authors.affiliation: Laboratory of Cellular Biochemistry, Animal Resource Sciences/Veterinary Medical Sciences, Graduate School of Agriculture and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan. ashiota@mail.ecc.u-tokyo.ac.jp
authors.forename: Kunio
authors.initials: K
authors.lastname: Shiota
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Kogo
authors.forename: Jun
authors.initials: J
authors.lastname: Ohgane
authors.forename: Takuya
authors.initials: T
authors.lastname: Imamura
authors.forename: Atsushi
authors.initials: A
authors.lastname: Urano
authors.forename: Koichiro
authors.initials: K
authors.lastname: Nishino
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tanaka
authors.forename: Naka
authors.initials: N
authors.lastname: Hattori
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D019070:Cell Lineage; D002478:Cells, Cultured; D018899:CpG Islands; D004247:DNA / Q000032:analysis; D019175:DNA Methylation; D005854:Germ Cells / Q000502:physiology*; D051379:Mice; D015183:Restriction Mapping / Q000379:methods; D013234:Stem Cells / Q000502:physiology*
chemical_list: D004247:DNA