title: DNA methylation in xeroderma pigmentosum.
abstract: DNA methylation was examined in xeroderma pigmentosum (XP) cells. The amount of 5-methylcytosine (mC) in DNA from XP cells was about 70% of that in DNA from normal controls. Southern hybridization analysis showed that the HLA-DR alpha gene in XP lymphocyte B cells was differently methylated from normals, but its expression was apparently unaffected. The methylation of dihydrofolate reductase, a housekeeping gene, was the same as in controls. The revertants to UV resistance from XP fibroblasts recovered a methylation level close to that of normal cells. Results suggested that XP DNA was undermethylated non-randomly, and that DNA methylation might be associated with DNA repair function.
authors.affiliation: Laboratory of Molecular Genetics, Biotechnology Institute, Akita Prefectural College of Agriculture, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Sano
authors.forename: N
authors.initials: N
authors.lastname: Shiomi
authors.forename: K
authors.initials: K
authors.lastname: Imanishi
authors.forename: O
authors.initials: O
authors.lastname: Maie
authors.forename: T
authors.initials: T
authors.lastname: Shiomi
mesh_terms: D044503:5-Methylcytosine; D002460:Cell Line; D003596:Cytosine / Q000031:analogs & derivatives* / Q000378:metabolism; D004247:DNA / Q000378:metabolism*; D004260:DNA Repair; D006684:HLA-DR Antigens / Q000235:genetics; D006801:Humans; D008745:Methylation; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics; D014983:Xeroderma Pigmentosum / Q000235:genetics*
chemical_list: D006684:HLA-DR Antigens; D044503:5-Methylcytosine; D003596:Cytosine; D004247:DNA; D013762:Tetrahydrofolate Dehydrogenase