Stability of DNA methylation of X-chromosome genes during aging.
The stability of DNA methylation during aging was assessed in two groups of young (5-20 years old) and old (85-95 years old) women in DNA from blood leukocytes. Three X-linked genes were investigated. Two, G6PD and GdX, are located on Xq28, on the inactivated portion of the X chromosome: demethylation of specific regions of both genes was shown previously to be directly correlated with gene reactivation. The third, MIC2, is located on the pseudoautosomal region of the X chromosome and escapes X inactivation. The 5' region of the G6PD and GdX genes and the body of the G6PD, GDX, and MIC2 genes were analyzed with specific DNA probes. No age-related changes in methylation pattern were detected. We can conclude therefore that the methylation pattern of the three X-linked genes is stable during aging in female leukocytes and that a high rate of age-related reactivation of X-linked genes may not be a feature of all X-linked loci.
Fondazione Rivetti, Laboratorio di Biochimica e Biologia Molecolare, Milan, Italy.
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Pagani
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Toniolo
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Vergani
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000235:genetics*; D015139:Blotting, Southern; D002237:Carbohydrate Dehydrogenases / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D004247:DNA / Q000378:metabolism*; D015245:Deoxyribonuclease BamHI; D019003:Deoxyribonuclease HpaII; D015252:Deoxyribonucleases, Type II Site-Specific; D005260:Female; D005786:Gene Expression Regulation / Q000235:genetics; D005948:Glucose Dehydrogenases / Q000235:genetics*; D006801:Humans; D008297:Male; D008745:Methylation; D014960:X Chromosome / Q000378:metabolism*
D004247:DNA; D002237:Carbohydrate Dehydrogenases; D005948:Glucose Dehydrogenases; D015245:Deoxyribonuclease BamHI; D019003:Deoxyribonuclease HpaII; C024388:CTGCAG-specific type II deoxyribonucleases; D015252:Deoxyribonucleases, Type II Site-Specific