Genomic 5-methyldeoxycytidine decreases with age.
Significant losses of DNA 5-methyldeoxycytidine residues in old age could disrupt cellular gene expression and contribute to the physiological decline of the animal. Thus, the 5-methyldeoxycytidine content of DNAs, isolated from the tissues of two rodent species of various ages, were determined. Mus musculus lost DNA methylation sites at a rate of about 4.7 X 10(4) (approximately 0.012% of the newborn level)/month. Peromyscus leucopus lost DNA 5-methyldeoxycytidine residues at a rate of only 2.3 X 10(4) (approximately 0.006% of the newborn level)/month. Since P. leucopus generally live twice as long as M. musculus, the rate of loss of DNA 5-methyldeoxycytidine residues appears to be inversely related to life span. Similar losses in genomic 5-methyldeoxycytidine content were also observed to correlate with donor age in cultured normal human bronchial epithelial cells.
D000375:Aging; D000818:Animals; D001923:Brain Chemistry; D004247:DNA / Q000032:analysis*; D003841:Deoxycytidine / Q000031:analogs & derivatives* / Q000032:analysis; D006801:Humans; D007413:Intestinal Mucosa / Q000032:analysis; D007421:Intestine, Small / Q000032:analysis; D008099:Liver / Q000032:analysis; D008297:Male; D008745:Methylation; D051379:Mice; D008810:Mice, Inbred C57BL; D010542:Peromyscus
D003841:Deoxycytidine; D004247:DNA; C016569:5-methyldeoxycytidine