Messenger RNA levels and methylation patterns of GAPDH and beta-actin genes in rat liver, spleen and brain in relation to aging.
Messenger RNA levels and methylation patterns of the glyceraldehyde-3-phosphate-dehydrogenase (GAPDH) and beta-actin genes were studied in spleen, liver and brain of 6-, 24- and 36-month old female inbred rats. In the spleen, the mRNA levels of both housekeeping genes significantly increased between 24 and 36 months. No age-related alterations in the expression of GAPDH or beta-actin mRNA were observed in brain or liver. A considerable intertissue and interindividual variation was observed in the mRNA levels of these genes in all age-groups as compared to the level of 28 S rRNA, which was used as an internal control. In this respect the interindividual variation in the level of GAPDH mRNA paralleled the variation observed in the beta-actin mRNA level in the three tissues studied. The methylation pattern of beta-actin was found to be tissue-specific in contrast to that of GAPDH, which was identical in all three tissues. No significant age-related alterations were observed in the GAPDH methylation pattern, whereas beta-actin appeared to become slightly demethylated with age in the spleen at the CpG site for which tissue-specificity was observed.
Slagboom
P E
PE
Department of Molecular Biology, TNO Institute for Experimental Gerontology, Rijswijk, The Netherlands.
de Leeuw
W J
WJ
Vijg
J
J
D000199:Actins / Q000235:genetics*; D000375:Aging / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000378:metabolism*; D004247:DNA / Q000235:genetics; D015342:DNA Probes; D005260:Female; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000235:genetics*; D015151:Immunoblotting; D008099:Liver / Q000378:metabolism*; D008745:Methylation; D009928:Organ Specificity / Q000502:physiology; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013154:Spleen / Q000378:metabolism*
D000199:Actins; D015342:DNA Probes; D012333:RNA, Messenger; D004247:DNA; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases