Slagboom P E, de Leeuw W J, Vijg J
Department of Molecular Biology, TNO Institute for Experimental Gerontology, Rijswijk, The Netherlands.
Mech Ageing Dev. 1990 Apr 30;53(3):243-57. doi: 10.1016/0047-6374(90)90042-e.
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.
研究了6个月、24个月和36个月大的雌性近交系大鼠脾脏、肝脏和大脑中甘油醛-3-磷酸脱氢酶（GAPDH）和β-肌动蛋白基因的信使核糖核酸（mRNA）水平及甲基化模式。在脾脏中，这两个管家基因的mRNA水平在24个月至36个月之间显著增加。在大脑或肝脏中未观察到GAPDH或β-肌动蛋白mRNA表达的年龄相关变化。与用作内部对照的28S核糖体RNA水平相比，在所有年龄组中，这些基因的mRNA水平均存在相当大的组织间和个体间差异。在这方面，GAPDH mRNA水平的个体间差异与所研究的三种组织中β-肌动蛋白mRNA水平的差异相似。发现β-肌动蛋白的甲基化模式具有组织特异性，而GAPDH的甲基化模式在所有三种组织中均相同。在GAPDH甲基化模式中未观察到显著的年龄相关变化，而β-肌动蛋白在脾脏中与组织特异性相关的CpG位点似乎随着年龄的增长而轻微去甲基化。
