Developmental- and tissue-specific DNA methylation patterns and expression of rat gamma-glutamyltransferase

In order to investigate the mechanism controlling gamma-glutamyltransferase (GGT) gene expression in adult and fetal rat tissues, as well as in H5-6 and Fao hepatoma cells, the relationship between DNA methylation and GGT expression was studied. Southern blot analysis of genomic DNA digested with MspI and HpaII showed that highly methylated DNA patterns observed especially in adult liver, heart and Fao cells as well as in fetal kidney, pancreas, lung and heart correlate well with low GGT activity determined in these tissues. In contrast, hypomethylated GGT DNA was found in fetal liver, adult kidney and lung, the tissues highly expressing GGT activity. So, observed developmental- and tissue-specific changes in the GGT gene methylation seem to play an important role in the control of GGT gene transcription.