A DNA Methylation Marker of Age in Mitochondrial DNA

In this study, we present a novel, reliable, PCR-based (i.e., sequence-specific) 6mA detection method that is free of technological artifacts and show in several genetic models that relative 6mA levels at different mtDNA sites (these levels actually show that how many percent of the individual mitochondrial genomes present in a given tissue sample are methylated at a selected adenine nucleobase) are significantly related to the age of the organism. Thus, N6-adenine methylation is an inherent process in the organization of mitochondrial genomes too. These results suggest that the widely observed age-related decline in mitochondrial function is strongly associated with changing 6mA levels and that biological age can be accurately determined from 6mA levels at certain mtDNA sites in a reliable, fast and cost-effective way. Furthermore, we reveal the enzymatic pathways of the mtDNA N6-adenine methylation and demethylation processes in C. elegans and Drosophila, showing the involvement of DNA N6-adenine methyltransferases and N6-methyladenine demethylases mediating 6mA metabolism in the nuclear genome. Together, these results suggest a fundamental role for mtDNA N6-adenine methylation in aging and reveal an efficient diagnostic technique to determine age using DNA.
Source: Fight Aging! - Category: Research Authors: Tags: Medicine, Biotech, Research Source Type: blogs