Ageing, Drosophila melanogaster and Epigenetics

Ageing is, needless to say, a highly complex phenomenon involving many distinguishable players and different types of age-related epigenetic alterations can be detected depending on genomic domains, cells, tissues or organs examined. [...]effects of a particular type of epigenetic modification on ageing process should be vigilantly evaluated. [...]a number of CpG dinucleotides (cytosine nucleotide is followed by a guanine nucleotide in 5'-3' direction) in CpG islands showed a reproducible increase in DNA methylation observed in aged mice and humans (6) and these DNA methylation changes can be used as epigenetic 'age predictors' or 'ageing clocks' (7). [...]both increase and/or reduction of DNA methylation may be correlated with ageing. Recent work in Caenorhabditis elegans (C. elegans) suggested the presence of a putative 6mA DNA methyltransferase (DAMT-1) which is believed to be responsible for 6mA modifications. A study in mice revealed de novo oscillating genes under CR display an enrichment of nicotinamide adenine dinucleotide (NAD)-dependent deacetylase sirtuin-1 (SIRT1) in the liver, followed by noticeable circadian hepatic signatures in NAD+related metabolites and also global protein acetylation (27).