Epigenetic ageing in an insect

A large body of ageing research is based on simple invertebrate models, yet we do not have an insect model for the important epigenetic aspects of ageing. An epigenetic clock is a biochemical test based on measuring the accumulation of chemical marks (DNA methylation) to DNA molecules. There is evidence epigenetic age mirrors true biological age and its associated morbidity and mortality better than chronological age. However, epigenetic clocks’ utility as measures of changes in biological age is limited as their mechanistic basis is not understood .

Ageing is a complex process influenced by many environmental and genetic components. The effects of these components influence each other making them difficult to investigate, especially in complex mammalian models. Therefore, a large body of ageing research is based on simple model invertebrate organisms . Advantages include easy and cheap to keep in a laboratory, short life span, genetic and molecular tools available, and a sequenced genome. However, the current invertebrate models of ageing (Drosophila and C. elegans) do not possess detectable DNA methylation, reducing their utility in studying the epigenetics of ageing.

Nasonia vitripennis, an emerging model system has a functional methylation system making it ideal to investigate the epigenetics of ageing. We therefore measured chronological ageing and changes in the epigenome using whole genome bisulfite sequencing (WGBS) in order to discover if Nasonia vitripennis possessed an epigenetic clock. The epigenetic age of each replicate is based on the average of each genes’ methylation state. This epigenetic age does indeed correlate with chronological age. This is similar to results in many vertebrates. However, this is the first time an epigenetic clock has been discovered in a tractable insect model.

This project will use survivourship analysis, state of the art behavioural tracking, machine learning, RNAi and whole genome bisulfite sequencing to explore insect epigenetic clock will open up a new area in biogerontology delving into the molecular mechanisms of the malleability of the epigenetic clock.