Project Highlights: Why individuals and species age so differently is an unanswered question in evolutionary biology. Diapause is an example of senescence plasticity, where the same genetics produces different ageing patterns in an organism. Using next-gen sequencing the project will measure DNA methylation across the genome of Nasonia and build the first insect epigenetic clock. Overview: This project will help understand why organisms age differently by establishing the effect of early life environments on epigenetic ageing in the model insect, Nasonia vitripennis. How individuals and species age so differently is one of the major unanswered questions in evolutionary biology with early life environments being a major predictor of lifespan. Ageing is a mechanistically complex process influenced by many environmental and genetic com- ponents. 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 inexpensive to keep in a laboratory, short life span, genetic and molecular tools available, and a sequenced genome. However, current invertebrate ageing models (Drosophila and C. elegans) do not possess certain chemical marks (DNA methylation), an important part of how most organisms age. An epigenetic clock is a biochemical test based on measuring the accumulation of this DNA methylation. There is evidence that epigenetic clocks mirror true biological age and its associated morbidity and mortality better than chronological age in many species including us. The jewel wasp, Nasonia vitripennis, an emerging model, has a functional methylation system, making it an ideal species to investigate the epigenetics of ageing. We have established an epige- netic clock in this species. Early life effects on ageing have pervasive influence on the ecology and evolution of a range of species from fish to birds to humans. It would be useful to study a dramatic example, where a distinct early life environment lead to a dramatic switch in ageing strategy, a so-called senescence plasticity. An example of this is larval diapause in Nasonia where if the mother experiences autumn-like conditions, her larval offspring become dorminant over winter and then as adults live much longer than adult Nasonia who haven't overwintered. Methodology: This project combines whole genome bisulfite sequencing of Nasonia, machine learning, RNAi knockdowns of methylation enzymes and high-throughput behavioural analysis, to analyse chrono- logical and epigenetic ageing in diapaused and non-diapaused Nasonia.