DYNAMETS

Transposable elements (TEs) are DNA sequences that can replicate and move within genomes, often playing key evolutionary roles. While TEs make up most of the genome in higher organisms, the majority are inactive fossils, leaving only a small, mobile fraction known as the "mobilome." Despite its significance in TE evolution, this active fraction remains poorly understood. Specifically, we do not know what factors govern the number, type, transposition rate, and impact of active TEs—which is critical for understanding their variation across species. This project will leverage our detailed understanding of TE epigenetic control in the model plant Arabidopsis thaliana to study the mobilome and its genetic and epigenetic regulators. By deploying genome-wide association studies (GWAS) in large experimental populations, we will identify cis- and trans-factors involved in the natural variation of TE silencing and transposition and directly test their roles using genome-editing techniques. The variation of TE activity and impact of their insertions on gene activity will be further examined through transcriptomic approaches, including allele-specific expression. These findings will be integrated into a comprehensive population genetics model of mobilome evolution. This international collaboration unites experts in Arabidopsis genomics and population genetics (Magnus Nordborg, GMI, Vienna), transposons (Leandro Quadrana, IPS2, France), and epigenetics (Pierre Baduel, IBENS, France), providing an unprecedented opportunity to investigate natural variation in TE activity and impact. Together, DYNAMETS will offer a species-wide perspective on transposition diversity, with key implications for understanding the forces driving genome evolution and rapid adaptation, particularly in response to environmental changes.