A comparative analysis of transposable element diversity and evolution across 75 bee genomes

Transposable elements (TEs) are repetitive DNA sequences that can alter their position and abundance within genomes. While TEs are known to have various impacts on genome structure and function, our understanding of how their evolution has shaped genome diversity across the Tree of Life remains limited. Here, we characterize TE dynamics across high-quality genome assemblies of 75 bee species to quantify their diversity in an evolutionary context. We find that bees show a striking amount of variation in repetitive element diversity and abundance, comprising between 10.3% to 80.4% of their entire genomes. We determine this variation is largely responsible for genome size differences, and lineages have unique signatures of TE accumulation with many genomes containing putatively functional TE copies. Additionally, we find a reduction of TE content to be associated with species that produce multiple generations per year. Our study provides the most comprehensive analysis of TE evolution across bees to date, allowing deep insight into genome evolution of the most species rich lineage of pollinating insects.