Genomic signatures of globally enhanced gene duplicate accumulation in the megadiverse higher Diptera fueling intralocus sexual conflict resolution.

Gene duplication is an important source of evolutionary innovation. To explore the relative impact of gene duplication during the diversification of major insect model system lineages, we performed a comparative analysis of lineage-specific gene duplications in the fruit fly (Diptera: Brachycera), the mosquito ae (Diptera: Culicomorpha), the red flour beetle (Coleoptera), and the honeybee (Hymenoptera). Focusing on close to 6,000 insect core gene families containing maximally six paralogs, we detected a conspicuously higher number of lineage-specific duplications in (689) compared to (315), (386), and (223). Based on analyses of sequence divergence, phylogenetic distribution, and gene ontology information, we present evidence that an increased background rate of gene duplicate accumulation played an exceptional role during the diversification of the higher Diptera (Brachycera), in part by providing enriched opportunities for intralocus sexual conflict resolution, which may have boosted speciation rates during the early radiation of the megadiverse brachyceran subclade Schizophora.