Meeting Abstract
Rove beetles comprise the largest family in Metazoa with nearly 64,000 species. The vast radiation of rove beetles can be attributed in part to their shortened elytra that enhanced abdomen flexibility, thereby allowing occupation of diverse and novel habitats. A second key innovation was the evolution of a defensive tergal gland in the largest subfamily Aleocharinae that can discharge volatiles through abdomen flexing to deter predators. The development of this gland has been proposed as a primary preadaptation for social insect symbiosis and many lineages have convergently evolved into highly social, symbiotic organisms through repeated changes in morphology, glandular chemistry and behavior to assimilate into the complex societies of ants and termites. In this study we investigate the evolutionary “ground state” of aleocharine beetles through genomic, transcriptomic and chemical profiling. We present the near chromosome-level genome assembly of Dalotia coriaria, a new genetic model system, and draft genome assemblies of 15 other species. Genomic scans for conservation of genes, gene families and genomic architecture in tergal gland development were assessed within the higher Aleocharinae and the convergently-derived defensive glands of Tribolium castaneum. Genes previously characterized to be specific to the gland tissue and volatile production in T. castaneum were compared with differential expression of control and gland tissue, targeted RNA interference and quantification of gland volatiles with GC/MS in D. coriaria. We highlight common molecular processes underlying the evolution of the defensive gland in beetles and those specific to the aleocharines that were key to their diversification.
