Phylogenomic analyses and divergence time estimation of Elateroidea (Coleoptera) based on RNA-Seq data.

Bioluminescence, the emission of visible light in a living organism, is an intriguing phenomenon observed in different species and environments. In terrestrial organisms, the bioluminescence is observed mainly in beetles of the Elateroidea superfamily (Coleoptera). Several phylogenetic studies have been used different strategies to propose a scenario for the origin and evolution of the bioluminescence within this group, however some of them showed incongruences, mainly about the relationship of the bioluminescent families. In order to increase the number of molecular markers available for Elateroidea species and to propose a more accurate phylogeny, with high supported topology, we employed the Next-Generation Sequencing (NGS) methodology to perform the RNA-Seq analysis of luminescent (Elateridae, Phengodidae, Rhagophthalmidae, and Lampyridae) and non-luminescent (Cantharidae) species of Neotropical beetles. We used the RNA-Seq data to construct a calibrated phylogeny of Elateroidea superfamily using a large number of nuclear molecular markers. The results indicate Lampyridae and Phengodidae/Rhagophthalmidae as sister-groups, suggesting that the bioluminescence evolved later in Elateridae than other families (Lampyridae, Phengodidae, and Rhagophthalmidae), and indicating the Upper Cretaceous as the period for the main diversification of Elateroidea bioluminescent species.