Diverse mobilome of Dichotomius (Luederwaldtinia) schiffleri (Coleoptera: Scarabaeidae) reveals long range horizontal transfer events of DNA transposons

Transposable elements (TEs) are mobile DNA sequences that are able to move from one genomic location to another. These selfish elements are known as genomic parasites, since they hijack the host molecular machinery to generate new copies of themselves. The mobilization of TEs can be seem as a natural mutagen because new TE copies can insert into different loci and impact host genomic structure through different mechanisms. Although our knowledge about TEs is improving with new genomes available, there is still very limited data about the mobilome of species from the Coleoptera order, the most specious order of insects, including species from the Scarabeidae family. Therefore, the main goal of this study was to characterize the mobilome of D. (Luederwaldtinia) schiffleri, based on low coverage genome sequencing, and reconstruct their evolutionary history. We used a combination of four different approaches for TEs characterization and maximum likelihood phylogenetic analysis to study their evolution. We found a large and diverse mobilome composed of 43 TE superfamilies, 22 DNA transposon and 21 Retrotransposons, accounting for 21% of the genome. Moreover, we found a number of incongruence between the TE and host phylogenetic trees in three DNA transposon TE superfamilies, which represents 5 TE families, suggesting possible horizontal transfer events between highly divergent taxa. In summary, we found an abundant and diverse mobilome and a number of horizontal transfer events that has shaped the evolutionary history of this species.