The genomic landscape and the evolution of New World pitvipers

Parkinson, Chris

Department of Biological Sciences

Clemson University

Clemson, South Carolina USA

The family Viperidae consists of three subfamilies, Viperinae, Azemiopinae, and Crotalinae, with the highest species diversity being in the Crotalinae. We have sequenced and assembled the genomes of representative species from all three subfamilies, including Echis carinatus, Azemiops feae, and multiple New World pitviper species. With these data, we are investigating the evolutionary history and biogeography of this family with a specific focus on New World pitvipers. Combining our newly sequenced genomes with previously published genomes, we aim to improve our understanding of chromosomal and venom gene family evolution. With these data, we find that most of the venom genes are found on microchromosomes, in contrast with Elapidae, and that substantial structural evolution has occurred across relatively short timescales. To further address evolutionary and biogeographic questions, we use a multi-omic approach combining multiple data types to infer one of the first phylogenomic inferences of this family. Using this phylogeny, we infer diversification rates and test models of biogeographic history. We reveal several novel, well-supported relationships within vipers which helps clarify taxonomy as well as a rapid speciation rate upon invasion of the New World. Together, we demonstrate the utility of the next-generation sequencing era in improving our understanding of genome biology, phylogenetics, systematics, and venom evolution within Viperidae.