Evolutionary Genomics of Reproductive Modes in Pitvipers

Lazzeroni, Maggie mlazzeroni@amnh.org

Hayashim, Cheryl

Burbrink, Frank Department of Herpetology The American Museum of Natural History

New York, New York, USA

Squamates (snakes and lizards) are an ideal system for studying the evolution of reproductive modes because viviparity has arisen as many as 115 times in this group, twice the amount than in any other vertebrate group. Although the ecological conditions impacting viviparity has been widely studied, we know relatively little about the genomics and physiological changes underlying transitions in reproductive modes. Debate surrounds the evolutionary possibility of reversals back to oviparity. Evidence of alternative genetic mechanisms, for reproductive processes in taxa that are purported reversals, would serve as strong evidence that these species are true reversals. Pit vipers have oviparous and viviparous species peppered throughout their phylogeny, making them an excellent group to study. To elucidate the genomics underlying evolutionary transitions between reproductive modes, we identified 758 candidate genes involved with the evolution of reproductive modes. We then sequenced 8 whole genomes of pit vipers (one of which is a purported reversal) and compared them to 5 published pit vipers genomes and 9 outgroups representing 6 snake families. We located our candidate loci in each species using BLAST+ and performed gene family analyses using BedTools and IQTree. This information will serve as a foundation for further research on the evolution of viviparity and oviparity.