The genomics of venom ontogeny in rattlesnakes

Rokyta, Darin R.

Florida State University

Department of Biological Science

Tallahassee, Florida USA

The major axis of venom variation in many pitviper species is related to animal age; adults and juveniles often show divergent expression patterns that result in compositionally and functional different venoms. We will first explore general patterns of venom variation in pitvipers native to the eastern United States and see that, although variation is the norm, the presence and extent of ontogenetic variation is highly variable among species. Crotalus adamanteus and Crotalus horridus, in particular, show striking patterns of venom ontogeny that include both gradual and abrupt changes in expression patterns with age. To determine the mechanisms underlying venom ontogeny in C. adamanteus, we applied cutting-edge genomic and epigenomic techniques to identify the regulatory control of venom expression in both adults and juveniles, then used comparative-genomic analyses to reveal how genes move into and out of the ontogenetic regulatory network.