Venomics analyses of Dipsadinae snakes focusing on adaptations to ophiophagy

Abstract

Advanced snakes developed a specialized toxin-producing maxillary gland enabling them to inoculate toxins into their prey. This gave them an advantage over other predators and allowed for their trophic niche diversification. Among the wide spectrum of feeding ecologies some snake groups became ophiophagous i.e. feeding mainly on other snakes. Due to the relationship between diet and venom composition, these ophiophagous groups probably needed to develop snake-specific toxins and some sort of resistance to the venoms of the snakes they preyed upon, linking these traits to the development of ophiophagy. In the neotropic, more precisely in the Dipsadidae family, there are several ophiophagous species. The genus Erythrolamprus (Tribe Xenodontini) and the genera Clelia and Boiruna (Tribe Pseudoboini) contain species that are snake specialists. However due to their relatively low medical relevance we have little information about their venoms in comparison to other snake families. On the other hand, venom resistance capabilities have been reported in some species of the genus Clelia finding an outstanding endurance to a wide spectrum of venoms from elapid and viperid snakes. This resistance is linked to blood plasma proteins which are mainly produced in the liver, althoughtalthough their nature and mode of action are largely unknown. In this project we intend to characterize the expression patterns of both the venom gland and the liver of ophiophagous and non-ophiophagous species from the tribes Xenodontini (Genus Erythrolamprus) and Pseudoboini (Genera Clelia and Boiruna) to comparatively assess whether or not they correlate with their feeding ecologies, to describe the possible factors involved with it and to check for convergent trends in both groups. (AU)