Jennifer Holt

Snake venom is one of the most extraordinarily diverse adaptations in the natural world, however, the reason for this remarkable diversity in venom composition remains elusive. One proposed hypothesis is that intricate coevolutionary interactions between venomous snakes and their antagonists (predators and prey) are providing a constant source of diversifying selection, thus driving extreme diversification. However, relatively little is known about the ecology of venomous snakes with respect to the species with which they are coevolving. Recently, studies on a well-known interaction between venomous snakes that produce alpha-neurotoxins and mammals which have resistance to this toxin at its receptor site (the muscular nicotinic acetylcholine receptor, nAChr) demonstrated that some mammals have evolved resistance to this venom toxin several times independently. However, surveys of this gene were only conducted across a wide coarse sampling of mammals, leaving out most species in the families Herpestidae and Viverridae, who are documented to predate upon alpha-neurotoxin-producing snakes, are widely dispersed across the regions of these snakes, and together represent the majority of mammalian snake eating predators. I examined nAChr sequences for members of the Families Herpestidae and Viverridae to determine whether or not alpha-neurotoxin resistance is present in these snake-eating species, and whether resistance has evolved independently among different species within Herpestidae and Viverridae or is ancestral to either or both groups.