Identification of the genetic basis of venom variation in three rattlesnake species

Rattlesnakes often express venom with a discreet effect, such as, neurotoxicity or hemotoxicity. However, within some species both neurotoxic or hemotoxic venom types are found within individuals. In this study, we sequenced the genomic regions of key venom in three species (Crotalus scutulatus, Mojave rattlesnake; C. helleri, Southern Pacific rattlesnake; C. horridus, Timber rattlesnake) known to express multiple venom types. Specifically, we sequenced the phospholipase A2 (PLA2) and metalloproteinase (MP) venom gene complexes because the rattlesnake neurotoxin is the product of the venom PLA2 gene complex and hemorrhagic rattlesnake venom is associated with high levels of MPs. The objective of this study was to identify the genetic basis of intra-species venom variation.