Rattling the border wall: Pathophysiological implications of functional and proteomic venom variation between Mexican and US subspecies of the desert rattlesnake Crotalus scutulatus

Comp Biochem Physiol C Toxicol Pharmacol. 2018 Feb:205:62-69. doi: 10.1016/j.cbpc.2017.10.008. Epub 2017 Oct 24.

Abstract

While some US populations of the Mohave rattlesnake (Crotalus scutulatus scutulatus) are infamous for being potently neurotoxic, the Mexican subspecies C. s. salvini (Huamantlan rattlesnake) has been largely unstudied beyond crude lethality testing upon mice. In this study we show that at least some populations of this snake are as potently neurotoxic as its northern cousin. Testing of the Mexican antivenom Antivipmyn showed a complete lack of neutralisation for the neurotoxic effects of C. s. salvini venom, while the neurotoxic effects of the US subspecies C. s. scutulatus were time-delayed but ultimately not eliminated. These results document unrecognised potent neurological effects of a Mexican snake and highlight the medical importance of this subspecies, a finding augmented by the ineffectiveness of the Antivipmyn antivenom. These results also influence our understanding of the venom evolution of Crotalus scutulatus, suggesting that neurotoxicity is the ancestral feature of this species, with the US populations which lack neurotoxicity being derived states.

Publication types

  • Comparative Study

MeSH terms

  • Animals
  • Antivenins / pharmacology
  • Arizona
  • Chickens
  • Crotalid Venoms / antagonists & inhibitors
  • Crotalid Venoms / chemistry
  • Crotalid Venoms / metabolism*
  • Crotalid Venoms / toxicity
  • Crotalus / growth & development
  • Crotalus / physiology*
  • Desert Climate
  • Evolution, Molecular*
  • Female
  • In Vitro Techniques
  • Lethal Dose 50
  • Male
  • Mexico
  • Mice, Inbred BALB C
  • Muscle Contraction / drug effects
  • Muscle, Skeletal / drug effects*
  • Muscle, Skeletal / innervation
  • Neuromuscular Blocking Agents / antagonists & inhibitors
  • Neuromuscular Blocking Agents / chemistry
  • Neuromuscular Blocking Agents / metabolism*
  • Neuromuscular Blocking Agents / toxicity
  • Neurotoxins / antagonists & inhibitors
  • Neurotoxins / chemistry
  • Neurotoxins / metabolism*
  • Neurotoxins / toxicity
  • Phospholipases A2 / chemistry
  • Phospholipases A2 / metabolism
  • Phospholipases A2 / toxicity
  • Proteomics / methods
  • Reptilian Proteins / antagonists & inhibitors
  • Reptilian Proteins / chemistry
  • Reptilian Proteins / metabolism*
  • Reptilian Proteins / toxicity
  • Species Specificity
  • Substrate Specificity
  • Texas

Substances

  • Antivenins
  • Crotalid Venoms
  • Neuromuscular Blocking Agents
  • Neurotoxins
  • Reptilian Proteins
  • Phospholipases A2