Ontogenetic change in the venom composition of one Mexican black-tailed rattlesnake (Crotalus molossus nigrescens) from Durango, Mexico

To corroborate the ontogenetic shift in the venom composition of the Mexican Black-tailed Rattlesnake (Crotalus molossus nigrescens) previously reported through the census approach, we evaluated the shift in the protein profile, lethality, and proteolytic and phospholipase activities of four venom samples obtained in 2015, 2018, 2019, and 2021 from one C. m. nigrescens individual (CMN06) collected in Durango, Mexico. We demonstrated that the venom of C. m. nigrescens changed from a myotoxin-rich venom to a phospholipase A2 and snake venom metalloproteinase-rich venom. Additionally, the proteolytic and phospholipase activities increased with age, but the lethality decreased approximately three times.

Automated summary

The venom composition of the Mexican Black-tailed Rattlesnake undergoes a shift during ontogeny, with a transition from a myotoxin-rich venom to a venom rich in phospholipase A2 and snake venom metalloproteinase. Additionally, proteolytic and phospholipase activities increase with age, while lethality decreases.