Alape-Girón, Alberto

Calvete, Juan J.

Escolano, José

Flores-Díaz, Marietta

Gutiérrez, J.M.

Sanz, Libia

Sasa, Mahmood

Repositorio Institucional de la Universidad de Córdoba

Posters Last minute211P. 127SNAKE VENOMICS AND ANTIVENOMICS OF MIDDLE AND SOUTH AMERICAN RATTLESNAKES. IDENTIFICATION OF NEUROTOXIN CROTOXIN AS AN ADAPTIVE TRAIT DURING CROTALUS DURiSSUS INVASION OF SOUTH AMERICA Juan J. Calvete1,,  José Escolano1, Marietta Flores-Díaz2, Alberto Alape-Girón2,Mahmood Sasa2, José María Gutiérrez2, Libia Sanz11  Instituto de Biomedicina de Valencia, C.S.I.C., Jaume Roig 11, 46010 Valencia, Spain. 2 Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa  Rica. Venoms of subspecies of neotropical rattlesnakes represent an example of adaptive phenotypic variation. Venom of adult Central American C. simus, formerly C. d. durissus, cause local tissue damage, hemorrhage, coagulopathy and cardiovacular shock, but is devoid of neurotoxicity and systemic myotoxicity. However, newborn C.simus venom resembles that of South American C.d. terrificus being both neuro- and myotoxic and devoid of hemorrhagic activity. The pathophysiology of C.d. terrificusenvenomation is due to the neurotoxic and myotoxic effects of crotoxin, a heterodimeric PLA2 causing progressive paralysis and myonecrosis. Venoms of the subspecies C. d. cumanensis and C. d. ruruima, inhabiting northern regions of South America, exhibit a mixed pattern, inducing neurotoxicity and hemorrhage. The phylogeographical pattern of Crotalus dispersal is consistent with a stepwise colonization from Mexico along the Central American Isthmus (1.85 Mya), followed by rapid dispersal into and across South America (1.5-1.1 Mya). Our venomic analyses indicate that the gain of neurotoxicity associated with increasing crotoxin expression represents the key axis along which overall venom toxicity has evolved during Crotalus durissus invasion of South America. Assuming a link between venom toxicity and increased crotoxin concentration, the identification of evolutionary trends may have an impact in defining the mixture of venoms for immunization to produce effective antivenoms. A Costa Rican antivenom against C. simus simus, is ineffective neutralizing both the venom of South American Crotalus durissus subspecies and of newborn C. simus simus.Similarly, South American antivenoms against C.d. terrificus neutralize lethality of Central American venoms but are ineffective at neutralizing the hemorrhagic activity of venoms from genus Crotalus. Such neutralizing profile is fully explained by the proteomic characterization of Crotalus (simus and durissus) venoms showing increasing amounts of crotoxin in the venoms of C. durissus subspecies along the north to south colonization pattern of this group of snakes.

Snake venomics and antivenomics of Middle and South America rattlesnakes.Identification of neurotoxin crotoxin as an adaptive trait during Crotalus Durissus invasion of South America

Snake venomics and antivenomics of Middle and South America rattlesnakes.Identification of neurotoxin crotoxin as an adaptive trait during Crotalus Durissus invasion of South America

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Repositorio Institucional de la Universidad de Córdoba