Ontogenetic Variation in Biological Activities of Venoms from Hybrids between Bothrops erythromelas and Bothrops neuwiedi Snakes

Abstract

Lance-headed snakes are found in Central and South America, and they account for most snakebites in Brazil. The phylogeny of South American pitvipers has been reviewed, and the presence of natural and non-natural hybrids between different species of Bothrops snakes demonstrates that reproductive isolation of several species is still incomplete. The present study aimed to analyze the biological features, particularly the thrombin-like activity, of venoms from hybrids born in captivity, from the mating of a female Bothrops erythromelas and a male Bothrops neuwiedi, two species whose venoms are known to display ontogenetic variation. Proteolytic activity on azocoll and amidolytic activity on N-benzoyl-DL-arginine-p-nitroanilide hydrochloride (BAPNA) were lowest when hybrids were 3 months old, and increased over body growth, reaching values similar to those of the father when hybrids were 12 months old. The clotting activity on plasma diminished as hybrids grew; venoms from 3- and 6-months old hybrids showed low clotting activity on fibrinogen (i.e., thrombin-like activity), like the mother venom, and such activity was detected only when hybrids were older than 1 year of age. Altogether, these results point out that venom features in hybrid snakes are genetically controlled during the ontogenetic development. Despite the presence of the thrombin-like enzyme gene(s) in hybrid snakes, they are silenced during the first six months of life.

Venom complexity of Bothrops atrox (common lancehead) siblings

“…Individual variability is a well-established concept when referring to intraspecific variation of snake venom composition and/or its activities, and may be related to ontogeny [ 23 - 25 ], diet [ 26 , 27 ], seasonality [ 28 ], geographical location [ 29 - 31 ], gender [ 32 - 35 ], and captivity [ 22 , 36 ]. Within the Bothrops species, B. jararaca venom is the most studied one regarding gender differences [ 32 , 37 ], contrary from B. atrox , despite its high geographic distribution and epidemiological representation.…”

Propriedade intelectual do soro antiofídico: a efetividade a partir da correlação entre os investimentos do governo federal nos principais institutos responsáveis pela produção do soro e realização de pesquisas para o tratamento de acidentes ofídicos no brasil, com relação ao número de vítimas fatais dos acidentes

“…Segundo Kasturiratne et al 14 , cerca de 20% das mais de 3 mil espécies de serpentes existentes no mundo são venenosas. O veneno dessas serpentes possui diferentes funcionalidades, desde imobilizar suas presas, até mecanismos de autodefesa 1, 8,15,16 . Apesar do reconhecimento da importância em se estudar os acidentes ofídicos 17,18 , existe uma limitação no fornecimento de informações sobre acidentes e mortalidade em todo o mundo 19 .…”

An overview of Bothrops erythromelas venom

“…Another study by Santoro et al (42) investigated the thrombinlike activity of venoms from hybrids born in captivity from the mating of a female B. erythromelas and a male B. neuwiedi, which are two species whose venoms are known to display ontogenetic variations. They found that the features of venoms from hybrid snakes are genetically controlled during ontogenetic development.…”