title: 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.
authors.affiliation: Laboratório de Fisiopatologia, Instituto Butantan, São Paulo-SP, Brazil.
authors.forename: Marcelo Larami
authors.initials: ML
authors.lastname: Santoro
authors.affiliation: Laboratório de Fisiopatologia, Instituto Butantan, São Paulo-SP, Brazil.
authors.forename: Thaís
authors.initials: T
authors.lastname: do Carmo
authors.affiliation: Laboratório de Fisiopatologia, Instituto Butantan, São Paulo-SP, Brazil.
authors.forename: Bruna Heloísa Lopes
authors.initials: BH
authors.lastname: Cunha
authors.affiliation: Laboratório de Fisiopatologia, Instituto Butantan, São Paulo-SP, Brazil.
authors.forename: André Fonseca
authors.initials: AF
authors.lastname: Alves
authors.affiliation: Laboratório Especial de Toxinologia Aplicada and Center of Toxins, Immune-Response and Cell Signaling, Instituto Butantan, São Paulo-SP, Brazil.
authors.forename: André
authors.initials: A
authors.lastname: Zelanis
authors.affiliation: Laboratório Especial de Toxinologia Aplicada and Center of Toxins, Immune-Response and Cell Signaling, Instituto Butantan, São Paulo-SP, Brazil.
authors.forename: Solange Maria de Toledo
authors.initials: SM
authors.lastname: Serrano
authors.affiliation: Laboratório de Herpetologia, Instituto Butantan, São Paulo-SP, Brazil.
authors.forename: Kathleen Fernandes
authors.initials: KF
authors.lastname: Grego
authors.affiliation: Laboratório de Herpetologia, Instituto Butantan, São Paulo-SP, Brazil.
authors.forename: Savio Stefanini
authors.initials: SS
authors.lastname: Sant'Anna
authors.affiliation: Laboratório de Imunopatologia, Instituto Butantan, São Paulo-SP, Brazil.
authors.forename: Katia Cristina
authors.initials: KC
authors.lastname: Barbaro
authors.affiliation: Laboratório de Herpetologia, Instituto Butantan, São Paulo-SP, Brazil.
authors.forename: Wilson
authors.initials: W
authors.lastname: Fernandes
mesh_terms: D000818:Animals; D012103:Batroxobin / Q000378:metabolism; D001777:Blood Coagulation / Q000187:drug effects; D017837:Bothrops / Q000235:genetics* / Q000254:growth & development*; D002417:Cattle; D003435:Crotalid Venoms / Q000378:metabolism* / Q000494:pharmacology; D005260:Female; D006824:Hybridization, Genetic; D008297:Male; D009024:Morphogenesis; D059748:Proteolysis; D013917:Thrombin / Q000378:metabolism
chemical_list: D003435:Crotalid Venoms; D012103:Batroxobin; D013917:Thrombin