Viperid venom glands with defective venom production. Morphological study

Giannotti, Karina Cristina; Sesso, Antônio; Grego, Kathleen Fernandes; Fernandes, Wilson Roberto; Cardoso, Rubens Pinto; Camargo, Gabriela Grilo; Carneiro, Sylvia Mendes

doi:10.1016/j.toxicon.2013.03.019

Cited by 6 publications

(3 citation statements)

References 47 publications

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“…Three broad mechanisms underlie chemical resistance: 1) compartmentalization (e.g., in a specialized gland), 2) metabolic detoxification (e.g., increased expression of P450 enzymes), and 3) target-site insensitivity; that is, amino acid changes in the molecular target of the compound that alter the toxin's ability to bind (Li et al 2002;Francis et al 2005;Petschenka and Dobler 2009;Giannotti et al 2013;Shear 2015). Organisms that are exposed to high levels of pesticides (e.g., cockroaches) or that accumulate chemicals for their own defense (e.g., danaine butterflies, Taricha newts) tend to have target-site insensitivity (Despr es et al 2007;Aardema et al 2012;Savitzky et al 2012;Zakon 2012;Bramer et al 2015;Hanifin and Gilly 2015).…”

Section: Introductionmentioning

confidence: 99%

Convergent Substitutions in a Sodium Channel Suggest Multiple Origins of Toxin Resistance in Poison Frogs

Tarvin

Santos

O’Connell

et al. 2016

Molecular Biology and Evolution

100

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Complex phenotypes typically have a correspondingly multifaceted genetic component. However, the genotype-phenotype association between chemical defense and resistance is often simple: genetic changes in the binding site of a toxin alter how it affects its target. Some toxic organisms, such as poison frogs (Anura: Dendrobatidae), have defensive alkaloids that disrupt the function of ion channels, proteins that are crucial for nerve and muscle activity. Using protein-docking models, we predict that three major classes of poison frog alkaloids (histrionicotoxins, pumiliotoxins, and batrachotoxins) bind to similar sites in the highly conserved inner pore of the muscle voltage-gated sodium channel, Nav1.4. We predict that poison frogs are somewhat resistant to these compounds because they have six types of amino acid replacements in the Nav1.4 inner pore that are absent in all other frogs except for a distantly related alkaloid-defended frog from Madagascar, Mantella aurantiaca. Protein-docking models and comparative phylogenetics support the role of these replacements in alkaloid resistance. Taking into account the four independent origins of chemical defense in Dendrobatidae, phylogenetic patterns of the amino acid replacements suggest that 1) alkaloid resistance in Nav1.4 evolved independently at least seven times in these frogs, 2) variation in resistance-conferring replacements is likely a result of differences in alkaloid exposure across species, and 3) functional constraint shapes the evolution of the Nav1.4 inner pore. Our study is the first to demonstrate the genetic basis of autoresistance in frogs with alkaloid defenses.

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Section: Introductionmentioning

confidence: 99%

Convergent Substitutions in a Sodium Channel Suggest Multiple Origins of Toxin Resistance in Poison Frogs

Tarvin

Santos

O’Connell

et al. 2016

Molecular Biology and Evolution

100

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“…Snake-related factors are responsible for the majority of cases of dry bites ( Figure 3 ), with failure to deliver venom being the main one. Failure to inject venom can in turn be caused by viral infections, physical agents, traumas during defense, excessive pressure on the venom glands (i.e., during manual extraction in captivity), and any other inflammatory response [ 104 ]. Therefore, venom gland tissue damage will result in empty venom glands and, consequently, in dry bites.…”

Section: The Snake Dry Bite Phenomenonmentioning

confidence: 99%

Current Knowledge on Snake Dry Bites

Pucca

Knudsen

Oliveira

et al. 2020

Toxins

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Snake ‘dry bites’ are characterized by the absence of venom being injected into the victim during a snakebite incident. The dry bite mechanism and diagnosis are quite complex, and the lack of envenoming symptoms in these cases may be misinterpreted as a miraculous treatment or as proof that the bite from the perpetrating snake species is rather harmless. The circumstances of dry bites and their clinical diagnosis are not well-explored in the literature, which may lead to ambiguity amongst treating personnel about whether antivenom is indicated or not. Here, the epidemiology and recorded history of dry bites are reviewed, and the clinical knowledge on the dry bite phenomenon is presented and discussed. Finally, this review proposes a diagnostic and therapeutic protocol to assist medical care after snake dry bites, aiming to improve patient outcomes.

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“…Na maioria dos criatórios de Bothrops, a extração manual de peçonha ocorre mensalmente, para evitar lesões na boca da serpente, o que poderia causar estomatite. Giannotti et. al (2013) estudaram alterações morfológicas nas glândulas de peçonha em serpentes que tiveram produção de peçonha deficiente, e encontraram lesões que indicam um excesso de pressão sofrida pelas glândulas durante o procedimento de extração.…”

Section: Introductionunclassified

Microbiota da cavidade oral e da peçonha de Bothrops atrox Linnaeus, 1758 (Ophidia: Viperidae)

Pereira¹

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Agradeço em primeiro lugar a Deus, pela força e pelas pessoas que sempre colocou em meu caminho para que essa conquista fosse possível.Aos meus pais Nelson e Maria, por todo apoio e incentivo.Aos familiares e amigos, por se fazerem presentes em minha vida e me auxiliarem durante esta trajetória, sobretudo, para conclusão desta pesquisa, foram fundamentais o apoio de Dayane Olímpia Gomes e Líria Queiroz Luz Hirano, para as quais deixo o meu eterno agradecimento.Aos colegas do LADOC, com os quais tive o privilégio de conhecer e conviver.Aos colegas do LAPAS, que também, sempre estiveram presentes em minha vida acadêmica e profissional, sobretudo ao professor André Luiz Quagliatto Santos, fundamental em todos os meus passos profissionais.A Pentapharm do Brasil, por me liberar para que eu conseguisse cumprir toda a pesquisa e créditos, e que disponibilizou os animais para colheita de material, em especial Adelheid Sandoz, José Marcos Dini e Didier Pierrat.Por fim, agradeço a professora Anna Monteiro Correia Lima, pela oportunidade desta realização, sempre me incentivando, aceitando minhas ideias e se fazendo presente em todas as etapas deste projeto. Fica a minha gratidão e admiração por esta excelente profissional.

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Viperid venom glands with defective venom production. Morphological study

Cited by 6 publications

References 47 publications

Convergent Substitutions in a Sodium Channel Suggest Multiple Origins of Toxin Resistance in Poison Frogs

Convergent Substitutions in a Sodium Channel Suggest Multiple Origins of Toxin Resistance in Poison Frogs

Current Knowledge on Snake Dry Bites

Microbiota da cavidade oral e da peçonha de Bothrops atrox Linnaeus, 1758 (Ophidia: Viperidae)

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