Vance G Nielsen, Nathaniel Frank, Brian J Turchioe
BACKGROUND: A phenomena of interest is the in vitro anticoagulant effects of neurotoxins found in elapid venoms that kill by paralysis. These enzymes include phospholipase A2 (PLA2), and it has recently been demonstrated that carbon monoxide inhibits the PLA2-dependent neurotoxin contained in Mojave rattlesnake type A venom. The purpose of this investigation was to assess if the anticoagulant activity of elapid venoms containing PLA2 and/or three finger toxins could be inhibited by carbon monoxide...
August 13, 2019: Blood Coagulation & Fibrinolysis: An International Journal in Haemostasis and Thrombosis
Giulia Zancolli, Juan J Calvete, Michael D Cardwell, Harry W Greene, William K Hayes, Matthew J Hegarty, Hans-Werner Herrmann, Andrew T Holycross, Dominic I Lannutti, John F Mulley, Libia Sanz, Zachary D Travis, Joshua R Whorley, Catharine E Wüster, Wolfgang Wüster
Understanding the origin and maintenance of phenotypic variation, particularly across a continuous spatial distribution, represents a key challenge in evolutionary biology. For this, animal venoms represent ideal study systems: they are complex, variable, yet easily quantifiable molecular phenotypes with a clear function. Rattlesnakes display tremendous variation in their venom composition, mostly through strongly dichotomous venom strategies, which may even coexist within a single species. Here, through dense, widespread population-level sampling of the Mojave rattlesnake, Crotalus scutulatus, we show that genomic structural variation at multiple loci underlies extreme geographical variation in venom composition, which is maintained despite extensive gene flow...
March 13, 2019: Proceedings. Biological Sciences
Jason L Strickland, Andrew J Mason, Darin R Rokyta, Christopher L Parkinson
Phenotypic diversity generated through altered gene expression is a primary mechanism facilitating evolutionary response in natural systems. By linking the phenotype to genotype through transcriptomics, it is possible to determine what changes are occurring at the molecular level. High phenotypic diversity has been documented in rattlesnake venom, which is under strong selection due to its role in prey acquisition and defense. Rattlesnake venom can be characterized by the presence (Type A) or absence (Type B) of a type of neurotoxic phospholipase A 2 (PLA 2 ), such as Mojave toxin, that increases venom toxicity...
March 23, 2018: Toxins
A Carl Whittington, Andrew J Mason, Darin R Rokyta
Evolutionary innovations and complex phenotypes seemingly require an improbable amount of genetic change to evolve. Rattlesnakes display two dramatically different venom phenotypes. Type I venoms are hemorrhagic with low systemic toxicity and high expression of tissue-destroying snake venom metalloproteinases. Type II venoms are highly neurotoxic and lack snake venom metalloproteinase expression and associated hemorrhagic activity. This dichotomy hinges on Mojave toxin (MTx), a phospholipase A2 (PLA2) based β-neurotoxin expressed in Type II venoms...
April 1, 2018: Molecular Biology and Evolution
Miguel Borja, Edgar Neri-Castro, Gamaliel Castañeda-Gaytán, Jason L Strickland, Christopher L Parkinson, Juan Castañeda-Gaytán, Roberto Ponce-López, Bruno Lomonte, Alejandro Olvera-Rodríguez, Alejandro Alagón, Rebeca Pérez-Morales
Rattlesnake venoms may be classified according to the presence/absence and relative abundance of the neurotoxic phospholipases A 2 s (PLA 2 s), such as Mojave toxin, and snake venom metalloproteinases (SVMPs). In Mexico, studies to determine venom variation in Mojave Rattlesnakes ( Crotalus scutulatus scutulatus ) are limited and little is known about the biological and proteolytic activities in this species. Tissue (34) and venom (29) samples were obtained from C. s. scutulatus from different locations within their distribution in Mexico...
January 8, 2018: Toxins
Esteban Cantú, Sahiti Mallela, Matthew Nyguen, Raúl Báez, Victoria Parra, Rachel Johnson, Kyle Wilson, Montamas Suntravat, Sara Lucena, Alexis Rodríguez-Acosta, Elda E Sánchez
Snake venoms are known to have different venom compositions and toxicity, but differences can also be found within populations of the same species contributing to the complexity of treatment of envenomated victims. One of the first well-documented intraspecies venom variations comes from the Mohave rattlesnake (Crotalus scutulatus scutulatus). Initially, three types of venoms were described; type A venom is the most toxic as a result of ~45% Mojave toxin in the venom composition, type B lacks the Mojave toxin but contains over 50% of snake venom metalloproteases (SVMPs)...
January 2017: Comparative Biochemistry and Physiology. Toxicology & Pharmacology: CBP
Noah L Dowell, Matt W Giorgianni, Victoria A Kassner, Jane E Selegue, Elda E Sanchez, Sean B Carroll
The genetic origin of novel traits is a central but challenging puzzle in evolutionary biology. Among snakes, phospholipase A2 (PLA2)-related toxins have evolved in different lineages to function as potent neurotoxins, myotoxins, or hemotoxins. Here, we traced the genomic origin and evolution of PLA2 toxins by examining PLA2 gene number, organization, and expression in both neurotoxic and non-neurotoxic rattlesnakes. We found that even though most North American rattlesnakes do not produce neurotoxins, the genes of a specialized heterodimeric neurotoxin predate the origin of rattlesnakes and were present in their last common ancestor (∼22 mya)...
September 26, 2016: Current Biology: CB
Cara Francesca Smith, Stephen P Mackessy
Hybridization between divergent species can be analyzed to elucidate expression patterns of distinct parental characteristics, as well as to provide information about the extent of reproductive isolation between species. A known hybrid cross between two rattlesnakes with highly divergent venom phenotypes provided the opportunity to examine occurrence of parental venom characteristics in the F1 hybrids as well as ontogenetic shifts in the expression of these characters as the hybrids aged. Although venom phenotypes of adult rattlesnake venoms are known for many species, the effect of hybridization on phenotype inheritance is not well understood, and effects of hybridization on venom ontogeny have not yet been investigated...
September 15, 2016: Toxicon: Official Journal of the International Society on Toxinology
Giulia Zancolli, Timothy G Baker, Axel Barlow, Rebecca K Bradley, Juan J Calvete, Kimberley C Carter, Kaylah de Jager, John Benjamin Owens, Jenny Forrester Price, Libia Sanz, Amy Scholes-Higham, Liam Shier, Liam Wood, Catharine E Wüster, Wolfgang Wüster
Venomous snakes often display extensive variation in venom composition both between and within species. However, the mechanisms underlying the distribution of different toxins and venom types among populations and taxa remain insufficiently known. Rattlesnakes (Crotalus, Sistrurus) display extreme inter- and intraspecific variation in venom composition, centered particularly on the presence or absence of presynaptically neurotoxic phospholipases A₂ such as Mojave toxin (MTX). Interspecific hybridization has been invoked as a mechanism to explain the distribution of these toxins across rattlesnakes, with the implicit assumption that they are adaptively advantageous...
June 16, 2016: Toxins
Bruno Lomonte, Diana Mora-Obando, Julián Fernández, Libia Sanz, Davinia Pla, José María Gutiérrez, Juan J Calvete
Bothriechis nigroviridis is an arboreal Neotropical pitviper found in Costa Rica and Panamá. A previous proteomic profiling of its venom revealed the presence of proteins with homology to the A and B subunits of crotoxin/Mojave toxin, a heterodimeric phospholipase A2 (PLA2) complex only described in rattlesnake venoms (genera Crotalus and Sistrurus). The native crotoxin-like heterodimer, named nigroviriditoxin, and its A and B subunits were isolated in the present work, and the complete amino acid sequence of the B subunit was determined...
January 2015: Toxicon: Official Journal of the International Society on Toxinology
Ruben K Dagda, Sardar Gasanov, Ysidro De La Oiii, Eppie D Rael, Carl S Lieb
The metalloproteinase composition and biochemical profiles of rattlesnake venom can be highly variable among rattlesnakes of the same species. We have previously shown that the neurotoxic properties of the Mojave rattlesnake (Crotalus scutulatus scutulatus) are associated with the presence of the Mojave toxin A subunit suggesting the existence of a genetic basis for rattlesnake venom composition. In this report, we hypothesized the existence of a genetic basis for intraspecies variation in metalloproteinase-associated biochemical properties of rattlesnake venom of the Mojave rattlesnake...
2013: Biochemistry Research International
Darin R Rokyta, Kenneth P Wray, Mark J Margres
BACKGROUND: Snake venoms generally show sequence and quantitative variation within and between species, but some rattlesnakes have undergone exceptionally rapid, dramatic shifts in the composition, lethality, and pharmacological effects of their venoms. Such shifts have occurred within species, most notably in Mojave (Crotalus scutulatus), South American (C. durissus), and timber (C. horridus) rattlesnakes, resulting in some populations with extremely potent, neurotoxic venoms without the hemorrhagic effects typical of rattlesnake bites...
2013: BMC Genomics
Shaun D Carstairs, Allyson A Kreshak, David A Tanen
BACKGROUND: Patients sustaining rattlesnake envenomation often develop thrombocytopenia, the etiology of which is not clear. Laboratory studies have demonstrated that venom from several species, including the Mojave rattlesnake (Crotalus scutulatus scutulatus), can inhibit platelet aggregation. In humans, administration of crotaline Fab antivenom has been shown to result in transient improvement of platelet levels; however, it is not known whether platelet aggregation also improves after antivenom administration...
May 2013: Academic Emergency Medicine: Official Journal of the Society for Academic Emergency Medicine
Daniel J Massey, Juan J Calvete, Elda E Sánchez, Libia Sanz, Kelvin Richards, Ryan Curtis, Keith Boesen
Twenty-one Mojave rattlesnakes, Crotalus scutulatus scutulatus (C. s. scutulatus), were collected from Arizona and New Mexico U.S.A. Venom proteome of each specimen was analyzed using reverse-phase HPLC and SDS-PAGE. The toxicity of venoms was analyzed using lethal dose 50 (LD(50)). Health severity outcomes between two Arizona counties U.S.A., Pima and Cochise, were determined by retrospective chart review of the Arizona Poison and Drug Information Center (APDIC) database between the years of 2002 and 2009...
May 17, 2012: Journal of Proteomics
Sarah R Hoggan, Amy Carr, Karen A Sausman
OBJECTIVE: To describe the clinical presentation and case management of a dog that developed ascending flaccid paralysis after being envenomated by a Southern Pacific rattlesnake. CASE SUMMARY: A dog was presented after it was bitten by a Southern Pacific rattlesnake. Only mild local edema and a minor coagulapathy developed, which is atypical for the Southern Pacific envenomation where hemotoxic effects are more commonly observed. Instead, a severe, rapidly progressing, ascending flaccid paralysis leading to acute respiratory failure, consistent with Mojave toxin, was seen...
October 2011: Journal of Veterinary Emergency and Critical Care
Juan J Calvete, Alicia Pérez, Bruno Lomonte, Elda E Sánchez, Libia Sanz
We report the proteomic and antivenomic characterization of Crotalus tigris venom. This venom exhibits the highest lethality for mice among rattlesnakes and the simplest toxin proteome reported to date. The venom proteome of C. tigris comprises 7-8 gene products from 6 toxin families; the presynaptic β-neurotoxic heterodimeric PLA(2), Mojave toxin, and two serine proteinases comprise, respectively, 66 and 27% of the C. tigris toxin arsenal, whereas a VEGF-like protein, a CRISP molecule, a medium-sized disintegrin, and 1-2 PIII-SVMPs each represent 0...
February 3, 2012: Journal of Proteome Research
E Magnanou, J R Malenke, M D Dearing
The ability of herbivores to switch diets is thought to be governed by biotransformation enzymes. To identify potential biotransformation enzymes, we conducted a large-scale study on the expression of biotransformation enzymes in herbivorous woodrats (Neotoma lepida). We compared gene expression in a woodrat population from the Great Basin that feeds on the ancestral diet of juniper to one from the Mojave Desert that putatively switched from feeding on juniper to feeding on creosote. Juniper and creosote have notable differences in secondary chemistry, and thus, should require different biotransformation enzymes for detoxification...
June 2009: Molecular Ecology
Jennifer D Jurado, Eppie D Rael, Carl S Lieb, Ernesto Nakayasu, William K Hayes, Sean P Bush, Jeremy A Ross
Complement inactivating properties were detected in venom from the southern California distribution of Crotalus oreganus helleri (Southern Pacific Rattlesnake). This activity showed strong geographic bias to the San Bernardino Mountain range, and venom from this area reacted strongly with Fraction 5 antiserum (AF5). However, venoms from the San Jacinto Mountain range, which have been previously shown to contain Mojave toxin, did not inhibit complement and did not react with AF5. AF5 has been previously shown to recognize a protease in C...
March 1, 2007: Toxicon: Official Journal of the International Society on Toxinology
Elda E Sánchez, Jacob A Galán, Randy L Powell, Steven R Reyes, Julio G Soto, William K Russell, David H Russell, John C Pérez
Venom from the Mohave rattlesnake, Crotalus scutulatus scutulatus, has been reported to be either: (1) neurotoxic; (2) hemorrhagic, or both (3) neurotoxic and hemorrhagic. In this study, 14 Mohave rattlesnakes from Arizona and Texas (USA) were analyzed for the presence of disintegrins and Mojave toxin. All venom samples were analyzed for the presence of hemorrhagic, proteolytic and disintegrin activities. The venoms were each chromatographed by reverse phase and their fractions tested for disintegrin activity...
June 2005: Comparative Biochemistry and Physiology. Toxicology & Pharmacology: CBP
Wendy J French, William K Hayes, Sean P Bush, Michael D Cardwell, Julia O Bader, Eppie D Rael
Mojave toxin (MT) was detected in five of 25 Crotalus helleri (Southern Pacific rattlesnake) sampled using anti-MT antibodies and nucleotide sequence analysis. All of the venoms that were positive for MT were collected from Mt San Jacinto in Riverside Co., California. Since this population is geographically isolated from C. scutulatus scutulatus (Mojave rattlesnake), it is unlikely that this finding is due to recent hybridization. MT concentration differences between C. helleri and C. s. scutulatus reflected the presence of 'isoforms' of the toxin in the venom...
December 1, 2004: Toxicon: Official Journal of the International Society on Toxinology
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