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Schendel V, Müller CHG, Kenning M, Maxwell M, Jenner RA, Undheim EAB, Sombke A. The venom and telopodal defence systems of the centipede Lithobius forficatus are functionally convergent serial homologues. BMC Biol 2024; 22:135. [PMID: 38867210 PMCID: PMC11170834 DOI: 10.1186/s12915-024-01925-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 05/22/2024] [Indexed: 06/14/2024] Open
Abstract
BACKGROUND Evolution of novelty is a central theme in evolutionary biology, yet studying the origins of traits with an apparently discontinuous origin remains a major challenge. Venom systems are a well-suited model for the study of this phenomenon because they capture several aspects of novelty across multiple levels of biological complexity. However, while there is some knowledge on the evolution of individual toxins, not much is known about the evolution of venom systems as a whole. One way of shedding light on the evolution of new traits is to investigate less specialised serial homologues, i.e. repeated traits in an organism that share a developmental origin. This approach can be particularly informative in animals with repetitive body segments, such as centipedes. RESULTS Here, we investigate morphological and biochemical aspects of the defensive telopodal glandular organs borne on the posterior legs of venomous stone centipedes (Lithobiomorpha), using a multimethod approach, including behavioural observations, comparative morphology, proteomics, comparative transcriptomics and molecular phylogenetics. We show that the anterior venom system and posterior telopodal defence system are functionally convergent serial homologues, where one (telopodal defence) represents a model for the putative early evolutionary state of the other (venom). Venom glands and telopodal glandular organs appear to have evolved from the same type of epidermal gland (four-cell recto-canal type) and while the telopodal defensive secretion shares a great degree of compositional overlap with centipede venoms in general, these similarities arose predominantly through convergent recruitment of distantly related toxin-like components. Both systems are composed of elements predisposed to functional innovation across levels of biological complexity that range from proteins to glands, demonstrating clear parallels between molecular and morphological traits in the properties that facilitate the evolution of novelty. CONCLUSIONS The evolution of the lithobiomorph telopodal defence system provides indirect empirical support for the plausibility of the hypothesised evolutionary origin of the centipede venom system, which occurred through functional innovation and gradual specialisation of existing epidermal glands. Our results thus exemplify how continuous transformation and functional innovation can drive the apparent discontinuous emergence of novelties on higher levels of biological complexity.
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Affiliation(s)
- Vanessa Schendel
- Centre for Advanced Imaging, The University of Queensland, St. Lucia, QLD, 4072, Australia
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD, 4072, Australia
| | - Carsten H G Müller
- Zoological Institute and Museum, University of Greifswald, Loitzer Strasse 26, Greifswald, 17489, Germany
| | - Matthes Kenning
- Zoological Institute and Museum, University of Greifswald, Loitzer Strasse 26, Greifswald, 17489, Germany
| | - Michael Maxwell
- Centre for Advanced Imaging, The University of Queensland, St. Lucia, QLD, 4072, Australia
| | | | - Eivind A B Undheim
- Centre for Advanced Imaging, The University of Queensland, St. Lucia, QLD, 4072, Australia.
- Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, Oslo, 0316, Norway.
| | - Andy Sombke
- Centre for Anatomy and Cell Biology, Cell and Developmental Biology, Medical University of Vienna, Schwarzspanierstrasse 17, Vienna, 1090, Austria.
- Department of Evolutionary Biology, Integrative Zoology, University of Vienna, Djerassiplatz 1, 1030, Austria.
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2
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Neri-Castro E, Zarzosa V, Lomonte B, Zamudio F, Hernandez-Orihuela L, Olvera-Rodríguez A, Rodríguez-Solís AM, Borja M, García-Vázquez UO, Jones JM, Parkinson CL, Alagón A. Exploring venom diversity in Mixcoatlus browni and Mixcoatlus barbouri: A comparative analysis of two rare Mexican snake species with crotoxin-like presence. Biochimie 2024; 225:81-88. [PMID: 38762000 DOI: 10.1016/j.biochi.2024.05.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 05/14/2024] [Accepted: 05/15/2024] [Indexed: 05/20/2024]
Abstract
The genus Mixcoatlus is composed of three species: Mixcoatlus barbouri, M. browni, and M. melanurus, of which the venom composition of M. melanurus, the most common species of the three, has only recently been described. However, very little is known about the natural history of M. barbouri and M. browni, and the venom composition of these two species has remained thus far unexplored. In this study we characterize the proteomic profiles and the main biochemical and toxic activities of these two venoms. Proteomic data obtained by shotgun analysis of whole venom identified 12 protein families for M. barbouri, and 13 for M. browni. The latter venom was further characterized by using a quantitative 'venomics' protocol, which revealed that it is mainly composed of 51.1 % phospholipases A2 (PLA2), 25.5 % snake venom serine proteases (SVSP), 4.6 % l-amino oxidases (LAO), and 3.6 % snake venom metalloproteases (SVMP), with lower percentages other six protein families. Both venoms contained homologs of the basic and acidic subunits of crotoxin. However, due to limitations in M. barbouri venom availability, we could only characterize the crotoxin-like protein of M. browni venom, which we have named Mixcoatlutoxin. It exhibited a lethal potency in mice like that described for classical rattlesnake crotoxins. These findings expand knowledge on the distribution of crotoxin-like heterodimeric proteins in viper snake species. Further investigation of the bioactivities of the venom of M. barbouri, on the other hand, remains necessary.
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Affiliation(s)
- Edgar Neri-Castro
- Investigador por México, Facultad de Ciencias Biológicas, Universidad Juárez del Estado de Durango, Avenida Universidad s/n. Fracc. Filadelfia, C.P. 35010, Gómez Palacio, Dgo, Mexico; Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad 2001, Chamilpa, C.P. 62210, Cuernavaca, Mor, Mexico.
| | - Vanessa Zarzosa
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad 2001, Chamilpa, C.P. 62210, Cuernavaca, Mor, Mexico
| | - Bruno Lomonte
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, 11501, Costa Rica
| | - Fernando Zamudio
- Investigador por México, Facultad de Ciencias Biológicas, Universidad Juárez del Estado de Durango, Avenida Universidad s/n. Fracc. Filadelfia, C.P. 35010, Gómez Palacio, Dgo, Mexico
| | - Lorena Hernandez-Orihuela
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad 2001, Chamilpa, C.P. 62210, Cuernavaca, Mor, Mexico
| | - Alejandro Olvera-Rodríguez
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad 2001, Chamilpa, C.P. 62210, Cuernavaca, Mor, Mexico
| | - Audrey Michelle Rodríguez-Solís
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad 2001, Chamilpa, C.P. 62210, Cuernavaca, Mor, Mexico
| | - Miguel Borja
- Investigador por México, Facultad de Ciencias Biológicas, Universidad Juárez del Estado de Durango, Avenida Universidad s/n. Fracc. Filadelfia, C.P. 35010, Gómez Palacio, Dgo, Mexico
| | - Uri O García-Vázquez
- Laboratorio de Sistemática Molecular, Carrera de Biología, UMIEZ, Facultad de Estudios Superiores Zaragoza, Universidad Nacional Autónoma de México, Batalla 5 de Mayo s/n, Ejército de Oriente, Ciudad de México, 09230, Mexico
| | | | - Chistopher L Parkinson
- Department of Biological Sciences and Department of Forestry, and Environmental Conservation, Clemson University, 190 Collings St. Clemson, SC, 29631, USA
| | - Alejandro Alagón
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad 2001, Chamilpa, C.P. 62210, Cuernavaca, Mor, Mexico.
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3
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Hus KK, Buczkowicz J, Pietrowska M, Petrilla V, Petrillová M, Legáth J, Litschka-Koen T, Bocian A. Venom diversity in Naja mossambica: Insights from proteomic and immunochemical analyses reveal intraspecific differences. PLoS Negl Trop Dis 2024; 18:e0012057. [PMID: 38557658 PMCID: PMC11008852 DOI: 10.1371/journal.pntd.0012057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 04/11/2024] [Accepted: 03/07/2024] [Indexed: 04/04/2024] Open
Abstract
BACKGROUND Intraspecific variations in snake venom composition have been extensively documented, contributing to the diverse clinical effects observed in envenomed patients. Understanding these variations is essential for developing effective snakebite management strategies and targeted antivenom therapies. We aimed to comprehensively investigate venoms from three distinct populations of N. mossambica from Eswatini, Limpopo, and KwaZulu-Natal regions in Africa in terms of their protein composition and reactivity with three commercial antivenoms (SAIMR polyvalent, EchiTAb+ICP, and Antivipmyn Africa). METHODOLOGY/PRINCIPAL FINDINGS Naja mossambica venoms from Eswatini region exhibited the highest content of neurotoxic proteins, constituting 20.70% of all venom proteins, compared to Limpopo (13.91%) and KwaZulu-Natal (12.80%), and was characterized by the highest diversity of neurotoxic proteins, including neurotoxic 3FTxs, Kunitz-type inhibitors, vespryns, and mamba intestinal toxin 1. KwaZulu-Natal population exhibited considerably lower cytotoxic 3FTx, higher PLA2 content, and significant diversity in low-abundant proteins. Conversely, Limpopo venoms demonstrated the least diversity as demonstrated by electrophoretic and mass spectrometry analyses. Immunochemical assessments unveiled differences in venom-antivenom reactivity, particularly concerning low-abundance proteins. EchiTAb+ICP antivenom demonstrated superior reactivity in serial dilution ELISA assays compared to SAIMR polyvalent. CONCLUSIONS/SIGNIFICANCE Our findings reveal a substantial presence of neurotoxic proteins in N. mossambica venoms, challenging previous understandings of their composition. Additionally, the detection of numerous peptides aligning to uncharacterized proteins or proteins with unknown functions underscores a critical issue with existing venom protein databases, emphasizing the substantial gaps in our knowledge of snake venom protein components. This underscores the need for enhanced research in this domain. Moreover, our in vitro immunological assays suggest EchiTAb+ICP's potential as an alternative to SAIMR antivenom, requiring confirmation through prospective in vivo neutralization studies.
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Affiliation(s)
- Konrad K. Hus
- Department of Biotechnology and Bioinformatics, Faculty of Chemistry, Rzeszow University of Technology, Rzeszow, Poland
| | - Justyna Buczkowicz
- Department of Biotechnology and Bioinformatics, Faculty of Chemistry, Rzeszow University of Technology, Rzeszow, Poland
| | - Monika Pietrowska
- Maria Sklodowska-Curie National Research Institute of Oncology, Gliwice, Poland
| | - Vladimír Petrilla
- Department of Biology and Physiology, University of Veterinary Medicine and Pharmacy, Košice, Slovakia
- Zoological Department, Zoological Garden Košice, Košice-Kavečany, Slovakia
| | - Monika Petrillová
- Department of General Competencies, University of Veterinary Medicine and Pharmacy, Košice, Slovakia
| | - Jaroslav Legáth
- Department of Biotechnology and Bioinformatics, Faculty of Chemistry, Rzeszow University of Technology, Rzeszow, Poland
- Department of Pharmacology and Toxicology, University of Veterinary Medicine and Pharmacy, Košice, Slovakia
| | | | - Aleksandra Bocian
- Department of Biotechnology and Bioinformatics, Faculty of Chemistry, Rzeszow University of Technology, Rzeszow, Poland
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4
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Balchan NR, Smith CF, Mackessy SP. A plethora of rodents: Rattlesnake predators generate unanticipated patterns of venom resistance in a grassland ecosystem. Toxicon X 2024; 21:100179. [PMID: 38144228 PMCID: PMC10746501 DOI: 10.1016/j.toxcx.2023.100179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 11/05/2023] [Accepted: 11/20/2023] [Indexed: 12/26/2023] Open
Abstract
Predation has the potential to impart strong selective pressures on organisms within their environments, resulting in adaptive changes in prey that minimize risk of predation. Pressures from venomous snakes present an exceptional challenge to prey, as venom represents a unique chemical arsenal evolutionarily tailored to incapacitate prey. In response, venom resistance has been detected in various snake prey species, and to varying degrees. This study analyzes venom resistance in an eastern Colorado grassland habitat, where the Prairie Rattlesnake (Crotalus viridis) and Desert Massasauga Rattlesnake (Sistrurus tergeminus edwardsii) co-occur with a suite of grassland rodents. We test for venom resistance across rodent and snake pairings using two geographically distant field sites to determine the role of 1) predation pressure and trophic ecology, and 2) sympatric and allopatric patterns of venom resistance. Resistance was measured using serum-based metalloproteinase inhibition assays to determine potential inhibition of proteolytic activity, augmented by median lethal dose (LD50) assays on rodent species to assess toxicity of crude venoms. Resistance is present in several rodent species, with strong resistance present in populations of Eastern Woodrat (Neotoma floridana), Ord's Kangaroo Rat (Dipodomys ordii), and Northern Grasshopper Mouse (Onychomys leucogaster). Resistance is less developed in other species, including the House Mouse (Mus musculus) and Plains Pocket Mouse (Perognathus flavescens). An unexpected differential is present, where Lincoln County Kangaroo Rats are highly resistant to venom of co-occurring Prairie Rattlesnakes yet are sensitive to an allopatric population of Prairie Rattlesnakes in Weld County. Lincoln Co. Northern Grasshopper Mice also demonstrate extremely elevated resistance to Weld Co. Prairie Rattlesnake venoms, and they may possess resistance mechanisms for myotoxin a, an abundant component of Weld Co. C. v viridis venoms. This study illustrates the complexity of venom resistance in biological communities that can exist when incorporating multiple species interactions. Future studies aimed at characterizing resistance mechanisms at the molecular level will provide a more detailed physiological context for understanding mechanisms by which resistance to venoms occurs.
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Affiliation(s)
- Neil R. Balchan
- Department of Biological Sciences, University of Northern Colorado, Greeley, CO, 80639, USA
- Department of Integrative Biology, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Cara F. Smith
- Department of Biological Sciences, University of Northern Colorado, Greeley, CO, 80639, USA
- Department of Biochemistry and Molecular Genetics, 12801 East 17th Avenue, University of Colorado Denver, Aurora, CO, 80045, USA
| | - Stephen P. Mackessy
- Department of Biological Sciences, University of Northern Colorado, Greeley, CO, 80639, USA
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5
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Bahmani K, Abdollahnia A, Vatanpour H, Ghassempour A, Kaboli M, Shahidi MR. Evaluation of venom diversity and antivenom quality from the venom of long-term captive vs recently wild captured Pseudocerastes persicus snake: An In vitro and In vivo study. Toxicon 2024; 241:107662. [PMID: 38417708 DOI: 10.1016/j.toxicon.2024.107662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Revised: 02/23/2024] [Accepted: 02/24/2024] [Indexed: 03/01/2024]
Abstract
Snakebite envenomation is a life-threatening condition and antivenoms are used as the most effective treatment. Venom obtained from snakes in long-term captivity showed some variations in comparison to the venom of the wild snakes. The objective of this study is to compare the venom of the Pseudocerastes persicus under long-term captivity and wild conditions as well as the antivenom obtained from these venoms. We have analyzed venom samples and produced trivalent antivenoms using the venom of long-term captive (LTC) or recently wild-captured (RWC) Pseudocerastes persicus, and RWC Macrovipera lebetina, and Echis carinatus. The HPLC analysis revealed that the RWC snakes' venom had three peaks that were not present in the LTC snake's venom. Further analysis using MALDI-TOF and MS/MS showed that the fraction with a retention time (RT) of 14 min contained a toxin from the Kunitz-type serine protease inhibitor (KUT) class, while the fraction with RT 21 a peptide identified within the snake venom metalloproteinase (SVMP) class. The third peak was identified as a sphingolipid. Interestingly, the in vivo preclinical tests showed no significant differences in the effectiveness of the antivenoms. which could be due to the cross-immunogenicity or cross-reactivity between different toxins in the venom. According to our results, small variations in the venom composition of a species do not lead to a decrease in the efficacy of the polyvalent antivenom.
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Affiliation(s)
- Kiumars Bahmani
- Department of Pharmacology and Toxicology, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Adel Abdollahnia
- Department of Phytochemistry, Medicinal Plants and Drugs Research Institute, Shahid Beheshti University, G.C., Evin, Tehran, Iran
| | - Hossein Vatanpour
- Department of Pharmacology and Toxicology, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| | - Alireza Ghassempour
- Department of Phytochemistry, Medicinal Plants and Drugs Research Institute, Shahid Beheshti University, G.C., Evin, Tehran, Iran.
| | - Mohammad Kaboli
- College of Natural Resources and Agriculture, University of Tehran, Karaj, Iran
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6
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Smith CF, Nikolakis ZL, Perry BW, Schield DR, Meik JM, Saviola AJ, Castoe TA, Parker J, Mackessy SP. The best of both worlds? Rattlesnake hybrid zones generate complex combinations of divergent venom phenotypes that retain high toxicity. Biochimie 2023; 213:176-189. [PMID: 37451532 DOI: 10.1016/j.biochi.2023.07.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 06/27/2023] [Accepted: 07/10/2023] [Indexed: 07/18/2023]
Abstract
Studying the consequences of hybridization between closely related species with divergent traits can reveal patterns of evolution that shape and maintain extreme trophic adaptations. Snake venoms are an excellent model system for examining the evolutionary and ecological patterns that underlie highly selected polymorphic traits. Here we investigate hybrid venom phenotypes that result from natural introgression between two rattlesnake species that express highly divergent venom phenotypes: Crotalus o. concolor and C. v. viridis. Though not yet documented, interbreeding between these species may lead to novel venom phenotypes with unique activities that break the typical trends of venom composition in rattlesnakes. The characteristics of these unusual phenotypes could unveil the roles of introgression in maintaining patterns of venom composition and variation, including the near ubiquitous dichotomy between neurotoxic or degradative venoms observed across rattlesnakes. We use RADseq data to infer patterns of gene flow and hybrid ancestry between these diverged lineages and link these genetic data with analyses of venom composition, biological activity, and whole animal model toxicity tests to understand the impacts of introgression on venom composition. We find that introgressed populations express admixed venom phenotypes that do not sacrifice biological activity (lethal toxicity) or overall abundance of dominant toxins compared to parental venoms. These hybridized venoms therefore do not represent a trade-off in functionality between the typical phenotypic extremes but instead represent a unique combination of characters whose expression appears limited to the hybrid zone.
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Affiliation(s)
- Cara F Smith
- School of Biological Sciences, 501 20th Street, University of Northern Colorado, Greeley, CO, 80639, USA
| | - Zachary L Nikolakis
- Department of Biology, 501 S. Nedderman Drive, University of Texas at Arlington, Arlington, TX, 76019, USA
| | - Blair W Perry
- Department of Biology, 501 S. Nedderman Drive, University of Texas at Arlington, Arlington, TX, 76019, USA
| | - Drew R Schield
- Department of Biology, 501 S. Nedderman Drive, University of Texas at Arlington, Arlington, TX, 76019, USA
| | - Jesse M Meik
- Department of Biological Sciences, Tarleton State University, 1333 W. Washington Street, Stephenville, TX, 76402, USA
| | - Anthony J Saviola
- Department of Biochemistry and Molecular Genetics, 12801 East 17th Avenue, University of Colorado Denver, Aurora, CO, 80045, USA
| | - Todd A Castoe
- Department of Biology, 501 S. Nedderman Drive, University of Texas at Arlington, Arlington, TX, 76019, USA
| | - Joshua Parker
- Fresno City College, 1101 E. University Avenue, Fresno, CA, 93741, USA
| | - Stephen P Mackessy
- School of Biological Sciences, 501 20th Street, University of Northern Colorado, Greeley, CO, 80639, USA.
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7
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Wster W, Tillack F. On the importance of types and the perils of en passant taxonomy: a brief history of the typification of Coluber naja Linnaeus, 1758 (Serpentes: Elapidae) and its implications, with the designation of a lectotype. Zootaxa 2023; 5346:403-419. [PMID: 38221330 DOI: 10.11646/zootaxa.5346.4.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Indexed: 01/16/2024]
Abstract
In response to the recent in passing (en passant) taxonomic decision to split Naja naja (Linnaeus) and recognise the Sri Lankan populations as a separate species, N. polyocellata Deraniyagala, we analyse the evidence underlying the proposal and its nomenclatural implications. The proposed split is weakly supported by the available evidence, so that retaining N. naja as a single species seems appropriate until further analysis. Moreover, the proposal raises several issues concerning types, type locality and nomenclature. Linnaeus description of Coluber naja was based on a single preserved specimen seen by him (now lost) and several illustrations in Sebas Thesaurus. The specimens that were the basis of these illustrations constitute part of the type series. Two of the latter specimens, ZMB 2795 and 2796, have been rediscovered in the collections of the Museum fr Naturkunde, Berlin. Here, we describe them, and determine that both are of Sri Lankan origin. To settle the question of the type and type locality of this iconic taxon, we designate ZMB 2796 as lectotype for the species, thereby implicitly restricting the type locality to Sri Lanka. The name polyocellata thus becomes a subjective junior synonym of Coluber naja, and the name Naja brasiliensis Laurenti, 1768 an objective junior synonym thereof. Any taxonomic recognition of additional diversity within N. naja would thus require the renaming of Indian, not Sri Lankan spectacled cobras, but should await a significant body of convincing evidence. We caution against taxonomic decisions taken in passing, based on limited evidence and without in-depth assessment of their nomenclatural implications.
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Affiliation(s)
- Wolfgang Wster
- Molecular Ecology and Evolution at Bangor; School of Natural Sciences; Bangor University; Bangor LL57 2UW; Wales; UK.
| | - Frank Tillack
- Museum fr Naturkunde; Leibniz-Institut fr Evolutions- und Biodiversittsforschung; Invalidenstrae 43; 10115 Berlin; Germany.
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Op den Brouw B, Fernandez-Rojo MA, Charlton T, Fry BG, Ikonomopoulou MP. Malaysian and Chinese King Cobra Venom Cytotoxicity in Melanoma and Neonatal Foreskin Fibroblasts Is Mediated by Age and Geography. Toxins (Basel) 2023; 15:549. [PMID: 37755975 PMCID: PMC10534572 DOI: 10.3390/toxins15090549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 08/24/2023] [Accepted: 08/31/2023] [Indexed: 09/28/2023] Open
Abstract
Snake venoms constitute a complex, rapidly evolving trait, whose composition varies between and within populations depending on geographical location, age and preys (diets). These factors have determined the adaptive evolution for predatory success and link venom heterogeneity with prey specificity. Moreover, understanding the evolutionary drivers of animal venoms has streamlined the biodiscovery of venom-derived compounds as drug candidates in biomedicine and biotechnology. The king cobra (Ophiophagus hannah; Cantor, 1836) is distributed in diverse habitats, forming independent populations, which confer differing scale markings, including between hatchlings and adults. Furthermore, king cobra venoms possess unique cytotoxic properties that are used as a defensive trait, but their toxins may also have utility as promising anticancer-agent candidates. However, the impact of geographical distribution and age on these potential venom applications has been typically neglected. In this study, we hypothesised that ontogenetic venom variation accompanies the morphological distinction between hatchlings and adults. We used non-transformed neonatal foreskin (NFF) fibroblasts to examine and compare the variability of venom cytotoxicity between adult captive breeding pairs from Malaysian and Chinese lineages, along with that of their progeny upon hatching. In parallel, we assessed the anticancer potential of these venoms in human-melanoma-patient-derived cells (MM96L). We found that in a geographical distribution and gender-independent manner, venoms from hatchlings were significantly less cytotoxic than those from adults (NFF; ~Log EC50: 0.5-0.6 vs. 0.2-0.35 mg/mL). This is consistent with neonates occupying a semifossorial habitat, while adults inhabit more above-ground habitats and are therefore more conspicuous to potential predators. We also observed that Malaysian venoms exhibited a slightly higher cytotoxicity than those from the Chinese cobra cohorts (NFF; Log EC50: 0.1-0.3 vs. 0.3-0.4 mg/mL), which is consistent with Malaysian king cobras being more strongly aposematically marked. These variations are therefore suggestive of differential anti-predator strategies associated with the occupation of distinct niches. However, all cobra venoms were similarly cytotoxic in both melanoma cells and fibroblasts, limiting their potential medical applications in their native forms.
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Affiliation(s)
- Bianca Op den Brouw
- Venom Evolution Lab, School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia;
| | - Manuel A. Fernandez-Rojo
- Hepatic Regenerative Medicine Group, Madrid Institute for Advanced Studies in Food, E28049 Madrid, Spain;
- Diamantina Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Tom Charlton
- Department of Natural Sciences, Manchester Metropolitan University, All Saints Building, Manchester M15 6BH, UK;
| | - Bryan G. Fry
- Venom Evolution Lab, School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia;
| | - Maria P. Ikonomopoulou
- Translational Venomics Group, Madrid Institute for Advanced Studies in Food, E28049 Madrid, Spain
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
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9
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Cummings CO, Eisenbarth JM. Snakebite Envenoming in Avian Species: A Systematic Scoping Review and Practitioner Experience Survey. J Avian Med Surg 2023; 37:118-131. [PMID: 37733451 PMCID: PMC10787666 DOI: 10.1647/22-00035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/23/2023]
Abstract
Snakebite envenoming in avian species is infrequently reported in the veterinary literature, although perhaps not as rarely as recent publications suggest. A systematic scoping review was performed on the topic using PubMed and Google Scholar, 21 veterinary textbooks, and 139 conference proceedings. A practitioner experience survey was also performed, with recruitment from Facebook groups for exotic animal practitioners and professional organization email listservs. Only 31 texts met our inclusion/exclusion criteria, which meant they described clinicopathologic signs of snakebite envenomation in avian species, the treatment of snakebite envenomation in avian species, or expanded the geographic range or the number of captive avian and snake species involved. Reports included approximately 15-20 different species of both snakes and birds worldwide; however, no reports described clinicopathologic signs of naturally occurring snakebites from Asia, Australasia, or Europe. The few responses from our practitioner experience survey suggest that snakebite envenomation may be more common than previously reported. Clinical signs of snake envenomation in birds appear to depend on the snake species involved but often include local swelling and subcutaneous edema or hemorrhage with paired fang marks; weakness, bleeding, neurologic deficits, and death may follow. A wide variety of treatment protocols have been used to counter snakebite envenomation in birds, including the successful use of antivenom. Based on this body of evidence, much remains to be learned about snakebite envenomation of birds, particularly about the efficacy of different treatment protocols.
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Affiliation(s)
- Charles O Cummings
- Tufts Clinical and Translational Science Institute, Tufts Medical Center, Boston, MA 02111, USA,
| | - Jessica M Eisenbarth
- Department of Clinical Sciences, Cummings School of Veterinary Medicine, Tufts University, North Grafton, MA 01536, USA
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10
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Rosales-García RA, Rautsaw RM, Hofmann EP, Grünwald CI, Franz-Chavez H, Ahumada-Carrillo IT, Ramirez-Chaparro R, de la Torre-Loranca MA, Strickland JL, Mason AJ, Holding ML, Borja M, Castañeda-Gaytan G, Myers EA, Sasa M, Rokyta DR, Parkinson CL. Sequence Divergence in Venom Genes Within and Between Montane Pitviper (Viperidae: Crotalinae: Cerrophidion) Species is Driven by Mutation-Drift Equilibrium. J Mol Evol 2023; 91:514-535. [PMID: 37269364 PMCID: PMC10995822 DOI: 10.1007/s00239-023-10115-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 05/03/2023] [Indexed: 06/05/2023]
Abstract
Snake venom can vary both among and within species. While some groups of New World pitvipers-such as rattlesnakes-have been well studied, very little is known about the venom of montane pitvipers (Cerrophidion) found across the Mesoamerican highlands. Compared to most well-studied rattlesnakes, which are widely distributed, the isolated montane populations of Cerrophidion may facilitate unique evolutionary trajectories and venom differentiation. Here, we describe the venom gland transcriptomes for populations of C. petlalcalensis, C. tzotzilorum, and C. godmani from Mexico, and a single individual of C. sasai from Costa Rica. We explore gene expression variation in Cerrophidion and sequence evolution of toxins within C. godmani specifically. Cerrophidion venom gland transcriptomes are composed primarily of snake venom metalloproteinases, phospholipase A[Formula: see text]s (PLA[Formula: see text]s), and snake venom serine proteases. Cerrophidion petlalcalensis shows little intraspecific variation; however, C. godmani and C. tzotzilorum differ significantly between geographically isolated populations. Interestingly, intraspecific variation was mostly attributed to expression variation as we did not detect signals of selection within C. godmani toxins. Additionally, we found PLA[Formula: see text]-like myotoxins in all species except C. petlalcalensis, and crotoxin-like PLA[Formula: see text]s in the southern population of C. godmani. Our results demonstrate significant intraspecific venom variation within C. godmani and C. tzotzilorum. The toxins of C. godmani show little evidence of directional selection where variation in toxin sequence is consistent with evolution under a model of mutation-drift equilibrium. Cerrophidion godmani individuals from the southern population may exhibit neurotoxic venom activity given the presence of crotoxin-like PLA[Formula: see text]s; however, further research is required to confirm this hypothesis.
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Affiliation(s)
| | - Rhett M Rautsaw
- Department of Biological Sciences, Clemson University, 190 Collings St., Clemson, SC, 29634, USA
| | - Erich P Hofmann
- Department of Biological Sciences, Clemson University, 190 Collings St., Clemson, SC, 29634, USA
- Science Department, Cape Fear Community College, Wilmington, NC, 28401, USA
| | | | - Hector Franz-Chavez
- Herp.mx A.C., Colima, Mexico
- Biodiversa A. C., Chapala, Jalisco, 45900, Mexico
| | | | | | | | - Jason L Strickland
- Department of Biological Sciences, Clemson University, 190 Collings St., Clemson, SC, 29634, USA
- Department of Biology, University of South Alabama, Mobile, AL, 36688, USA
| | - Andrew J Mason
- Department of Biological Sciences, Clemson University, 190 Collings St., Clemson, SC, 29634, USA
- Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, Columbus, OH, 43210, USA
| | - Matthew L Holding
- Department of Biological Sciences, Clemson University, 190 Collings St., Clemson, SC, 29634, USA
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Miguel Borja
- Facultad de Ciencias Biológicas, Universdad Juárez del Estado de Durango, Gómez Palacio, Durango, 35010, Mexico
| | - Gamaliel Castañeda-Gaytan
- Facultad de Ciencias Biológicas, Universdad Juárez del Estado de Durango, Gómez Palacio, Durango, 35010, Mexico
| | - Edward A Myers
- Department of Biological Sciences, Clemson University, 190 Collings St., Clemson, SC, 29634, USA
| | - Mahmood Sasa
- Centro Investigaciones en Biodiversidad y Ecología Tropical and Instituto Clodomiro Picado, Universidad de Costa Rica, San José, Costa Rica
| | - Darin R Rokyta
- Department of Biological Science, Florida State University, Tallahassee, FL, 32306, USA
| | - Christopher L Parkinson
- Department of Biological Sciences, Clemson University, 190 Collings St., Clemson, SC, 29634, USA.
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11
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Heptinstall TC, Strickland JL, Rosales-Garcia RA, Rautsaw RM, Simpson CL, Nystrom GS, Ellsworth SA, Hogan MP, Borja M, Fernandes Campos P, Grazziotin FG, Rokyta DR, Junqueira-de-Azevedo ILM, Parkinson CL. Venom phenotype conservation suggests integrated specialization in a lizard-eating snake. Toxicon 2023; 229:107135. [PMID: 37146732 PMCID: PMC11000244 DOI: 10.1016/j.toxicon.2023.107135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 04/18/2023] [Accepted: 04/24/2023] [Indexed: 05/07/2023]
Abstract
Biological specialization reduces the size of niche space while increasing efficiency in the use of available resources. Specialization often leads to phenotypic changes via natural selection aligning with niche space constraints. Commonly observed changes are in size, shape, behavior, and traits associated with feeding. One often selected trait for dietary specialization is venom, which, in snakes, often shows variation dependent on diet across and within species. The Neotropical Blunt-headed Treesnake (Imantodes cenchoa) is a highly specialized, rear-fanged, arboreal, lizard hunter that displays a long thin body, enlarged eyes, and a large Duvernoy's gland. However, toxin characterization of I. cenchoa has never been completed. Here, we use RNA-seq and mass spectrometry to assemble, annotate, and analyze the venom gland transcriptomes of four I. cenchoa from across their range. We find a lack of significant venom variation at the sequence and expression levels, suggesting venom conservation across the species. We propose this conservation provides evidence of a specialized venom repertoire, adapted to maximize efficiency of capturing and processing lizards. Importantly, this study provides the most complete venom gland transcriptomes of I. cenchoa and evidence of venom specialization in a rear-fanged snake, giving insight into selective pressures of venom across all snake species.
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Affiliation(s)
| | - Jason L Strickland
- Department of Biological Sciences, Clemson University, Clemson, SC, 29634, USA; Department of Biology, University of South Alabama, Mobile, AL, 36688, USA
| | | | - Rhett M Rautsaw
- Department of Biological Sciences, Clemson University, Clemson, SC, 29634, USA; School of Biological Sciences, Washington State University, Pullman, WA, 99164, USA; Department of Integrative Biology, University of South Florida, Tampa, FL, 33620, USA
| | - Cassandra L Simpson
- Department of Biological Sciences, Clemson University, Clemson, SC, 29634, USA
| | - Gunnar S Nystrom
- Department of Biological Science, Florida State University, Tallahassee, FL, 32306, USA
| | - Schyler A Ellsworth
- Department of Biological Science, Florida State University, Tallahassee, FL, 32306, USA
| | - Michael P Hogan
- Department of Biological Science, Florida State University, Tallahassee, FL, 32306, USA
| | - Miguel Borja
- Facultad de Ciencias Biológicas, Universdad Juárez del Estado de Durango, Av. Universidad s/n. Fracc. Filadelfia, C.P. 35070, Gómez Palacio, Dgo., Mexico
| | | | - Felipe G Grazziotin
- Laboratório Especial de Colecões Zoológicas, Instituto Butantan, São Paulo, São Paulo, Brazil
| | - Darin R Rokyta
- Department of Biological Science, Florida State University, Tallahassee, FL, 32306, USA
| | | | - Christopher L Parkinson
- Department of Biological Sciences, Clemson University, Clemson, SC, 29634, USA; Department of Forestry and Environmental Conservation, Clemson University, Clemson, SC, 29634, USA.
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12
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Smith CF, Nikolakis ZL, Ivey K, Perry BW, Schield DR, Balchan NR, Parker J, Hansen KC, Saviola AJ, Castoe TA, Mackessy SP. Snakes on a plain: biotic and abiotic factors determine venom compositional variation in a wide-ranging generalist rattlesnake. BMC Biol 2023; 21:136. [PMID: 37280596 DOI: 10.1186/s12915-023-01626-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Accepted: 05/12/2023] [Indexed: 06/08/2023] Open
Abstract
BACKGROUND Snake venoms are trophic adaptations that represent an ideal model to examine the evolutionary factors that shape polymorphic traits under strong natural selection. Venom compositional variation is substantial within and among venomous snake species. However, the forces shaping this phenotypic complexity, as well as the potential integrated roles of biotic and abiotic factors, have received little attention. Here, we investigate geographic variation in venom composition in a wide-ranging rattlesnake (Crotalus viridis viridis) and contextualize this variation by investigating dietary, phylogenetic, and environmental variables that covary with venom. RESULTS Using shotgun proteomics, venom biochemical profiling, and lethality assays, we identify 2 distinct divergent phenotypes that characterize major axes of venom variation in this species: a myotoxin-rich phenotype and a snake venom metalloprotease (SVMP)-rich phenotype. We find that dietary availability and temperature-related abiotic factors are correlated with geographic trends in venom composition. CONCLUSIONS Our findings highlight the potential for snake venoms to vary extensively within species, for this variation to be driven by biotic and abiotic factors, and for the importance of integrating biotic and abiotic variation for understanding complex trait evolution. Links between venom variation and variation in biotic and abiotic factors indicate that venom variation likely results from substantial geographic variation in selection regimes that determine the efficacy of venom phenotypes across populations and snake species. Our results highlight the cascading influence of abiotic factors on biotic factors that ultimately shape venom phenotype, providing evidence for a central role of local selection as a key driver of venom variation.
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Affiliation(s)
- Cara F Smith
- Department of Biological Sciences, University of Northern Colorado, 501 20th Street, Greeley, CO, 80639, USA
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver, 12801 East 17th Avenue, Aurora, CO, 80045, USA
| | - Zachary L Nikolakis
- Department of Biology, University of Texas at Arlington, 501 S. Nedderman Drive, Arlington, TX, 76019, USA
| | - Kathleen Ivey
- Department of Biology, University of Texas at Arlington, 501 S. Nedderman Drive, Arlington, TX, 76019, USA
| | - Blair W Perry
- Department of Biology, University of Texas at Arlington, 501 S. Nedderman Drive, Arlington, TX, 76019, USA
| | - Drew R Schield
- Department of Biology, University of Texas at Arlington, 501 S. Nedderman Drive, Arlington, TX, 76019, USA
- Current address: Department of Ecology & Evolutionary Biology, University of Colorado, 1900 Pleasant Street, Boulder, CO, 80309, USA
| | - Neil R Balchan
- Department of Biological Sciences, University of Northern Colorado, 501 20th Street, Greeley, CO, 80639, USA
| | - Joshua Parker
- Fresno City College, 1101 E. University Avenue, Fresno, CA, 93741, USA
| | - Kirk C Hansen
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver, 12801 East 17th Avenue, Aurora, CO, 80045, USA
| | - Anthony J Saviola
- Department of Biochemistry and Molecular Genetics, University of Colorado Denver, 12801 East 17th Avenue, Aurora, CO, 80045, USA
| | - Todd A Castoe
- Department of Biology, University of Texas at Arlington, 501 S. Nedderman Drive, Arlington, TX, 76019, USA
| | - Stephen P Mackessy
- Department of Biological Sciences, University of Northern Colorado, 501 20th Street, Greeley, CO, 80639, USA.
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13
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Avella I, Damm M, Freitas I, Wüster W, Lucchini N, Zuazo Ó, Süssmuth RD, Martínez-Freiría F. One Size Fits All-Venomics of the Iberian Adder ( Vipera seoanei, Lataste 1878) Reveals Low Levels of Venom Variation across Its Distributional Range. Toxins (Basel) 2023; 15:371. [PMID: 37368672 PMCID: PMC10301717 DOI: 10.3390/toxins15060371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 05/18/2023] [Accepted: 05/30/2023] [Indexed: 06/29/2023] Open
Abstract
European vipers (genus Vipera) are medically important snakes displaying considerable venom variation, occurring at different levels in this group. The presence of intraspecific venom variation, however, remains understudied in several Vipera species. Vipera seoanei is a venomous snake endemic to the northern Iberian Peninsula and south-western France, presenting notable phenotypic variation and inhabiting several diverse habitats across its range. We analysed the venoms of 49 adult specimens of V. seoanei from 20 localities across the species' Iberian distribution. We used a pool of all individual venoms to generate a V. seoanei venom reference proteome, produced SDS-PAGE profiles of all venom samples, and visualised patterns of variation using NMDS. By applying linear regression, we then assessed presence and nature of venom variation between localities, and investigated the effect of 14 predictors (biological, eco-geographic, genetic) on its occurrence. The venom comprised at least 12 different toxin families, of which five (i.e., PLA2, svSP, DI, snaclec, svMP) accounted for about 75% of the whole proteome. The comparative analyses of the SDS-PAGE venom profiles showed them to be remarkably similar across the sampled localities, suggesting low geographic variability. The regression analyses suggested significant effects of biological and habitat predictors on the little variation we detected across the analysed V. seoanei venoms. Other factors were also significantly associated with the presence/absence of individual bands in the SDS-PAGE profiles. The low levels of venom variability we detected within V. seoanei might be the result of a recent population expansion, or of processes other than directional positive selection.
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Affiliation(s)
- Ignazio Avella
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Campus de Vairão, Universidade do Porto, 4485-661 Vairão, Portugal; (I.F.); (N.L.)
- Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, 4099-002 Porto, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, 4485-661 Vairão, Portugal
| | - Maik Damm
- Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 124, 10623 Berlin, Germany; (M.D.)
| | - Inês Freitas
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Campus de Vairão, Universidade do Porto, 4485-661 Vairão, Portugal; (I.F.); (N.L.)
- Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, 4099-002 Porto, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, 4485-661 Vairão, Portugal
| | - Wolfgang Wüster
- Molecular Ecology and Evolution at Bangor, School of Natural Sciences, Bangor University, Bangor LL57 2UW, UK;
| | - Nahla Lucchini
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Campus de Vairão, Universidade do Porto, 4485-661 Vairão, Portugal; (I.F.); (N.L.)
- Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, 4099-002 Porto, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, 4485-661 Vairão, Portugal
| | - Óscar Zuazo
- Calle La Puebla 1, 26250 Santo Domingo de la Calzada, Spain
| | - Roderich D. Süssmuth
- Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 124, 10623 Berlin, Germany; (M.D.)
| | - Fernando Martínez-Freiría
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Campus de Vairão, Universidade do Porto, 4485-661 Vairão, Portugal; (I.F.); (N.L.)
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, 4485-661 Vairão, Portugal
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14
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Venom comparisons of endemic and micro-endemic speckled rattlesnakes Crotalus mitchellii, C. polisi and C. thalassoporus from Baja California Peninsula. Toxicon 2023; 224:107030. [PMID: 36649760 DOI: 10.1016/j.toxicon.2023.107030] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 01/05/2023] [Accepted: 01/12/2023] [Indexed: 01/15/2023]
Abstract
A high diversity of rattlesnake species can be found in the Baja California peninsula and the island of the Gulf of California, nevertheless, their venom has been poorly evaluated. The aim of this work was to present the first characterization of endemic Crotalus mitchellii, micro endemic C. polisi and C. thalassoporus venoms. All samples provoke human plasma coagulation showing doses in the rank of 2.3-41.0 μg and also produce rapid hydrolysis of the alpha chain of bovine fibrinogen while the beta chain is attacked at larger incubation periods by C. polisi and especially by C. thalassoporus. Phospholipase activity ranging from 23.2 to 173.8 U/mg. The venoms of C. thalassoporus and C. polisi show very high hemorrhagic activity (from 0.03 to 0.31 μg). A total of 130 toxin-related proteins were identified and classified into ten families. Crotalus mitchellii venom was characterized by high abundance of crotoxin-like and other phospholipase proteins (34.5%) and serine proteinases (29.8%). Crotalus polisi showed a similar proportion of metalloproteinases (34%) and serine proteinases (22.8%) components with important contribution of C-type lectins (14.3%) and CRiSP (14.0%) proteins. Venom of C. thalassoporus is dominated by metalloproteases that amount to more than 66% of total toxin proteins. These results provide a foundation for comprehending the biological, ecological and evolutionary significance of venom composition of speckled rattlesnake from the Baja California peninsula.
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15
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Smelski G, Cardwell M, Larsen J. Neurotoxic respiratory failure absent following Arizona rattlesnake bites. Toxicon 2023; 224:107034. [PMID: 36690088 DOI: 10.1016/j.toxicon.2023.107034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 01/15/2023] [Accepted: 01/19/2023] [Indexed: 01/21/2023]
Abstract
Warnings of neurotoxic respiratory paralysis following envenomation by rattlesnakes (Crotalus sp.) have been included in numerous scholarly publications over the past 60 years, resulting in fear and anxiety in the public and among clinicians. We examine the validity of the widespread belief that rattlesnakes in the arid southwestern United States, and particularly the Mohave Rattlesnake (Crotalus scutulatus), pose a significant risk of medically relevant respiratory weakness and paralysis in humans. A retrospective review of 3440 suspected rattlesnake bites reported to the Arizona Poison and Drug Information Center between 1999 and 2020 produced no evidence of respiratory weakness in a region with three species known to express significant amounts of neurotoxin in their venoms: Crotalus concolor, C. tigris, and the more widely distributed C. scutulatus. A literature review produced numerous warnings regarding respiratory paralysis following envenomation by rattlesnakes in our region that either lacked references or cited sources that did not contain strong supportive data. We found no case reports of neurotoxic respiratory weakness following Arizona rattlesnake bites in the literature and such reports in surrounding states were scant. We conclude that neurotoxic respiratory failure in this region following rattlesnake envenomation is extraordinarily rare. All rattlesnake bites should receive the same consideration and critical care, and warnings about significant risk of respiratory failure are unwarranted, regardless of species involved.
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Affiliation(s)
- Geoffrey Smelski
- Arizona Poison and Drug Information Center, 1295 N Martin Ave., Tucson, AZ, USA.
| | - Michael Cardwell
- Arizona Poison and Drug Information Center, 1295 N Martin Ave., Tucson, AZ, USA; Department of Biology, San Diego State University, 5500 Campanile Dr., San Diego, CA, USA.
| | - Jaiva Larsen
- Arizona Poison and Drug Information Center, 1295 N Martin Ave., Tucson, AZ, USA; Department of Emergency Medicine, University of Arizona College of Medicine, 1501 N Campbell Ave., Tucson, AZ, USA.
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16
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Grabowsky ER, Saviola AJ, Alvarado-Díaz J, Mascareñas AQ, Hansen KC, Yates JR, Mackessy SP. Montane Rattlesnakes in México: Venoms of Crotalus tancitarensis and Related Species within the Crotalus intermedius Group. Toxins (Basel) 2023; 15:72. [PMID: 36668891 PMCID: PMC9867100 DOI: 10.3390/toxins15010072] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 01/04/2023] [Accepted: 01/10/2023] [Indexed: 01/15/2023] Open
Abstract
The Crotalus intermedius group is a clade of rattlesnakes consisting of several species adapted to a high elevation habitat, primarily in México. Crotalus tancitarensis was previously classified as C. intermedius, until individuals occurring on Cerro Tancítaro in Michoacán, México, were reevaluated and classified as a new species (C. tancitarensis) based on scale pattern and geographic location. This study aimed to characterize the venom of C. tancitarensis and compare the venom profile to those of other species within the Crotalus intermedius group using gel electrophoresis, biochemical assays, reverse-phase high performance liquid chromatography, mass spectrometry, and lethal toxicity (LD50) assays. Results show that the venom profiles of species within the Crotalus intermedius group are similar, but with distinct differences in phospholipase A2 (PLA2), metalloproteinase PI (SVMP PI), and kallikrein-like serine proteinase (SVSP) activity and relative abundance. Proteomic analysis indicated that the highland forms produce venoms with 50-60 protein isoforms and a composition typical of type I rattlesnake venoms (abundant SVMPs, lack of presynaptic PLA2-based neurotoxins), as well as a diversity of typical Crotalus venom components such as serine proteinases, PLA2s, C-type lectins, and less abundant toxins (LAAOs, CRiSPs, etc.). The overall venom profile of C. tancitarensis appears most similar to C. transversus, which is consistent with a previous mitochondrial DNA analysis of the Crotalus intermedius group. These rattlesnakes of the Mexican highlands represent a radiation of high elevation specialists, and in spite of divergence of species in these Sky Island habitats, venom composition of species analyzed here has remained relatively conserved. The majority of protein family isoforms are conserved in all members of the clade, and as seen in other more broadly distributed rattlesnake species, differences in their venoms are largely due to relative concentrations of specific components.
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Affiliation(s)
- Emily R. Grabowsky
- School of Biological Sciences, University of Northern Colorado, Greeley, CO 80639, USA
| | - Anthony J. Saviola
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Department of Molecular Medicine and Neurobiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Javier Alvarado-Díaz
- INIRENA (Instituto de Investigaciones sobre los Recursos Naturales), Morelia CP 58330, Michoacán, Mexico
| | | | - Kirk C. Hansen
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - John R. Yates
- Department of Molecular Medicine and Neurobiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Stephen P. Mackessy
- School of Biological Sciences, University of Northern Colorado, Greeley, CO 80639, USA
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17
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Schield DR, Perry BW, Adams RH, Holding ML, Nikolakis ZL, Gopalan SS, Smith CF, Parker JM, Meik JM, DeGiorgio M, Mackessy SP, Castoe TA. The roles of balancing selection and recombination in the evolution of rattlesnake venom. Nat Ecol Evol 2022; 6:1367-1380. [PMID: 35851850 PMCID: PMC9888523 DOI: 10.1038/s41559-022-01829-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 06/15/2022] [Indexed: 02/02/2023]
Abstract
The origin of snake venom involved duplication and recruitment of non-venom genes into venom systems. Several studies have predicted that directional positive selection has governed this process. Venom composition varies substantially across snake species and venom phenotypes are locally adapted to prey, leading to coevolutionary interactions between predator and prey. Venom origins and contemporary snake venom evolution may therefore be driven by fundamentally different selection regimes, yet investigations of population-level patterns of selection have been limited. Here, we use whole-genome data from 68 rattlesnakes to test hypotheses about the factors that drive genomic diversity and differentiation in major venom gene regions. We show that selection has resulted in long-term maintenance of genetic diversity within and between species in multiple venom gene families. Our findings are inconsistent with a dominant role of directional positive selection and instead support a role of long-term balancing selection in shaping venom evolution. We also detect rapid decay of linkage disequilibrium due to high recombination rates in venom regions, suggesting that venom genes have reduced selective interference with nearby loci, including other venom paralogues. Our results provide an example of long-term balancing selection that drives trans-species polymorphism and help to explain how snake venom keeps pace with prey resistance.
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Affiliation(s)
- Drew R Schield
- Department of Biology, University of Texas at Arlington, Arlington, TX, USA.
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA.
| | - Blair W Perry
- Department of Biology, University of Texas at Arlington, Arlington, TX, USA
- School of Biological Sciences, Washington State University, Pullman, WA, USA
| | - Richard H Adams
- Department of Biological and Environmental Sciences, Georgia College and State University, Milledgeville, GA, USA
| | | | | | | | - Cara F Smith
- School of Biological Sciences, University of Northern Colorado, Greeley, CO, USA
| | - Joshua M Parker
- Life Science Department, Fresno City College, Fresno, CA, USA
| | - Jesse M Meik
- Department of Biological Sciences, Tarleton State University, Stephenville, TX, USA
| | - Michael DeGiorgio
- Department of Electrical Engineering and Computer Science, Florida Atlantic University, Boca Raton, FL, USA
| | - Stephen P Mackessy
- School of Biological Sciences, University of Northern Colorado, Greeley, CO, USA
| | - Todd A Castoe
- Department of Biology, University of Texas at Arlington, Arlington, TX, USA.
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18
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Favourable climatic niche in low elevations outside the flood zone characterises the distribution pattern of venomous snakes in Bangladesh. JOURNAL OF TROPICAL ECOLOGY 2022. [DOI: 10.1017/s0266467422000359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Abstract
Snakes are sensitive to both environmental and climate gradients. To design conservation plans, a scientific understanding of snake habitats in light of environmental and climatic variables is an essential prerequisite. For venomous snakes, denoting favourable habitats should also be relevant for snakebite management. We have considered 18 spatial variables to portray the range of terrestrial venomous snake distribution in Bangladesh. Our results indicate that the distribution of 29 studied venomous snakes in this country is primarily driven by climatic and environmental variables. We found that especially low elevation and flood risk constrain the distribution of those terrestrial snakes, i.e. regular floods in central Bangladesh push venomous snakes towards the edges of the country. Moreover, none of these species occupies the whole of its anticipated climatically favourable area. Projections into the future indicated that 11 studied species, Amphiesma platyceps, Boiga siamensis, Chrysopelea ornata, Pseudoxenodon macrops, Rhabdophis himalayanus, Rhabdophis subminiatus, Bungarus lividus, Ophiophagus hannah, Daboia russelii, Ovophis monticola and Trimeresurus popeiorum will lose their entire climatically suitable area within the country. Therefore, we suggest establishing more protected areas in the hilly ecosystems in the eastern part and in the mangrove forests in the south-western corner of Bangladesh to mitigate future extinction risks, such as climate change, sea-level rise and increase in flood severity. Conserving village forests and croplands, which are subject to rapid change, will also need to be addressed equally, as these are inhabited by almost one-third of the studied species. The occurrence of the cobras and kraits in village forests and cropland dominant habitats demands more attention to minimise snakebite related mortality and morbidity.
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Divergent Specialization of Simple Venom Gene Profiles among Rear-Fanged Snake Genera ( Helicops and Leptodeira, Dipsadinae, Colubridae). Toxins (Basel) 2022; 14:toxins14070489. [PMID: 35878227 PMCID: PMC9319703 DOI: 10.3390/toxins14070489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 07/11/2022] [Accepted: 07/12/2022] [Indexed: 01/27/2023] Open
Abstract
Many venomous animals express toxins that show extraordinary levels of variation both within and among species. In snakes, most studies of venom variation focus on front-fanged species in the families Viperidae and Elapidae, even though rear-fanged snakes in other families vary along the same ecological axes important to venom evolution. Here we characterized venom gland transcriptomes from 19 snakes across two dipsadine rear-fanged genera (Leptodeira and Helicops, Colubridae) and two front-fanged genera (Bothrops, Viperidae; Micrurus, Elapidae). We compared patterns of composition, variation, and diversity in venom transcripts within and among all four genera. Venom gland transcriptomes of rear-fanged Helicops and Leptodeira and front-fanged Micrurus are each dominated by expression of single toxin families (C-type lectins, snake venom metalloproteinase, and phospholipase A2, respectively), unlike highly diverse front-fanged Bothrops venoms. In addition, expression patterns of congeners are much more similar to each other than they are to species from other genera. These results illustrate the repeatability of simple venom profiles in rear-fanged snakes and the potential for relatively constrained venom composition within genera.
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20
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Harrison CM, Colbert J, Richter CJ, McDonald PJ, Trumbull LM, Ellsworth SA, Hogan MP, Rokyta DR, Margres MJ. Using Morphological, Genetic, and Venom Analyses to Present Current and Historic Evidence of Crotalus horridus x adamanteus Hybridization on Jekyll Island, Georgia. SOUTHEAST NAT 2022. [DOI: 10.1656/058.021.0209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
| | - Joseph Colbert
- Jekyll Island Authority Conservation Department, Jekyll Island, GA 31527
| | - Collin J. Richter
- Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602
| | - Preston J. McDonald
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620
| | - Lauren M. Trumbull
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620
| | - Schyler A. Ellsworth
- Department of Biological Sciences, Florida State University, Tallahassee, FL 33306
| | - Michael P. Hogan
- Department of Biological Sciences, Florida State University, Tallahassee, FL 33306
| | - Darin R. Rokyta
- Department of Biological Sciences, Florida State University, Tallahassee, FL 33306
| | - Mark J. Margres
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620
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21
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VenomMaps: Updated species distribution maps and models for New World pitvipers (Viperidae: Crotalinae). Sci Data 2022; 9:232. [PMID: 35614080 PMCID: PMC9132920 DOI: 10.1038/s41597-022-01323-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 04/19/2022] [Indexed: 11/19/2022] Open
Abstract
Beyond providing critical information to biologists, species distributions are useful for naturalists, curious citizens, and applied disciplines including conservation planning and medical intervention. Venomous snakes are one group that highlight the importance of having accurate information given their cosmopolitan distribution and medical significance. Envenomation by snakebite is considered a neglected tropical disease by the World Health Organization and venomous snake distributions are used to assess vulnerability to snakebite based on species occurrence and antivenom/healthcare accessibility. However, recent studies highlighted the need for updated fine-scale distributions of venomous snakes. Pitvipers (Viperidae: Crotalinae) are responsible for >98% of snakebites in the New World. Therefore, to begin to address the need for updated fine-scale distributions, we created VenomMaps, a database and web application containing updated distribution maps and species distribution models for all species of New World pitvipers. With these distributions, biologists can better understand the biogeography and conservation status of this group, researchers can better assess vulnerability to snakebite, and medical professionals can easily discern species found in their area. Measurement(s) | Species Distributions | Technology Type(s) | Geographic Information System • Species Distribution Model (MaxEnt/kuenm) | Factor Type(s) | Occurrence Records • Environmental Data | Sample Characteristic - Organism | Crotalinae | Sample Characteristic - Location | North America • South America |
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22
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Bucciarelli GM, Alsalek F, Kats LB, Green DB, Shaffer HB. Toxic Relationships and Arms-Race Coevolution Revisited. Annu Rev Anim Biosci 2022; 10:63-80. [PMID: 35167315 DOI: 10.1146/annurev-animal-013120-024716] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Toxin evolution in animals is one of the most fascinating and complex subjects of scientific inquiry today. Gaining an understanding of toxins poses a multifaceted challenge given the diverse modes of acquisition, evolutionary adaptations, and abiotic components that affect toxin phenotypes. Here, we highlight some of the main genetic and ecological factors that influence toxin evolution and discuss the role of antagonistic interactions and coevolutionary dynamics in shaping the direction and extent of toxicity and resistance in animals. We focus on toxic Pacific newts (family Salamandridae, genus Taricha) as a system to investigate and better evaluate the widely distributed toxin they possess, tetrodotoxin (TTX), and the hypothesized model of arms-race coevolution with snake predators that is used to explain phenotypic patterns of newt toxicity. Finally, we propose an alternative coevolutionary model that incorporates TTX-producing bacteria and draws from an elicitor-receptor concept to explain TTX evolution and ecology.
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Affiliation(s)
- G M Bucciarelli
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California, USA; , , .,La Kretz Center for California Conservation Science, University of California, Los Angeles, California, USA
| | - Farid Alsalek
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California, USA; , ,
| | - L B Kats
- Natural Science Division, Pepperdine University, Malibu, California, USA; ,
| | - D B Green
- Natural Science Division, Pepperdine University, Malibu, California, USA; ,
| | - H B Shaffer
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California, USA; , , .,La Kretz Center for California Conservation Science, University of California, Los Angeles, California, USA
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23
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Varying Intensities of Introgression Obscure Incipient Venom-Associated Speciation in the Timber Rattlesnake ( Crotalus horridus). Toxins (Basel) 2021; 13:toxins13110782. [PMID: 34822565 PMCID: PMC8625053 DOI: 10.3390/toxins13110782] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 10/14/2021] [Accepted: 10/25/2021] [Indexed: 11/16/2022] Open
Abstract
Ecologically divergent selection can lead to the evolution of reproductive isolation through the process of ecological speciation, but the balance of responsible evolutionary forces is often obscured by an inadequate assessment of demographic history and the genetics of traits under selection. Snake venoms have emerged as a system for studying the genetic basis of adaptation because of their genetic tractability and contributions to fitness, and speciation in venomous snakes can be associated with ecological diversification such as dietary shifts and corresponding venom changes. Here, we explored the neurotoxic (type A)–hemotoxic (type B) venom dichotomy and the potential for ecological speciation among Timber Rattlesnake (Crotalus horridus) populations. Previous work identified the genetic basis of this phenotypic difference, enabling us to characterize the roles geography, history, ecology, selection, and chance play in determining when and why new species emerge or are absorbed. We identified significant genetic, proteomic, morphological, and ecological/environmental differences at smaller spatial scales, suggestive of incipient ecological speciation between type A and type B C. horridus. Range-wide analyses, however, rejected the reciprocal monophyly of venom type, indicative of varying intensities of introgression and a lack of reproductive isolation across the range. Given that we have now established the phenotypic distributions and ecological niche models of type A and B populations, genome-wide data are needed and capable of determining whether type A and type B C. horridus represent distinct, reproductively isolated lineages due to incipient ecological speciation or differentiated populations within a single species.
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24
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Colis-Torres A, Neri-Castro E, Strickland JL, Olvera-Rodríguez A, Borja M, Calvete J, Jones J, Parkinson CL, Bañuelos J, López de León J, Alagón A. Intraspecific venom variation of Mexican West Coast Rattlesnakes (Crotalus basiliscus) and its implications for antivenom production. Biochimie 2021; 192:111-124. [PMID: 34656669 DOI: 10.1016/j.biochi.2021.10.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 09/17/2021] [Accepted: 10/11/2021] [Indexed: 11/02/2022]
Abstract
Intraspecific variation in snake venoms has been widely documented worldwide. However, there are few studies on this subject in Mexico. Venom characterization studies provide important data used to predict clinical syndromes, to evaluate the efficacy of antivenoms and, in some cases, to improve immunogenic mixtures in the production of antivenoms. In the present work, we evaluated the intraspecific venom variation of Crotalus basiliscus, a rattlesnake of medical importance and whose venom is used in the immunization of horses to produce one of the Mexican antivenoms. Our results demonstrate that there is variation in biological and biochemical activities among adult venoms and that there is an ontogenetic change from juvenile to adult venoms. Juvenile venoms were more lethal and had higher percentages of crotamine and crotoxin, while adult venoms had higher percentages of snake venom metalloproteases (SVMPs). Additionally, we documented crotoxin-like PLA2 variation in which specimens from Zacatecas, Sinaloa and Michoacán (except 1) lacked the neurotoxin, while the rest of the venoms had it. Finally, we evaluated the efficacy of three lots of Birmex antivenom and all three were able to neutralize the lethality of four representative venoms but were not able to neutralize crotamine. We also observed significant differences in the LD50 values neutralized per vial among the different lots. Based on these results, we recommend including venoms containing crotamine in the production of antivenom for a better immunogenic mixture and to improve the homogeneity of lots.
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Affiliation(s)
- Andrea Colis-Torres
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico
| | - Edgar Neri-Castro
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico
| | - Jason L Strickland
- Department of Biology, University of South Alabama, 5871 USA Dr. N, Mobile, AL, 36688, USA
| | - Alejandro Olvera-Rodríguez
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico
| | - Miguel Borja
- Facultad Ciencias Biológicas, Universidad Juárez del Estado de Durango, Av. Universidad s/n. Fracc. Filadelfia, C.P. 35010, Gómez Palacio, Dgo, Mexico
| | - Juan Calvete
- Laboratorio de Venómica Evolutiva y Traslacional, Instituto de Biomedicina de Valencia, Consejo Superior de Investigaciones Científicas, Jaime Roig 11, 46010, Valencia, Spain
| | - Jason Jones
- Herp.mx A.C, Villa del Álvarez, Colima, Mexico
| | - Christopher L Parkinson
- Department of Biological Sciences and Department of Forestry, and Environmental Conservation, Clemson University, 190 Collings St. Clemson, SC, 29631, USA
| | - Jorge Bañuelos
- Herp.mx A.C, Villa del Álvarez, Colima, Mexico; Unidad Académica de Ciencias Biológicas, Universidad Autónoma de Zacatecas, Edificio de Biología Campus II Ave. Preparatoria S/N, Col. Agronómica, 98066, ZacatecasZacatecas, Mexico
| | - Jorge López de León
- Hospital General Norberto Treviño Zapata, Ciudad Victoria, Tamaulipas, Mexico
| | - Alejandro Alagón
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico.
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25
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Pintor AF, Ray N, Longbottom J, Bravo-Vega CA, Yousefi M, Murray KA, Ediriweera DS, Diggle PJ. Addressing the global snakebite crisis with geo-spatial analyses - Recent advances and future direction. Toxicon X 2021; 11:100076. [PMID: 34401744 PMCID: PMC8350508 DOI: 10.1016/j.toxcx.2021.100076] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 07/13/2021] [Accepted: 07/14/2021] [Indexed: 02/08/2023] Open
Abstract
Venomous snakebite is a neglected tropical disease that annually leads to hundreds of thousands of deaths or long-term physical and mental ailments across the developing world. Insufficient data on spatial variation in snakebite risk, incidence, human vulnerability, and accessibility of medical treatment contribute substantially to ineffective on-ground management. There is an urgent need to collect data, fill knowledge gaps and address on-ground management problems. The use of novel, and transdisciplinary approaches that take advantage of recent advances in spatio-temporal models, 'big data', high performance computing, and fine-scale spatial information can add value to snakebite management by strategically improving our understanding and mitigation capacity of snakebite. We review the background and recent advances on the topic of snakebite related geospatial analyses and suggest avenues for priority research that will have practical on-ground applications for snakebite management and mitigation. These include streamlined, targeted data collection on snake distributions, snakebites, envenomings, venom composition, health infrastructure, and antivenom accessibility along with fine-scale models of spatio-temporal variation in snakebite risk and incidence, intraspecific venom variation, and environmental change modifying human exposure. These measures could improve and 'future-proof' antivenom production methods, antivenom distribution and stockpiling systems, and human-wildlife conflict management practices, while simultaneously feeding into research on venom evolution, snake taxonomy, ecology, biogeography, and conservation.
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Affiliation(s)
- Anna F.V. Pintor
- Division of Data, Analytics and Delivery for Impact (DDI), World Health Organization, Geneva, Switzerland
- Australian Institute of Tropical Health and Medicine, Division of Tropical Health and Medicine, James Cook University, Cairns, Australia
| | - Nicolas Ray
- GeoHealth Group, Institute of Global Health, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- Institute for Environmental Sciences, University of Geneva, Geneva, Switzerland
| | - Joshua Longbottom
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- Centre for Health Informatics, Computing and Statistics, Lancaster Medical School, Lancaster University, Lancaster, United Kingdom
| | - Carlos A. Bravo-Vega
- Research Group in Mathematical and Computational Biology (BIOMAC), Department of Biomedical Engineering, University of Los Andes, Bogotá, Colombia
| | - Masoud Yousefi
- School of Biology, College of Science, University of Tehran, Iran
| | - Kris A. Murray
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, UK
- MRC Unit the Gambia at London School of Hygiene and Tropical Medicine, Atlantic Blvd, Fajara, Gambia
| | - Dileepa S. Ediriweera
- Health Data Science Unit, Faculty of Medicine, University of Kelaniya, Ragama, Sri Lanka
| | - Peter J. Diggle
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
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26
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Franco-Servín C, Neri-Castro E, Bénard-Valle M, Alagón A, Rosales-García RA, Guerrero-Alba R, Poblano-Sánchez JE, Silva-Briano M, Guerrero-Barrera AL, Sigala-Rodríguez JJ. Biological and Biochemical Characterization of Coronado Island Rattlesnake ( Crotalus helleri caliginis) Venom and Antivenom Neutralization. Toxins (Basel) 2021; 13:toxins13080582. [PMID: 34437453 PMCID: PMC8402616 DOI: 10.3390/toxins13080582] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 08/05/2021] [Accepted: 08/11/2021] [Indexed: 01/18/2023] Open
Abstract
The Baja California Peninsula has over 250 islands and islets with many endemic species. Among them, rattlesnakes are the most numerous but also one of the least studied groups. The study of island rattlesnake venom could guide us to a better understanding of evolutionary processes and the description of novel toxins. Crotalus helleri caliginis venom samples were analyzed to determine possible ontogenetic variation with SDS-PAGE in one and two dimensions and with RP-HPLC. Western Blot, ELISA, and amino-terminal sequencing were used to determine the main components of the venom. The biological and biochemical activities demonstrate the similarity of C. helleri caliginis venom to the continental species C. helleri helleri, with both having low proteolytic and phospholipase A2 (PLA2) activity but differing due to the absence of neurotoxin (crotoxin-like) in the insular species. The main components of the snake venom were metalloproteases, serine proteases, and crotamine, which was the most abundant toxin group (30–35% of full venom). The crotamine was isolated using size-exclusion chromatography where its functional effects were tested on mouse phrenic nerve–hemidiaphragm preparations in which a significant reduction in muscle twitch contractions were observed. The two Mexican antivenoms could neutralize the lethality of C. helleri caliginis venom but not the crotamine effects.
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Affiliation(s)
- Cristian Franco-Servín
- Laboratorio de Biología Celular y Tisular, Departamento de Morfología, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Av. Universidad 940, Aguascalientes CP 20131, Ags, Mexico;
- Colección Zoológica, Departamento de Biología, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Av. Universidad 940, Aguascalientes CP 20131, Ags, Mexico;
| | - Edgar Neri-Castro
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad # 2001 Colonia Chamilpa, Cuernavaca CP 62210, Morelos, Mexico; (E.N.-C.); (M.B.-V.); (A.A.)
| | - Melisa Bénard-Valle
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad # 2001 Colonia Chamilpa, Cuernavaca CP 62210, Morelos, Mexico; (E.N.-C.); (M.B.-V.); (A.A.)
| | - Alejandro Alagón
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad # 2001 Colonia Chamilpa, Cuernavaca CP 62210, Morelos, Mexico; (E.N.-C.); (M.B.-V.); (A.A.)
| | - Ramsés Alejandro Rosales-García
- Colección Zoológica, Departamento de Biología, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Av. Universidad 940, Aguascalientes CP 20131, Ags, Mexico;
| | - Raquel Guerrero-Alba
- Laboratorio de Electrofisiología, Departamento de Fisiología y Farmacología, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Av. Universidad 940, Aguascalientes CP 20131, Ags, Mexico;
| | - José Emanuel Poblano-Sánchez
- Laboratorio Clínico de Especialidades del Hospital General ISSSTE, Av. Universidad 410, Aguascalientes CP 20010, Ags, Mexico;
| | - Marcelo Silva-Briano
- Laboratorio de Ecología, Departamento de Biología, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Av. Universidad 940, Aguascalientes CP 20131, Ags, Mexico;
| | - Alma Lilián Guerrero-Barrera
- Laboratorio de Biología Celular y Tisular, Departamento de Morfología, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Av. Universidad 940, Aguascalientes CP 20131, Ags, Mexico;
- Correspondence: (A.L.G.-B.); (J.J.S.-R.)
| | - José Jesús Sigala-Rodríguez
- Colección Zoológica, Departamento de Biología, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Av. Universidad 940, Aguascalientes CP 20131, Ags, Mexico;
- Correspondence: (A.L.G.-B.); (J.J.S.-R.)
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27
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Calvete JJ, Lomonte B, Saviola AJ, Bonilla F, Sasa M, Williams DJ, Undheim EA, Sunagar K, Jackson TN. Mutual enlightenment: A toolbox of concepts and methods for integrating evolutionary and clinical toxinology via snake venomics and the contextual stance. Toxicon X 2021; 9-10:100070. [PMID: 34195606 PMCID: PMC8234350 DOI: 10.1016/j.toxcx.2021.100070] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 06/01/2021] [Accepted: 06/07/2021] [Indexed: 12/21/2022] Open
Abstract
Snakebite envenoming is a neglected tropical disease that may claim over 100,000 human lives annually worldwide. Snakebite occurs as the result of an interaction between a human and a snake that elicits either a defensive response from the snake or, more rarely, a feeding response as the result of mistaken identity. Snakebite envenoming is therefore a biological and, more specifically, an ecological problem. Snake venom itself is often described as a "cocktail", as it is a heterogenous mixture of molecules including the toxins (which are typically proteinaceous) responsible for the pathophysiological consequences of envenoming. The primary function of venom in snake ecology is pre-subjugation, with defensive deployment of the secretion typically considered a secondary function. The particular composition of any given venom cocktail is shaped by evolutionary forces that include phylogenetic constraints associated with the snake's lineage and adaptive responses to the snake's ecological context, including the taxa it preys upon and by which it is predated upon. In the present article, we describe how conceptual frameworks from ecology and evolutionary biology can enter into a mutually enlightening relationship with clinical toxinology by enabling the consideration of snakebite envenoming from an "ecological stance". We detail the insights that may emerge from such a perspective and highlight the ways in which the high-fidelity descriptive knowledge emerging from applications of -omics era technologies - "venomics" and "antivenomics" - can combine with evolutionary explanations to deliver a detailed understanding of this multifactorial health crisis.
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Affiliation(s)
- Juan J. Calvete
- Evolutionary and Translational Venomics Laboratory, Instituto de Biomedicina de Valencia, CSIC, Valencia, Spain
| | - Bruno Lomonte
- Unidad de Proteómica, Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Anthony J. Saviola
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Fabián Bonilla
- Laboratorio de Investigación en Animales Peligrosos (LIAP), Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Mahmood Sasa
- Laboratorio de Investigación en Animales Peligrosos (LIAP), Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
- Museo de Zoología, Centro de Investigaciones en Biodiversidad y Ecología Tropical, Universidad de Costa Rica, Costa Rica
| | | | - Eivind A.B. Undheim
- Centre for Biodiversity Dynamics, Department of Biology, NTNU, Trondheim, Norway
- Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Kartik Sunagar
- Evolutionary Venomics Lab, Centre for Ecological Sciences, Indian Institute of Science, Bangalore, Karnataka, India
| | - Timothy N.W. Jackson
- Australian Venom Research Unit, Department of Pharmacology and Therapeutics, University of Melbourne, Melbourne, Australia
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28
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Hofmann EP, Rautsaw RM, Mason AJ, Strickland JL, Parkinson CL. Duvernoy's Gland Transcriptomics of the Plains Black-Headed Snake, Tantilla nigriceps (Squamata, Colubridae): Unearthing the Venom of Small Rear-Fanged Snakes. Toxins (Basel) 2021; 13:toxins13050336. [PMID: 34066626 PMCID: PMC8148590 DOI: 10.3390/toxins13050336] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 05/03/2021] [Accepted: 05/04/2021] [Indexed: 12/13/2022] Open
Abstract
The venoms of small rear-fanged snakes (RFS) remain largely unexplored, despite increased recognition of their importance in understanding venom evolution more broadly. Sequencing the transcriptome of venom-producing glands has greatly increased the ability of researchers to examine and characterize the toxin repertoire of small taxa with low venom yields. Here, we use RNA-seq to characterize the Duvernoy’s gland transcriptome of the Plains Black-headed Snake, Tantilla nigriceps, a small, semi-fossorial colubrid that feeds on a variety of potentially dangerous arthropods including centipedes and spiders. We generated transcriptomes of six individuals from three localities in order to both characterize the toxin expression of this species for the first time, and to look for initial evidence of venom variation in the species. Three toxin families—three-finger neurotoxins (3FTxs), cysteine-rich secretory proteins (CRISPs), and snake venom metalloproteinases (SVMPIIIs)—dominated the transcriptome of T. nigriceps; 3FTx themselves were the dominant toxin family in most individuals, accounting for as much as 86.4% of an individual’s toxin expression. Variation in toxin expression between individuals was also noted, with two specimens exhibiting higher relative expression of c-type lectins than any other sample (8.7–11.9% compared to <1%), and another expressed CRISPs higher than any other toxin. This study provides the first Duvernoy’s gland transcriptomes of any species of Tantilla, and one of the few transcriptomic studies of RFS not predicated on a single individual. This initial characterization demonstrates the need for further study of toxin expression variation in this species, as well as the need for further exploration of small RFS venoms.
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Affiliation(s)
- Erich P. Hofmann
- Department of Biological Sciences, Clemson University, Clemson, SC 29634, USA; (E.P.H.); (R.M.R.); (A.J.M.); (J.L.S.)
| | - Rhett M. Rautsaw
- Department of Biological Sciences, Clemson University, Clemson, SC 29634, USA; (E.P.H.); (R.M.R.); (A.J.M.); (J.L.S.)
| | - Andrew J. Mason
- Department of Biological Sciences, Clemson University, Clemson, SC 29634, USA; (E.P.H.); (R.M.R.); (A.J.M.); (J.L.S.)
| | - Jason L. Strickland
- Department of Biological Sciences, Clemson University, Clemson, SC 29634, USA; (E.P.H.); (R.M.R.); (A.J.M.); (J.L.S.)
| | - Christopher L. Parkinson
- Department of Biological Sciences, Clemson University, Clemson, SC 29634, USA; (E.P.H.); (R.M.R.); (A.J.M.); (J.L.S.)
- Department of Forestry and Environmental Conservation, Clemson University, Clemson, SC 29634, USA
- Correspondence:
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29
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Wood AW, Duda TF. Reticulate evolution in Conidae: Evidence of nuclear and mitochondrial introgression. Mol Phylogenet Evol 2021; 161:107182. [PMID: 33892099 DOI: 10.1016/j.ympev.2021.107182] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 04/07/2021] [Accepted: 04/15/2021] [Indexed: 10/21/2022]
Abstract
Conidae is a hyperdiverse family of marine snails that has many hallmarks of adaptive radiation. Hybridization and introgression may contribute to such instances of rapid diversification by generating novel gene combinations that facilitate exploitation of distinct niches. Here we evaluated whether or not these mechanisms may have contributed to the evolutionary history of a subgenus of Conidae (Virroconus). Several observations hint at evidence of past introgression for members of this group, including incongruence between phylogenetic relationships inferred from mitochondrial gene sequences and morphology and widespread sympatry of many Virroconus species in the Indo-West Pacific. We generated and analyzed transcriptome data of Virroconus species to (i) infer a robust nuclear phylogeny, (ii) assess mitochondrial and nuclear gene tree discordance, and (iii) formally test for introgression of nuclear loci. We identified introgression of mitochondrial genomes and nuclear gene regions between ancestors of one pair of Virroconus species, and mitochondrial introgression between another pair. We also found evidence of adaptive introgression of conotoxin venom loci between a third pair of species. Together, our results demonstrate that hybridization and introgression impacted the evolutionary history of Virroconus and hence may have contributed to the adaptive radiation of Conidae.
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Affiliation(s)
- Andrew W Wood
- University of Michigan, Department of Ecology & Evolutionary Biology, 1105 North University Avenue, Biological Sciences Building, Ann Arbor, MI 48109-1085, USA.
| | - Thomas F Duda
- University of Michigan, Department of Ecology & Evolutionary Biology, 1105 North University Avenue, Biological Sciences Building, Ann Arbor, MI 48109-1085, USA.
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op den Brouw B, Coimbra FCP, Bourke LA, Huynh TM, Vlecken DHW, Ghezellou P, Visser JC, Dobson JS, Fernandez-Rojo MA, Ikonomopoulou MP, Casewell NR, Ali SA, Fathinia B, Hodgson WC, Fry BG. Extensive Variation in the Activities of Pseudocerastes and Eristicophis Viper Venoms Suggests Divergent Envenoming Strategies Are Used for Prey Capture. Toxins (Basel) 2021; 13:112. [PMID: 33540884 PMCID: PMC7913145 DOI: 10.3390/toxins13020112] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 01/27/2021] [Accepted: 01/27/2021] [Indexed: 11/28/2022] Open
Abstract
Snakes of the genera Pseudocerastes and Eristicophis (Viperidae: Viperinae) are known as the desert vipers due to their association with the arid environments of the Middle East. These species have received limited research attention and little is known about their venom or ecology. In this study, a comprehensive analysis of desert viper venoms was conducted by visualising the venom proteomes via gel electrophoresis and assessing the crude venoms for their cytotoxic, haemotoxic, and neurotoxic properties. Plasmas sourced from human, toad, and chicken were used as models to assess possible prey-linked venom activity. The venoms demonstrated substantial divergence in composition and bioactivity across all experiments. Pseudocerastes urarachnoides venom activated human coagulation factors X and prothrombin and demonstrated potent procoagulant activity in human, toad, and chicken plasmas, in stark contrast to the potent neurotoxic venom of P. fieldi. The venom of E. macmahonii also induced coagulation, though this did not appear to be via the activation of factor X or prothrombin. The coagulant properties of P. fieldi and P. persicus venoms varied among plasmas, demonstrating strong anticoagulant activity in the amphibian and human plasmas but no significant effect in that of bird. This is conjectured to reflect prey-specific toxin activity, though further ecological studies are required to confirm any dietary associations. This study reinforces the notion that phylogenetic relatedness of snakes cannot readily predict venom protein composition or function. The significant venom variation between these species raises serious concerns regarding antivenom paraspecificity. Future assessment of antivenom is crucial.
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Affiliation(s)
- Bianca op den Brouw
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia; (F.C.P.C.); (L.A.B.); (J.C.V.); (J.S.D.)
| | - Francisco C. P. Coimbra
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia; (F.C.P.C.); (L.A.B.); (J.C.V.); (J.S.D.)
| | - Lachlan A. Bourke
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia; (F.C.P.C.); (L.A.B.); (J.C.V.); (J.S.D.)
| | - Tam Minh Huynh
- Monash Venom Group, Faculty of Medicine, Nursing & Health Sciences, Monash University, Clayton, VIC 3800, Australia; (T.M.H.); (W.C.H.)
| | - Danielle H. W. Vlecken
- Department of Animal Science and Health, Institute of Biology Leiden, 2333 BE Leiden, The Netherlands;
| | - Parviz Ghezellou
- Medicinal Plants and Drugs Research Institute, Shahid Beheshti University, 1983969411 Tehran, Iran;
- Institute of Inorganic and Analytical Chemistry, Justus Liebig University Giessen, 35392 Giessen, Germany
| | - Jeroen C. Visser
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia; (F.C.P.C.); (L.A.B.); (J.C.V.); (J.S.D.)
| | - James S. Dobson
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia; (F.C.P.C.); (L.A.B.); (J.C.V.); (J.S.D.)
| | - Manuel A. Fernandez-Rojo
- Madrid Institute for Advanced Studies in Food, E28049 Madrid, Spain; (M.A.F.-R.); (M.P.I.)
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Maria P. Ikonomopoulou
- Madrid Institute for Advanced Studies in Food, E28049 Madrid, Spain; (M.A.F.-R.); (M.P.I.)
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Nicholas R. Casewell
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK;
| | - Syed A. Ali
- HEJ Research Institute of Chemistry, International Centre for Chemical and Biological Sciences (ICCBS), University of Karachi, Karachi 75270, Pakistan;
| | - Behzad Fathinia
- Department of Biology, Faculty of Science, Yasouj University, 75914 Yasouj, Iran;
| | - Wayne C. Hodgson
- Monash Venom Group, Faculty of Medicine, Nursing & Health Sciences, Monash University, Clayton, VIC 3800, Australia; (T.M.H.); (W.C.H.)
| | - Bryan G. Fry
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia; (F.C.P.C.); (L.A.B.); (J.C.V.); (J.S.D.)
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31
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Margres MJ, Rautsaw RM, Strickland JL, Mason AJ, Schramer TD, Hofmann EP, Stiers E, Ellsworth SA, Nystrom GS, Hogan MP, Bartlett DA, Colston TJ, Gilbert DM, Rokyta DR, Parkinson CL. The Tiger Rattlesnake genome reveals a complex genotype underlying a simple venom phenotype. Proc Natl Acad Sci U S A 2021; 118:e2014634118. [PMID: 33468678 PMCID: PMC7848695 DOI: 10.1073/pnas.2014634118] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Variation in gene regulation is ubiquitous, yet identifying the mechanisms producing such variation, especially for complex traits, is challenging. Snake venoms provide a model system for studying the phenotypic impacts of regulatory variation in complex traits because of their genetic tractability. Here, we sequence the genome of the Tiger Rattlesnake, which possesses the simplest and most toxic venom of any rattlesnake species, to determine whether the simple venom phenotype is the result of a simple genotype through gene loss or a complex genotype mediated through regulatory mechanisms. We generate the most contiguous snake-genome assembly to date and use this genome to show that gene loss, chromatin accessibility, and methylation levels all contribute to the production of the simplest, most toxic rattlesnake venom. We provide the most complete characterization of the venom gene-regulatory network to date and identify key mechanisms mediating phenotypic variation across a polygenic regulatory network.
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Affiliation(s)
- Mark J Margres
- Department of Biological Sciences, Clemson University, Clemson, SC 29634;
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620
| | - Rhett M Rautsaw
- Department of Biological Sciences, Clemson University, Clemson, SC 29634
| | - Jason L Strickland
- Department of Biological Sciences, Clemson University, Clemson, SC 29634
- Department of Biology, University of South Alabama, Mobile, AL 36688
| | - Andrew J Mason
- Department of Biological Sciences, Clemson University, Clemson, SC 29634
| | - Tristan D Schramer
- Department of Biological Sciences, Clemson University, Clemson, SC 29634
| | - Erich P Hofmann
- Department of Biological Sciences, Clemson University, Clemson, SC 29634
| | - Erin Stiers
- Department of Biological Sciences, Clemson University, Clemson, SC 29634
| | - Schyler A Ellsworth
- Department of Biological Science, Florida State University, Tallahassee, FL 32306
| | - Gunnar S Nystrom
- Department of Biological Science, Florida State University, Tallahassee, FL 32306
| | - Michael P Hogan
- Department of Biological Science, Florida State University, Tallahassee, FL 32306
| | - Daniel A Bartlett
- Department of Biological Science, Florida State University, Tallahassee, FL 32306
| | - Timothy J Colston
- Department of Biological Science, Florida State University, Tallahassee, FL 32306
| | - David M Gilbert
- Department of Biological Science, Florida State University, Tallahassee, FL 32306
| | - Darin R Rokyta
- Department of Biological Science, Florida State University, Tallahassee, FL 32306
| | - Christopher L Parkinson
- Department of Biological Sciences, Clemson University, Clemson, SC 29634;
- Department of Forestry and Environmental Conservation, Clemson University, Clemson, SC 29634
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32
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Lara-Galván JL, Martínez-Montoya JF, Sigala-Rodríguez JJ, Esparza-Estrada CE, Rosas-Rosas OC, Ávila-Herrera L, Barbosa AM. Rattlesnake ( Crotalus spp.) distribution and diversity in Zacatecas, Mexico. Zookeys 2020; 1005:103-132. [PMID: 33390757 PMCID: PMC7762751 DOI: 10.3897/zookeys.1005.56964] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 11/03/2020] [Indexed: 01/22/2023] Open
Abstract
Mexico is home to a large number of reptile species and has one of the greatest diversities of venomous snakes, among which the rattlesnakes pertaining to the Crotalus genus stand out. Out of more than 40 species in the country, nine are found in Zacatecas: C.aquilus, C.atrox, C.basiliscus, C.lepidus, C.molossus, C.polystictus, C.pricei, C.scutulatus and C.willardi. Although these reptiles are important, due to their relevance in terms of ecology, cultural use and public health, their conservation is impacted by multiple factors, such as habitat fragmentation and indiscriminate killing. Thus, most species within this genus are found in some type of risk category at both the national and international level. The purpose of this study was to determine the potential distribution and diversity of rattlesnakes at the municipal level in the understudied state of Zacatecas. To do this, we analyzed and described the global distribution of nine rattlesnake species by building species distribution models, which determined their potential distribution based on a set of ecological variables and presence records. The resulting models were used to assess the diversity of rattlesnake species potentially present in each municipality within the state. Thirty-nine (67.24 %) out of fifty-eight municipalities registered at least one rattlesnake species. Fresnillo, Sombrerete and Valparaíso were some of the municipalities showing greatest diversity. Moreover, C.atrox, C.lepidus, C.molossus and C.scutulatus were the most widely found species in the state. On the other hand, C.basiliscus, C.polystictus, C.pricei and C.willardi were rarely spotted and so, information on their distribution patterns within Zacatecas is limited. Finally, the areas having the largest potential for the distribution of these species were defined. These findings should make field work much more time- and cost-effective, facilitating the collection of in situ data that are useful for management and conservation plans of these species in Zacatecas.
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Affiliation(s)
- Jesús Lenin Lara-Galván
- Colegio de Postgraduados, Campus San Luis Potosí, Posgrado en Innovación en Manejo de Recursos Naturales. Iturbide 73, Salinas de Hidalgo, San Luis Potosí, CP. 78622, México Colegio de Postgraduados Salinas de Hidalgo Mexico
| | - Juan Felipe Martínez-Montoya
- Colegio de Postgraduados, Campus San Luis Potosí, Posgrado en Innovación en Manejo de Recursos Naturales. Iturbide 73, Salinas de Hidalgo, San Luis Potosí, CP. 78622, México Colegio de Postgraduados Salinas de Hidalgo Mexico
| | - José Jesús Sigala-Rodríguez
- Colección Zoológica. Universidad Autónoma de Aguascalientes. Aguascalientes, Ags. CP. 20131, México Universidad Autónoma de Aguascalientes Aguascalientes Mexico
| | - Citlalli Edith Esparza-Estrada
- Colección Zoológica. Universidad Autónoma de Aguascalientes. Aguascalientes, Ags. CP. 20131, México Universidad Autónoma de Aguascalientes Aguascalientes Mexico.,Instituto de Ecología, A.C., Red de Biología Evolutiva, Laboratorio de Macroecología Evolutiva. Carretera Antigua a Coatepec 351, El Haya, Xalapa, CP. 91070, Veracruz, México Instituto de Ecología, A.C. Xalapa Mexico
| | - Octavio César Rosas-Rosas
- Colegio de Postgraduados, Campus San Luis Potosí, Posgrado en Innovación en Manejo de Recursos Naturales. Iturbide 73, Salinas de Hidalgo, San Luis Potosí, CP. 78622, México Colegio de Postgraduados Salinas de Hidalgo Mexico
| | - Lucía Ávila-Herrera
- Presidencia Municipal de Valparaíso. Constitución Sn, Capulín de la Sierra, CP. 99200. Valparaíso, Zacatecas, México Presidencia Municipal de Valparaíso Valparaíso Mexico
| | - A Márcia Barbosa
- CIBIO/InBIO, Universidade de Évora. 7004-516. Évora. Portugal Universidade de Évora Évora Portugal
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33
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Neri-Castro E, Sanz L, Olvera-Rodríguez A, Bénard-Valle M, Alagón A, Calvete JJ. Venomics and biochemical analysis of the black-tailed horned pitviper, Mixcoatlus melanurus, and characterization of Melanurutoxin, a novel crotoxin homolog. J Proteomics 2020; 225:103865. [DOI: 10.1016/j.jprot.2020.103865] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 05/28/2020] [Accepted: 06/03/2020] [Indexed: 10/24/2022]
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Lomonte B, Díaz C, Chaves F, Fernández J, Ruiz M, Salas M, Zavaleta A, Calvete JJ, Sasa M. Comparative characterization of Viperidae snake venoms from Perú reveals two compositional patterns of phospholipase A 2 expression. Toxicon X 2020; 7:100044. [PMID: 32550596 PMCID: PMC7285926 DOI: 10.1016/j.toxcx.2020.100044] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 05/09/2020] [Accepted: 05/25/2020] [Indexed: 12/16/2022] Open
Abstract
Snake species within the Bothrops complex (sensu lato) are of medical relevance in Latin America, but knowledge on their venom characteristics is limited, or even unavailable, for some taxa. Perú harbors 17 species of pit vipers, within the genera Bothrops, Bothriechis, Bothrocophias, Porthidium, Crotalus, and Lachesis. This study compared the venoms of twelve species, through chromatographic and electrophoretic profiles, as well as proteolytic and phospholipase A2 (PLA2) activities. Also, proteomic profiles were analyzed for nine of the venoms using a shotgun approach. Results unveiled conspicuous differences in the expression of venom PLA2s among species, six of them presenting scarce levels as judged by RP-HPLC profiles. Since most species within the bothropoid lineage possess venoms with high to intermediate abundances of this protein family, our findings suggest the existence of a phenotypic duality in the expression of venom PLA2s within the Bothrops (sensu lato) complex. Bothrops barnetti and Bothrocophias andianus venoms, very scarce in PLA2s, were shown to lack significant myotoxic activity, highlighting that the observed variability in PLA2 expression bears toxicological correlations with effects attributed to these proteins. Finally, an attempt to identify phylogenetic relationships of bothropoid species from Perú presenting low- or high-PLA2 venom phenotypes showed an interspersed pattern, thus precluding a simple phylogenetic interpretation of this venom compositional dichotomy. Venoms from 12 viperids of Perú were compared. Conspicuous differences in the expression of PLA2 were found. Venoms presenting scarce levels of PLA2 lack myotoxicity. A new phenotypic dichotomy in venom PLA2 expression is described within Bothrops (sensu lato).
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Affiliation(s)
- Bruno Lomonte
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Cecilia Díaz
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica.,Departamento de Bioquímica, Escuela de Medicina, Universidad de Costa Rica, San José, Costa Rica
| | - Fernando Chaves
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Julián Fernández
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Marco Ruiz
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - María Salas
- Departamento Académico de Ciencias Celulares y Moleculares, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Alfonso Zavaleta
- Departamento Académico de Ciencias Celulares y Moleculares, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Juan J Calvete
- Laboratorio de Venómica Evolutiva y Traslacional, Instituto de Biomedicina de Valencia, CSIC, Valencia, Spain
| | - Mahmood Sasa
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica.,Escuela de Biología, Universidad de Costa Rica, San José, Costa Rica
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35
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Zancolli G, Calvete JJ, Cardwell MD, Greene HW, Hayes WK, Hegarty MJ, Herrmann HW, Holycross AT, Lannutti DI, Mulley JF, Sanz L, Travis ZD, Whorley JR, Wüster CE, Wüster W. When one phenotype is not enough: divergent evolutionary trajectories govern venom variation in a widespread rattlesnake species. Proc Biol Sci 2020; 286:20182735. [PMID: 30862287 DOI: 10.1098/rspb.2018.2735] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
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. Unexpectedly, neither diet composition nor neutral population structure explain venom variation. Instead, venom divergence is strongly correlated with environmental conditions. Individual toxin genes correlate with distinct environmental factors, suggesting that different selective pressures can act on individual loci independently of their co-expression patterns or genomic proximity. Our results challenge common assumptions about diet composition as the key selective driver of snake venom evolution and emphasize how the interplay between genomic architecture and local-scale spatial heterogeneity in selective pressures may facilitate the retention of adaptive functional polymorphisms across a continuous space.
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Affiliation(s)
- Giulia Zancolli
- 1 Molecular Ecology and Fisheries Genetics Laboratory, School of Natural Sciences, Bangor University , Bangor LL57 2UW , UK
| | - Juan J Calvete
- 2 Evolutionary and Translational Venomics Laboratory, CSIC , Jaume Roig 11, Valencia 46010 , Spain
| | - Michael D Cardwell
- 3 Department of Biology, San Diego State University , San Diego, CA 92182 , USA
| | - Harry W Greene
- 4 Department of Ecology and Evolutionary Biology, Cornell University , Corson Hall, Ithaca, NY 14853 , USA
| | - William K Hayes
- 5 Department of Earth and Biological Sciences, School of Medicine, Loma Linda University , Loma Linda, CA 92350 , USA
| | - Matthew J Hegarty
- 6 Institute of Biological, Environmental and Rural Sciences, Aberystwyth University , Aberystwyth SY23 3EE , UK
| | - Hans-Werner Herrmann
- 7 Wildlife Conservation and Management, School of Natural Resources and the Environment, University of Arizona , 1064 East Lowell Street (ENR2), Tucson, AZ 85721 , USA
| | - Andrew T Holycross
- 8 Natural History Collections, Arizona State University , 734 W. Alameda Drive, Tempe, AZ 85282 , USA
| | - Dominic I Lannutti
- 9 Department of Biological Sciences, University of Texas at El Paso , 500 W. University, El Paso, TX 79968 , USA
| | - John F Mulley
- 1 Molecular Ecology and Fisheries Genetics Laboratory, School of Natural Sciences, Bangor University , Bangor LL57 2UW , UK
| | - Libia Sanz
- 2 Evolutionary and Translational Venomics Laboratory, CSIC , Jaume Roig 11, Valencia 46010 , Spain
| | - Zachary D Travis
- 5 Department of Earth and Biological Sciences, School of Medicine, Loma Linda University , Loma Linda, CA 92350 , USA
| | - Joshua R Whorley
- 10 Seattle Central College, Science, Technology, Engineering & Mathematics Division , 1701 Broadway Ave. E., Seattle, WA 98122 , USA
| | - Catharine E Wüster
- 1 Molecular Ecology and Fisheries Genetics Laboratory, School of Natural Sciences, Bangor University , Bangor LL57 2UW , UK
| | - Wolfgang Wüster
- 1 Molecular Ecology and Fisheries Genetics Laboratory, School of Natural Sciences, Bangor University , Bangor LL57 2UW , UK
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Mason AJ, Margres MJ, Strickland JL, Rokyta DR, Sasa M, Parkinson CL. Trait differentiation and modular toxin expression in palm-pitvipers. BMC Genomics 2020; 21:147. [PMID: 32046632 PMCID: PMC7014597 DOI: 10.1186/s12864-020-6545-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 01/30/2020] [Indexed: 12/22/2022] Open
Abstract
Background Modularity is the tendency for systems to organize into semi-independent units and can be a key to the evolution and diversification of complex biological systems. Snake venoms are highly variable modular systems that exhibit extreme diversification even across very short time scales. One well-studied venom phenotype dichotomy is a trade-off between neurotoxicity versus hemotoxicity that occurs through the high expression of a heterodimeric neurotoxic phospholipase A2 (PLA2) or snake venom metalloproteinases (SVMPs). We tested whether the variation in these venom phenotypes could occur via variation in regulatory sub-modules through comparative venom gland transcriptomics of representative Black-Speckled Palm-Pitvipers (Bothriechis nigroviridis) and Talamancan Palm-Pitvipers (B. nubestris). Results We assembled 1517 coding sequences, including 43 toxins for B. nigroviridis and 1787 coding sequences including 42 toxins for B. nubestris. The venom gland transcriptomes were extremely divergent between these two species with one B. nigroviridis exhibiting a primarily neurotoxic pattern of expression, both B. nubestris expressing primarily hemorrhagic toxins, and a second B. nigroviridis exhibiting a mixed expression phenotype. Weighted gene coexpression analyses identified six submodules of transcript expression variation, one of which was highly associated with SVMPs and a second which contained both subunits of the neurotoxic PLA2 complex. The sub-module association of these toxins suggest common regulatory pathways underlie the variation in their expression and is consistent with known patterns of inheritance of similar haplotypes in other species. We also find evidence that module associated toxin families show fewer gene duplications and transcript losses between species, but module association did not appear to affect sequence diversification. Conclusion Sub-modular regulation of expression likely contributes to the diversification of venom phenotypes within and among species and underscores the role of modularity in facilitating rapid evolution of complex traits.
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Affiliation(s)
- Andrew J Mason
- Department of Biological Sciences, Clemson University, 190 Collings St., Clemson, SC, 29634, USA
| | - Mark J Margres
- Department of Biological Sciences, Clemson University, 190 Collings St., Clemson, SC, 29634, USA
| | - Jason L Strickland
- Department of Biological Sciences, Clemson University, 190 Collings St., Clemson, SC, 29634, USA
| | - Darin R Rokyta
- Department of Biological Sciences, Florida State University, Tallahassee, FL, 24105, USA
| | - Mahmood Sasa
- Instituto Clodomiro Picado, Facultad de Microbiologia, Universidad de Costa Rica, San Jose, Costa Rica
| | - Christopher L Parkinson
- Department of Biological Sciences, Clemson University, 190 Collings St., Clemson, SC, 29634, USA. .,Department of Forestry, and Environmental Conservation, Clemson University, Clemson, SC, USA.
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37
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Kitahara MV, Jaimes‐Becerra A, Gamero‐Mora E, Padilla G, Doonan LB, Ward M, Marques AC, Morandini AC, Long PF. Reciprocal transplantation of the heterotrophic coral Tubastraea coccinea (Scleractinia: Dendrophylliidae) between distinct habitats did not alter its venom toxin composition. Ecol Evol 2020; 10:1794-1803. [PMID: 32128117 PMCID: PMC7042732 DOI: 10.1002/ece3.5959] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 12/06/2019] [Accepted: 12/09/2019] [Indexed: 12/11/2022] Open
Abstract
Tubastraea coccinea is an azooxanthellate coral species recorded in the Indian and Atlantic oceans and is presently widespread in the southwestern Atlantic with an alien status for Brazil. T. coccinea outcompete other native coral species by using a varied repertoire of biological traits. For example, T. coccinea has evolved potent venom capable of immobilizing and digesting zooplankton prey. Diversification and modification of venom toxins can provide potential adaptive benefits to individual fitness, yet acquired alteration of venom composition in cnidarians is poorly understood as the adaptive flexibility affecting toxin composition in these ancient lineages has been largely ignored. We used quantitative high-throughput proteomics to detect changes in toxin expression in clonal fragments of specimens collected and interchanged from two environmentally distinct and geographically separate study sites. Unexpectedly, despite global changes in protein expression, there were no changes in the composition and abundance of toxins from coral fragments recovered from either site, and following clonal transplantation between sites. There were also no apparent changes to the cnidome (cnidae) and gross skeletal or soft tissue morphologies of the specimens. These results suggest that the conserved toxin complexity of T. coccinea co-evolved with innovation of the venom delivery system, and its morphological development and phenotypic expression are not modulated by habitat pressures over short periods of time. The adaptive response of the venom trait to specific predatory regimes, however, necessitates further consideration.
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Affiliation(s)
- Marcelo V. Kitahara
- Departamento de Ciências do MarUniversidade Federal de São PauloSantosBrazil
- Centro de Biologia Marinha (CEBIMar)Universidade de São PauloSão SebastiãoBrazil
| | - Adrian Jaimes‐Becerra
- Departamento de ZoologiaInstituto de BiociênciasUniversidade de São PauloSão PauloBrazil
| | - Edgar Gamero‐Mora
- Departamento de ZoologiaInstituto de BiociênciasUniversidade de São PauloSão PauloBrazil
| | - Gabriel Padilla
- Departmento de MicrobiologiaInstituto de Ciências BiomédicasUniversidade de São PauloSão PauloBrazil
| | - Liam B. Doonan
- School of Cancer & Pharmaceutical SciencesFaculty of Life Sciences & MedicineKing's College LondonLondonUK
| | | | - Antonio C. Marques
- Departamento de ZoologiaInstituto de BiociênciasUniversidade de São PauloSão PauloBrazil
| | - André C. Morandini
- Departamento de ZoologiaInstituto de BiociênciasUniversidade de São PauloSão PauloBrazil
| | - Paul F. Long
- School of Cancer & Pharmaceutical SciencesFaculty of Life Sciences & MedicineKing's College LondonLondonUK
- Faculdade de Ciências FarmacêuticasUniversidade de São PauloSão PauloBrazil
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38
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Barkan NP, Chevalier M, Pradervand JN, Guisan A. Alteration of Bumblebee Venom Composition toward Higher Elevation. Toxins (Basel) 2019; 12:toxins12010004. [PMID: 31861682 PMCID: PMC7020474 DOI: 10.3390/toxins12010004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 12/11/2019] [Accepted: 12/17/2019] [Indexed: 12/12/2022] Open
Abstract
Venomous animals use venom, a complex biofluid composed of unique mixtures of proteins and peptides, for either predation or defense. Bumblebees, which occur in various habitats due to their unique thermoregulatory properties, mainly use venom for defense. Herein, we conducted an exploratory analysis of the venom composition of a bumblebee species (Bombus pascuorum) along an elevation gradient in the western Swiss Alps using shot-gun proteomic approaches to assess whether their defense mechanism varies along the gradient. The gradient was characterized by high temperatures and low humidity at low elevations and low temperatures and high humidity at high elevations. Venom composition is changing along the elevation gradient, with proteomic variation in the abundances of pain-inducing and allergenic proteins. In particular, the abundance of phospholipase A2-like, the main component of bumblebee venom, gradually decreases toward higher elevation (lower temperature), suggesting venom alteration and thus a decrease in bumblebee defense towards harsher environments. Larger datasets may complement this study to validate the observed novel trends.
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Affiliation(s)
- Nezahat Pınar Barkan
- Department of Ecology and Evolution, University of Lausanne, CH-1015 Biophore, Lausanne, Switzerland; (N.P.B.); (M.C.)
| | - Mathieu Chevalier
- Department of Ecology and Evolution, University of Lausanne, CH-1015 Biophore, Lausanne, Switzerland; (N.P.B.); (M.C.)
| | - Jean-Nicolas Pradervand
- Swiss Ornithological Institute, Valais Field Station, Rue du Rhône 11, CH-1950 Sion, Switzerland;
| | - Antoine Guisan
- Department of Ecology and Evolution, University of Lausanne, CH-1015 Biophore, Lausanne, Switzerland; (N.P.B.); (M.C.)
- Institute of Earth Surface Dynamics, University of Lausanne, CH-1015 Géopolis, Lausanne, Switzerland
- Correspondence: ; Tel.: +41-(0)21-692-42-54
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Rautsaw RM, Hofmann EP, Margres MJ, Holding ML, Strickland JL, Mason AJ, Rokyta DR, Parkinson CL. Intraspecific sequence and gene expression variation contribute little to venom diversity in sidewinder rattlesnakes ( Crotalus cerastes). Proc Biol Sci 2019; 286:20190810. [PMID: 31266424 DOI: 10.1098/rspb.2019.0810] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Traits can evolve rapidly through changes in gene expression or protein-coding sequences. However, these forms of genetic variation can be correlated and changes to one can influence the other. As a result, we might expect traits lacking differential expression to preferentially evolve through changes in protein sequences or morphological adaptation. Given the lack of differential expression across the distribution of sidewinder rattlesnakes ( Crotalus cerastes), we tested this hypothesis by comparing the coding regions of genes expressed in the venom gland transcriptomes and fang morphology. We calculated Tajima's D and FST across four populations comparing toxin and nontoxin loci. Overall, we found little evidence of directional selection or differentiation between populations, suggesting that changes to protein sequences do not underlie the evolution of sidewinder venom or that toxins are under extremely variant selection pressures. Although low-expression toxins do not have higher sequence divergence between populations, they do have more standing variation on which selection can act. Additionally, we found significant differences in fang length among populations. The lack of differential expression and sequence divergence suggests sidewinders-given their generalist diet, moderate gene flow and environmental variation-are under stabilizing selection which functions to maintain a generalist phenotype. Overall, we demonstrate the importance of examining the relationship between gene expression and protein-coding changes to understand the evolution of complex traits.
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Affiliation(s)
- Rhett M Rautsaw
- 1 Department of Biological Sciences, Clemson University , Clemson, SC 29634 , USA
| | - Erich P Hofmann
- 1 Department of Biological Sciences, Clemson University , Clemson, SC 29634 , USA
| | - Mark J Margres
- 1 Department of Biological Sciences, Clemson University , Clemson, SC 29634 , USA
| | - Matthew L Holding
- 1 Department of Biological Sciences, Clemson University , Clemson, SC 29634 , USA.,3 Department of Biological Science, Florida State University , Tallahassee, FL 32306 , USA
| | - Jason L Strickland
- 1 Department of Biological Sciences, Clemson University , Clemson, SC 29634 , USA
| | - Andrew J Mason
- 1 Department of Biological Sciences, Clemson University , Clemson, SC 29634 , USA
| | - Darin R Rokyta
- 3 Department of Biological Science, Florida State University , Tallahassee, FL 32306 , USA
| | - Christopher L Parkinson
- 1 Department of Biological Sciences, Clemson University , Clemson, SC 29634 , USA.,2 Department of Forestry and Environmental Conservation, Clemson University , Clemson, SC 29634 , USA
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40
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Schield DR, Perry BW, Adams RH, Card DC, Jezkova T, Pasquesi GIM, Nikolakis ZL, Row K, Meik JM, Smith CF, Mackessy SP, Castoe TA. Allopatric divergence and secondary contact with gene flow: a recurring theme in rattlesnake speciation. Biol J Linn Soc Lond 2019. [DOI: 10.1093/biolinnean/blz077] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Abstract
The study of recently diverged lineages whose geographical ranges come into contact can provide insight into the early stages of speciation and the potential roles of reproductive isolation in generating and maintaining species. Such insight can also be important for understanding the strategies and challenges for delimiting species within recently diverged species complexes. Here, we use mitochondrial and nuclear genetic data to study population structure, gene flow and demographic history across a geographically widespread rattlesnake clade, the western rattlesnake species complex (Crotalus cerberus, Crotalus viridis, Crotalus oreganus and relatives), which contains multiple lineages with ranges that overlap geographically or contact one another. We find evidence that the evolutionary history of this group does not conform to a bifurcating tree model and that pervasive gene flow has broadly influenced patterns of present-day genetic diversity. Our results suggest that lineage diversity has been shaped largely by drift and divergent selection in isolation, followed by secondary contact, in which reproductive isolating mechanisms appear weak and insufficient to prevent introgression, even between anciently diverged lineages. The complexity of divergence and secondary contact with gene flow among lineages also provides new context for why delimiting species within this complex has been difficult and contentious historically.
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Affiliation(s)
- Drew R Schield
- Department of Biology, University of Texas at Arlington, Arlington, TX, USA
| | - Blair W Perry
- Department of Biology, University of Texas at Arlington, Arlington, TX, USA
| | - Richard H Adams
- Department of Biology, University of Texas at Arlington, Arlington, TX, USA
| | - Daren C Card
- Department of Biology, University of Texas at Arlington, Arlington, TX, USA
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
- Museum of Comparative Zoology, Harvard University, Cambridge, MA, USA
| | - Tereza Jezkova
- Department of Biology, Miami University of Ohio, Oxford, OH, USA
| | | | | | - Kristopher Row
- Department of Biology, University of Texas at Arlington, Arlington, TX, USA
| | - Jesse M Meik
- Department of Biological Sciences, Tarleton State University, Stephenville, TX, USA
| | - Cara F Smith
- School of Biological Sciences, University of Northern Colorado, Greeley, CO, USA
| | - Stephen P Mackessy
- School of Biological Sciences, University of Northern Colorado, Greeley, CO, USA
| | - Todd A Castoe
- Department of Biology, University of Texas at Arlington, Arlington, TX, USA
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41
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Evidence for Snake Venom Plasticity in a Long-Term Study with Individual Captive Bothrops atrox. Toxins (Basel) 2019; 11:toxins11050294. [PMID: 31137619 PMCID: PMC6563259 DOI: 10.3390/toxins11050294] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 05/15/2019] [Accepted: 05/21/2019] [Indexed: 12/14/2022] Open
Abstract
Variability in snake venom composition has been frequently reported and correlated to the adaptability of snakes to environmental conditions. Previous studies report plasticity for the venom phenotype. However, these observations are not conclusive, as the results were based on pooled venoms, which present high individual variability. Here we tested the hypothesis of plasticity by influence of confinement and single diet type in the venom composition of 13 adult specimens of Bothrops atrox snakes, maintained under captivity for more than three years. Individual variability in venom composition was observed in samples extracted just after the capture of the snakes. However, composition was conserved in venoms periodically extracted from nine specimens, which presented low variability restricted to the less abundant components. In a second group, composed of four snakes, drastic changes were observed in the venom samples extracted at different periods, mostly related to snake venom metalloproteinases (SVMPs), the core function toxins of B. atrox venom, which occurred approximately between 400 and 500 days in captivity. These data show plasticity in the venom phenotype during the lifetime of adult snakes maintained under captive conditions. Causes or functional consequences involved in the phenotype modification require further investigations.
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42
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Rex CJ, Mackessy SP. Venom composition of adult Western Diamondback Rattlesnakes (Crotalus atrox) maintained under controlled diet and environmental conditions shows only minor changes. Toxicon 2019; 164:51-60. [PMID: 30954451 DOI: 10.1016/j.toxicon.2019.03.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 03/26/2019] [Accepted: 03/31/2019] [Indexed: 12/16/2022]
Abstract
Many species of snakes produce venom as a chemical means of procuring potentially fractious prey. Studies have increasingly focused on venom compositional variation between and within individual snakes of the same species/subspecies, with significant differences often being observed. This variation in composition has been attributed to differences in age, season, diet, and environment, suggesting that these factors could help explain the inter- and intra-specific variation found in some snake venoms, perhaps via some type of feedback mechanism(s). To address several of these possible sources of variation, this study utilized wild-caught Western Diamondback Rattlesnakes (Crotalus atrox) from Cochise Co., AZ. Sixteen adult C. atrox were maintained in the lab on a diet of NSA mice for eight months to determine whether venom composition changed in captivity under a static diet in a stable environment. Reducing 1-D SDS-PAGE, fibrinogen degradation assays, reversed-phase HPLC, and MALDI-TOF mass spectrometry revealed only minor differences over time within individuals. Venom L-amino acid oxidase (LAAO) and phosphodiesterase activities significantly increased over the course of captivity, with no changes occurring in azocasein metalloproteinase, kallikrein-like serine proteinase (KLSP), or thrombin-like serine proteinase (TLSP) activities. Snake total length was positively correlated with TLSP activity and negatively correlated with LAAO and KLSP activity. There was typically a much higher degree of variation between individuals than within individuals for all analyses performed and measurements collected. Because the overall "fingerprint" of each snake's venom remained more/less constant, it is concluded that biologically significant changes in venom composition did not occur within individual C. atrox as a function of captivity/diet. However, this study does indicate that differences in activity levels do occur in minor venom enzyme components, but the differences observed are likely to be of minimal significance to the production of antivenom or to subsequent treatment of human envenomations.
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Affiliation(s)
- Christopher J Rex
- Department of Biological Sciences, 501 20th St., University of Northern Colorado, Greeley, CO, 80639-0017, USA
| | - Stephen P Mackessy
- Department of Biological Sciences, 501 20th St., University of Northern Colorado, Greeley, CO, 80639-0017, USA.
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43
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Harris RJ, Jenner RA. Evolutionary Ecology of Fish Venom: Adaptations and Consequences of Evolving a Venom System. Toxins (Basel) 2019; 11:E60. [PMID: 30678265 PMCID: PMC6409815 DOI: 10.3390/toxins11020060] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 01/14/2019] [Accepted: 01/18/2019] [Indexed: 01/21/2023] Open
Abstract
Research on venomous animals has mainly focused on the molecular, biochemical, and pharmacological aspects of venom toxins. However, it is the relatively neglected broader study of evolutionary ecology that is crucial for understanding the biological relevance of venom systems. As fish have convergently evolved venom systems multiple times, it makes them ideal organisms to investigate the evolutionary ecology of venom on a broader scale. This review outlines what is known about how fish venom systems evolved as a result of natural enemy interactions and about the ecological consequences of evolving a venom system. This review will show how research on the evolutionary ecology of venom in fish can aid in understanding the evolutionary ecology of animal venoms more generally. Further, understanding these broad ecological questions can shed more light on the other areas of toxinology, with applications across multiple disciplinary fields.
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Affiliation(s)
- Richard J Harris
- Venom Evolution Lab, School of Biological Sciences, The University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia.
| | - Ronald A Jenner
- Department of Life Sciences, the Natural History Museum, Cromwell Road, SW7 5BD London, UK.
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