1
|
Bekešová B, Petrilla V, Polláková M, Andrejčáková Z, Vlčková R, Dyba B, Sopková D, Petrillová M, Petrovová E, Legáth J. A Comparative Analysis of the Cytotoxic and Vascular Activity Effects of Western Diamondback Rattlesnake ( Crotalus atrox) and Eastern Diamondback Rattlesnake ( Crotalus adamanteus) Venoms Using a Chick Embryo Model. Animals (Basel) 2024; 14:1634. [PMID: 38891681 PMCID: PMC11171291 DOI: 10.3390/ani14111634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2024] [Revised: 05/28/2024] [Accepted: 05/28/2024] [Indexed: 06/21/2024] Open
Abstract
Crotalus snakebites induce various toxicological effects, encompassing neurological, myotoxic, and cytotoxic symptoms, with potentially fatal outcomes. Investigating venom toxicity is essential for public health, and developing new tools allows for these effects to be studied more comprehensively. The research goals include the elucidation of the physiological consequences of venom exposure and the assessment of toxicity using animal models. Chicken embryos serve as valuable models for assessing venom toxicity through the chick embryotoxicity screening test (CHEST) and the chick chorioallantoic membrane (CAM) assay, particularly useful for evaluating vascular impacts. C. adamanteus venom application resulted in higher embryotoxicity and morphological abnormalities, such as Siamese twins. The CAM assay demonstrated the hemorrhagic effects of venom, varying with venom type and concentration. The irritant potential of both venom types was classified as slight or moderate depending on their concentration. Additionally, acetylcholinesterase (AChE) activity was performed to receive information about organ toxicity. The results show that both venoms induced changes in the whole embryo, heart, and liver weights, but the C. adamanteus venom was identified as more toxic. Specific venom concentrations affected AChE activity in embryonic tissues. These findings underscore the embryotoxic and vasoactive properties of Crotalus venoms, providing valuable insights into their mechanisms of toxicity and potential applications in biomedicine.
Collapse
Affiliation(s)
- Barbora Bekešová
- Department of Biology and Physiology, University of Veterinary Medicine and Pharmacy, Komenského 73, 041 81 Košice, Slovakia; (V.P.); (M.P.); (Z.A.); (R.V.); (D.S.)
| | - Vladimír Petrilla
- Department of Biology and Physiology, University of Veterinary Medicine and Pharmacy, Komenského 73, 041 81 Košice, Slovakia; (V.P.); (M.P.); (Z.A.); (R.V.); (D.S.)
- Zoological Department, Zoological Garden Košice, Široká 31, 040 06 Košice-Kavečany, Slovakia
| | - Magdaléna Polláková
- Department of Biology and Physiology, University of Veterinary Medicine and Pharmacy, Komenského 73, 041 81 Košice, Slovakia; (V.P.); (M.P.); (Z.A.); (R.V.); (D.S.)
| | - Zuzana Andrejčáková
- Department of Biology and Physiology, University of Veterinary Medicine and Pharmacy, Komenského 73, 041 81 Košice, Slovakia; (V.P.); (M.P.); (Z.A.); (R.V.); (D.S.)
| | - Radoslava Vlčková
- Department of Biology and Physiology, University of Veterinary Medicine and Pharmacy, Komenského 73, 041 81 Košice, Slovakia; (V.P.); (M.P.); (Z.A.); (R.V.); (D.S.)
| | - Barbara Dyba
- Department of Biochemistry and Biophysics, University of the National Education Commission, Podchorążych 2 Street, 30-084 Cracow, Poland;
| | - Drahomíra Sopková
- Department of Biology and Physiology, University of Veterinary Medicine and Pharmacy, Komenského 73, 041 81 Košice, Slovakia; (V.P.); (M.P.); (Z.A.); (R.V.); (D.S.)
| | - Monika Petrillová
- Department of General Competencies, University of Veterinary Medicine and Pharmacy, Komenského 73, 041 81 Košice, Slovakia;
| | - Eva Petrovová
- Department of Morphological Disciplines, University of Veterinary Medicine and Pharmacy, Komenského 73, 041 81 Košice, Slovakia;
| | - Jaroslav Legáth
- Department of Pharmacology and Toxicology, University of Veterinary Medicine and Pharmacy, Komenského 73, 041 81 Kosice, Slovakia;
- Department of Biotechnology and Bioinformatics, Faculty of Chemistry, Rzeszow University of Technology, Powstańców Warszawy 6, 35-959 Rzeszów, Poland
| |
Collapse
|
2
|
Phan P, Deshwal A, McMahon TA, Slikas M, Andrews E, Becker B, Kumar TKS. A Review of Rattlesnake Venoms. Toxins (Basel) 2023; 16:2. [PMID: 38276526 PMCID: PMC10818703 DOI: 10.3390/toxins16010002] [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: 11/01/2023] [Revised: 12/08/2023] [Accepted: 12/12/2023] [Indexed: 01/27/2024] Open
Abstract
Venom components are invaluable in biomedical research owing to their specificity and potency. Many of these components exist in two genera of rattlesnakes, Crotalus and Sistrurus, with high toxicity and proteolytic activity variation. This review focuses on venom components within rattlesnakes, and offers a comparison and itemized list of factors dictating venom composition, as well as presenting their known characteristics, activities, and significant applications in biosciences. There are 64 families and subfamilies of proteins present in Crotalus and Sistrurus venom. Snake venom serine proteases (SVSP), snake venom metalloproteases (SVMP), and phospholipases A2 (PLA2) are the standard components in Crotalus and Sistrurus venom. Through this review, we highlight gaps in the knowledge of rattlesnake venom; there needs to be more information on the venom composition of three Crotalus species and one Sistrurus subspecies. We discuss the activity and importance of both major and minor components in biomedical research and drug development.
Collapse
Affiliation(s)
- Phuc Phan
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA;
| | - Anant Deshwal
- Department of Biology, Bradley University, Peoria, IL 61625, USA; (T.A.M.); (M.S.); (E.A.)
| | - Tyler Anthony McMahon
- Department of Biology, Bradley University, Peoria, IL 61625, USA; (T.A.M.); (M.S.); (E.A.)
| | - Matthew Slikas
- Department of Biology, Bradley University, Peoria, IL 61625, USA; (T.A.M.); (M.S.); (E.A.)
| | - Elodie Andrews
- Department of Biology, Bradley University, Peoria, IL 61625, USA; (T.A.M.); (M.S.); (E.A.)
| | - Brian Becker
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR 72701, USA;
| | | |
Collapse
|
3
|
Maag DW, Francioli YZ, Shaw N, Soni AY, Castoe TA, Schuett GW, Clark RW. Hunting behavior and feeding ecology of Mojave rattlesnakes ( Crotalus scutulatus), prairie rattlesnakes ( Crotalus viridis), and their hybrids in southwestern New Mexico. Ecol Evol 2023; 13:e10683. [PMID: 38020675 PMCID: PMC10630157 DOI: 10.1002/ece3.10683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 10/16/2023] [Accepted: 10/17/2023] [Indexed: 12/01/2023] Open
Abstract
Predators must contend with numerous challenges to successfully find and subjugate prey. Complex traits related to hunting are partially controlled by a large number of co-evolved genes, which may be disrupted in hybrids. Accordingly, research on the feeding ecology of animals in hybrid zones has shown that hybrids sometimes exhibit transgressive or novel behaviors, yet for many taxa, empirical studies of predation and diet across hybrid zones are lacking. We undertook the first such field study for a hybrid zone between two snake species, the Mojave rattlesnake (Crotalus scutulatus) and the prairie rattlesnake (Crotalus viridis). Specifically, we leveraged established field methods to quantify the hunting behaviors of animals, their prey communities, and the diet of individuals across the hybrid zone in southwestern New Mexico, USA. We found that, even though hybrids had significantly lower body condition indices than snakes from either parental group, hybrids were generally similar to non-hybrids in hunting behavior, prey encounter rates, and predatory attack and success. We also found that, compared to C. scutulatus, C. viridis was significantly more active while hunting at night and abandoned ambush sites earlier in the morning, and hybrids tended to be more viridis-like in this respect. Prey availability was similar across the study sites, including within the hybrid zone, with kangaroo rats (Dipodomys spp.) as the most common small mammal, both in habitat surveys and the frequency of encounters with hunting rattlesnakes. Analysis of prey remains in stomachs and feces also showed broad similarity in diets, with all snakes preying primarily on small mammals and secondarily on lizards. Taken together, our results suggest that the significantly lower body condition of hybrids does not appear to be driven by differences in their hunting behavior or diet and may instead relate to metabolic efficiency or other physiological traits we have not yet identified.
Collapse
Affiliation(s)
- Dylan W. Maag
- Department of BiologySan Diego State UniversitySan DiegoCaliforniaUSA
- Department of Evolution, Ecology, and Organismal BiologyUniversity of California, RiversideRiversideCaliforniaUSA
| | | | - Noelle Shaw
- Department of BiologySan Diego State UniversitySan DiegoCaliforniaUSA
| | - Ashana Y. Soni
- Department of BiologySan Diego State UniversitySan DiegoCaliforniaUSA
| | - Todd A. Castoe
- Department of BiologyUniversity of Texas at ArlingtonArlingtonTexasUSA
| | - Gordon W. Schuett
- Department of Biology, Neuroscience InstituteGeorgia State UniversityAtlantaGeorgiaUSA
- Chiricahua Desert MuseumRodeoNew MexicoUSA
| | - Rulon W. Clark
- Department of BiologySan Diego State UniversitySan DiegoCaliforniaUSA
- Chiricahua Desert MuseumRodeoNew MexicoUSA
| |
Collapse
|
4
|
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.
Collapse
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.
| |
Collapse
|
5
|
Nikolakis ZL, Schield DR, Westfall AK, Perry BW, Ivey KN, Orton RW, Hales NR, Adams RH, Meik JM, Parker JM, Smith CF, Gompert Z, Mackessy SP, Castoe TA. Evidence that genomic incompatibilities and other multilocus processes impact hybrid fitness in a rattlesnake hybrid zone. Evolution 2022; 76:2513-2530. [PMID: 36111705 DOI: 10.1111/evo.14612] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Revised: 06/24/2022] [Accepted: 08/15/2022] [Indexed: 01/22/2023]
Abstract
Hybrid zones provide valuable opportunities to understand the genomic mechanisms that promote speciation by providing insight into factors involved in intermediate stages of speciation. Here, we investigate introgression in a hybrid zone between two rattlesnake species (Crotalus viridis and Crotalus oreganus concolor) that have undergone historical allopatric divergence and recent range expansion and secondary contact. We use Bayesian genomic cline models to characterize genomic patterns of introgression between these lineages and identify loci potentially subject to selection in hybrids. We find evidence for a large number of genomic regions with biased ancestry that deviate from the genomic background in hybrids (i.e., excess ancestry loci), which tend to be associated with genomic regions with higher recombination rates. We also identify suites of excess ancestry loci that show highly correlated allele frequencies (including conspecific and heterospecific combinations) across physically unlinked genomic regions in hybrids. Our findings provide evidence for multiple multilocus evolutionary processes impacting hybrid fitness in this system.
Collapse
Affiliation(s)
- Zachary L Nikolakis
- Department of Biology, University of Texas at Arlington, Arlington, Texas, 76019
| | - Drew R Schield
- Department of Biology, University of Texas at Arlington, Arlington, Texas, 76019.,Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, Colorado, 80309
| | - Aundrea K Westfall
- Department of Biology, University of Texas at Arlington, Arlington, Texas, 76019
| | - Blair W Perry
- Department of Biology, University of Texas at Arlington, Arlington, Texas, 76019
| | - Kathleen N Ivey
- Department of Biology, University of Texas at Arlington, Arlington, Texas, 76019
| | - Richard W Orton
- Department of Biology, University of Texas at Arlington, Arlington, Texas, 76019
| | - Nicole R Hales
- Department of Biology, University of Texas at Arlington, Arlington, Texas, 76019
| | - Richard H Adams
- Department of Biological and Environmental Sciences, Georgia College and State University, Milledgeville, Georgia, 31061
| | - Jesse M Meik
- Department of Biological Sciences, Tarleton State University, Stephenville, Texas, 76402
| | - Joshua M Parker
- Department of Life Sciences, Fresno City College, Fresno, California, 93741
| | - Cara F Smith
- School of Biological Sciences, University of Northern Colorado, Greeley, Colorado, 80639
| | | | - Stephen P Mackessy
- School of Biological Sciences, University of Northern Colorado, Greeley, Colorado, 80639
| | - Todd A Castoe
- Department of Biology, University of Texas at Arlington, Arlington, Texas, 76019
| |
Collapse
|
6
|
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
| |
Collapse
|
7
|
Cardwell MD, Massey DJ, Smelski G, Wüster W. Mohave Rattlesnake (Crotalus scutulatus) Identification Revisited. Wilderness Environ Med 2022; 33:210-218. [PMID: 35221167 DOI: 10.1016/j.wem.2022.01.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 01/05/2022] [Accepted: 01/14/2022] [Indexed: 10/19/2022]
Abstract
Crotalus scutulatus (Mohave rattlesnake) is a clinically significant pit viper broadly distributed across much of the arid southwestern United States and mainland Mexico. Identification of C scutulatus is a concern among emergency medical service and emergency department personnel owing to its reputation for severe envenomations and difficulty in visually differentiating between C scutulatus and other species, primarily Crotalus atrox (western diamond-backed rattlesnake). We contrast distinctive characteristics of C scutulatus, C atrox, and 3 other sympatric species: Crotalus molossus, Crotalus ornatus, and Crotalus viridis (western and eastern black-tailed rattlesnakes and prairie rattlesnake, respectively). Greenish coloration eliminates C atrox but does not confirm C scutulatus. Obvious coarse and fine speckling of the dorsal pattern and a pale postocular stripe intersecting the mouth characterize C atrox. Dorsal speckling is insignificant or absent in the other species, whereas the pale postocular stripe passes above the mouth in C scutulatus and C viridis and is absent in C molossus and C ornatus. Tails boldly ringed with alternating black and white or contrasting shades of gray are shared by C atrox and C scutulatus, respectively, but a lack of boldly ringed tails characterizes the other species. The proximal rattle segment is yellow and black, or entirely yellow, in C scutulatus but black in the others. The most reliable visual identifications are based on evaluations of multiple traits, all of which are variable to some extent. Traits such as tail ring width and the size and number of crown scales have frequently been overemphasized in the past.
Collapse
Affiliation(s)
- Michael D Cardwell
- Arizona Poison and Drug Information Center, Tucson, Arizona; Biology Department, San Diego State University, San Diego, California.
| | - Daniel J Massey
- Arizona Poison and Drug Information Center, Tucson, Arizona; Banner University Medical Center, Tucson, Arizona
| | | | - Wolfgang Wüster
- Molecular Ecology and Evolution at Bangor, School of Natural Sciences, Bangor University, Bangor, United Kingdom; Chiricahua Desert Museum, Rodeo, New Mexico
| |
Collapse
|
8
|
Roldán-Padrón O, Cruz-Pérez MS, Castro-Guillén JL, García-Arredondo JA, Mendiola-Olaya E, Saldaña-Gutiérrez C, Herrera-Paniagua P, Blanco-Labra A, García-Gasca T. Hybridization between Crotalus aquilus and Crotalus polystictus Species: A Comparison of Their Venom Toxicity and Enzymatic Activities. BIOLOGY 2022; 11:661. [PMID: 35625389 PMCID: PMC9138290 DOI: 10.3390/biology11050661] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Revised: 04/15/2022] [Accepted: 04/17/2022] [Indexed: 06/15/2023]
Abstract
Hybridization is defined as the interbreeding of individuals from two populations distinguishable by one or more heritable characteristics. Snake hybridization represents an interesting opportunity to analyze variability and how genetics affect the venom components between parents and hybrids. Snake venoms exhibit a high degree of variability related to biological and biogeographical factors. The aim of this work is to analyze the protein patterns and enzymatic activity of some of the main hemotoxic enzymes in snake venoms, such as serine proteases (trypsin-like, chymotrypsin-like, and elastase-like), metalloproteases, hyaluronidases, and phospholipase A2. The lethal dose of 50 (LD50) of venom from the Crotalus aquilus (Cabf) and Crotalus polystictus (Cpbm) parents and their hybrids in captivity was determined, and phenetic analysis is also conducted, which showed a high similarity between the hybrids and C. polystictus. The protein banding patterns and enzymatic activity analyze by zymography resulted in a combination of proteins from the parental venoms in the hybrids, with variability among them. In some cases, the enzymatic activity is higher in the hybrids with a lower LD50 than in the parents, indicating higher toxicity. These data show the variability among snake venoms and suggest that hybridization is an important factor in changes in protein concentration, peptide variability, and enzymatic activity that affect toxicity and lethality.
Collapse
Affiliation(s)
- Octavio Roldán-Padrón
- Laboratorio de Biología Celular y Molecuar, Facultad de Ciencias Naturales, Universidad Autónoma de Querétaro, Av. de las Ciencias S/N, Juriquilla, Queretaro 76230, Qro, Mexico; (O.R.-P.); (M.S.C.-P.); (C.S.-G.); (P.H.-P.)
| | - Martha Sandra Cruz-Pérez
- Laboratorio de Biología Celular y Molecuar, Facultad de Ciencias Naturales, Universidad Autónoma de Querétaro, Av. de las Ciencias S/N, Juriquilla, Queretaro 76230, Qro, Mexico; (O.R.-P.); (M.S.C.-P.); (C.S.-G.); (P.H.-P.)
| | - José Luis Castro-Guillén
- Departamento de Biotecnología y Bioquímica, Centro de Investigación y Estudios Avanzados del IPN, Km. 9.6 Libramiento Norte Carr. Irapuato-León, Irapuato 36824, Gto, Mexico; (J.L.C.-G.); (E.M.-O.)
| | - José Alejandro García-Arredondo
- Laboratorio de Química Medicinal, Facultad de Química, Universidad Autónoma de Querétaro, Cerro de las Campanas S/N, Centro Universitario, Queretaro 76010, Qro, Mexico;
| | - Elizabeth Mendiola-Olaya
- Departamento de Biotecnología y Bioquímica, Centro de Investigación y Estudios Avanzados del IPN, Km. 9.6 Libramiento Norte Carr. Irapuato-León, Irapuato 36824, Gto, Mexico; (J.L.C.-G.); (E.M.-O.)
| | - Carlos Saldaña-Gutiérrez
- Laboratorio de Biología Celular y Molecuar, Facultad de Ciencias Naturales, Universidad Autónoma de Querétaro, Av. de las Ciencias S/N, Juriquilla, Queretaro 76230, Qro, Mexico; (O.R.-P.); (M.S.C.-P.); (C.S.-G.); (P.H.-P.)
| | - Patricia Herrera-Paniagua
- Laboratorio de Biología Celular y Molecuar, Facultad de Ciencias Naturales, Universidad Autónoma de Querétaro, Av. de las Ciencias S/N, Juriquilla, Queretaro 76230, Qro, Mexico; (O.R.-P.); (M.S.C.-P.); (C.S.-G.); (P.H.-P.)
| | - Alejandro Blanco-Labra
- Departamento de Biotecnología y Bioquímica, Centro de Investigación y Estudios Avanzados del IPN, Km. 9.6 Libramiento Norte Carr. Irapuato-León, Irapuato 36824, Gto, Mexico; (J.L.C.-G.); (E.M.-O.)
| | - Teresa García-Gasca
- Laboratorio de Biología Celular y Molecuar, Facultad de Ciencias Naturales, Universidad Autónoma de Querétaro, Av. de las Ciencias S/N, Juriquilla, Queretaro 76230, Qro, Mexico; (O.R.-P.); (M.S.C.-P.); (C.S.-G.); (P.H.-P.)
| |
Collapse
|
9
|
Characterization of the venom and external morphology of a natural hybrid between Crotalus atrox and Crotalus mictlantecuhtli. Toxicon 2022; 207:43-47. [PMID: 35007607 DOI: 10.1016/j.toxicon.2022.01.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 12/21/2021] [Accepted: 01/03/2022] [Indexed: 11/20/2022]
Abstract
Here we report, for the first time, a natural hybrid between Crotalus atrox and C. mictlantecuhtli based on intermediate characteristics of the external morphology and venom. Morphologically, the individual had characteristics of both parent species. The hybrid's venom exhibited an intermediate composition including the presence of crotoxin which has never been documented in C. atrox but is well documented in C. mictlantecuhtli. The hybrid's venom was highly toxic and showed an intermediate proteolytic activity between the parental species. The two Mexican antivenoms were able to neutralize the hybrid's venom's lethality.
Collapse
|
10
|
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.
Collapse
|
11
|
Myers EA. Genome-wide data reveal extensive gene flow during the diversification of the western rattlesnakes (Viperidae: Crotalinae: Crotalus). Mol Phylogenet Evol 2021; 165:107313. [PMID: 34537323 DOI: 10.1016/j.ympev.2021.107313] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 08/28/2021] [Accepted: 09/14/2021] [Indexed: 11/15/2022]
Abstract
Hybridization and introgression are important, but often overlooked processes when inferring phylogenies. When these processes are not accounted for and a strictly diverging phylogenetic model is applied to groups with a history of hybridization, phylogenetic inference and parameter estimation can be inaccurate. Recent developments in phylogenetic network approaches coupled with the increasing availability of genomic data allow inferences of reticulate evolutionary histories across the tree of life. The western rattlesnake species group (C. viridis species complex, C. mitchellii species complex, C. scutulutas, and C. tigris) is an iconic snake lineage that is widespread across western North America. This group is composed of several species complexes with unclear species limits, likely the result of ongoing gene flow among nascent lineages. Here I generate reduced representation genomic data and test for a history of reticulation within this group. I demonstrate that all species have undergone hybridization with at least one other lineage, suggesting introgression is widespread in this group. Topologies differ between phylogenies estimated under the multispecies coalescent and multispecies network coalescent methods, indicating that gene flow has obscured phylogenetic relationships within this group. These past introgression events are predominantly restricted to species that co-occur geographically. However, within species that have a history of introgression, this signature is detected regardless of specimen sampling across geography. Overall, my results suggest the accumulation of reproductive isolating barriers occurs slowly in rattlesnakes which likely leads to the difficulty in delimiting species, furthermore, the results of this study have implications for trait evolution in this group.
Collapse
Affiliation(s)
- Edward A Myers
- Department of Herpetology, American Museum of Natural History, New York, NY, USA; Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.
| |
Collapse
|
12
|
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.
Collapse
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.)
| |
Collapse
|
13
|
Seneci L, Zdenek CN, Bourke LA, Cochran C, Sánchez EE, Neri-Castro E, Bénard-Valle M, Alagón A, Frank N, Fry BG. A symphony of destruction: Dynamic differential fibrinogenolytic toxicity by rattlesnake (Crotalus and Sistrurus) venoms. Comp Biochem Physiol C Toxicol Pharmacol 2021; 245:109034. [PMID: 33766656 PMCID: PMC8162888 DOI: 10.1016/j.cbpc.2021.109034] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 03/02/2021] [Accepted: 03/15/2021] [Indexed: 12/15/2022]
Abstract
What factors influence the evolution of a heavily selected functional trait in a diverse clade? This study adopts rattlesnakes as a model group to investigate the evolutionary history of venom coagulotoxicity in the wider context of phylogenetics, natural history, and biology. Venom-induced clotting of human plasma and fibrinogen was determined and mapped onto the rattlesnake phylogenetic tree to reconstruct the evolution of coagulotoxicity across the group. Our results indicate that venom phenotype is often independent of phylogenetic relationships in rattlesnakes, suggesting the importance of diet and/or other environmental variables in driving venom evolution. Moreover, the striking inter- and intraspecific variability in venom activity on human blood highlights the considerable variability faced by physicians treating envenomation. This study is the most comprehensive effort to date to describe and characterize the evolutionary and biological aspects of coagulotoxins in rattlesnake venom. Further research at finer taxonomic levels is recommended to elucidate patterns of variation within species and lineages.
Collapse
Affiliation(s)
- Lorenzo Seneci
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia; Institute of Biology Leiden (IBL), Leiden University, 2333 BE Leiden, the Netherlands
| | - Christina N Zdenek
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia
| | - Lachlan A Bourke
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia
| | - Chip Cochran
- Department of Earth and Biological Sciences, Loma Linda University, Loma Linda, CA 92350, USA
| | - Elda E Sánchez
- National Natural Toxins Research Center (NNTRC), Department of Chemistry, Texas A&M University-Kingsville, MSC 224, 975 West Avenue B, Kingsville, TX 78363, USA
| | - Edgar Neri-Castro
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnologa, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Morelos 62210, Mexico
| | - Melisa Bénard-Valle
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnologa, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Morelos 62210, Mexico
| | - Alejandro Alagón
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnologa, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Morelos 62210, Mexico
| | | | - Bryan G Fry
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia.
| |
Collapse
|
14
|
Deshwal A, Phan P, Datta J, Kannan R, Thallapuranam SK. A Meta-Analysis of the Protein Components in Rattlesnake Venom. Toxins (Basel) 2021; 13:toxins13060372. [PMID: 34071038 DOI: 10.3390/toxins13060372] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 05/20/2021] [Accepted: 05/21/2021] [Indexed: 11/16/2022] Open
Abstract
The specificity and potency of venom components give them a unique advantage in developing various pharmaceutical drugs. Though venom is a cocktail of proteins, rarely are the synergy and association between various venom components studied. Understanding the relationship between various components of venom is critical in medical research. Using meta-analysis, we observed underlying patterns and associations in the appearance of the toxin families. For Crotalus, Dis has the most associations with the following toxins: PDE; BPP; CRL; CRiSP; LAAO; SVMP P-I and LAAO; SVMP P-III and LAAO. In Sistrurus venom, CTL and NGF have the most associations. These associations can predict the presence of proteins in novel venom and understand synergies between venom components for enhanced bioactivity. Using this approach, the need to revisit the classification of proteins as major components or minor components is highlighted. The revised classification of venom components is based on ubiquity, bioactivity, the number of associations, and synergies. The revised classification can be expected to trigger increased research on venom components, such as NGF, which have high biomedical significance. Using hierarchical clustering, we observed that the genera's venom compositions were similar, based on functional characteristics rather than phylogenetic relationships.
Collapse
Affiliation(s)
- Anant Deshwal
- Division of Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Phuc Phan
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA
| | - Jyotishka Datta
- Department of Statistics, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Ragupathy Kannan
- Department of Biology, University of Arkansas-Fort Smith, Fort Smith, AR 72913, USA
| | | |
Collapse
|
15
|
Holding ML, Strickland JL, Rautsaw RM, Hofmann EP, Mason AJ, Hogan MP, Nystrom GS, Ellsworth SA, Colston TJ, Borja M, Castañeda-Gaytán G, Grünwald CI, Jones JM, Freitas-de-Sousa LA, Viala VL, Margres MJ, Hingst-Zaher E, Junqueira-de-Azevedo ILM, Moura-da-Silva AM, Grazziotin FG, Gibbs HL, Rokyta DR, Parkinson CL. Phylogenetically diverse diets favor more complex venoms in North American pitvipers. Proc Natl Acad Sci U S A 2021; 118:e2015579118. [PMID: 33875585 PMCID: PMC8092465 DOI: 10.1073/pnas.2015579118] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
The role of natural selection in the evolution of trait complexity can be characterized by testing hypothesized links between complex forms and their functions across species. Predatory venoms are composed of multiple proteins that collectively function to incapacitate prey. Venom complexity fluctuates over evolutionary timescales, with apparent increases and decreases in complexity, and yet the causes of this variation are unclear. We tested alternative hypotheses linking venom complexity and ecological sources of selection from diet in the largest clade of front-fanged venomous snakes in North America: the rattlesnakes, copperheads, cantils, and cottonmouths. We generated independent transcriptomic and proteomic measures of venom complexity and collated several natural history studies to quantify dietary variation. We then constructed genome-scale phylogenies for these snakes for comparative analyses. Strikingly, prey phylogenetic diversity was more strongly correlated to venom complexity than was overall prey species diversity, specifically implicating prey species' divergence, rather than the number of lineages alone, in the evolution of complexity. Prey phylogenetic diversity further predicted transcriptomic complexity of three of the four largest gene families in viper venom, showing that complexity evolution is a concerted response among many independent gene families. We suggest that the phylogenetic diversity of prey measures functionally relevant divergence in the targets of venom, a claim supported by sequence diversity in the coagulation cascade targets of venom. Our results support the general concept that the diversity of species in an ecological community is more important than their overall number in determining evolutionary patterns in predator trait complexity.
Collapse
Affiliation(s)
- Matthew L Holding
- Department of Biological Sciences, Clemson University, Clemson, SC 29634;
- Department of Biological Science, Florida State University, Tallahassee, FL 32306
| | - Jason L Strickland
- Department of Biological Sciences, Clemson University, Clemson, SC 29634
| | - Rhett M Rautsaw
- Department of Biological Sciences, Clemson University, Clemson, SC 29634
| | - Erich P Hofmann
- Department of Biological Sciences, Clemson University, Clemson, SC 29634
| | - Andrew J Mason
- Department of Biological Sciences, Clemson University, Clemson, SC 29634
- Department of Evolution, Ecology and Organismal Biology, The Ohio State University, Columbus, OH 43210
| | - Michael P Hogan
- Department of Biological Science, Florida State University, Tallahassee, FL 32306
| | - Gunnar S Nystrom
- Department of Biological Science, Florida State University, Tallahassee, FL 32306
| | - Schyler A Ellsworth
- Department of Biological Science, Florida State University, Tallahassee, FL 32306
| | - Timothy J Colston
- Department of Biological Science, Florida State University, Tallahassee, FL 32306
| | - Miguel Borja
- Facultad de Ciencias Biológicas, Universidad Juárez del Estado de Durango, C.P. 35010 Gómez Palacio, Dgo., Mexico
| | - Gamaliel Castañeda-Gaytán
- Facultad de Ciencias Biológicas, Universidad Juárez del Estado de Durango, C.P. 35010 Gómez Palacio, Dgo., Mexico
| | | | - Jason M Jones
- HERP.MX A.C., Villa del Álvarez, Colima 28973, Mexico
| | | | - Vincent Louis Viala
- Laboratório de Toxinologia Aplicada, Instituto Butantan, São Paulo 05503-900, Brazil
- Center of Toxins, Immune-Response and Cell Signaling, São Paulo 05503-900, Brazil
| | - Mark J Margres
- Department of Biological Sciences, Clemson University, Clemson, SC 29634
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138
| | | | - Inácio L M Junqueira-de-Azevedo
- Laboratório de Toxinologia Aplicada, Instituto Butantan, São Paulo 05503-900, Brazil
- Center of Toxins, Immune-Response and Cell Signaling, São Paulo 05503-900, Brazil
| | - Ana M Moura-da-Silva
- Laboratório de Imunopatologia, Instituto Butantan, São Paulo 05503-900, Brazil
- Instituto de Pesquisa Clínica Carlos Borborema, Fundação de Medicina Tropical Doutor Heitor Vieira Dourado, Manaus 69040, Brazil
| | - Felipe G Grazziotin
- Laboratório de Coleções Zoológicas, Instituto Butantan, São Paulo 05503-900, Brazil
| | - H Lisle Gibbs
- Department of Evolution, Ecology and Organismal Biology, The Ohio State University, Columbus, OH 43210
| | - 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
| |
Collapse
|
16
|
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]
|
17
|
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.
Collapse
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
| |
Collapse
|
18
|
Evidence for divergent patterns of local selection driving venom variation in Mojave Rattlesnakes (Crotalus scutulatus). Sci Rep 2018; 8:17622. [PMID: 30514908 PMCID: PMC6279745 DOI: 10.1038/s41598-018-35810-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 11/09/2018] [Indexed: 01/20/2023] Open
Abstract
Snake venoms represent an enriched system for investigating the evolutionary processes that lead to complex and dynamic trophic adaptations. It has long been hypothesized that natural selection may drive geographic variation in venom composition, yet previous studies have lacked the population genetic context to examine these patterns. We leverage range-wide sampling of Mojave Rattlesnakes (Crotalus scutulatus) and use a combination of venom, morphological, phylogenetic, population genetic, and environmental data to characterize the striking dichotomy of neurotoxic (Type A) and hemorrhagic (Type B) venoms throughout the range of this species. We find that three of the four previously identified major lineages within C. scutulatus possess a combination of Type A, Type B, and a ‘mixed’ Type A + B venom phenotypes, and that fixation of the two main venom phenotypes occurs on a more fine geographic scale than previously appreciated. We also find that Type A + B individuals occur in regions of inferred introgression, and that this mixed phenotype is comparatively rare. Our results support strong directional local selection leading to fixation of alternative venom phenotypes on a fine geographic scale, and are inconsistent with balancing selection to maintain both phenotypes within a single population. Our comparisons to biotic and abiotic factors further indicate that venom phenotype correlates with fang morphology and climatic variables. We hypothesize that links to fang morphology may be indicative of co-evolution of venom and other trophic adaptations, and that climatic variables may be linked to prey distributions and/or physiology, which in turn impose selection pressures on snake venoms.
Collapse
|
19
|
Schield DR, Adams RH, Card DC, Corbin AB, Jezkova T, Hales NR, Meik JM, Perry BW, Spencer CL, Smith LL, García GC, Bouzid NM, Strickland JL, Parkinson CL, Borja M, Castañeda-Gaytán G, Bryson RW, Flores-Villela OA, Mackessy SP, Castoe TA. Cryptic genetic diversity, population structure, and gene flow in the Mojave rattlesnake (Crotalus scutulatus). Mol Phylogenet Evol 2018; 127:669-681. [DOI: 10.1016/j.ympev.2018.06.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 05/30/2018] [Accepted: 06/06/2018] [Indexed: 10/28/2022]
|
20
|
Schezaro-Ramos R, Da Silva SL, Pereira BB, Santa Fé Miguel AT, Mendes B, Mogollón NGS, Hyslop S, Carregari VC, Almeida JR. In vitro effects of Crotalus atrox snake venom on chick and mouse neuromuscular preparations. Comp Biochem Physiol C Toxicol Pharmacol 2018; 209:37-45. [PMID: 29604435 DOI: 10.1016/j.cbpc.2018.03.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 03/06/2018] [Accepted: 03/24/2018] [Indexed: 12/25/2022]
Abstract
The neuromuscular effect of venoms is not a major clinical manifestation shared between rattlesnakes native to the Americas, which showed two different venom phenotypes. Taking into account this dichotomy, nerve muscle preparations from mice and chicks were used to investigate the ability of Crotalus atrox venom to induce in vitro neurotoxicity and myotoxicity. Unlike crotalic venoms of South America, low concentrations of C. atrox venom did not result in significant effects on mouse neuromuscular preparations. The venom was more active on avian nerve-muscle, showing reduction of twitch heights after 120 min of incubation with 10, 30 and 100 μg/mL of venom with diminished responses to agonists and KCl. Histological analysis highlighted that C. atrox was myotoxic in both species of experimental animals; as evidenced by degenerative events, including edematous cells, delta lesions, hypercontracted fibers and muscle necrosis, which can lead to neurotoxic action. These results provide key insights into the myotoxicity and low neurotoxicity of C. atrox in two animal models, corroborating with previous genomic and proteomic findings and would be useful for a deeper understanding of venom evolution in snakes belonging to the genus Crotalus.
Collapse
Affiliation(s)
- Raphael Schezaro-Ramos
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Saulo L Da Silva
- Ikiam - Universidad Regional Amazónica, Km 7 Via Muyuna, Tena, Napo, Ecuador
| | - Beatriz B Pereira
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Ananda T Santa Fé Miguel
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Bruno Mendes
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | | | - Stephen Hyslop
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Victor C Carregari
- Proteomic and Metabonomic Laboratory, Fondazione Santa Lucia, Rome, Italy
| | - José R Almeida
- Ikiam - Universidad Regional Amazónica, Km 7 Via Muyuna, Tena, Napo, Ecuador.
| |
Collapse
|
21
|
Proteopeptidomic, Functional and Immunoreactivity Characterization of Bothrops moojeni Snake Venom: Influence of Snake Gender on Venom Composition. Toxins (Basel) 2018; 10:toxins10050177. [PMID: 29701671 PMCID: PMC5983233 DOI: 10.3390/toxins10050177] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 04/22/2018] [Accepted: 04/23/2018] [Indexed: 01/14/2023] Open
Abstract
Venom composition varies across snakes from all taxonomic levels and is influenced by the snakes’ age, habitat, diet, and sexual dimorphism. The present study reports the first in-depth investigation of venom composition in male and female Bothrops moojeni (B. moojeni) snakes (BmooM and BmooF, respectively) through three proteomics approaches associated with functional, cytotoxic, and immunoreactivity characterization. Compared with BmooM venom, BmooF venom exhibited weaker hyaluronidase, metalloproteinase, and phospholipase activity; stronger recognition by anti-bothropic serum; 1.4-fold stronger cytotoxicity; and greater number of peptides. The increased L-amino acid oxidase expression probably accounted for the stronger immunoreactivity and cytotoxicity of BmooF venom. BmooF and BmooM venom shared only 19% peptides. Some venom components were gender-specific, such as phospholipases B, phospholipase inhibitor, and hyaluronidases in BmooM, and cysteine-rich secretory proteins in BmooF. In conclusion, we describe herein the first proteomics study of B. moojeni snake venom and an in-depth characterization of gender-specific differences in venom composition. Altogether, our findings not only stress the importance of considering the snake’s gender during antivenom production, but also help to identify new potential drugs and biotechnological tools.
Collapse
|
22
|
Calvete JJ, Rodríguez Y, Quesada-Bernat S, Pla D. Toxin-resolved antivenomics-guided assessment of the immunorecognition landscape of antivenoms. Toxicon 2018; 148:107-122. [PMID: 29704534 DOI: 10.1016/j.toxicon.2018.04.015] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 03/26/2018] [Accepted: 04/22/2018] [Indexed: 01/23/2023]
Abstract
Snakebite envenoming represents a major issue in rural areas of tropical and subtropical regions across sub-Saharan Africa, South to Southeast Asia, Latin America and Oceania. Antivenoms constitute the only scientifically validated therapy for snakebite envenomings, provided they are safe, effective, affordable, accessible and administered appropriately. However, the lack of financial incentives in a technology that has remained relatively unchanged for more than a century, has contributed to some manufacturers leaving the market and others downscaling production or increasing the prices, leading to a decline in the availability and accessibility for these life-saving antidotes to millions of rural poor most at risk from snakebites in low income countries. The shortage of antivenoms can be significantly alleviated by optimizing the use of current antivenoms (through the assessment of their specific and paraspecific efficacy against the different medically relevant homologous and heterologous snake venoms) and by generating novel polyspecific antivenoms exhibiting broad clinical spectrum and wide geographic distribution range. Research on venoms has been continuously enhanced by advances in technology. Particularly, the last decade has witnessed the development of omics strategies for unravelling the toxin composition of venoms ("venomics") and to assess the immunorecognition profile of antivenoms ("antivenomics"). Here, we review recent developments and reflect on near future innovations that promise to revolutionize the mutually enlightening relationship between evolutionary and translational venomics.
Collapse
Affiliation(s)
- Juan J Calvete
- Evolutionary and Translational Venomics Laboratory, Consejo Superior de Investigaciones Científicas (CSIC), Valencia, Spain.
| | - Yania Rodríguez
- Evolutionary and Translational Venomics Laboratory, Consejo Superior de Investigaciones Científicas (CSIC), Valencia, Spain
| | - Sarai Quesada-Bernat
- Evolutionary and Translational Venomics Laboratory, Consejo Superior de Investigaciones Científicas (CSIC), Valencia, Spain
| | - Davinia Pla
- Evolutionary and Translational Venomics Laboratory, Consejo Superior de Investigaciones Científicas (CSIC), Valencia, Spain.
| |
Collapse
|
23
|
Strickland JL, Mason AJ, Rokyta DR, Parkinson CL. Phenotypic Variation in Mojave Rattlesnake (Crotalus scutulatus) Venom Is Driven by Four Toxin Families. Toxins (Basel) 2018; 10:toxins10040135. [PMID: 29570631 PMCID: PMC5923301 DOI: 10.3390/toxins10040135] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 03/16/2018] [Accepted: 03/18/2018] [Indexed: 02/04/2023] Open
Abstract
Phenotypic diversity generated through altered gene expression is a primary mechanism facilitating evolutionary response in natural systems. By linking the phenotype to genotype through transcriptomics, it is possible to determine what changes are occurring at the molecular level. High phenotypic diversity has been documented in rattlesnake venom, which is under strong selection due to its role in prey acquisition and defense. Rattlesnake venom can be characterized by the presence (Type A) or absence (Type B) of a type of neurotoxic phospholipase A2 (PLA2), such as Mojave toxin, that increases venom toxicity. Mojave rattlesnakes (Crotalus scutulatus), represent this diversity as both venom types are found within this species and within a single panmictic population in the Sonoran Desert. We used comparative venom gland transcriptomics of nine specimens of C. scutulatus from this region to test whether expression differences explain diversity within and between venom types. Type A individuals expressed significantly fewer toxins than Type B individuals owing to the diversity of C-type lectins (CTLs) and snake venom metalloproteinases (SVMPs) found in Type B animals. As expected, both subunits of Mojave toxin were exclusively found in Type A individuals but we found high diversity in four additional PLA2s that was not associated with a venom type. Myotoxin a expression and toxin number variation was not associated with venom type, and myotoxin a had the highest range of expression of any toxin class. Our study represents the most comprehensive transcriptomic profile of the venom type dichotomy in rattlesnakes and C. scutulatus. Even intra-specifically, Mojave rattlesnakes showcase the diversity of snake venoms and illustrate that variation within venom types blurs the distinction of the venom dichotomy.
Collapse
Affiliation(s)
- Jason L Strickland
- Department of Biology, University of Central Florida, 4110 Libra Drive, Orlando, FL 32816, USA.
| | - Andrew J Mason
- Department of Biological Sciences, Clemson University, 190 Collings St., Clemson, SC 29634, USA.
| | - Darin R Rokyta
- Department of Biological Science, Florida State University, 319 Stadium Drive, Tallahassee, FL 32306, USA.
| | - Christopher L Parkinson
- Department of Biology, University of Central Florida, 4110 Libra Drive, Orlando, FL 32816, USA.
| |
Collapse
|
24
|
Dowell NL, Giorgianni MW, Griffin S, Kassner VA, Selegue JE, Sanchez EE, Carroll SB. Extremely Divergent Haplotypes in Two Toxin Gene Complexes Encode Alternative Venom Types within Rattlesnake Species. Curr Biol 2018; 28:1016-1026.e4. [PMID: 29576471 DOI: 10.1016/j.cub.2018.02.031] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 01/11/2018] [Accepted: 02/14/2018] [Indexed: 11/17/2022]
Abstract
Natural selection is generally expected to favor one form of a given trait within a population. The presence of multiple functional variants of traits involved in activities such as feeding, reproduction, or the defense against predators is relatively uncommon within animal species. The genetic architecture and evolutionary mechanisms underlying the origin and maintenance of such polymorphisms are of special interest. Among rattlesnakes, several instances of the production of biochemically distinct neurotoxic or hemorrhagic venom types within the same species are known. Here, we investigated the genetic basis of this phenomenon in three species and found that neurotoxic and hemorrhagic individuals of the same species possess markedly different haplotypes at two toxin gene complexes. For example, neurotoxic and hemorrhagic Crotalus scutulatus individuals differ by 5 genes at the phospholipase A2 (PLA2) toxin gene complex and by 11 genes at the metalloproteinase (MP) gene complex. A similar set of extremely divergent haplotypes also underlies alternate venom types within C. helleri and C. horridus. We further show that the MP and PLA2 haplotypes of neurotoxic C. helleri appear to have been acquired through hybridization with C. scutulatus-a rare example of the horizontal transfer of a potentially highly adaptive suite of genes. These large structural variants appear analogous to immunity gene complexes in host-pathogen arms races and may reflect the impact of balancing selection at the PLA2 and MP complexes for predation on different prey.
Collapse
Affiliation(s)
- Noah L Dowell
- Howard Hughes Medical Institute and Laboratory of Molecular Biology, University of Wisconsin, Madison, 1525 Linden Drive, Madison, WI 53706, USA
| | - Matt W Giorgianni
- Howard Hughes Medical Institute and Laboratory of Molecular Biology, University of Wisconsin, Madison, 1525 Linden Drive, Madison, WI 53706, USA
| | - Sam Griffin
- Howard Hughes Medical Institute and Laboratory of Molecular Biology, University of Wisconsin, Madison, 1525 Linden Drive, Madison, WI 53706, USA
| | - Victoria A Kassner
- Howard Hughes Medical Institute and Laboratory of Molecular Biology, University of Wisconsin, Madison, 1525 Linden Drive, Madison, WI 53706, USA
| | - Jane E Selegue
- Howard Hughes Medical Institute and Laboratory of Molecular Biology, University of Wisconsin, Madison, 1525 Linden Drive, Madison, WI 53706, USA
| | - Elda E Sanchez
- National Natural Toxins Research Center and Department of Chemistry, Texas A&M University, Kingsville, MSC 224, Kingsville, TX 78363, USA
| | - Sean B Carroll
- Howard Hughes Medical Institute and Laboratory of Molecular Biology, University of Wisconsin, Madison, 1525 Linden Drive, Madison, WI 53706, USA.
| |
Collapse
|
25
|
Biological and Proteolytic Variation in the Venom of Crotalus scutulatus scutulatus from Mexico. Toxins (Basel) 2018; 10:toxins10010035. [PMID: 29316683 PMCID: PMC5793122 DOI: 10.3390/toxins10010035] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 12/24/2017] [Accepted: 01/04/2018] [Indexed: 11/18/2022] Open
Abstract
Rattlesnake venoms may be classified according to the presence/absence and relative abundance of the neurotoxic phospholipases A2s (PLA2s), such as Mojave toxin, and snake venom metalloproteinases (SVMPs). In Mexico, studies to determine venom variation in Mojave Rattlesnakes (Crotalus scutulatus scutulatus) are limited and little is known about the biological and proteolytic activities in this species. Tissue (34) and venom (29) samples were obtained from C. s. scutulatus from different locations within their distribution in Mexico. Mojave toxin detection was carried out at the genomic (by PCR) and protein (by ELISA) levels for all tissue and venom samples. Biological activity was tested on representative venoms by measuring LD50 and hemorrhagic activity. To determine the approximate amount of SVMPs, 15 venoms were separated by RP-HPLC and variation in protein profile and proteolytic activity was evaluated by SDS-PAGE (n = 28) and Hide Powder Azure proteolytic analysis (n = 27). Three types of venom were identified in Mexico which is comparable to the intraspecific venom diversity observed in the Sonoran Desert of Arizona, USA: Venom Type A (∼Type II), with Mojave toxin, highly toxic, lacking hemorrhagic activity, and with scarce proteolytic activity; Type B (∼Type I), without Mojave toxin, less toxic than Type A, highly hemorrhagic and proteolytic; and Type A + B, containing Mojave toxin, as toxic as venom Type A, variable in hemorrhagic activity and with intermediate proteolytic activity. We also detected a positive correlation between SVMP abundance and hemorrhagic and proteolytic activities. Although more sampling is necessary, our results suggest that venoms containing Mojave toxin and venom lacking this toxin are distributed in the northwest and southeast portions of the distribution in Mexico, respectively, while an intergradation in the middle of both zones is present.
Collapse
|
26
|
Zancolli G, Sanz L, Calvete JJ, Wüster W. Venom On-a-Chip: A Fast and Efficient Method for Comparative Venomics. Toxins (Basel) 2017; 9:toxins9060179. [PMID: 28555029 PMCID: PMC5488029 DOI: 10.3390/toxins9060179] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 05/23/2017] [Accepted: 05/24/2017] [Indexed: 12/30/2022] Open
Abstract
Venom research has attracted an increasing interest in disparate fields, from drug development and pharmacology, to evolutionary biology and ecology, and rational antivenom production. Advances in “-omics” technologies have allowed the characterization of an increasing number of animal venoms, but the methodology currently available is suboptimal for large-scale comparisons of venom profiles. Here, we describe a fast, reproducible and semi-automated protocol for investigating snake venom variability, especially at the intraspecific level, using the Agilent Bioanalyzer on-chip technology. Our protocol generated a phenotype matrix which can be used for robust statistical analysis and correlations of venom variation with ecological correlates, or other extrinsic factors. We also demonstrate the ease and utility of combining on-chip technology with previously fractionated venoms for detection of specific individual toxin proteins. Our study describes a novel strategy for rapid venom discrimination and analysis of compositional variation at multiple taxonomic levels, allowing researchers to tackle evolutionary questions and unveiling the drivers of the incredible biodiversity of venoms.
Collapse
Affiliation(s)
- Giulia Zancolli
- Molecular Ecology and Fisheries Genetics Lab, School of Biological Sciences, Bangor University, Bangor LL57 2UW, UK.
| | - Libia Sanz
- Venomics and Structural Proteomics Laboratory, Instituto de Biomedicina de Valencia, CSIC, Jaume Roig 11, Valencia 46010, Spain.
| | - Juan J Calvete
- Venomics and Structural Proteomics Laboratory, Instituto de Biomedicina de Valencia, CSIC, Jaume Roig 11, Valencia 46010, Spain.
| | - Wolfgang Wüster
- Molecular Ecology and Fisheries Genetics Lab, School of Biological Sciences, Bangor University, Bangor LL57 2UW, UK.
| |
Collapse
|
27
|
Venomics: integrative venom proteomics and beyond*. Biochem J 2017; 474:611-634. [DOI: 10.1042/bcj20160577] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 12/31/2016] [Accepted: 01/03/2017] [Indexed: 01/15/2023]
Abstract
Venoms are integrated phenotypes that evolved independently in, and are used for predatory and defensive purposes by, a wide phylogenetic range of organisms. The same principles that contribute to the evolutionary success of venoms, contribute to making the study of venoms of great interest in such diverse fields as evolutionary ecology and biotechnology. Evolution is profoundly contingent, and nature also reinvents itself continuosly. Changes in a complex phenotypic trait, such as venom, reflect the influences of prior evolutionary history, chance events, and selection. Reconstructing the natural history of venoms, particularly those of snakes, which will be dealt with in more detail in this review, requires the integration of different levels of knowledge into a meaningful and comprehensive evolutionary framework for separating stochastic changes from adaptive evolution. The application of omics technologies and other disciplines have contributed to a qualitative and quantitative advance in the road map towards this goal. In this review we will make a foray into the world of animal venoms, discuss synergies and complementarities of the different approaches used in their study, and identify current bottlenecks that prevent inferring the evolutionary mechanisms and ecological constraints that molded snake venoms to their present-day variability landscape.
Collapse
|
28
|
The effects of hybridization on divergent venom phenotypes: Characterization of venom from Crotalus scutulatus scutulatus × Crotalus oreganus helleri hybrids. Toxicon 2016; 120:110-23. [DOI: 10.1016/j.toxicon.2016.08.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Revised: 07/27/2016] [Accepted: 08/01/2016] [Indexed: 11/20/2022]
|