1
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Hirst SR, Rautsaw RM, VanHorn CM, Beer MA, McDonald PJ, Rosales García RA, Rodriguez Lopez B, Rubio Rincón A, Franz Chávez H, Vásquez-Cruz V, Kelly Hernández A, Storfer A, Borja M, Castañeda-Gaytán G, Frandsen PB, Parkinson CL, Strickland JL, Margres MJ. Where the "ruber" Meets the Road: Using the Genome of the Red Diamond Rattlesnake to Unravel the Evolutionary Processes Driving Venom Evolution. Genome Biol Evol 2024; 16:evae198. [PMID: 39255072 DOI: 10.1093/gbe/evae198] [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: 06/07/2024] [Revised: 08/15/2024] [Accepted: 09/02/2024] [Indexed: 09/12/2024] Open
Abstract
Understanding the proximate and ultimate causes of phenotypic variation is fundamental in evolutionary research, as such variation provides the substrate for selection to act upon. Although trait variation can arise due to selection, the importance of neutral processes is sometimes understudied. We presented the first reference-quality genome of the Red Diamond Rattlesnake (Crotalus ruber) and used range-wide 'omic data to estimate the degree to which neutral and adaptive evolutionary processes shaped venom evolution. We characterized population structure and found substantial genetic differentiation across two populations, each with distinct demographic histories. We identified significant differentiation in venom expression across age classes with substantially reduced but discernible differentiation across populations. We then used conditional redundancy analysis to test whether venom expression variation was best predicted by neutral divergence patterns or geographically variable (a)biotic factors. Snake size was the most significant predictor of venom variation, with environment, prey availability, and neutral sequence variation also identified as significant factors, though to a lesser degree. By directly including neutrality in the model, our results confidently highlight the predominant, yet not singular, role of life history in shaping venom evolution.
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Affiliation(s)
- Samuel R Hirst
- Department of Integrative Biology, University of South Florida, Tampa, FL, USA
| | - Rhett M Rautsaw
- Department of Integrative Biology, University of South Florida, Tampa, FL, USA
- School of Biological Sciences, Washington State University, Pullman, WA, USA
| | - Cameron M VanHorn
- Department of Integrative Biology, University of South Florida, Tampa, FL, USA
| | - Marc A Beer
- School of Biological Sciences, Washington State University, Pullman, WA, USA
| | - Preston J McDonald
- Department of Integrative Biology, University of South Florida, Tampa, FL, USA
| | | | - Bruno Rodriguez Lopez
- Facultad de Ciencias Biológicas, Universidad Juárez del Estado de Durango, Durango, Mexico
| | - Alexandra Rubio Rincón
- Facultad de Ciencias Biológicas, Universidad Juárez del Estado de Durango, Durango, Mexico
| | | | - Víctor Vásquez-Cruz
- Facultad de Ciencias Biológicas y Agropecuarias, Universidad Veracruzana, Veracruz, Mexico
- PIMVS Herpetario Palancoatl, Veracruz, Mexico
| | | | - Andrew Storfer
- School of Biological Sciences, Washington State University, Pullman, WA, USA
| | - Miguel Borja
- Facultad de Ciencias Biológicas, Universidad Juárez del Estado de Durango, Durango, Mexico
| | | | - Paul B Frandsen
- Department of Plant and Wildlife Sciences, Brigham Young University, Provo, UT, USA
| | | | | | - Mark J Margres
- Department of Integrative Biology, University of South Florida, Tampa, FL, USA
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2
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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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3
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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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4
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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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5
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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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6
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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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7
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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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8
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Malhotra A, Wüster W, Owens JB, Hodges CW, Jesudasan A, Ch G, Kartik A, Christopher P, Louies J, Naik H, Santra V, Kuttalam SR, Attre S, Sasa M, Bravo-Vega C, Murray KA. Promoting co-existence between humans and venomous snakes through increasing the herpetological knowledge base. Toxicon X 2021; 12:100081. [PMID: 34522881 PMCID: PMC8426276 DOI: 10.1016/j.toxcx.2021.100081] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 07/28/2021] [Accepted: 08/04/2021] [Indexed: 11/23/2022] Open
Abstract
Snakebite incidence at least partly depends on the biology of the snakes involved. However, studies of snake biology have been largely neglected in favour of anthropic factors, with the exception of taxonomy, which has been recognised for some decades to affect the design of antivenoms. Despite this, within-species venom variation and the unpredictability of the correlation with antivenom cross-reactivity has continued to be problematic. Meanwhile, other aspects of snake biology, including behaviour, spatial ecology and activity patterns, distribution, and population demography, which can contribute to snakebite mitigation and prevention, remain underfunded and understudied. Here, we review the literature relevant to these aspects of snakebite and illustrate how demographic, spatial, and behavioural studies can improve our understanding of why snakebites occur and provide evidence for prevention strategies. We identify the large gaps that remain to be filled and urge that, in the future, data and relevant metadata be shared openly via public data repositories so that studies can be properly replicated and data used in future meta-analyses.
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Affiliation(s)
- Anita Malhotra
- Molecular Ecology and Evolution @ Bangor, School of Natural Sciences, Bangor University, 3rd floor ECW, Deiniol Road, Bangor, LL57 2UW, UK
| | - Wolfgang Wüster
- Molecular Ecology and Evolution @ Bangor, School of Natural Sciences, Bangor University, 3rd floor ECW, Deiniol Road, Bangor, LL57 2UW, UK
| | - John Benjamin Owens
- Molecular Ecology and Evolution @ Bangor, School of Natural Sciences, Bangor University, 3rd floor ECW, Deiniol Road, Bangor, LL57 2UW, UK
- Captive & Field Herpetology Ltd, Wales, 13 Hirfron, Holyhead, Llaingoch, Anglesey, LL65 1YU, UK
| | - Cameron Wesley Hodges
- School of Biology, Institute of Science, Suranaree University of Technology, Muang Nakhon Ratchasima, Thailand
| | - Allwin Jesudasan
- Madras Crocodile Bank Trust, Centre for Herpetology, Post bag No.4, Vadanamelli Village, East Coast Road, Mamallapuram, 603 104, Tamil Nadu, India
| | - Gnaneswar Ch
- Madras Crocodile Bank Trust, Centre for Herpetology, Post bag No.4, Vadanamelli Village, East Coast Road, Mamallapuram, 603 104, Tamil Nadu, India
| | - Ajay Kartik
- Madras Crocodile Bank Trust, Centre for Herpetology, Post bag No.4, Vadanamelli Village, East Coast Road, Mamallapuram, 603 104, Tamil Nadu, India
| | - Peter Christopher
- Madras Crocodile Bank Trust, Centre for Herpetology, Post bag No.4, Vadanamelli Village, East Coast Road, Mamallapuram, 603 104, Tamil Nadu, India
| | | | - Hiral Naik
- School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg. P. O. Wits, 2050, Gauteng, South Africa
- Save the Snakes, R527, Blyderus, Hoedspruit, 1380, South Africa
| | - Vishal Santra
- Captive & Field Herpetology Ltd, Wales, 13 Hirfron, Holyhead, Llaingoch, Anglesey, LL65 1YU, UK
- Society for Nature Conservation, Research and Community Engagement (CONCERN), Nalikul, Hooghly, West Bengal 712407, India
| | - Sourish Rajagopalan Kuttalam
- Society for Nature Conservation, Research and Community Engagement (CONCERN), Nalikul, Hooghly, West Bengal 712407, India
| | - Shaleen Attre
- Durrell Institute of Conservation and Ecology, School of Anthropology and Conservation, Marlowe Building, University of Kent, Canterbury, Kent, CT2 7NR, UK
| | - Mahmood Sasa
- Instituto Clodomiro Picado, Universidad de Costa Rica, San José, Costa Rica
- Escuela de Biología, Universidad de Costa Rica, San José, Costa Rica
| | - Carlos Bravo-Vega
- Research Group in Mathematical and Computational Biology (BIOMAC), Department of Biomedical Engineering, University of the Andes, Bogotá, Colombia
| | - Kris A. Murray
- MRC Centre for Global Infectious Disease Analysis, Imperial College London, UK
- MRC Unit The Gambia at London School of Hygiene and Tropical Medicine, Atlantic Boulevard, Fajara, Gambia
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9
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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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10
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Rautsaw RM, Schramer TD, Acuña R, Arick LN, DiMeo M, Mercier KP, Schrum M, Mason AJ, Margres MJ, Strickland JL, Parkinson CL. Genomic Adaptations to Salinity Resist Gene Flow in the Evolution of Floridian Watersnakes. Mol Biol Evol 2021; 38:745-760. [PMID: 33035326 PMCID: PMC7947766 DOI: 10.1093/molbev/msaa266] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The migration-selection balance often governs the evolution of lineages, and speciation with gene flow is now considered common across the tree of life. Ecological speciation is a process that can facilitate divergence despite gene flow due to strong selective pressures caused by ecological differences; however, the exact traits under selection are often unknown. The transition from freshwater to saltwater habitats provides strong selection targeting traits with osmoregulatory function. Several lineages of North American watersnakes (Nerodia spp.) are known to occur in saltwater habitat and represent a useful system for studying speciation by providing an opportunity to investigate gene flow and evaluate how species boundaries are maintained or degraded. We use double digest restriction-site associated DNA sequencing to characterize the migration-selection balance and test for evidence of ecological divergence within the Nerodia fasciata-clarkii complex in Florida. We find evidence of high intraspecific gene flow with a pattern of isolation-by-distance underlying subspecific lineages. However, we identify genetic structure indicative of reduced gene flow between inland and coastal lineages suggesting divergence due to isolation-by-environment. This pattern is consistent with observed environmental differences where the amount of admixture decreases with increased salinity. Furthermore, we identify significantly enriched terms related to osmoregulatory function among a set of candidate loci, including several genes that have been previously implicated in adaptation to salinity stress. Collectively, our results demonstrate that ecological differences, likely driven by salinity, cause strong divergent selection which promotes divergence in the N. fasciata-clarkii complex despite significant gene flow.
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Affiliation(s)
- Rhett M Rautsaw
- Department of Biological Sciences, Clemson University, Clemson, SC.,Department of Biology, University of Central Florida, Orlando, FL
| | | | - Rachel Acuña
- Department of Biology, University of Central Florida, Orlando, FL
| | - Lindsay N Arick
- Department of Biology, University of Central Florida, Orlando, FL
| | - Mark DiMeo
- Department of Biological Sciences, Clemson University, Clemson, SC.,Department of Biology, University of Central Florida, Orlando, FL
| | - Kathryn P Mercier
- Department of Biological Sciences, Clemson University, Clemson, SC.,Department of Biology, University of Central Florida, Orlando, FL.,Department of Biology, City College of New York, New York, NY.,PhD Program in Biology, The Graduate Center of the City University of New York, New York, NY
| | - Michael Schrum
- Department of Biology, University of Central Florida, Orlando, FL
| | - Andrew J Mason
- Department of Biological Sciences, Clemson University, Clemson, SC.,Department of Biology, University of Central Florida, Orlando, FL
| | - Mark J Margres
- Department of Biological Sciences, Clemson University, Clemson, SC.,Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA.,Department of Integrative Biology, University of South Florida, Tampa, FL
| | - Jason L Strickland
- Department of Biological Sciences, Clemson University, Clemson, SC.,Department of Biology, University of Central Florida, Orlando, FL.,Department of Biology, University of South Alabama, Mobile, AL
| | - Christopher L Parkinson
- Department of Biological Sciences, Clemson University, Clemson, SC.,Department of Biology, University of Central Florida, Orlando, FL.,Department of Forestry and Environmental Conservation, Clemson University, Clemson, SC
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11
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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: 41] [Impact Index Per Article: 13.7] [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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12
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Surm JM, Moran Y. Insights into how development and life-history dynamics shape the evolution of venom. EvoDevo 2021; 12:1. [PMID: 33413660 PMCID: PMC7791878 DOI: 10.1186/s13227-020-00171-w] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 12/22/2020] [Indexed: 02/07/2023] Open
Abstract
Venomous animals are a striking example of the convergent evolution of a complex trait. These animals have independently evolved an apparatus that synthesizes, stores, and secretes a mixture of toxic compounds to the target animal through the infliction of a wound. Among these distantly related animals, some can modulate and compartmentalize functionally distinct venoms related to predation and defense. A process to separate distinct venoms can occur within and across complex life cycles as well as more streamlined ontogenies, depending on their life-history requirements. Moreover, the morphological and cellular complexity of the venom apparatus likely facilitates the functional diversity of venom deployed within a given life stage. Intersexual variation of venoms has also evolved further contributing to the massive diversity of toxic compounds characterized in these animals. These changes in the biochemical phenotype of venom can directly affect the fitness of these animals, having important implications in their diet, behavior, and mating biology. In this review, we explore the current literature that is unraveling the temporal dynamics of the venom system that are required by these animals to meet their ecological functions. These recent findings have important consequences in understanding the evolution and development of a convergent complex trait and its organismal and ecological implications.
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Affiliation(s)
- Joachim M Surm
- Department of Ecology, Evolution and Behavior, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, 9190401, Jerusalem, Israel.
| | - Yehu Moran
- Department of Ecology, Evolution and Behavior, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, 9190401, Jerusalem, Israel.
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13
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Spontaneous Tumor Regression in Tasmanian Devils Associated with RASL11A Activation. Genetics 2020; 215:1143-1152. [PMID: 32554701 DOI: 10.1534/genetics.120.303428] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 06/12/2020] [Indexed: 12/30/2022] Open
Abstract
Spontaneous tumor regression has been documented in a small proportion of human cancer patients, but the specific mechanisms underlying tumor regression without treatment are not well understood. Tasmanian devils are threatened with extinction from a transmissible cancer due to universal susceptibility and a near 100% case fatality rate. In over 10,000 cases, <20 instances of natural tumor regression have been detected. Previous work in this system has focused on Tasmanian devil genetic variation associated with the regression phenotype. Here, we used comparative and functional genomics to identify tumor genetic variation associated with tumor regression. We show that a single point mutation in the 5' untranslated region of the putative tumor suppressor RASL11A significantly contributes to tumor regression. RASL11A was expressed in regressed tumors but silenced in wild-type, nonregressed tumors, consistent with RASL11A downregulation in human cancers. Induced RASL11A expression significantly reduced tumor cell proliferation in vitro The RAS pathway is frequently altered in human cancers, and RASL11A activation may provide a therapeutic treatment option for Tasmanian devils as well as a general mechanism for tumor inhibition.
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14
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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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15
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Patton A, Apodaca JJ, Corser JD, Wilson CR, Williams LA, Cameron AD, Wake DB. A New Green Salamander in the Southern Appalachians: Evolutionary History of Aneides aeneus and Implications for Management and Conservation with the Description of a Cryptic Microendemic Species. COPEIA 2019. [DOI: 10.1643/ch-18-052] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Austin Patton
- School of Biological Sciences, Washington State University, Pullman, Washington 99164
| | - Joseph J. Apodaca
- Amphibian and Reptile Conservancy and Tangled Bank Conservation, 128 Bingham Road, Suite 1150, Asheville, North Carolina 28806; . Send reprint requests to this address
| | - Jeffrey D. Corser
- New York Natural Heritage Program, SUNY College of Environmental Science and Forestry, 625 Broadway, 5th Floor, Albany, New York 12233
| | | | - Lori A. Williams
- North Carolina Wildlife Resources Commission, 177 Mountain Laurel Lane, Fletcher, North Carolina 28732
| | - Alan D. Cameron
- North Carolina Wildlife Resources Commission, 177 Mountain Laurel Lane, Fletcher, North Carolina 28732
| | - David B. Wake
- Museum of Vertebrate Zoology, University of California, Berkeley, California 94720-3160
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16
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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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17
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Petras D, Hempel BF, Göçmen B, Karis M, Whiteley G, Wagstaff SC, Heiss P, Casewell NR, Nalbantsoy A, Süssmuth RD. Intact protein mass spectrometry reveals intraspecies variations in venom composition of a local population of Vipera kaznakovi in Northeastern Turkey. J Proteomics 2019; 199:31-50. [PMID: 30763806 PMCID: PMC7613002 DOI: 10.1016/j.jprot.2019.02.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 01/30/2019] [Accepted: 02/10/2019] [Indexed: 12/16/2022]
Abstract
We report on the variable venom composition of a population of the Caucasus viper (Vipera kaznakovi) in Northeastern Turkey. We applied a combination of venom gland transcriptomics, de-complexing bottom-up and top-down venomics. In contrast to sole bottom-up venomics approaches and gel or chromatography based venom comparison, our combined approach enables a faster and more detailed comparison of venom proteomes from multiple individuals. In total, we identified peptides and proteins from 15 toxin families, including snake venom metalloproteinases (svMP; 37.8%), phospholipases A2 (PLA2; 19.0%), snake venom serine proteinases (svSP; 11.5%), C-type lectins (CTL; 6.9%) and cysteine-rich secretory proteins (CRISP; 5.0%), in addition to several low abundant toxin families. Furthermore, we identified intraspecies variations of the venom composition of V. kaznakovi, and find these were mainly driven by the age of the animals, with lower svSP abundance detected in juveniles. On the proteoform level, several small molecular weight toxins between 5 and 8 kDa in size, as well as PLA2s, drove the differences observed between juvenile and adult individuals. This study provides novel insights into the venom variability of V. kaznakovi and highlights the utility of intact mass profiling for fast and detailed comparison of snake venom. BIOLOGICAL SIGNIFICANCE: Population level and ontogenetic venom variation (e.g. diet, habitat, sex or age) can result in a loss of antivenom efficacy against snakebites from wide ranging snake populations. The current state of the art for the analysis of snake venoms are de-complexing bottom-up proteomics approaches. While useful, these have the significant drawback of being time-consuming and following costly protocols, and consequently are often applied to pooled venom samples. To overcome these shortcomings and to enable rapid and detailed profiling of large numbers of individual venom samples, we integrated an intact protein analysis workflow into a transcriptomics-guided bottom-up approach. The application of this workflow to snake individuals of a local population of V. kaznakovi revealed intraspecies variations in venom composition, which are primarily explained by the age of the animals, and highlighted svSP abundance to be one of the molecular drivers for the compositional differences observed.
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Affiliation(s)
- Daniel Petras
- Technische Universität Berlin, Institut für Chemie, Strasse des 17. Juni 124, 10623 Berlin, Germany; University of California San Diego, Collaborative Mass Spectrometry Innovation Center, 9500 Gilman Drive, La Jolla, CA 92093, United States.
| | - Benjamin-Florian Hempel
- Technische Universität Berlin, Institut für Chemie, Strasse des 17. Juni 124, 10623 Berlin, Germany
| | - Bayram Göçmen
- Zoology Section, Department of Biology, Faculty of Science, Ege University, 35100 Bornova, Izmir, Turkey
| | - Mert Karis
- Zoology Section, Department of Biology, Faculty of Science, Ege University, 35100 Bornova, Izmir, Turkey
| | - Gareth Whiteley
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, United Kingdom
| | - Simon C Wagstaff
- Research Computing Unit, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, United Kingdom
| | - Paul Heiss
- Technische Universität Berlin, Institut für Chemie, Strasse des 17. Juni 124, 10623 Berlin, Germany
| | - Nicholas R Casewell
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, United Kingdom
| | - Ayse Nalbantsoy
- Department of Bioengineering, Faculty of Engineering, Ege University, Bornova 35100, Izmir, Turkey.
| | - Roderich D Süssmuth
- Technische Universität Berlin, Institut für Chemie, Strasse des 17. Juni 124, 10623 Berlin, Germany.
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