1
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Hogan MP, Holding ML, Nystrom GS, Colston TJ, Bartlett DA, Mason AJ, Ellsworth SA, Rautsaw RM, Lawrence KC, Strickland JL, He B, Fraser P, Margres MJ, Gilbert DM, Gibbs HL, Parkinson CL, Rokyta DR. The genetic regulatory architecture and epigenomic basis for age-related changes in rattlesnake venom. Proc Natl Acad Sci U S A 2024; 121:e2313440121. [PMID: 38578985 PMCID: PMC11032440 DOI: 10.1073/pnas.2313440121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 03/13/2024] [Indexed: 04/07/2024] Open
Abstract
Developmental phenotypic changes can evolve under selection imposed by age- and size-related ecological differences. Many of these changes occur through programmed alterations to gene expression patterns, but the molecular mechanisms and gene-regulatory networks underlying these adaptive changes remain poorly understood. Many venomous snakes, including the eastern diamondback rattlesnake (Crotalus adamanteus), undergo correlated changes in diet and venom expression as snakes grow larger with age, providing models for identifying mechanisms of timed expression changes that underlie adaptive life history traits. By combining a highly contiguous, chromosome-level genome assembly with measures of expression, chromatin accessibility, and histone modifications, we identified cis-regulatory elements and trans-regulatory factors controlling venom ontogeny in the venom glands of C. adamanteus. Ontogenetic expression changes were significantly correlated with epigenomic changes within genes, immediately adjacent to genes (e.g., promoters), and more distant from genes (e.g., enhancers). We identified 37 candidate transcription factors (TFs), with the vast majority being up-regulated in adults. The ontogenetic change is largely driven by an increase in the expression of TFs associated with growth signaling, transcriptional activation, and circadian rhythm/biological timing systems in adults with corresponding epigenomic changes near the differentially expressed venom genes. However, both expression activation and repression contributed to the composition of both adult and juvenile venoms, demonstrating the complexity and potential evolvability of gene regulation for this trait. Overall, given that age-based trait variation is common across the tree of life, we provide a framework for understanding gene-regulatory-network-driven life-history evolution more broadly.
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Affiliation(s)
- Michael P. Hogan
- Department of Biological Science, Florida State University, Tallahassee, FL32306
| | - Matthew L. Holding
- Department of Biological Science, Florida State University, Tallahassee, FL32306
- Life Sciences Institute, University of Michigan, Ann Arbor, MI48109
| | - Gunnar S. Nystrom
- Department of Biological Science, Florida State University, Tallahassee, FL32306
| | - Timothy J. Colston
- Department of Biological Science, Florida State University, Tallahassee, FL32306
- Department of Biology, University of Puerto Rico at Mayagüez, Mayagüez, PR00681
| | - Daniel A. Bartlett
- Department of Biological Science, Florida State University, Tallahassee, FL32306
| | - Andrew J. Mason
- Department of Biological Sciences, Clemson University, Clemson, SC29634
- Department of Evolution, Ecology and Organismal Biology, The Ohio State University, Columbus, OH43210
| | - Schyler A. Ellsworth
- Department of Biological Science, Florida State University, Tallahassee, FL32306
| | - Rhett M. Rautsaw
- Department of Biological Sciences, Clemson University, Clemson, SC29634
- Department of Integrative Biology, University of South Florida, Tampa, FL33620
- School of Biological Sciences, Washington State University, Pullman, WA99164
| | - Kylie C. Lawrence
- Department of Biological Science, Florida State University, Tallahassee, FL32306
| | - Jason L. Strickland
- Department of Biological Sciences, Clemson University, Clemson, SC29634
- Department of Biology, University of South Alabama, Mobile, AL36688
| | - Bing He
- Department of Biological Science, Florida State University, Tallahassee, FL32306
| | - Peter Fraser
- Department of Biological Science, Florida State University, Tallahassee, FL32306
| | - Mark J. Margres
- Department of Integrative Biology, University of South Florida, Tampa, FL33620
| | - David M. Gilbert
- Laboratory of Chromosome Replication and Epigenome Regulation, San Diego Biomedical Research Institute, San Diego, CA92121
| | - H. Lisle Gibbs
- Department of Evolution, Ecology and Organismal Biology, The Ohio State University, Columbus, OH43210
| | - Christopher L. Parkinson
- Department of Biological Sciences, Clemson University, Clemson, SC29634
- Department of Forestry and Environmental Conservation, Clemson University, Clemson, SC29634
| | - Darin R. Rokyta
- Department of Biological Science, Florida State University, Tallahassee, FL32306
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2
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Gallinson DG, Kozakiewicz CP, Rautsaw RM, Beer MA, Ruiz-Aravena M, Comte S, Hamilton DG, Kerlin DH, McCallum HI, Hamede R, Jones ME, Storfer A, McMinds R, Margres MJ. Intergenomic signatures of coevolution between Tasmanian devils and an infectious cancer. Proc Natl Acad Sci U S A 2024; 121:e2307780121. [PMID: 38466855 PMCID: PMC10962979 DOI: 10.1073/pnas.2307780121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 01/17/2024] [Indexed: 03/13/2024] Open
Abstract
Coevolution is common and frequently governs host-pathogen interaction outcomes. Phenotypes underlying these interactions often manifest as the combined products of the genomes of interacting species, yet traditional quantitative trait mapping approaches ignore these intergenomic interactions. Devil facial tumor disease (DFTD), an infectious cancer afflicting Tasmanian devils (Sarcophilus harrisii), has decimated devil populations due to universal host susceptibility and a fatality rate approaching 100%. Here, we used a recently developed joint genome-wide association study (i.e., co-GWAS) approach, 15 y of mark-recapture data, and 960 genomes to identify intergenomic signatures of coevolution between devils and DFTD. Using a traditional GWA approach, we found that both devil and DFTD genomes explained a substantial proportion of variance in how quickly susceptible devils became infected, although genomic architectures differed across devils and DFTD; the devil genome had fewer loci of large effect whereas the DFTD genome had a more polygenic architecture. Using a co-GWA approach, devil-DFTD intergenomic interactions explained ~3× more variation in how quickly susceptible devils became infected than either genome alone, and the top genotype-by-genotype interactions were significantly enriched for cancer genes and signatures of selection. A devil regulatory mutation was associated with differential expression of a candidate cancer gene and showed putative allele matching effects with two DFTD coding sequence variants. Our results highlight the need to account for intergenomic interactions when investigating host-pathogen (co)evolution and emphasize the importance of such interactions when considering devil management strategies.
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Affiliation(s)
- Dylan G. Gallinson
- Department of Integrative Biology, University of South Florida, Tampa, FL33620
- College of Public Health, University of South Florida, Tampa, FL33620
| | - Christopher P. Kozakiewicz
- School of Biological Sciences, Washington State University, Pullman, WA99163
- W.K. Kellogg Biological Station, Department of Integrative Biology, Michigan State University, Hickory Corners, MI49060
| | - Rhett M. Rautsaw
- Department of Integrative Biology, University of South Florida, Tampa, FL33620
- School of Biological Sciences, Washington State University, Pullman, WA99163
| | - Marc A. Beer
- School of Biological Sciences, Washington State University, Pullman, WA99163
| | - Manuel Ruiz-Aravena
- School of Natural Sciences, University of Tasmania, Hobart, TAS7001, Australia
- Department of Public and Ecosystem Health, Cornell University, Ithaca, NY14853
| | - Sebastien Comte
- School of Natural Sciences, University of Tasmania, Hobart, TAS7001, Australia
- New South Wales Department of Primary Industries, Vertebrate Pest Research Unit, Orange, NSW2800, Australia
| | - David G. Hamilton
- School of Natural Sciences, University of Tasmania, Hobart, TAS7001, Australia
| | - Douglas H. Kerlin
- Centre for Planetary Health and Food Security, Griffith University, Nathan, QLD4111, Australia
| | - Hamish I. McCallum
- Centre for Planetary Health and Food Security, Griffith University, Nathan, QLD4111, Australia
| | - Rodrigo Hamede
- School of Natural Sciences, University of Tasmania, Hobart, TAS7001, Australia
- CANECEV Centre de Recherches Ecologiques et Evolutives sur le Cancer, Montpellier34394, France
| | - Menna E. Jones
- School of Natural Sciences, University of Tasmania, Hobart, TAS7001, Australia
| | - Andrew Storfer
- School of Biological Sciences, Washington State University, Pullman, WA99163
| | - Ryan McMinds
- Department of Integrative Biology, University of South Florida, Tampa, FL33620
- College of Public Health, University of South Florida, Tampa, FL33620
| | - Mark J. Margres
- Department of Integrative Biology, University of South Florida, Tampa, FL33620
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3
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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4
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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5
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Holding ML, Trevine VC, Zinenko O, Strickland JL, Rautsaw RM, Mason AJ, Hogan MP, Parkinson CL, Grazziotin FG, Santana SE, Davis MA, Rokyta DR. Evolutionary allometry and ecological correlates of fang length evolution in vipers. Proc Biol Sci 2022; 289:20221132. [PMID: 36300520 PMCID: PMC9449470 DOI: 10.1098/rspb.2022.1132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 08/11/2022] [Indexed: 12/14/2022] Open
Abstract
Traits for prey acquisition form the phenotypic interface of predator-prey interactions. In venomous predators, morphological variation in venom delivery apparatus like fangs and stingers may be optimized for dispatching prey. Here, we determine how a single dimension of venom injection systems evolves in response to variation in the size, climatic conditions and dietary ecology of viperid snakes. We measured fang length in more than 1900 museum specimens representing 199 viper species (55% of recognized species). We find both phylogenetic signal and within-clade variation in relative fang length across vipers suggesting both general taxonomic trends and potential adaptive divergence in fang length. We recover positive evolutionary allometry and little static allometry in fang length. Proportionally longer fangs have evolved in larger species, which may facilitate venom injection in more voluminous prey. Finally, we leverage climatic and diet data to assess the global correlates of fang length. We find that models of fang length evolution are improved through the inclusion of both temperature and diet, particularly the extent to which diets are mammal-heavy diets. These findings demonstrate how adaptive variation can emerge among components of complex prey capture systems.
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Affiliation(s)
- Matthew L. Holding
- Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA
| | - Vivian C. Trevine
- Laboratório de Coleções Zoológicas, Instituto Butantan, Av. Vital Brazil, 1500, 05503-900 São Paulo, SP, Brazil
| | - Oleksandr Zinenko
- V. N. Karazin Kharkiv National University, 4 Svobody square, Kharkiv 61022, Ukraine
| | - Jason L. Strickland
- Department of Biological Sciences, Clemson University, 190 Collings street, Clemson, SC 29634, USA
| | - Rhett M. Rautsaw
- Department of Biological Sciences, Clemson University, 190 Collings street, Clemson, SC 29634, USA
| | - Andrew J. Mason
- Department of Biological Sciences, Clemson University, 190 Collings street, Clemson, SC 29634, USA
| | - Michael P. Hogan
- Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA
| | - Christopher L. Parkinson
- Department of Biological Sciences, Clemson University, 190 Collings street, Clemson, SC 29634, USA
| | - Felipe G. Grazziotin
- Laboratório de Coleções Zoológicas, Instituto Butantan, Av. Vital Brazil, 1500, 05503-900 São Paulo, SP, Brazil
| | - Sharlene E. Santana
- Department of Biology and Burke Museum of Natural History and Culture, University of Washington, Seattle, WA 98105, USA
| | - Mark A. Davis
- Illinois Natural History Survey, University of Illinois, Champaign, IL 61820, USA
| | - Darin R. Rokyta
- Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA
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Myers EA, Strickland JL, Rautsaw RM, Mason AJ, Schramer TD, Nystrom GS, Hogan MP, Yooseph S, Rokyta DR, Parkinson CL. De Novo Genome Assembly Highlights the Role of Lineage-Specific Duplications in the Evolution of Venom in Fea’s Viper. Genome Biol Evol 2022; 14:6603630. [PMID: 35670514 PMCID: PMC9256536 DOI: 10.1093/gbe/evac082] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/25/2022] [Indexed: 11/12/2022] Open
Abstract
Despite the medical significance to humans and important ecological roles filled by vipers, few high-quality genomic resources exist for these snakes outside of a few genera of pitvipers. Here we sequence, assemble, and annotate the genome of Fea’s Viper (Azemiops feae). This taxon is distributed in East Asia and belongs to a monotypic subfamily, sister to the pitvipers. The newly sequenced genome resulted in a 1.56 Gb assembly, a contig N50 of 1.59 Mb, with 97.6% of the genome assembly in contigs >50 Kb, and a BUSCO completeness of 92.4%. We found that A. feae venom is primarily composed of phospholipase A2 (PLA2) proteins expressed by genes that likely arose from lineage-specific PLA2 gene duplications. Additionally, we show that renin, an enzyme associated with blood pressure regulation in mammals and known from the venoms of two viper species including A. feae, is expressed in the venom gland at comparative levels to known toxins and is present in the venom proteome. The cooption of this gene as a toxin may be more widespread in viperids than currently known. To investigate the historical population demographics of A. feae, we performed coalescent-based analyses and determined that the effective population size has remained stable over the last 100 kyr. This suggests Quaternary glacial cycles likely had minimal influence on the demographic history of A. feae. This newly assembled genome will be an important resource for studying the genomic basis of phenotypic evolution and understanding the diversification of venom toxin gene families.
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Affiliation(s)
- Edward A. Myers
- Department of Biological Sciences, Clemson University , Clemson, SC 29634, USA
| | - 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
| | - Andrew J. Mason
- Department of Biological Sciences, Clemson University , Clemson, SC 29634, USA
- Department of Evolution, Ecology and Organismal Biology, The Ohio State University , Columbus, OH 43210, USA
| | - Tristan D. Schramer
- Department of Biological Sciences, Clemson University , Clemson, SC 29634, USA
| | - Gunnar S. Nystrom
- 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
| | - Shibu Yooseph
- Department of Computer Science, Genomics and Bioinformatics Cluster, University of Central Florida, 4000 Central Florida Blvd , Orlando, FL, 32816, USA
| | - 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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7
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Mason AJ, Holding ML, Rautsaw RM, Rokyta DR, Parkinson CL, Gibbs HL. Venom gene sequence diversity and expression jointly shape diet adaptation in pitvipers. Mol Biol Evol 2022; 39:6567549. [PMID: 35413123 PMCID: PMC9040050 DOI: 10.1093/molbev/msac082] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Understanding the joint roles of protein sequence variation and differential expression during adaptive evolution is a fundamental, yet largely unrealized goal of evolutionary biology. Here, we use phylogenetic path analysis to analyze a comprehensive venom-gland transcriptome dataset spanning three genera of pitvipers to identify the functional genetic basis of a key adaptation (venom complexity) linked to diet breadth (DB). The analysis of gene-family-specific patterns reveals that, for genes encoding two of the most important venom proteins (snake venom metalloproteases and snake venom serine proteases), there are direct, positive relationships between sequence diversity (SD), expression diversity (ED), and increased DB. Further analysis of gene-family diversification for these proteins showed no constraint on how individual lineages achieved toxin gene SD in terms of the patterns of paralog diversification. In contrast, another major venom protein family (PLA2s) showed no relationship between venom molecular diversity and DB. Additional analyses suggest that other molecular mechanisms—such as higher absolute levels of expression—are responsible for diet adaptation involving these venom proteins. Broadly, our findings argue that functional diversity generated through sequence and expression variations jointly determine adaptation in the key components of pitviper venoms, which mediate complex molecular interactions between the snakes and their prey.
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Affiliation(s)
- Andrew J Mason
- Department of Evolution, Ecology and Organismal Biology, The Ohio State University, Columbus, OH, USA
| | | | - Rhett M Rautsaw
- Department of Biological Sciences, Clemson University, Clemson, SC, USA
| | - Darin R Rokyta
- Department of Biological Science, Florida State University, Tallahassee, FL, USA
| | - Christopher L Parkinson
- Department of Biological Sciences, Clemson University, Clemson, SC, USA.,Department of Forestry and Environmental Conservation, Clemson University, Clemson, SC, USA
| | - H Lisle Gibbs
- Department of Evolution, Ecology and Organismal Biology, The Ohio State University, Columbus, OH, USA
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8
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Schramer TD, Rautsaw RM, Bayona-Serrano JD, Nystrom GS, West TR, Ortiz-Medina JA, Sabido-Alpuche B, Meneses-Millán M, Borja M, Junqueira-de-Azevedo ILM, Rokyta DR, Parkinson CL. An integrative view of the toxic potential of Conophis lineatus (Dipsadidae: Xenodontinae), a medically relevant rear-fanged snake. Toxicon 2021; 205:38-52. [PMID: 34793822 DOI: 10.1016/j.toxicon.2021.11.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 10/25/2021] [Accepted: 11/10/2021] [Indexed: 10/19/2022]
Abstract
Most traditional research on snake venoms has focused on front-fanged snake families (Viperidae, Elapidae, and Atractaspididae). However, venom is now generally accepted as being a much more broadly possessed trait within snakes, including species traditionally considered harmless. Unfortunately, due to historical inertia and methodological challenges, the toxin repertoires of non-front-fanged snake families (e.g., Colubridae, Dipsadidae, and Natricidae) have been heavily neglected despite the knowledge of numerous species capable of inflicting medically relevant envenomations. Integrating proteomic data for validation, we perform a de novo assembly and analysis of the Duvernoy's venom gland transcriptome of the Central American Road Guarder (Dipsadidae: Xenodontinae: Conophis lineatus), a species known for its potent bite. We identified 28 putative toxin transcripts from 13 toxin families in the Duvernoy's venom gland transcriptome, comprising 63.7% of total transcriptome expression. In addition to ubiquitous snake toxin families, we proteomically confirmed several atypical venom components. The most highly expressed toxins (55.6% of total toxin expression) were recently described snake venom matrix metalloproteases (svMMPs), with 48.0% of svMMP expression contributable to a novel svMMP isoform. We investigate the evolution of the new svMMP isoform in the context of rear-fanged snakes using phylogenetics. Finally, we examine the morphology of the venom apparatus using μCT and explore how the venom relates to autecology and the highly hemorrhagic effects seen in human envenomations. Importantly, we provide the most complete venom characterization of this medically relevant snake species to date, producing insights into the effects and evolution of its venom, and point to future research directions to better understand the venoms of 'harmless' non-front-fanged snakes.
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Affiliation(s)
- Tristan D Schramer
- Department of Biological Sciences, Clemson University, Clemson, SC, USA.
| | - Rhett M Rautsaw
- Department of Biological Sciences, Clemson University, Clemson, SC, USA
| | | | - Gunnar S Nystrom
- Department of Biological Science, Florida State University, Tallahassee, FL, USA
| | - Taylor R West
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Javier A Ortiz-Medina
- Departamento de Sistemática y Ecología Acuática, El Colegio de La Frontera Sur, Unidad Chetumal, Chetumal, Quintana Roo, Mexico; Unidad de Manejo para La Conservación de La Vida Silvestre, Tsáab Kaan, Baca, Yucatán, Mexico; HERP.MX A.C., Villa de Álvarez, Colima, Mexico
| | - Bianca Sabido-Alpuche
- Unidad de Manejo para La Conservación de La Vida Silvestre, Tsáab Kaan, Baca, Yucatán, Mexico
| | - Marcos Meneses-Millán
- Unidad de Manejo para La Conservación de La Vida Silvestre, Tsáab Kaan, Baca, Yucatán, Mexico
| | - Miguel Borja
- Facultad de Ciencias Biológicas, Universidad Juárez Del Estado de Durango, Gómez Palacio, Durango, Mexico
| | - Inácio L M Junqueira-de-Azevedo
- Laboratório de Toxinologia Aplicada, Instituto Butantan, São Paulo, Brazil; Center of Toxins, Immune-Response and Cell Signaling (CeTICS), São Paulo, Brazil
| | - Darin R Rokyta
- Department of Biological Science, Florida State University, Tallahassee, FL, USA
| | - Christopher L Parkinson
- Department of Biological Sciences, Clemson University, Clemson, SC, USA; Department of Forestry and Environmental Conservation, Clemson University, Clemson, SC, USA.
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9
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Jenkins DG, Ohyama L, López‐Borghesi F, Hart JD, Bogotá‐Gregory JD, Rautsaw RM, Roldán VC, Guilfoyle K, Jarvis A, Loch J, Mercier K, Myers O, Shaw R, Volk D, Bard AM. Biogeography and predictors of wildlife killed on roads at peninsular Florida State Parks. Ecol Evol 2021. [DOI: 10.1002/ece3.7743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- David G. Jenkins
- Department of Biology University of Central Florida Orlando FL USA
| | - Leo Ohyama
- Department of Entomology and Nematology University of Florida Gainesville FL USA
| | | | - Jacob D. Hart
- Department of Biology University of Central Florida Orlando FL USA
| | | | - Rhett M. Rautsaw
- Department of Biological Sciences Clemson University Clemson SC USA
| | - Vanessa Correa Roldán
- Department of Biology University of Central Florida Orlando FL USA
- Department of Ichthyology Museum of Natural History Universidad Nacional Mayor de San Marcos Lima Perú
| | - Kevin Guilfoyle
- Department of Biology University of Central Florida Orlando FL USA
| | - Anik Jarvis
- Department of Biology University of Central Florida Orlando FL USA
| | - Jennifer Loch
- Department of Biology University of Central Florida Orlando FL USA
| | - Kathryn Mercier
- Department of Biology City College of New York New York NY USA
- PhD Program in Biology The Graduate Center of the City University of New York New York NY USA
| | | | - Rachel Shaw
- Department of Biology University of Central Florida Orlando FL USA
| | | | - Alice M. Bard
- Florida Department of Environmental Protection Florida Park Service Apopka FL USA
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Hofmann EP, Rautsaw RM, Mason AJ, Strickland JL, Parkinson CL. Duvernoy's Gland Transcriptomics of the Plains Black-Headed Snake, Tantilla nigriceps (Squamata, Colubridae): Unearthing the Venom of Small Rear-Fanged Snakes. Toxins (Basel) 2021; 13:toxins13050336. [PMID: 34066626 PMCID: PMC8148590 DOI: 10.3390/toxins13050336] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 05/03/2021] [Accepted: 05/04/2021] [Indexed: 12/13/2022] Open
Abstract
The venoms of small rear-fanged snakes (RFS) remain largely unexplored, despite increased recognition of their importance in understanding venom evolution more broadly. Sequencing the transcriptome of venom-producing glands has greatly increased the ability of researchers to examine and characterize the toxin repertoire of small taxa with low venom yields. Here, we use RNA-seq to characterize the Duvernoy’s gland transcriptome of the Plains Black-headed Snake, Tantilla nigriceps, a small, semi-fossorial colubrid that feeds on a variety of potentially dangerous arthropods including centipedes and spiders. We generated transcriptomes of six individuals from three localities in order to both characterize the toxin expression of this species for the first time, and to look for initial evidence of venom variation in the species. Three toxin families—three-finger neurotoxins (3FTxs), cysteine-rich secretory proteins (CRISPs), and snake venom metalloproteinases (SVMPIIIs)—dominated the transcriptome of T. nigriceps; 3FTx themselves were the dominant toxin family in most individuals, accounting for as much as 86.4% of an individual’s toxin expression. Variation in toxin expression between individuals was also noted, with two specimens exhibiting higher relative expression of c-type lectins than any other sample (8.7–11.9% compared to <1%), and another expressed CRISPs higher than any other toxin. This study provides the first Duvernoy’s gland transcriptomes of any species of Tantilla, and one of the few transcriptomic studies of RFS not predicated on a single individual. This initial characterization demonstrates the need for further study of toxin expression variation in this species, as well as the need for further exploration of small RFS venoms.
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Affiliation(s)
- Erich P. Hofmann
- Department of Biological Sciences, Clemson University, Clemson, SC 29634, USA; (E.P.H.); (R.M.R.); (A.J.M.); (J.L.S.)
| | - Rhett M. Rautsaw
- Department of Biological Sciences, Clemson University, Clemson, SC 29634, USA; (E.P.H.); (R.M.R.); (A.J.M.); (J.L.S.)
| | - Andrew J. Mason
- Department of Biological Sciences, Clemson University, Clemson, SC 29634, USA; (E.P.H.); (R.M.R.); (A.J.M.); (J.L.S.)
| | - Jason L. Strickland
- Department of Biological Sciences, Clemson University, Clemson, SC 29634, USA; (E.P.H.); (R.M.R.); (A.J.M.); (J.L.S.)
| | - Christopher L. Parkinson
- Department of Biological Sciences, Clemson University, Clemson, SC 29634, USA; (E.P.H.); (R.M.R.); (A.J.M.); (J.L.S.)
- Department of Forestry and Environmental Conservation, Clemson University, Clemson, SC 29634, USA
- Correspondence:
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12
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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: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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.
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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
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13
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Nachtigall PG, Rautsaw RM, Ellsworth SA, Mason AJ, Rokyta DR, Parkinson CL, Junqueira-de-Azevedo ILM. ToxCodAn: a new toxin annotator and guide to venom gland transcriptomics. Brief Bioinform 2021; 22:6235957. [PMID: 33866357 DOI: 10.1093/bib/bbab095] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/15/2021] [Accepted: 03/03/2021] [Indexed: 01/23/2023] Open
Abstract
MOTIVATION Next-generation sequencing has become exceedingly common and has transformed our ability to explore nonmodel systems. In particular, transcriptomics has facilitated the study of venom and evolution of toxins in venomous lineages; however, many challenges remain. Primarily, annotation of toxins in the transcriptome is a laborious and time-consuming task. Current annotation software often fails to predict the correct coding sequence and overestimates the number of toxins present in the transcriptome. Here, we present ToxCodAn, a python script designed to perform precise annotation of snake venom gland transcriptomes. We test ToxCodAn with a set of previously curated transcriptomes and compare the results to other annotators. In addition, we provide a guide for venom gland transcriptomics to facilitate future research and use Bothrops alternatus as a case study for ToxCodAn and our guide. RESULTS Our analysis reveals that ToxCodAn provides precise annotation of toxins present in the transcriptome of venom glands of snakes. Comparison with other annotators demonstrates that ToxCodAn has better performance with regard to run time ($>20x$ faster), coding sequence prediction ($>3x$ more accurate) and the number of toxins predicted (generating $>4x$ less false positives). In this sense, ToxCodAn is a valuable resource for toxin annotation. The ToxCodAn framework can be expanded in the future to work with other venomous lineages and detect novel toxins.
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Affiliation(s)
- Pedro G Nachtigall
- Laboratório de Toxinologia Aplicada, CeTICS, Instituto Butantan, São Paulo, SP 05503-900, Brazil
| | - Rhett M Rautsaw
- Department of Biological Sciences, Clemson University, Clemson, SC 29634, USA
| | - Schyler A Ellsworth
- Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA
| | - Andrew J Mason
- Department of Biological Sciences, Clemson University, Clemson, SC 29634, USA
- Department of Evolution, Ecology and Organismal Biology, The Ohio State University, Columbus, OH 43210 USA
| | - 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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14
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Margres MJ, Rautsaw RM, Strickland JL, Mason AJ, Schramer TD, Hofmann EP, Stiers E, Ellsworth SA, Nystrom GS, Hogan MP, Bartlett DA, Colston TJ, Gilbert DM, Rokyta DR, Parkinson CL. The Tiger Rattlesnake genome reveals a complex genotype underlying a simple venom phenotype. Proc Natl Acad Sci U S A 2021; 118:e2014634118. [PMID: 33468678 PMCID: PMC7848695 DOI: 10.1073/pnas.2014634118] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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15
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Bayona-Serrano JD, Viala VL, Rautsaw RM, Schramer TD, Barros-Carvalho GA, Nishiyama MY, Freitas-de-Sousa LA, Moura-da-Silva AM, Parkinson CL, Grazziotin FG, Junqueira-de-Azevedo ILM. Replacement and Parallel Simplification of Nonhomologous Proteinases Maintain Venom Phenotypes in Rear-Fanged Snakes. Mol Biol Evol 2020; 37:3563-3575. [PMID: 32722789 PMCID: PMC8525196 DOI: 10.1093/molbev/msaa192] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/29/2023] Open
Abstract
Novel phenotypes are commonly associated with gene duplications and neofunctionalization, less documented are the cases of phenotypic maintenance through the recruitment of novel genes. Proteolysis is the primary toxic character of many snake venoms, and ADAM metalloproteinases, named snake venom metalloproteinases (SVMPs), are largely recognized as the major effectors of this phenotype. However, by investigating original transcriptomes from 58 species of advanced snakes (Caenophidia) across their phylogeny, we discovered that a different enzyme, matrix metalloproteinase (MMP), is actually the dominant venom component in three tribes (Tachymenini, Xenodontini, and Conophiini) of rear-fanged snakes (Dipsadidae). Proteomic and functional analyses of these venoms further indicate that MMPs are likely playing an "SVMP-like" function in the proteolytic phenotype. A detailed look into the venom-specific sequences revealed a new highly expressed MMP subtype, named snake venom MMP (svMMP), which originated independently on at least three occasions from an endogenous MMP-9. We further show that by losing ancillary noncatalytic domains present in its ancestors, svMMPs followed an evolutionary path toward a simplified structure during their expansion in the genomes, thus paralleling what has been proposed for the evolution of their Viperidae counterparts, the SVMPs. Moreover, we inferred an inverse relationship between the expression of svMMPs and SVMPs along the evolutionary history of Xenodontinae, pointing out that one type of enzyme may be substituting for the other, whereas the general (metallo)proteolytic phenotype is maintained. These results provide rare evidence on how relevant phenotypic traits can be optimized via natural selection on nonhomologous genes, yielding alternate biochemical components.
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Affiliation(s)
| | - Vincent Louis Viala
- Laboratório Especial de Toxinologia Aplicada, Instituto Butantan, São Paulo, Brazil
- Center of Toxins, Immune-Response and Cell Signaling (CeTICS), São Paulo, Brazil
| | - Rhett M Rautsaw
- Department of Biological Sciences, Clemson University, Clemson, SC
| | | | | | - Milton Yutaka Nishiyama
- Laboratório Especial de Toxinologia Aplicada, Instituto Butantan, São Paulo, Brazil
- Center of Toxins, Immune-Response and Cell Signaling (CeTICS), São Paulo, Brazil
| | | | - Ana Maria Moura-da-Silva
- Laboratório de Imunopatologia, Instituto Butantan, São Paulo, Brazil
- Instituto de Pesquisa Clínica Carlos Borborema, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil
| | - Christopher L Parkinson
- Department of Biological Sciences, Clemson University, Clemson, SC
- Department of Forestry and Environmental Conservation, Clemson University, Clemson, SC
| | | | - Inácio L M Junqueira-de-Azevedo
- Laboratório Especial de Toxinologia Aplicada, Instituto Butantan, São Paulo, Brazil
- Center of Toxins, Immune-Response and Cell Signaling (CeTICS), São Paulo, Brazil
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Hofmann EP, Rautsaw RM, Strickland JL, Holding ML, Hogan MP, Mason AJ, Rokyta DR, Parkinson CL. Comparative venom-gland transcriptomics and venom proteomics of four Sidewinder Rattlesnake (Crotalus cerastes) lineages reveal little differential expression despite individual variation. Sci Rep 2018; 8:15534. [PMID: 30341342 PMCID: PMC6195556 DOI: 10.1038/s41598-018-33943-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 10/03/2018] [Indexed: 11/24/2022] Open
Abstract
Changes in gene expression can rapidly influence adaptive traits in the early stages of lineage diversification. Venom is an adaptive trait comprised of numerous toxins used for prey capture and defense. Snake venoms can vary widely between conspecific populations, but the influence of lineage diversification on such compositional differences are unknown. To explore venom differentiation in the early stages of lineage diversification, we used RNA-seq and mass spectrometry to characterize Sidewinder Rattlesnake (Crotalus cerastes) venom. We generated the first venom-gland transcriptomes and complementary venom proteomes for eight individuals collected across the United States and tested for expression differences across life history traits and between subspecific, mitochondrial, and phylotranscriptomic hypotheses. Sidewinder venom was comprised primarily of hemorrhagic toxins, with few cases of differential expression attributable to life history or lineage hypotheses. However, phylotranscriptomic lineage comparisons more than doubled instances of significant expression differences compared to all other factors. Nevertheless, only 6.4% of toxins were differentially expressed overall, suggesting that shallow divergence has not led to major changes in Sidewinder venom composition. Our results demonstrate the need for consensus venom-gland transcriptomes based on multiple individuals and highlight the potential for discrepancies in differential expression between different phylogenetic hypotheses.
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Affiliation(s)
- Erich P Hofmann
- Clemson University, Department of Biological Sciences, Clemson, SC, 29634, USA
| | - Rhett M Rautsaw
- Clemson University, Department of Biological Sciences, Clemson, SC, 29634, USA
| | - Jason L Strickland
- Clemson University, Department of Biological Sciences, Clemson, SC, 29634, USA
- University of Central Florida, Department of Biology, Orlando, FL, 32816, USA
| | - Matthew L Holding
- Clemson University, Department of Biological Sciences, Clemson, SC, 29634, USA
- Florida State University, Department of Biological Science, Tallahassee, FL, 32306, USA
| | - Michael P Hogan
- Florida State University, Department of Biological Science, Tallahassee, FL, 32306, USA
| | - Andrew J Mason
- Clemson University, Department of Biological Sciences, Clemson, SC, 29634, USA
| | - Darin R Rokyta
- Florida State University, Department of Biological Science, Tallahassee, FL, 32306, USA
| | - Christopher L Parkinson
- Clemson University, Department of Biological Sciences, Clemson, SC, 29634, USA.
- Clemson University, Department of Forestry and Environmental Conservation, Clemson, SC, 29634, USA.
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Rautsaw RM, Martin SA, Vincent BA, Lanctot K, Bolt MR, Seigel RA, Parkinson CL. Stopped Dead in Their Tracks: The Impact of Railways on Gopher Tortoise (Gopherus polyphemus) Movement and Behavior. COPEIA 2018. [DOI: 10.1643/ce-17-635] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Martin SA, Rautsaw RM, Robb F, Bolt MR, Parkinson CL, Seigel RA. Set AHDriFT: Applying game cameras to drift fences for surveying herpetofauna and small mammals. WILDLIFE SOC B 2017. [DOI: 10.1002/wsb.805] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Scott A. Martin
- Department of Biological Sciences; Towson University; 8000 York Road Towson MD 21252 USA
| | - Rhett M. Rautsaw
- Department of Biology; University of Central Florida; 4000 Central Florida Boulevard Orlando FL 32816 USA
| | - Frank Robb
- Biomedical Science; Eastern Florida State College; 1311US HWY 1, Titusville FL 32796 USA
| | - M. Rebecca Bolt
- Integrated Mission Support Services; Mail Code IMSS-200; Kennedy Space Center FL 32899 USA
| | - Christopher L. Parkinson
- Department of Biology; University of Central Florida; 4000 Central Florida Boulevard Orlando FL 32816 USA
| | - Richard A. Seigel
- Department of Biological Sciences; Towson University; 8000 York Road Towson MD 21252 USA
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Martin SA, Rautsaw RM, Bolt R, Parkinson CL, Seigel RA. Adapting coastal management to climate change: Mitigating our shrinking shorelines. J Wildl Manage 2017. [DOI: 10.1002/jwmg.21275] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Scott A. Martin
- Department of Biological Sciences; Towson University; 8000 York Road Towson MD 21252 USA
| | - Rhett M. Rautsaw
- Department of Biology; University of Central Florida; 4000 Central Florida Blvd. Orlando FL 32816 USA
| | - Rebecca Bolt
- Integrated Mission Support Services; Mail Code IMSS-200; Kennedy Space Center FL 32899 USA
| | - Christopher L. Parkinson
- Department of Biology; University of Central Florida; 4000 Central Florida Blvd. Orlando FL 32816 USA
| | - Richard A. Seigel
- Department of Biological Sciences; Towson University; 8000 York Road Towson MD 21252 USA
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