1
|
Michálek O, King GF, Pekár S. Prey specificity of predatory venoms. Biol Rev Camb Philos Soc 2024. [PMID: 38991997 DOI: 10.1111/brv.13120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2024] [Revised: 07/01/2024] [Accepted: 07/03/2024] [Indexed: 07/13/2024]
Abstract
Venom represents a key adaptation of many venomous predators, allowing them to immobilise prey quickly through chemical rather than physical warfare. Evolutionary arms races between prey and a predator are believed to be the main factor influencing the potency and composition of predatory venoms. Predators with narrowly restricted diets are expected to evolve specifically potent venom towards their focal prey, with lower efficacy on alternative prey. Here, we evaluate hypotheses on the evolution of prey-specific venom, focusing on the effect of restricted diet, prey defences, and prey resistance. Prey specificity as a potential evolutionary dead end is also discussed. We then provide an overview of the current knowledge on venom prey specificity, with emphasis on snakes, cone snails, and spiders. As the current evidence for venom prey specificity is still quite limited, we also overview the best approaches and methods for its investigation and provide a brief summary of potential model groups. Finally, possible applications of prey-specific toxins are discussed.
Collapse
Affiliation(s)
- Ondřej Michálek
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, Brno, 611 37, Czech Republic
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland, 4072, Australia
| | - Glenn F King
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland, 4072, Australia
- Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, St. Lucia, Queensland, 4072, Australia
| | - Stano Pekár
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, Brno, 611 37, Czech Republic
| |
Collapse
|
2
|
Oliveira LD, Nachtigall PG, Vialla VL, Campos PF, Costa-Neves AD, Zaher H, Silva NJD, Grazziotin FG, Wilkinson M, Junqueira-de-Azevedo ILM. Comparing morphological and secretory aspects of cephalic glands among the New World coral snakes brings novel insights on their biological roles. Toxicon 2023; 234:107285. [PMID: 37683698 DOI: 10.1016/j.toxicon.2023.107285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 09/05/2023] [Accepted: 09/06/2023] [Indexed: 09/10/2023]
Abstract
Oral and other cephalic glands have been surveyed by several studies with distinct purposes. Despite the wide diversity and medical relevance of the New World coral snakes, studies focusing on understanding the biological roles of the glands within this group are still scarce. Specifically, the venom glands of some coral snakes were previously investigated but all other cephalic glands remain uncharacterized. In this sense, performing morphological and molecular analysis of these glands may help better understand their biological role. Here, we studied the morphology of the venom, infralabial, rictal, and harderian glands of thirteen species of Micrurus and Micruroides euryxanthus. We also performed a molecular characterization of these glands from selected species of Micrurus using transcriptomic and proteomic approaches. We described substantial morphological variation in the cephalic glands of New World coral snakes and structural evidence for protein-secreting cells in the inferior rictal glands. Our molecular analysis revealed that the venom glands, as expected, are majorly devoted to toxin production, however, the infralabial and inferior rictal glands also expressed some toxin genes at low to medium levels, despite the marked morphological differences. On the other hand, the harderian glands were dominated by the expression of lipocalins, but do not produce toxins. Our integrative analysis, including the prediction of biological processes and pathways, helped decipher some important traits of cephalic glands and better understand their biology.
Collapse
Affiliation(s)
- Leonardo de Oliveira
- Laboratório de Toxinologia Aplicada, Centre of Toxins, Immune-Response and Cell Signaling (CeTICS), Instituto Butantan, São Paulo, 05503-900, Brazil; Herpetology, The Natural History Museum, London, SW7 5BD, United Kingdom.
| | - Pedro Gabriel Nachtigall
- Laboratório de Toxinologia Aplicada, Centre of Toxins, Immune-Response and Cell Signaling (CeTICS), Instituto Butantan, São Paulo, 05503-900, Brazil
| | - Vincent Louis Vialla
- Laboratório de Toxinologia Aplicada, Centre of Toxins, Immune-Response and Cell Signaling (CeTICS), Instituto Butantan, São Paulo, 05503-900, Brazil
| | - Pollyanna F Campos
- Laboratório de Toxinologia Aplicada, Centre of Toxins, Immune-Response and Cell Signaling (CeTICS), Instituto Butantan, São Paulo, 05503-900, Brazil
| | | | - Hussam Zaher
- Museu de Zoologia da Universidade de São Paulo, Avenida Nazaré 481, Ipiranga, 04263-000, São Paulo, Brazil
| | - Nelson Jorge da Silva
- Programa de Pós-Graduação em Ciências Ambientais e Saúde, Pontifícia Universidade Católica de Goiás, Goiânia, Goiás, 74605-140, Brazil
| | - Felipe G Grazziotin
- Laboratório de Coleções Zoológicas, Instituto Butantan, São Paulo, 05503-900, Brazil
| | - Mark Wilkinson
- Herpetology, The Natural History Museum, London, SW7 5BD, United Kingdom
| | - Inácio L M Junqueira-de-Azevedo
- Laboratório de Toxinologia Aplicada, Centre of Toxins, Immune-Response and Cell Signaling (CeTICS), Instituto Butantan, São Paulo, 05503-900, Brazil
| |
Collapse
|
3
|
Ye X, He C, Yang Y, Sun YH, Xiong S, Chan KC, Si Y, Xiao S, Zhao X, Lin H, Mei Y, Yao Y, Ye G, Wu F, Fang Q. Comprehensive isoform-level analysis reveals the contribution of alternative isoforms to venom evolution and repertoire diversity. Genome Res 2023; 33:1554-1567. [PMID: 37798117 PMCID: PMC10620052 DOI: 10.1101/gr.277707.123] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 08/08/2023] [Indexed: 10/07/2023]
Abstract
Animal venom systems have emerged as valuable models for investigating how novel polygenic phenotypes may arise from gene evolution by varying molecular mechanisms. However, a significant portion of venom genes produce alternative mRNA isoforms that have not been extensively characterized, hindering a comprehensive understanding of venom biology. In this study, we present a full-length isoform-level profiling workflow integrating multiple RNA sequencing technologies, allowing us to reconstruct a high-resolution transcriptome landscape of venom genes in the parasitoid wasp Pteromalus puparum Our findings demonstrate that more than half of the venom genes generate multiple isoforms within the venom gland. Through mass spectrometry analysis, we confirm that alternative splicing contributes to the diversity of venom proteins, acting as a mechanism for expanding the venom repertoire. Notably, we identified seven venom genes that exhibit distinct isoform usages between the venom gland and other tissues. Furthermore, evolutionary analyses of venom serpin3 and orcokinin further reveal that the co-option of an ancient isoform and a newly evolved isoform, respectively, contributes to venom recruitment, providing valuable insights into the genetic mechanisms driving venom evolution in parasitoid wasps. Overall, our study presents a comprehensive investigation of venom genes at the isoform level, significantly advancing our understanding of alternative isoforms in venom diversity and evolution and setting the stage for further in-depth research on venoms.
Collapse
Affiliation(s)
- Xinhai Ye
- State Key Laboratory of Rice Biology and Breeding & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China
- Shanghai Institute for Advanced Study, Zhejiang University, Shanghai 201203, China
- College of Computer Science and Technology, Zhejiang University, Hangzhou 310027, China
| | - Chun He
- State Key Laboratory of Rice Biology and Breeding & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China;
| | - Yi Yang
- State Key Laboratory of Rice Biology and Breeding & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yu H Sun
- Department of Biology, University of Rochester, Rochester, New York 14627, USA
| | - Shijiao Xiong
- State Key Laboratory of Rice Biology and Breeding & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China
| | - Kevin C Chan
- Shanghai Institute for Advanced Study, Zhejiang University, Shanghai 201203, China
| | - Yuxuan Si
- College of Computer Science and Technology, Zhejiang University, Hangzhou 310027, China
| | - Shan Xiao
- State Key Laboratory of Rice Biology and Breeding & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China
| | - Xianxin Zhao
- State Key Laboratory of Rice Biology and Breeding & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China
| | - Haiwei Lin
- State Key Laboratory of Rice Biology and Breeding & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yang Mei
- State Key Laboratory of Rice Biology and Breeding & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yufeng Yao
- Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310020, China
| | - Gongyin Ye
- State Key Laboratory of Rice Biology and Breeding & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China
| | - Fei Wu
- Shanghai Institute for Advanced Study, Zhejiang University, Shanghai 201203, China;
- College of Computer Science and Technology, Zhejiang University, Hangzhou 310027, China
| | - Qi Fang
- State Key Laboratory of Rice Biology and Breeding & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China;
| |
Collapse
|
4
|
Calvete JJ, Lomonte B, Lorente C, Pla D, Zollweg M, Mebs D. Proteomic analysis of the mandibular glands from the Chinese crocodile lizard, Shinisaurus crocodilurus - Another venomous lizard? Toxicon 2023; 225:107050. [PMID: 36736630 DOI: 10.1016/j.toxicon.2023.107050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 01/19/2023] [Accepted: 01/29/2023] [Indexed: 02/05/2023]
Abstract
Based on its phylogenetic relationship to monitor lizards (Varanidae), Gila monsters (Heloderma spp.), and the earless monitor Lanthanotus borneesis, the Chinese crocodile lizard, Shinisaurus crocodilurus, has been assigned to the Toxicofera clade, which comprises venomous reptiles. However, no data about composition and biological activities of its oral secretion have been reported. In the present study, a proteomic analysis of the mandibular gland of S. crocodilurus and, for comparison, of the herbivorous Solomon Island skink Corucia zebrata, was performed. Scanning electron microscopy (SEM) of the teeth from S. crocodilurus revealed a sharp ridge on the anterior surface, but no grooves, whereas those of C. zebrata possess a flattened crown with a pointed cusp. Proteomic analysis of their gland extracts provided no evidence of venom-derived peptides or proteins, strongly supporting the non-venomous character of these lizards. Data are available via ProteomeXchange with identifier PXD039424.
Collapse
Affiliation(s)
- Juan J Calvete
- Laboratorio de Venómica Evolutiva y Traslacional, Instituto de Biomedicina de Valencia, C.S.I.C., Jaime Roig 11, 46010, Valencia, Spain.
| | - Bruno Lomonte
- Instituto Clodomiro Picado, Facultad de Microbiologia, Universidad de Costa Rica, San José 11501, Costa Rica.
| | - Carolina Lorente
- Laboratorio de Venómica Evolutiva y Traslacional, Instituto de Biomedicina de Valencia, C.S.I.C., Jaime Roig 11, 46010, Valencia, Spain.
| | - Davinia Pla
- Laboratorio de Venómica Evolutiva y Traslacional, Instituto de Biomedicina de Valencia, C.S.I.C., Jaime Roig 11, 46010, Valencia, Spain.
| | | | - Dietrich Mebs
- Institute of Legal Medicine, Goethe University of Frankfurt, Kennedyallee 104, D-60569, Frankfurt, Germany.
| |
Collapse
|
5
|
Warrell DA, Williams DJ. Clinical aspects of snakebite envenoming and its treatment in low-resource settings. Lancet 2023; 401:1382-1398. [PMID: 36931290 DOI: 10.1016/s0140-6736(23)00002-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 11/26/2022] [Accepted: 12/18/2022] [Indexed: 03/16/2023]
Abstract
There is increasing recognition of the public health importance of snakebite envenoming. Worldwide annual incidence is likely to be 5 million bites, with mortality exceeding 150 000 deaths, and the resulting physical and psychological morbidity leads to substantial social and economic repercussions. Prevention through community education by trained health workers is the most effective and economically viable strategy for reducing risk of bites and envenoming. Clinical challenges to effective treatment are most substantial in rural areas of low-resource settings, where snakebites are most common. Classic skills of history taking, physical examination, and use of affordable point-of-care tests should be followed by monitoring of evolving local and systemic envenoming. Despite the profusion of new ideas for interventions, hyperimmune equine or ovine plasma-derived antivenoms remain the only specific treatment for snakebite envenoming. The enormous interspecies and intraspecies complexity and diversity of snake venoms, revealed by modern venomics, demands a radical redesign of many current antivenoms.
Collapse
Affiliation(s)
- David A Warrell
- Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK; Experimental Medicine Division, John Radcliffe Hospital, Headington, UK.
| | - David J Williams
- Regulation and Prequalification Department, World Health Organization, Geneva, Switzerland
| |
Collapse
|
6
|
Genomic, transcriptomic, and epigenomic analysis of a medicinal snake, Bungarus multicinctus, to provides insights into the origin of Elapidae neurotoxins. Acta Pharm Sin B 2022; 13:2234-2249. [DOI: 10.1016/j.apsb.2022.11.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 10/20/2022] [Accepted: 11/11/2022] [Indexed: 11/19/2022] Open
|
7
|
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.
Collapse
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.
| |
Collapse
|
8
|
Gopalan SS, Perry BW, Schield DR, Smith CF, Mackessy SP, Castoe TA. Origins, genomic structure and copy number variation of snake venom myotoxins. Toxicon 2022; 216:92-106. [PMID: 35820472 DOI: 10.1016/j.toxicon.2022.06.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 06/21/2022] [Accepted: 06/27/2022] [Indexed: 10/17/2022]
Abstract
Crotamine, myotoxin a and homologs are short peptides that often comprise major fractions of rattlesnake venoms and have been extensively studied for their bioactive properties. These toxins are thought to be important for rapidly immobilizing mammalian prey and are implicated in serious, and sometimes fatal, responses to envenomation in humans. While high quality reference genomes for multiple venomous snakes are available, the loci that encode myotoxins have not been successfully assembled in any existing genome assembly. Here, we integrate new and existing genomic and transcriptomic data from the Prairie Rattlesnake (Crotalus viridis viridis) to reconstruct, characterize, and infer the chromosomal locations of myotoxin-encoding loci. We integrate long-read transcriptomics (Pacific Bioscience's Iso-Seq) and short-read RNA-seq to infer gene sequence diversity and characterize patterns of myotoxin and paralogous β-defensin expression across multiple tissues. We also identify two long non-coding RNA sequences which both encode functional myotoxins, demonstrating a newly discovered source of venom coding sequence diversity. We also integrate long-range mate-pair chromatin contact data and linked-read sequencing to infer the structure and chromosomal locations of the three myotoxin-like loci. Further, we conclude that the venom-associated myotoxin is located on chromosome 1 and is adjacent to non-venom paralogs. Consistent with this locus contributing to venom composition, we find evidence that the promoter of this gene is selectively open in venom gland tissue and contains transcription factor binding sites implicated in broad trans-regulatory pathways that regulate snake venoms. This study provides the best genomic reconstruction of myotoxin loci to date and raises questions about the physiological roles and interplay between myotoxin and related genes, as well as the genomic origins of snake venom variation.
Collapse
Affiliation(s)
- Siddharth S Gopalan
- Department of Biology, 501 S. Nedderman Dr., The University of Texas Arlington, Arlington, TX, 76019, USA
| | - Blair W Perry
- Department of Biology, 501 S. Nedderman Dr., The University of Texas Arlington, Arlington, TX, 76019, USA; School of Biological Sciences, Washington State University, Pullman, WA, 99164, USA
| | - Drew R Schield
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, 80309, USA
| | - Cara F Smith
- School of Biological Sciences, 501 20th Street, University of Northern Colorado, Greeley, CO, 80639, USA; Department of Biochemistry and Molecular Biology, 12801 East 17th Avenue, University of Colorado Denver, Aurora, CO, 80045, USA
| | - Stephen P Mackessy
- School of Biological Sciences, 501 20th Street, University of Northern Colorado, Greeley, CO, 80639, USA
| | - Todd A Castoe
- Department of Biology, 501 S. Nedderman Dr., The University of Texas Arlington, Arlington, TX, 76019, USA.
| |
Collapse
|
9
|
Rao WQ, Kalogeropoulos K, Allentoft ME, Gopalakrishnan S, Zhao WN, Workman CT, Knudsen C, Jiménez-Mena B, Seneci L, Mousavi-Derazmahalleh M, Jenkins TP, Rivera-de-Torre E, Liu SQ, Laustsen AH. The rise of genomics in snake venom research: recent advances and future perspectives. Gigascience 2022; 11:6562531. [PMID: 35365832 PMCID: PMC8975721 DOI: 10.1093/gigascience/giac024] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 02/12/2022] [Accepted: 02/13/2022] [Indexed: 12/12/2022] Open
Abstract
Snake venoms represent a danger to human health, but also a gold mine of bioactive proteins that can be harnessed for drug discovery purposes. The evolution of snakes and their venom has been studied for decades, particularly via traditional morphological and basic genetic methods alongside venom proteomics. However, while the field of genomics has matured rapidly over the past 2 decades, owing to the development of next-generation sequencing technologies, snake genomics remains in its infancy. Here, we provide an overview of the state of the art in snake genomics and discuss its potential implications for studying venom evolution and toxinology. On the basis of current knowledge, gene duplication and positive selection are key mechanisms in the neofunctionalization of snake venom proteins. This makes snake venoms important evolutionary drivers that explain the remarkable venom diversification and adaptive variation observed in these reptiles. Gene duplication and neofunctionalization have also generated a large number of repeat sequences in snake genomes that pose a significant challenge to DNA sequencing, resulting in the need for substantial computational resources and longer sequencing read length for high-quality genome assembly. Fortunately, owing to constantly improving sequencing technologies and computational tools, we are now able to explore the molecular mechanisms of snake venom evolution in unprecedented detail. Such novel insights have the potential to affect the design and development of antivenoms and possibly other drugs, as well as provide new fundamental knowledge on snake biology and evolution.
Collapse
Affiliation(s)
- Wei-Qiao Rao
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads 224, 2800 Kongens Lyngby, Denmark.,Department of Mass Spectrometry, Beijing Genomics Institute-Research, 518083, Shenzhen, China
| | - Konstantinos Kalogeropoulos
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads 224, 2800 Kongens Lyngby, Denmark
| | - Morten E Allentoft
- Trace and Environmental DNA (TrEnD) Laboratory, School of Molecular and Life Sciences, Curtin University, Kent Street, 6102, Bentley Perth, Australia.,Globe Institute, University of Copenhagen, Øster Voldgade 5, 1350, Copenhagen, Denmark
| | - Shyam Gopalakrishnan
- Globe Institute, University of Copenhagen, Øster Voldgade 5, 1350, Copenhagen, Denmark
| | - Wei-Ning Zhao
- Department of Mass Spectrometry, Beijing Genomics Institute-Research, 518083, Shenzhen, China
| | - Christopher T Workman
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads 224, 2800 Kongens Lyngby, Denmark
| | - Cecilie Knudsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads 224, 2800 Kongens Lyngby, Denmark
| | - Belén Jiménez-Mena
- DTU Aqua, Technical University of Denmark, Vejlsøvej 39, 8600, Silkeborg, Denmark
| | - Lorenzo Seneci
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads 224, 2800 Kongens Lyngby, Denmark
| | - Mahsa Mousavi-Derazmahalleh
- Trace and Environmental DNA (TrEnD) Laboratory, School of Molecular and Life Sciences, Curtin University, Kent Street, 6102, Bentley Perth, Australia
| | - Timothy P Jenkins
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads 224, 2800 Kongens Lyngby, Denmark
| | - Esperanza Rivera-de-Torre
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads 224, 2800 Kongens Lyngby, Denmark
| | - Si-Qi Liu
- Department of Mass Spectrometry, Beijing Genomics Institute-Research, 518083, Shenzhen, China
| | - Andreas H Laustsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads 224, 2800 Kongens Lyngby, Denmark
| |
Collapse
|
10
|
Abstract
The venom glands of reptiles, particularly those of front-fanged advanced snakes, must satisfy conflicting biological demands: rapid synthesis of potentially labile and highly toxic proteins, storage in the gland lumen for long periods, stabilization of the stored secretions, immediate activation of toxins upon deployment and protection of the animal from the toxic effects of its own venom. This dynamic system could serve as a model for the study of a variety of different phenomena involving exocrine gland activation, protein synthesis, stabilization of protein products and secretory mechanisms. However, these studies have been hampered by a lack of a long-term model that can be propagated in the lab (as opposed to whole-animal studies). Numerous attempts have been made to extend the lifetime of venom gland secretory cells, but only recently has an organoid model been shown to have the requisite qualities of recapitulation of the native system, self-propagation and long-term viability (>1 year). A tractable model is now available for myriad cell- and molecular-level studies of venom glands, protein synthesis and secretion. However, venom glands of reptiles are not identical, and many differ very extensively in overall architecture, microanatomy and protein products produced. This Review summarizes the similarities among and differences between venom glands of helodermatid lizards and of rear-fanged and front-fanged snakes, highlighting those areas that are well understood and identifying areas where future studies can fill in significant gaps in knowledge of these ancient, yet fascinating systems.
Collapse
Affiliation(s)
- Stephen P Mackessy
- School of Biological Sciences, University of Northern Colorado, 501 20th St., CB 92, Greeley, CO 80639-0017, USA
| |
Collapse
|
11
|
The Enzymatic Core of Scorpion Venoms. Toxins (Basel) 2022; 14:toxins14040248. [PMID: 35448857 PMCID: PMC9030722 DOI: 10.3390/toxins14040248] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 03/16/2022] [Accepted: 03/26/2022] [Indexed: 12/11/2022] Open
Abstract
Enzymes are an integral part of animal venoms. Unlike snakes, in which enzymes play a primary role in envenomation, in scorpions, their function appears to be ancillary in most species. Due to this, studies on the diversity of scorpion venom components have focused primarily on the peptides responsible for envenomation (toxins) and a few others (e.g., antimicrobials), while enzymes have been overlooked. In this work, a comprehensive study on enzyme diversity in scorpion venoms was performed by transcriptomic and proteomic techniques. Enzymes of 63 different EC types were found, belonging to 330 orthogroups. Of them, 24 ECs conform the scorpion venom enzymatic core, since they were determined to be present in all the studied scorpion species. Transferases and lyases are reported for the first time. Novel enzymes, which can play different roles in the venom, including direct toxicity, as venom spreading factors, activators of venom components, venom preservatives, or in prey pre-digestion, were described and annotated. The expression profile for transcripts coding for venom enzymes was analyzed, and shown to be similar among the studied species, while being significantly different from their expression pattern outside the telson.
Collapse
|
12
|
Snake Venomics: Fundamentals, Recent Updates, and a Look to the Next Decade. Toxins (Basel) 2022; 14:toxins14040247. [PMID: 35448856 PMCID: PMC9028316 DOI: 10.3390/toxins14040247] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 03/18/2022] [Accepted: 03/21/2022] [Indexed: 01/11/2023] Open
Abstract
Venomic research, powered by techniques adapted from proteomics, transcriptomics, and genomics, seeks to unravel the diversity and complexity of venom through which knowledge can be applied in the treatment of envenoming, biodiscovery, and conservation. Snake venom proteomics is most extensively studied, but the methods varied widely, creating a massive amount of information which complicates data comparison and interpretation. Advancement in mass spectrometry technology, accompanied by growing databases and sophisticated bioinformatic tools, has overcome earlier limitations of protein identification. The progress, however, remains challenged by limited accessibility to samples, non-standardized quantitative methods, and biased interpretation of -omic data. Next-generation sequencing (NGS) technologies enable high-throughput venom-gland transcriptomics and genomics, complementing venom proteomics by providing deeper insights into the structural diversity, differential expression, regulation and functional interaction of the toxin genes. Venomic tissue sampling is, however, difficult due to strict regulations on wildlife use and transfer of biological materials in some countries. Limited resources for techniques and funding are among other pertinent issues that impede the progress of venomics, particularly in less developed regions and for neglected species. Genuine collaboration between international researchers, due recognition of regional experts by global organizations (e.g., WHO), and improved distribution of research support, should be embraced.
Collapse
|
13
|
Bucciarelli GM, Lechner M, Fontes A, Kats LB, Eisthen HL, Shaffer HB. From Poison to Promise: The Evolution of Tetrodotoxin and Its Potential as a Therapeutic. Toxins (Basel) 2021; 13:toxins13080517. [PMID: 34437388 PMCID: PMC8402337 DOI: 10.3390/toxins13080517] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 07/17/2021] [Accepted: 07/20/2021] [Indexed: 11/16/2022] Open
Abstract
Tetrodotoxin (TTX) is a potent neurotoxin that was first identified in pufferfish but has since been isolated from an array of taxa that host TTX-producing bacteria. However, determining its origin, ecosystem roles, and biomedical applications has challenged researchers for decades. Recognized as a poison and for its lethal effects on humans when ingested, TTX is primarily a powerful sodium channel inhibitor that targets voltage-gated sodium channels, including six of the nine mammalian isoforms. Although lethal doses for humans range from 1.5-2.0 mg TTX (blood level 9 ng/mL), when it is administered at levels far below LD50, TTX exhibits therapeutic properties, especially to treat cancer-related pain, neuropathic pain, and visceral pain. Furthermore, TTX can potentially treat a variety of medical ailments, including heroin and cocaine withdrawal symptoms, spinal cord injuries, brain trauma, and some kinds of tumors. Here, we (i) describe the perplexing evolution and ecology of tetrodotoxin, (ii) review its mechanisms and modes of action, and (iii) offer an overview of the numerous ways it may be applied as a therapeutic. There is much to be explored in these three areas, and we offer ideas for future research that combine evolutionary biology with therapeutics. The TTX system holds great promise as a therapeutic and understanding the origin and chemical ecology of TTX as a poison will only improve its general benefit to humanity.
Collapse
Affiliation(s)
- Gary M. Bucciarelli
- Department of Ecology and Evolutionary Biology & UCLA La Kretz Center for California Conservation Science, Institute of the Environment and Sustainability, University of California, Los Angeles, CA 90095, USA; (M.L.); (H.B.S.)
- Correspondence:
| | - Maren Lechner
- Department of Ecology and Evolutionary Biology & UCLA La Kretz Center for California Conservation Science, Institute of the Environment and Sustainability, University of California, Los Angeles, CA 90095, USA; (M.L.); (H.B.S.)
| | - Audrey Fontes
- Natural Science Division, Pepperdine University, Malibu, CA 90263, USA; (A.F.); (L.B.K.)
| | - Lee B. Kats
- Natural Science Division, Pepperdine University, Malibu, CA 90263, USA; (A.F.); (L.B.K.)
| | - Heather L. Eisthen
- Department of Integrative Biology, Michigan State University, East Lansing, MI 48824, USA;
| | - H. Bradley Shaffer
- Department of Ecology and Evolutionary Biology & UCLA La Kretz Center for California Conservation Science, Institute of the Environment and Sustainability, University of California, Los Angeles, CA 90095, USA; (M.L.); (H.B.S.)
| |
Collapse
|
14
|
Damm M, Hempel BF, Süssmuth RD. Old World Vipers-A Review about Snake Venom Proteomics of Viperinae and Their Variations. Toxins (Basel) 2021; 13:toxins13060427. [PMID: 34204565 PMCID: PMC8235416 DOI: 10.3390/toxins13060427] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 06/11/2021] [Accepted: 06/16/2021] [Indexed: 12/12/2022] Open
Abstract
Fine-tuned by millions of years of evolution, snake venoms have frightened but also fascinated humanity and nowadays they constitute potential resources for drug development, therapeutics and antivenoms. The continuous progress of mass spectrometry techniques and latest advances in proteomics workflows enabled toxinologists to decipher venoms by modern omics technologies, so-called ‘venomics’. A tremendous upsurge reporting on snake venom proteomes could be observed. Within this review we focus on the highly venomous and widely distributed subfamily of Viperinae (Serpentes: Viperidae). A detailed public literature database search was performed (2003–2020) and we extensively reviewed all compositional venom studies of the so-called Old-World Vipers. In total, 54 studies resulted in 89 venom proteomes. The Viperinae venoms are dominated by four major, four secondary, six minor and several rare toxin families and peptides, respectively. The multitude of different venomics approaches complicates the comparison of venom composition datasets and therefore we differentiated between non-quantitative and three groups of quantitative workflows. The resulting direct comparisons within these groups show remarkable differences on the intra- and interspecies level across genera with a focus on regional differences. In summary, the present compilation is the first comprehensive up-to-date database on Viperinae venom proteomes and differentiating between analytical methods and workflows.
Collapse
Affiliation(s)
- Maik Damm
- Department of Chemistry, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany;
| | - Benjamin-Florian Hempel
- BIH Center for Regenerative Therapies, Berlin Institute of Health at Charité-Universitätsmedizin Berlin, (BCRT), 10117 Berlin, Germany;
| | - Roderich D. Süssmuth
- Department of Chemistry, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany;
- Correspondence: ; Tel.: +49-(0)30-314-24205
| |
Collapse
|
15
|
Pardos-Blas JR, Irisarri I, Abalde S, Afonso CML, Tenorio MJ, Zardoya R. The genome of the venomous snail Lautoconus ventricosus sheds light on the origin of conotoxin diversity. Gigascience 2021; 10:giab037. [PMID: 34037232 PMCID: PMC8152183 DOI: 10.1093/gigascience/giab037] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 03/23/2021] [Accepted: 04/30/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Venoms are deadly weapons to subdue prey or deter predators that have evolved independently in many animal lineages. The genomes of venomous animals are essential to understand the evolutionary mechanisms involved in the origin and diversification of venoms. RESULTS Here, we report the chromosome-level genome of the venomous Mediterranean cone snail, Lautoconus ventricosus (Caenogastropoda: Conidae). The total size of the assembly is 3.59 Gb; it has high contiguity (N50 = 93.53 Mb) and 86.6 Mb of the genome assembled into the 35 largest scaffolds or pseudochromosomes. On the basis of venom gland transcriptomes, we annotated 262 complete genes encoding conotoxin precursors, hormones, and other venom-related proteins. These genes were scattered in the different pseudochromosomes and located within repetitive regions. The genes encoding conotoxin precursors were normally structured into 3 exons, which did not necessarily coincide with the 3 structural domains of the corresponding proteins. Additionally, we found evidence in the L. ventricosus genome for a past whole-genome duplication event by means of conserved gene synteny with the Pomacea canaliculata genome, the only one available at the chromosome level within Caenogastropoda. The whole-genome duplication event was further confirmed by the presence of a duplicated hox gene cluster. Key genes for gastropod biology including those encoding proteins related to development, shell formation, and sex were located in the genome. CONCLUSIONS The new high-quality L. ventricosus genome should become a reference for assembling and analyzing new gastropod genomes and will contribute to future evolutionary genomic studies among venomous animals.
Collapse
Affiliation(s)
- José Ramón Pardos-Blas
- Departamento de Biodiversidad y Biología Evolutiva, Museo Nacional de Ciencias Naturales (MNCN-CSIC), José Gutiérrez Abascal 2, 28006 Madrid, Spain
| | - Iker Irisarri
- Departamento de Biodiversidad y Biología Evolutiva, Museo Nacional de Ciencias Naturales (MNCN-CSIC), José Gutiérrez Abascal 2, 28006 Madrid, Spain
- Department of Applied Bioinformatics, Institute for Microbiology and Genetics, University of Goettingen, Goldschmidtstr. 1, D-37077 Goettingen, Germany
- Campus Institute Data Science (CIDAS), Goettingen, Wilhelmsplatz 1, D-37073, Germany
| | - Samuel Abalde
- Departamento de Biodiversidad y Biología Evolutiva, Museo Nacional de Ciencias Naturales (MNCN-CSIC), José Gutiérrez Abascal 2, 28006 Madrid, Spain
- Department of Zoology, Swedish Museum of Natural History, Frescativägen 40, 11418 Stockholm, Sweden
| | - Carlos M L Afonso
- Centre of Marine Sciences (CCMAR), Universidade do Algarve, Campus de Gambelas, 8005–139 Faro, Portugal
| | - Manuel J Tenorio
- Departamento CMIM y Q. Inorgánica-INBIO, Facultad de Ciencias, Universidad de Cadiz, 11510 Puerto Real, Cádiz, Spain
| | - Rafael Zardoya
- Departamento de Biodiversidad y Biología Evolutiva, Museo Nacional de Ciencias Naturales (MNCN-CSIC), José Gutiérrez Abascal 2, 28006 Madrid, Spain
| |
Collapse
|
16
|
Almeida DD, Viala VL, Nachtigall PG, Broe M, Gibbs HL, Serrano SMDT, Moura-da-Silva AM, Ho PL, Nishiyama-Jr MY, Junqueira-de-Azevedo ILM. Tracking the recruitment and evolution of snake toxins using the evolutionary context provided by the Bothrops jararaca genome. Proc Natl Acad Sci U S A 2021; 118:e2015159118. [PMID: 33972420 PMCID: PMC8157943 DOI: 10.1073/pnas.2015159118] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Venom is a key adaptive innovation in snakes, and how nonvenom genes were co-opted to become part of the toxin arsenal is a significant evolutionary question. While this process has been investigated through the phylogenetic reconstruction of toxin sequences, evidence provided by the genomic context of toxin genes remains less explored. To investigate the process of toxin recruitment, we sequenced the genome of Bothrops jararaca, a clinically relevant pitviper. In addition to producing a road map with canonical structures of genes encoding 12 toxin families, we inferred most of the ancestral genes for their loci. We found evidence that 1) snake venom metalloproteinases (SVMPs) and phospholipases A2 (PLA2) have expanded in genomic proximity to their nonvenomous ancestors; 2) serine proteinases arose by co-opting a local gene that also gave rise to lizard gilatoxins and then expanded; 3) the bradykinin-potentiating peptides originated from a C-type natriuretic peptide gene backbone; and 4) VEGF-F was co-opted from a PGF-like gene and not from VEGF-A. We evaluated two scenarios for the original recruitment of nontoxin genes for snake venom: 1) in locus ancestral gene duplication and 2) in locus ancestral gene direct co-option. The first explains the origins of two important toxins (SVMP and PLA2), while the second explains the emergence of a greater number of venom components. Overall, our results support the idea of a locally assembled venom arsenal in which the most clinically relevant toxin families expanded through posterior gene duplications, regardless of whether they originated by duplication or gene co-option.
Collapse
Affiliation(s)
- Diego Dantas Almeida
- Laboratório de Toxinologia Aplicada, Center of Toxins, Immune-Response and Cell Signaling, Instituto Butantan, São Paulo 05503-900, Brazil
| | - Vincent Louis Viala
- Laboratório de Toxinologia Aplicada, Center of Toxins, Immune-Response and Cell Signaling, Instituto Butantan, São Paulo 05503-900, Brazil
| | - Pedro Gabriel Nachtigall
- Laboratório de Toxinologia Aplicada, Center of Toxins, Immune-Response and Cell Signaling, Instituto Butantan, São Paulo 05503-900, Brazil
| | - Michael Broe
- Department of Evolution, Ecology and Organismal Biology, The Ohio State University, Columbus, OH 43210
| | - H Lisle Gibbs
- Department of Evolution, Ecology and Organismal Biology, The Ohio State University, Columbus, OH 43210
| | - Solange Maria de Toledo Serrano
- Laboratório de Toxinologia Aplicada, Center of Toxins, Immune-Response and Cell Signaling, Instituto Butantan, São Paulo 05503-900, Brazil
| | - Ana Maria Moura-da-Silva
- Laboratório de Imunopatologia, Instituto Butantan, São Paulo 05503-900, Brazil
- Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas (UEA), Manaus 69040-000, Brazil
| | - Paulo Lee Ho
- Serviço de Bacteriologia, Divisão BioIndustrial, Instituto Butantan, São Paulo 05503-900, Brazil
| | - Milton Yutaka Nishiyama-Jr
- Laboratório de Toxinologia Aplicada, Center of Toxins, Immune-Response and Cell Signaling, Instituto Butantan, São Paulo 05503-900, Brazil
| | - Inácio L M Junqueira-de-Azevedo
- Laboratório de Toxinologia Aplicada, Center of Toxins, Immune-Response and Cell Signaling, Instituto Butantan, São Paulo 05503-900, Brazil;
| |
Collapse
|
17
|
Jackson TNW, Koludarov I. How the Toxin got its Toxicity. Front Pharmacol 2020; 11:574925. [PMID: 33381030 PMCID: PMC7767849 DOI: 10.3389/fphar.2020.574925] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 10/20/2020] [Indexed: 12/17/2022] Open
Abstract
Venom systems are functional and ecological traits, typically used by one organism to subdue or deter another. A predominant subset of their constituent molecules—“toxins”—share this ecological function and are therefore molecules that mediate interactions between organisms. Such molecules have been referred to as “exochemicals.” There has been debate within the field of toxinology concerning the evolutionary pathways leading to the “recruitment” of a gene product for a toxic role within venom. We review these discussions and the evidence interpreted in support of alternate pathways, along with many of the most popular models describing the origin of novel molecular functions in general. We note that such functions may arise with or without gene duplication occurring and are often the consequence of a gene product encountering a novel “environment,” i.e., a range of novel partners for molecular interaction. After stressing the distinction between “activity” and “function,” we describe in detail the results of a recent study which reconstructed the evolutionary history of a multigene family that has been recruited as a toxin and argue that these results indicate that a pluralistic approach to understanding the origin of novel functions is advantageous. This leads us to recommend that an expansive approach be taken to the definition of “neofunctionalization”—simply the origins of a novel molecular function by any process—and “recruitment”—the “weaponization” of a molecule via the acquisition of a toxic function in venom, by any process. Recruitment does not occur at the molecular level or even at the level of gene expression, but only when a confluence of factors results in the ecological deployment of a physiologically active molecule as a toxin. Subsequent to recruitment, the evolutionary regime of a gene family may shift into a more dynamic form of “birth-and-death.” Thus, recruitment leads to a form of “downwards causation,” in which a change at the ecological level at which whole organisms interact leads to a change in patterns of evolution at the genomic level.
Collapse
Affiliation(s)
- Timothy N W Jackson
- Australian Venom Research Unit, Department of Pharmacology and Therapeutics, University of Melbourne, Melbourne, Australia
| | - Ivan Koludarov
- Animal Venomics Group, Justus Leibig University, Giessen, Germany
| |
Collapse
|
18
|
Toxin-like neuropeptides in the sea anemone Nematostella unravel recruitment from the nervous system to venom. Proc Natl Acad Sci U S A 2020; 117:27481-27492. [PMID: 33060291 DOI: 10.1073/pnas.2011120117] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The sea anemone Nematostella vectensis (Anthozoa, Cnidaria) is a powerful model for characterizing the evolution of genes functioning in venom and nervous systems. Although venom has evolved independently numerous times in animals, the evolutionary origin of many toxins remains unknown. In this work, we pinpoint an ancestral gene giving rise to a new toxin and functionally characterize both genes in the same species. Thus, we report a case of protein recruitment from the cnidarian nervous to venom system. The ShK-like1 peptide has a ShKT cysteine motif, is lethal for fish larvae and packaged into nematocysts, the cnidarian venom-producing stinging capsules. Thus, ShK-like1 is a toxic venom component. Its paralog, ShK-like2, is a neuropeptide localized to neurons and is involved in development. Both peptides exhibit similarities in their functional activities: They provoke contraction in Nematostella polyps and are toxic to fish. Because ShK-like2 but not ShK-like1 is conserved throughout sea anemone phylogeny, we conclude that the two paralogs originated due to a Nematostella-specific duplication of a ShK-like2 ancestor, a neuropeptide-encoding gene, followed by diversification and partial functional specialization. ShK-like2 is represented by two gene isoforms controlled by alternative promoters conferring regulatory flexibility throughout development. Additionally, we characterized the expression patterns of four other peptides with structural similarities to studied venom components and revealed their unexpected neuronal localization. Thus, we employed genomics, transcriptomics, and functional approaches to reveal one venom component, five neuropeptides with two different cysteine motifs, and an evolutionary pathway from nervous to venom system in Cnidaria.
Collapse
|
19
|
Esteves FG, Dos Santos-Pinto JRA, Ferro M, Sialana FJ, Smidak R, Rares LC, Nussbaumer T, Rattei T, Bilban M, Bacci Júnior M, Lubec G, Palma MS. Revealing the Venomous Secrets of the Spider's Web. J Proteome Res 2020; 19:3044-3059. [PMID: 32538095 DOI: 10.1021/acs.jproteome.0c00086] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Orb-weaving spiders use a highly strong, sticky and elastic web to catch their prey. These web properties alone would be enough for the entrapment of prey; however, these spiders may be hiding venomous secrets in the web, which current research is revealing. Here, we provide strong proteotranscriptomic evidence for the presence of toxin/neurotoxin-like proteins, defensins, and proteolytic enzymes on the web silk from Nephila clavipes spider. The results from quantitative-based transcriptomic and proteomic approaches showed that silk-producing glands produce an extensive repertoire of toxin/neurotoxin-like proteins, similar to those already reported in spider venoms. Meanwhile, the insect toxicity results demonstrated that these toxic components can be lethal and/or paralytic chemical weapons used for prey capture on the web, and the presence of fatty acids in the web may be a responsible mechanism opening the way to the web toxins for accessing the interior of prey's body, as shown here. Comparative phylogenomic-level evolutionary analyses revealed orthologous genes among two spider groups, Araneomorphae and Mygalomorphae, and the findings showed protein sequences similar to toxins found in the taxa Scorpiones and Hymenoptera in addition to Araneae. Overall, these data represent a valuable resource to further investigate other spider web toxin systems and also suggest that N. clavipes web is not a passive mechanical trap for prey capture, but it exerts an active role in prey paralysis/killing using a series of neurotoxins.
Collapse
Affiliation(s)
- Franciele Grego Esteves
- Center of the Study of Social Insects, Department of General and Applied Biology, Institute of Biosciences of Rio Claro, University of São Paulo State (UNESP), Rio Claro, SP 13506-900, Brazil
| | - José Roberto Aparecido Dos Santos-Pinto
- Center of the Study of Social Insects, Department of General and Applied Biology, Institute of Biosciences of Rio Claro, University of São Paulo State (UNESP), Rio Claro, SP 13506-900, Brazil
| | - Milene Ferro
- Center of the Study of Social Insects, Department of General and Applied Biology, Institute of Biosciences of Rio Claro, University of São Paulo State (UNESP), Rio Claro, SP 13506-900, Brazil
| | - Fernando J Sialana
- Department of Pharmaceutical Chemistry, University of Vienna, Vienna 1090, Austria
| | - Roman Smidak
- Department of Pharmaceutical Chemistry, University of Vienna, Vienna 1090, Austria
| | - Lucaciu Calin Rares
- Division of Computational System Biology, Department of Microbiology and Ecosystem Science, University of Vienna, 1090 Vienna, Austria
| | - Thomas Nussbaumer
- Division of Computational System Biology, Department of Microbiology and Ecosystem Science, University of Vienna, 1090 Vienna, Austria
| | - Thomas Rattei
- Division of Computational System Biology, Department of Microbiology and Ecosystem Science, University of Vienna, 1090 Vienna, Austria
| | - Martin Bilban
- Department of Laboratory Medicine and Core Facility Genomics, Medical University of Vienna, 1090 Vienna, Austria
| | - Mauricio Bacci Júnior
- Center of the Study of Social Insects, Department of General and Applied Biology, Institute of Biosciences of Rio Claro, University of São Paulo State (UNESP), Rio Claro, SP 13506-900, Brazil
| | - Gert Lubec
- Paracelsus Medical University, A 5020 Salzburg, Austria
| | - Mario Sergio Palma
- Center of the Study of Social Insects, Department of General and Applied Biology, Institute of Biosciences of Rio Claro, University of São Paulo State (UNESP), Rio Claro, SP 13506-900, Brazil
| |
Collapse
|
20
|
Casewell NR, Jackson TNW, Laustsen AH, Sunagar K. Causes and Consequences of Snake Venom Variation. Trends Pharmacol Sci 2020; 41:570-581. [PMID: 32564899 PMCID: PMC7116101 DOI: 10.1016/j.tips.2020.05.006] [Citation(s) in RCA: 175] [Impact Index Per Article: 43.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 05/25/2020] [Accepted: 05/31/2020] [Indexed: 11/30/2022]
Abstract
Snake venoms are mixtures of toxins that vary extensively between and within snake species. This variability has serious consequences for the management of the world’s 1.8 million annual snakebite victims. Advances in ‘omic’ technologies have empowered toxinologists to comprehensively characterize snake venom compositions, unravel the molecular mechanisms that underpin venom variation, and elucidate the ensuing functional consequences. In this review, we describe how such mechanistic processes have resulted in suites of toxin isoforms that cause diverse pathologies in human snakebite victims and we detail how variation in venom composition can result in treatment failure. Finally, we outline current therapeutic approaches designed to circumvent venom variation and deliver next-generation treatments for the world’s most lethal neglected tropical disease.
Collapse
Affiliation(s)
- Nicholas R Casewell
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.
| | - Timothy N W Jackson
- Australian Venom Research Unit, Department of Pharmacology and Therapeutics, University of Melbourne, Victoria, Australia
| | - Andreas H Laustsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Kartik Sunagar
- Evolutionary Venomics Laboratory, Centre for Ecological Sciences, Indian Institute of Science, Bangalore 560012, Karnataka, India
| |
Collapse
|
21
|
Modahl CM, Roointan A, Rogers J, Currier K, Mackessy SP. Interspecific and intraspecific venom enzymatic variation among cobras (Naja sp. and Ophiophagus hannah). Comp Biochem Physiol C Toxicol Pharmacol 2020; 232:108743. [PMID: 32194156 DOI: 10.1016/j.cbpc.2020.108743] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Revised: 02/28/2020] [Accepted: 03/10/2020] [Indexed: 02/07/2023]
Abstract
The genera Ophiophagus and Naja comprise part of a clade of snakes referred to as cobras, dangerously venomous front-fanged snakes in the family Elapidae responsible for significant human mortality and morbidity throughout Asia and Africa. We evaluated venom enzyme variation for eleven cobra species and three N. kaouthia populations using SDS-PAGE venom fingerprinting and numerous enzyme assays. Acetylcholinesterase and PLA2 activities were the most variable between species, and PLA2 activity was significantly different between Malaysian and Thailand N. kaouthia populations. Venom metalloproteinase activity was low and significantly different among most species, but levels were identical for N. kaouthia populations; minor variation in venom L-amino acid oxidase and phosphodiesterase activities were seen between cobra species. Naja siamensis venom lacked the α-fibrinogenolytic activity common to other cobra venoms. In addition, venom from N. siamensis had no detectable metalloproteinase activity and exhibited an SDS-PAGE profile with reduced abundance of higher mass proteins. Venom profiles from spitting cobras (N. siamensis, N. pallida, and N. mossambica) exhibited similar reductions in higher mass proteins, suggesting the evolution of venoms of reduced complexity and decreased enzymatic activity among spitting cobras. Generally, the venom proteomes of cobras show highly abundant three-finger toxin diversity, followed by large quantities of PLA2s. However, PLA2 bands and activity were very reduced for N. haje, N. annulifera and N. nivea. Venom compositionalenzy analysis provides insight into the evolution, diversification and distribution of different venom phenotypes that complements venomic data, and this information is critical for the development of effective antivenoms and snakebite treatment.
Collapse
Affiliation(s)
- Cassandra M Modahl
- School of Biological Sciences, University of Northern Colorado, 501 20th St., Greeley, CO 80639-0017, USA; Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, 117543, Singapore
| | - Amir Roointan
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, 117543, Singapore; Regenerative Medicine Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Jessica Rogers
- School of Biological Sciences, University of Northern Colorado, 501 20th St., Greeley, CO 80639-0017, USA
| | - Katelyn Currier
- School of Biological Sciences, University of Northern Colorado, 501 20th St., Greeley, CO 80639-0017, USA
| | - Stephen P Mackessy
- School of Biological Sciences, University of Northern Colorado, 501 20th St., Greeley, CO 80639-0017, USA.
| |
Collapse
|
22
|
Zancolli G, Casewell NR. Venom Systems as Models for Studying the Origin and Regulation of Evolutionary Novelties. Mol Biol Evol 2020; 37:2777-2790. [DOI: 10.1093/molbev/msaa133] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Abstract
A central goal in biology is to determine the ways in which evolution repeats itself. One of the most remarkable examples in nature of convergent evolutionary novelty is animal venom. Across diverse animal phyla, various specialized organs and anatomical structures have evolved from disparate developmental tissues to perform the same function, that is, produce and deliver a cocktail of potent molecules to subdue prey or predators. Venomous organisms therefore offer unique opportunities to investigate the evolutionary processes of convergence of key adaptive traits, and the molecular mechanisms underlying the emergence of novel genes, cells, and tissues. Indeed, some venomous species have already proven to be highly amenable as models for developmental studies, and recent work with venom gland organoids provides manipulatable systems for directly testing important evolutionary questions. Here, we provide a synthesis of the current knowledge that could serve as a starting point for the establishment of venom systems as new models for evolutionary and molecular biology. In particular, we highlight the potential of various venomous species for the study of cell differentiation and cell identity, and the regulatory dynamics of rapidly evolving, highly expressed, tissue-specific, gene paralogs. We hope that this review will encourage researchers to look beyond traditional study organisms and consider venom systems as useful tools to explore evolutionary novelties.
Collapse
Affiliation(s)
- Giulia Zancolli
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Nicholas R Casewell
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| |
Collapse
|
23
|
Mason AJ, Margres MJ, Strickland JL, Rokyta DR, Sasa M, Parkinson CL. Trait differentiation and modular toxin expression in palm-pitvipers. BMC Genomics 2020; 21:147. [PMID: 32046632 PMCID: PMC7014597 DOI: 10.1186/s12864-020-6545-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 01/30/2020] [Indexed: 12/22/2022] Open
Abstract
Background Modularity is the tendency for systems to organize into semi-independent units and can be a key to the evolution and diversification of complex biological systems. Snake venoms are highly variable modular systems that exhibit extreme diversification even across very short time scales. One well-studied venom phenotype dichotomy is a trade-off between neurotoxicity versus hemotoxicity that occurs through the high expression of a heterodimeric neurotoxic phospholipase A2 (PLA2) or snake venom metalloproteinases (SVMPs). We tested whether the variation in these venom phenotypes could occur via variation in regulatory sub-modules through comparative venom gland transcriptomics of representative Black-Speckled Palm-Pitvipers (Bothriechis nigroviridis) and Talamancan Palm-Pitvipers (B. nubestris). Results We assembled 1517 coding sequences, including 43 toxins for B. nigroviridis and 1787 coding sequences including 42 toxins for B. nubestris. The venom gland transcriptomes were extremely divergent between these two species with one B. nigroviridis exhibiting a primarily neurotoxic pattern of expression, both B. nubestris expressing primarily hemorrhagic toxins, and a second B. nigroviridis exhibiting a mixed expression phenotype. Weighted gene coexpression analyses identified six submodules of transcript expression variation, one of which was highly associated with SVMPs and a second which contained both subunits of the neurotoxic PLA2 complex. The sub-module association of these toxins suggest common regulatory pathways underlie the variation in their expression and is consistent with known patterns of inheritance of similar haplotypes in other species. We also find evidence that module associated toxin families show fewer gene duplications and transcript losses between species, but module association did not appear to affect sequence diversification. Conclusion Sub-modular regulation of expression likely contributes to the diversification of venom phenotypes within and among species and underscores the role of modularity in facilitating rapid evolution of complex traits.
Collapse
Affiliation(s)
- Andrew J Mason
- Department of Biological Sciences, Clemson University, 190 Collings St., Clemson, SC, 29634, USA
| | - Mark J Margres
- Department of Biological Sciences, Clemson University, 190 Collings St., Clemson, SC, 29634, USA
| | - Jason L Strickland
- Department of Biological Sciences, Clemson University, 190 Collings St., Clemson, SC, 29634, USA
| | - Darin R Rokyta
- Department of Biological Sciences, Florida State University, Tallahassee, FL, 24105, USA
| | - Mahmood Sasa
- Instituto Clodomiro Picado, Facultad de Microbiologia, Universidad de Costa Rica, San Jose, Costa Rica
| | - Christopher L Parkinson
- Department of Biological Sciences, Clemson University, 190 Collings St., Clemson, SC, 29634, USA. .,Department of Forestry, and Environmental Conservation, Clemson University, Clemson, SC, USA.
| |
Collapse
|
24
|
Jenner RA, von Reumont BM, Campbell LI, Undheim EAB. Parallel Evolution of Complex Centipede Venoms Revealed by Comparative Proteotranscriptomic Analyses. Mol Biol Evol 2019; 36:2748-2763. [PMID: 31396628 PMCID: PMC6878950 DOI: 10.1093/molbev/msz181] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Centipedes are among the most ancient groups of venomous predatory arthropods. Extant species belong to five orders, but our understanding of the composition and evolution of centipede venoms is based almost exclusively on one order, Scolopendromorpha. To gain a broader and less biased understanding we performed a comparative proteotranscriptomic analysis of centipede venoms from all five orders, including the first venom profiles for the orders Lithobiomorpha, Craterostigmomorpha, and Geophilomorpha. Our results reveal an astonishing structural diversity of venom components, with 93 phylogenetically distinct protein and peptide families. Proteomically-annotated gene trees of these putative toxin families show that centipede venom composition is highly dynamic across macroevolutionary timescales, with numerous gene duplications as well as functional recruitments and losses of toxin gene families. Strikingly, not a single family is found in the venoms of representatives of all five orders, with 67 families being unique for single orders. Ancestral state reconstructions reveal that centipede venom originated as a simple cocktail comprising just four toxin families, with very little compositional evolution happening during the approximately 50 My before the living orders had diverged. Venom complexity then increased in parallel within the orders, with scolopendromorphs evolving particularly complex venoms. Our results show that even venoms composed of toxins evolving under the strong constraint of negative selection can have striking evolutionary plasticity on the compositional level. We show that the functional recruitments and losses of toxin families that shape centipede venom arsenals are not concentrated early in their evolutionary history, but happen frequently throughout.
Collapse
Affiliation(s)
- Ronald A Jenner
- Department of Life Sciences, Natural History Museum, London, United Kingdom
| | - Bjoern M von Reumont
- LOEWE Centre for Translational Biodiversity Genomics (LOEWE-TBG), Frankfurt, Germany
- Institute for Insect Biotechnology, Justus-Liebig University Giessen, Giessen, Germany
- Department of Bioresources, Fraunhofer Institute for Molecular Biology and Applied Ecology, Animal Venomics, Giessen, Germany
| | - Lahcen I Campbell
- The European Molecular Biology Laboratory, The European Bioinformatics Institute, Hinxton, United Kingdom
| | - Eivind A B Undheim
- Centre for Advanced Imaging, University of Queensland, St Lucia, Australia
- Institute for Molecular Bioscience, University of Queensland, St Lucia, Australia
- Centre for Ecology and Evolutionary Synthesis, Department of Bioscience, University of Oslo, Oslo, Norway
| |
Collapse
|
25
|
Ritschard EA, Whitelaw B, Albertin CB, Cooke IR, Strugnell JM, Simakov O. Coupled Genomic Evolutionary Histories as Signatures of Organismal Innovations in Cephalopods: Co-evolutionary Signatures Across Levels of Genome Organization May Shed Light on Functional Linkage and Origin of Cephalopod Novelties. Bioessays 2019; 41:e1900073. [PMID: 31664724 DOI: 10.1002/bies.201900073] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 09/05/2019] [Indexed: 12/07/2023]
Abstract
How genomic innovation translates into organismal organization remains largely unanswered. Possessing the largest invertebrate nervous system, in conjunction with many species-specific organs, coleoid cephalopods (octopuses, squids, cuttlefishes) provide exciting model systems to investigate how organismal novelties evolve. However, dissecting these processes requires novel approaches that enable deeper interrogation of genome evolution. Here, the existence of specific sets of genomic co-evolutionary signatures between expanded gene families, genome reorganization, and novel genes is posited. It is reasoned that their co-evolution has contributed to the complex organization of cephalopod nervous systems and the emergence of ecologically unique organs. In the course of reviewing this field, how the first cephalopod genomic studies have begun to shed light on the molecular underpinnings of morphological novelty is illustrated and their impact on directing future research is described. It is argued that the application and evolutionary profiling of evolutionary signatures from these studies will help identify and dissect the organismal principles of cephalopod innovations. By providing specific examples, the implications of this approach both within and beyond cephalopod biology are discussed.
Collapse
Affiliation(s)
- Elena A Ritschard
- Department for Molecular Evolution and Development, University of Vienna, Austria
| | - Brooke Whitelaw
- Centre for Sustainable Tropical Fisheries and Aquaculture, College of Science and Engineering, James Cook University, Townsville, Queensland, 4811, Australia
| | | | - Ira R Cooke
- Department of Molecular and Cell Biology, James Cook University, Townsville, Queensland, 4811, Australia
| | - Jan M Strugnell
- Centre for Sustainable Tropical Fisheries and Aquaculture, College of Science and Engineering, James Cook University, Townsville, Queensland, 4811, Australia
- Department of Ecology, Environment and Evolution, La Trobe University, Melbourne, Victoria, 3086, Australia
| | - Oleg Simakov
- Department for Molecular Evolution and Development, University of Vienna, Austria
| |
Collapse
|
26
|
Modahl CM, Mackessy SP. Venoms of Rear-Fanged Snakes: New Proteins and Novel Activities. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00279] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
|
27
|
Sirot LK. On the evolutionary origins of insect seminal fluid proteins. Gen Comp Endocrinol 2019; 278:104-111. [PMID: 30682344 DOI: 10.1016/j.ygcen.2019.01.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 01/11/2019] [Accepted: 01/17/2019] [Indexed: 02/06/2023]
Abstract
In most cases, proteins affect the phenotype of the individual in which they are produced. However, in some cases, proteins have evolved in such a way that they are able to influence the phenotype of another individual of the same or of a different species ("influential proteins"). Examples of interspecific influential proteins include venom proteins and proteins produced by parasites that influence their hosts' physiology or behavior. Examples of intraspecific influential proteins include those produced by both mothers and fetuses that mitigate maternal resource allocation and proteins transferred to females in the seminal fluid during mating that change female physiology and behavior. Although there has been much interest in the functions and evolutionary dynamics of these influential proteins, less is known about the origin of these proteins. Where does the DNA that encodes the proteins that can impact another individual's phenotype come from and how do the proteins acquire their influential abilities? In this mini-review, I use insect seminal fluid proteins as a case study to consider the origin of intraspecific influential proteins. The existing data suggest that influential insect seminal fluid proteins arise both through co-option of existing genes (both single copy genes and gene duplicates) and de novo evolution. Other mechanisms for the origin of new insect seminal fluid proteins (e.g., retrotransoposition and horizontal gene transfer) are plausible but have not yet been demonstrated. Additional gaps in our understanding of the origin of insect seminal fluid proteins include an understanding of the cis-regulatory elements that designate expression in the male reproductive tract and of the evolutionary steps by which individual proteins come to depend on other seminal fluid proteins for their activity within the mated female.
Collapse
Affiliation(s)
- Laura King Sirot
- Department of Biology, The College of Wooster, Wooster, OH 44691, United States.
| |
Collapse
|
28
|
Williams HF, Layfield HJ, Vallance T, Patel K, Bicknell AB, Trim SA, Vaiyapuri S. The Urgent Need to Develop Novel Strategies for the Diagnosis and Treatment of Snakebites. Toxins (Basel) 2019; 11:E363. [PMID: 31226842 PMCID: PMC6628419 DOI: 10.3390/toxins11060363] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 06/18/2019] [Accepted: 06/18/2019] [Indexed: 01/09/2023] Open
Abstract
Snakebite envenoming (SBE) is a priority neglected tropical disease, which kills in excess of 100,000 people per year. Additionally, many millions of survivors also suffer through disabilities and long-term health consequences. The only treatment for SBE, antivenom, has a number of major associated problems, not least, adverse reactions and limited availability. This emphasises the necessity for urgent improvements to the management of this disease. Administration of antivenom is too frequently based on symptomatology, which results in wasting crucial time. The majority of SBE-affected regions rely on broad-spectrum polyvalent antivenoms that have a low content of case-specific efficacious immunoglobulins. Research into small molecular therapeutics such as varespladib/methyl-varespladib (PLA2 inhibitors) and batimastat/marimastat (metalloprotease inhibitors) suggest that such adjunctive treatments could be hugely beneficial to victims. Progress into toxin-specific monoclonal antibodies as well as alternative binding scaffolds such as aptamers hold much promise for future treatment strategies. SBE is not implicit during snakebite, due to venom metering. Thus, the delay between bite and symptom presentation is critical and when symptoms appear it may often already be too late to effectively treat SBE. The development of reliable diagnostical tools could therefore initiate a paradigm shift in the treatment of SBE. While the complete eradication of SBE is an impossibility, mitigation is in the pipeline, with new treatments and diagnostics rapidly emerging. Here we critically review the urgent necessity for the development of diagnostic tools and improved therapeutics to mitigate the deaths and disabilities caused by SBE.
Collapse
Affiliation(s)
| | | | - Thomas Vallance
- School of Pharmacy, University of Reading, Reading RG6 6AH, UK.
| | - Ketan Patel
- School of Biological Sciences, University of Reading, Reading RG6 6AH, UK.
| | - Andrew B Bicknell
- School of Biological Sciences, University of Reading, Reading RG6 6AH, UK.
| | | | | |
Collapse
|
29
|
Drukewitz SH, von Reumont BM. The Significance of Comparative Genomics in Modern Evolutionary Venomics. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00163] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
|
30
|
Miwa JM, Anderson KR, Hoffman KM. Lynx Prototoxins: Roles of Endogenous Mammalian Neurotoxin-Like Proteins in Modulating Nicotinic Acetylcholine Receptor Function to Influence Complex Biological Processes. Front Pharmacol 2019; 10:343. [PMID: 31114495 PMCID: PMC6502960 DOI: 10.3389/fphar.2019.00343] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 03/19/2019] [Indexed: 12/19/2022] Open
Abstract
The cholinergic system modulates many biological functions, due to the widespread distribution of cholinergic neuronal terminals, and the diffuse release of its neurotransmitter, acetylcholine. Several layers of regulation help to refine and control the scope of this excitatory neurotransmitter system. One such regulatory mechanism is imparted through endogenous toxin-like proteins, prototoxins, which largely control the function of nicotinic receptors of the cholinergic system. Prototoxins and neurotoxins share the distinct three finger toxin fold, highly effective as a receptor binding protein, and the former are expressed in the mammalian brain, immune system, epithelium, etc. Prototoxins and elapid snake neurotoxins appear to be related through gene duplication and divergence from a common ancestral gene. Protein modulators can provide a graded response of the cholinergic system, and within the brain, stabilize neural circuitry through direct interaction with nicotinic receptors. Understanding the roles of each prototoxin (e.g., lynx1, lynx2/lypd1, PSCA, SLURP1, SLURP2, Lypd6, lypd6b, lypdg6e, PATE-M, PATE-B, etc.), their binding specificity and unique expression profile, has the potential to uncover many fascinating cholinergic-dependent mechanisms in the brain. Each family member can provide a spatially restricted level of control over nAChR function based on its expression in the brain. Due to the difficulty in the pharmacological targeting of nicotinic receptors in the brain as a result of widespread expression patterns and similarities in receptor sequences, unique interfaces between prototoxin and nicotinic receptor could provide more specific targeting than nicotinic receptors alone. As such, this family is intriguing from a long-term therapeutic perspective.
Collapse
Affiliation(s)
- Julie M Miwa
- Department of Biological Sciences, Lehigh University, Bethlehem, PA, United States
| | - Kristin R Anderson
- Department of Biological Sciences, Lehigh University, Bethlehem, PA, United States
| | - Katie M Hoffman
- Department of Biological Sciences, Lehigh University, Bethlehem, PA, United States
| |
Collapse
|
31
|
Mongiardino Koch N, Gauthier JA. Noise and biases in genomic data may underlie radically different hypotheses for the position of Iguania within Squamata. PLoS One 2018; 13:e0202729. [PMID: 30133514 PMCID: PMC6105018 DOI: 10.1371/journal.pone.0202729] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 08/08/2018] [Indexed: 12/23/2022] Open
Abstract
Squamate reptiles are a major component of vertebrate biodiversity whose crown-clade traces its origin to a narrow window of time in the Mesozoic during which the main subclades diverged in rapid succession. Deciphering phylogenetic relationships among these lineages has proven challenging given the conflicting signals provided by genomic and phenomic data. Most notably, the placement of Iguania has routinely differed between data sources, with morphological evidence supporting a sister relationship to the remaining squamates (Scleroglossa hypothesis) and molecular data favoring a highly nested position alongside snakes and anguimorphs (Toxicofera hypothesis). We provide novel insights by generating an expanded morphological dataset and exploring the presence of phylogenetic signal, noise, and biases in molecular data. Our analyses confirm the presence of strong conflicting signals for the position of Iguania between morphological and molecular datasets. However, we also find that molecular data behave highly erratically when inferring the deepest branches of the squamate tree, a consequence of limited phylogenetic signal to resolve this ancient radiation with confidence. This, in turn, seems to result from a rate of evolution that is too high for historical signals to survive to the present. Finally, we detect significant systematic biases, with iguanians and snakes sharing faster rates of molecular evolution and a similarly biased nucleotide composition. A combination of scant phylogenetic signal, high levels of noise, and the presence of systematic biases could result in the misplacement of Iguania. We regard this explanation to be at least as plausible as the complex scenario of convergence and reversals required for morphological data to be misleading. We further evaluate and discuss the utility of morphological data to resolve ancient radiations, as well as its impact in combined-evidence phylogenomic analyses, with results relevant for the assessment of evidence and conflict across the Tree of Life.
Collapse
Affiliation(s)
- Nicolás Mongiardino Koch
- Department of Geology and Geophysics, Yale University, New Haven, Connecticut, United States of America
| | - Jacques A. Gauthier
- Department of Geology and Geophysics, Yale University, New Haven, Connecticut, United States of America
- Yale Peabody Museum of Natural History, New Haven, Connecticut, United States of America
| |
Collapse
|
32
|
Carregari VC, Rosa-Fernandes L, Baldasso P, Bydlowski SP, Marangoni S, Larsen MR, Palmisano G. Snake Venom Extracellular vesicles (SVEVs) reveal wide molecular and functional proteome diversity. Sci Rep 2018; 8:12067. [PMID: 30104604 PMCID: PMC6089973 DOI: 10.1038/s41598-018-30578-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 06/04/2018] [Indexed: 12/19/2022] Open
Abstract
Proteins constitute almost 95% of snake venom's dry weight and are produced and released by venom glands in a solubilized form during a snake bite. These proteins are responsible for inducing several pharmacological effects aiming to immobilize and initiate the pre-digestion of the prey. This study shows that proteins can be secreted and confined in snake venom extracellular vesicles (SVEVs) presenting a size distribution between 50 nm and 500 nm. SVEVs isolated from lyophilized venoms collected from four different species of snakes (Agkistrodon contortrix contortrix, Crotalus atrox, Crotalus viridis and Crotalus cerberus oreganus) were analyzed by mass spectrometry-based proteomic, which allowed the identification of proteins belonging to eight main functional protein classes such as SVMPs, serine proteinases, PLA2, LAAO, 5'nucleotidase, C-type lectin, CRISP and Disintegrin. Biochemical assays indicated that SVEVs are functionally active, showing high metalloproteinase and fibrinogenolytic activity besides being cytotoxic against HUVEC cells. Overall, this study comprehensively depicts the protein composition of SVEVs for the first time. In addition, the molecular function of some of the described proteins suggests a central role for SVEVs in the cytotoxicity of the snake venom and sheds new light in the envenomation process.
Collapse
Affiliation(s)
- Victor Corassolla Carregari
- Department of Biochemistry, Institute of Biology (IB), Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, SP, Brazil.,GlycoProteomics Laboratory, Department of Parasitology, ICB, University of São Paulo, São Paulo, Brazil
| | - Livia Rosa-Fernandes
- GlycoProteomics Laboratory, Department of Parasitology, ICB, University of São Paulo, São Paulo, Brazil.,Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Paulo Baldasso
- Department of Biochemistry, Institute of Biology (IB), Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Sergio Paulo Bydlowski
- Laboratory of Genetics and Molecular Hematology (LIM31), University of São Paulo Medical School (FMUSP), São Paulo, Brazil
| | - Sergio Marangoni
- Department of Biochemistry, Institute of Biology (IB), Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Martin R Larsen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Giuseppe Palmisano
- GlycoProteomics Laboratory, Department of Parasitology, ICB, University of São Paulo, São Paulo, Brazil.
| |
Collapse
|
33
|
Perry BW, Card DC, McGlothlin JW, Pasquesi GIM, Adams RH, Schield DR, Hales NR, Corbin AB, Demuth JP, Hoffmann FG, Vandewege MW, Schott RK, Bhattacharyya N, Chang BSW, Casewell NR, Whiteley G, Reyes-Velasco J, Mackessy SP, Gamble T, Storey KB, Biggar KK, Passow CN, Kuo CH, McGaugh SE, Bronikowski AM, de Koning APJ, Edwards SV, Pfrender ME, Minx P, Brodie ED, Brodie ED, Warren WC, Castoe TA. Molecular Adaptations for Sensing and Securing Prey and Insight into Amniote Genome Diversity from the Garter Snake Genome. Genome Biol Evol 2018; 10:2110-2129. [PMID: 30060036 PMCID: PMC6110522 DOI: 10.1093/gbe/evy157] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/26/2018] [Indexed: 12/26/2022] Open
Abstract
Colubridae represents the most phenotypically diverse and speciose family of snakes, yet no well-assembled and annotated genome exists for this lineage. Here, we report and analyze the genome of the garter snake, Thamnophis sirtalis, a colubrid snake that is an important model species for research in evolutionary biology, physiology, genomics, behavior, and the evolution of toxin resistance. Using the garter snake genome, we show how snakes have evolved numerous adaptations for sensing and securing prey, and identify features of snake genome structure that provide insight into the evolution of amniote genomes. Analyses of the garter snake and other squamate reptile genomes highlight shifts in repeat element abundance and expansion within snakes, uncover evidence of genes under positive selection, and provide revised neutral substitution rate estimates for squamates. Our identification of Z and W sex chromosome-specific scaffolds provides evidence for multiple origins of sex chromosome systems in snakes and demonstrates the value of this genome for studying sex chromosome evolution. Analysis of gene duplication and loss in visual and olfactory gene families supports a dim-light ancestral condition in snakes and indicates that olfactory receptor repertoires underwent an expansion early in snake evolution. Additionally, we provide some of the first links between secreted venom proteins, the genes that encode them, and their evolutionary origins in a rear-fanged colubrid snake, together with new genomic insight into the coevolutionary arms race between garter snakes and highly toxic newt prey that led to toxin resistance in garter snakes.
Collapse
Affiliation(s)
- Blair W Perry
- Department of Biology, University of Texas at Arlington, Arlington
| | - Daren C Card
- Department of Biology, University of Texas at Arlington, Arlington
| | - Joel W McGlothlin
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia
| | | | - Richard H Adams
- Department of Biology, University of Texas at Arlington, Arlington
| | - Drew R Schield
- Department of Biology, University of Texas at Arlington, Arlington
| | - Nicole R Hales
- Department of Biology, University of Texas at Arlington, Arlington
| | - Andrew B Corbin
- Department of Biology, University of Texas at Arlington, Arlington
| | - Jeffery P Demuth
- Department of Biology, University of Texas at Arlington, Arlington
| | - Federico G Hoffmann
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Mississippi State.,Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Starkville
| | - Michael W Vandewege
- Department of Biology, Institute for Genomics and Evolutionary Medicine, Temple University
| | - Ryan K Schott
- Department of Ecology and Evolutionary Biology, Department of Cell and Systems Biology, Centre for the Analysis of Genome Evolution & Function, University of Toronto, Ontario, Canada.,Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, District of Columbia
| | - Nihar Bhattacharyya
- Department of Cell and Systems Biology, University of Toronto, Ontario, Canada
| | - Belinda S W Chang
- Department of Ecology and Evolutionary Biology, Department of Cell and Systems Biology, Centre for the Analysis of Genome Evolution & Function, University of Toronto, Ontario, Canada
| | - Nicholas R Casewell
- Alistair Reid Venom Research Unit, Parasitology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
| | - Gareth Whiteley
- Alistair Reid Venom Research Unit, Parasitology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom
| | - Jacobo Reyes-Velasco
- Department of Biology, University of Texas at Arlington, Arlington.,Department of Biology, New York University Abu Dhabi, Saadiyat Island, Abu Dhabi, United Arab Emirates
| | | | - Tony Gamble
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53201, USA.,Bell Museum of Natural History, University of Minnesota, Saint Paul, MN, USA
| | - Kenneth B Storey
- Institute of Biochemistry, Carleton University, Ottawa, Ontario, Canada
| | - Kyle K Biggar
- Institute of Biochemistry, Carleton University, Ottawa, Ontario, Canada
| | | | - Chih-Horng Kuo
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan
| | | | - Anne M Bronikowski
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University
| | - A P Jason de Koning
- Department of Biochemistry and Molecular Biology, Department of Medical Genetics, Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Alberta, Canada
| | - Scott V Edwards
- Department of Organismic and Evolutionary Biology and Museum of Comparative Zoology, Harvard University
| | - Michael E Pfrender
- Department of Biological Sciences and Environmental Change Initiative, University of Notre Dame
| | - Patrick Minx
- The McDonnell Genome Institute, Washington University School of Medicine, St. Louis
| | | | | | - Wesley C Warren
- The McDonnell Genome Institute, Washington University School of Medicine, St. Louis
| | - Todd A Castoe
- Department of Biology, University of Texas at Arlington, Arlington
| |
Collapse
|
34
|
Macrander J, Panda J, Janies D, Daly M, Reitzel AM. Venomix: a simple bioinformatic pipeline for identifying and characterizing toxin gene candidates from transcriptomic data. PeerJ 2018; 6:e5361. [PMID: 30083468 PMCID: PMC6074769 DOI: 10.7717/peerj.5361] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 07/09/2018] [Indexed: 12/12/2022] Open
Abstract
The advent of next-generation sequencing has resulted in transcriptome-based approaches to investigate functionally significant biological components in a variety of non-model organism. This has resulted in the area of “venomics”: a rapidly growing field using combined transcriptomic and proteomic datasets to characterize toxin diversity in a variety of venomous taxa. Ultimately, the transcriptomic portion of these analyses follows very similar pathways after transcriptome assembly often including candidate toxin identification using BLAST, expression level screening, protein sequence alignment, gene tree reconstruction, and characterization of potential toxin function. Here we describe the Python package Venomix, which streamlines these processes using common bioinformatic tools along with ToxProt, a publicly available annotated database comprised of characterized venom proteins. In this study, we use the Venomix pipeline to characterize candidate venom diversity in four phylogenetically distinct organisms, a cone snail (Conidae; Conus sponsalis), a snake (Viperidae; Echis coloratus), an ant (Formicidae; Tetramorium bicarinatum), and a scorpion (Scorpionidae; Urodacus yaschenkoi). Data on these organisms were sampled from public databases, with each original analysis using different approaches for transcriptome assembly, toxin identification, or gene expression quantification. Venomix recovered numerically more candidate toxin transcripts for three of the four transcriptomes than the original analyses and identified new toxin candidates. In summary, we show that the Venomix package is a useful tool to identify and characterize the diversity of toxin-like transcripts derived from transcriptomic datasets. Venomix is available at: https://bitbucket.org/JasonMacrander/Venomix/.
Collapse
Affiliation(s)
- Jason Macrander
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, United States of America.,Department of Evolution, Ecology, and Organismal Biology, Ohio State University, Columbus, OH, United States of America
| | - Jyothirmayi Panda
- College of Computing and Informatics, University of North Carolina at Charlotte, Charlotte, NC, United States of America
| | - Daniel Janies
- College of Computing and Informatics, University of North Carolina at Charlotte, Charlotte, NC, United States of America.,Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, NC, United States of America
| | - Marymegan Daly
- Department of Evolution, Ecology, and Organismal Biology, Ohio State University, Columbus, OH, United States of America
| | - Adam M Reitzel
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC, United States of America
| |
Collapse
|
35
|
Zhao F, Lan X, Li T, Xiang Y, Zhao F, Zhang Y, Lee WH. Proteotranscriptomic Analysis and Discovery of the Profile and Diversity of Toxin-like Proteins in Centipede. Mol Cell Proteomics 2018; 17:709-720. [PMID: 29339413 DOI: 10.1074/mcp.ra117.000431] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 12/15/2017] [Indexed: 12/17/2022] Open
Abstract
Centipedes are one of the oldest venomous animals and use their venoms as weapons to attack prey or protect themselves. Their venoms contain various components with different biomedical and pharmacological properties. However, little attention has been paid to the profiles and diversity of their toxin-like proteins/peptides. In this study, we used a proteotranscriptomic approach to uncover the diversity of centipede toxin-like proteins in Scolopendra subspinipes mutilans Nine hundred twenty-three and 6,736 peptides, which were separately isolated from venom and torso tissues, respectively, were identified by ESI-MS/MS and deduced from their transcriptomes. Finally, 1369 unique proteins were identified in the proteome, including 100 proteins that exhibited overlapping expression in venom and torso tissues. Of these proteins, at least 40 proteins were identified as venom toxin-like proteins. Meanwhile, transcriptome mining identified ∼10-fold more toxin-like proteins and enabled the characterization of the precursor architecture of mature toxin-like peptides. Importantly, combined with proteomic and transcriptomic analyses, 25 toxin-like proteins/peptides (neurotoxins accounted for 50%) were expressed outside the venom gland and involved in gene recruitment processes. These findings highlight the extensive diversity of centipede toxin-like proteins and provide a new foundation for the medical-pharmaceutical use of centipede toxin-like proteins. Moreover, we are the first group to report the gene recruitment activity of venom toxin-like proteins in centipede, similar to snakes.
Collapse
Affiliation(s)
- Feng Zhao
- From the ‡Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, 32 East Jiao-Chang Road, Kunming, Yunnan 650223, China; .,§Key Laboratory of Subtropical Medicinal Edible Resources Development and Utilization in Yunnan Province, Department of Biology and Chemistry, Puer University, 6 Xueyuan Road, Puer, Yunnan 665000, China.,¶Institute of Comparative Study of Traditional Materia Medica, Institute of Integrative Medicine of Fudan University, Shanghai China
| | - Xinqiang Lan
- From the ‡Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, 32 East Jiao-Chang Road, Kunming, Yunnan 650223, China.,‖Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, Yunnan 650204, China
| | - Tao Li
- §Key Laboratory of Subtropical Medicinal Edible Resources Development and Utilization in Yunnan Province, Department of Biology and Chemistry, Puer University, 6 Xueyuan Road, Puer, Yunnan 665000, China.,¶Institute of Comparative Study of Traditional Materia Medica, Institute of Integrative Medicine of Fudan University, Shanghai China
| | - Yang Xiang
- From the ‡Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, 32 East Jiao-Chang Road, Kunming, Yunnan 650223, China
| | - Fang Zhao
- §Key Laboratory of Subtropical Medicinal Edible Resources Development and Utilization in Yunnan Province, Department of Biology and Chemistry, Puer University, 6 Xueyuan Road, Puer, Yunnan 665000, China.,¶Institute of Comparative Study of Traditional Materia Medica, Institute of Integrative Medicine of Fudan University, Shanghai China
| | - Yun Zhang
- From the ‡Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, 32 East Jiao-Chang Road, Kunming, Yunnan 650223, China; .,**Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming 650223, China
| | - Wen-Hui Lee
- From the ‡Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, 32 East Jiao-Chang Road, Kunming, Yunnan 650223, China;
| |
Collapse
|
36
|
Krishnan NM, Panda B. Comparative analyses of putative toxin gene homologs from an Old World viper, Daboia russelii. PeerJ 2017; 5:e4104. [PMID: 29230357 PMCID: PMC5721910 DOI: 10.7717/peerj.4104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 11/07/2017] [Indexed: 11/25/2022] Open
Abstract
Availability of snake genome sequences has opened up exciting areas of research on comparative genomics and gene diversity. One of the challenges in studying snake genomes is the acquisition of biological material from live animals, especially from the venomous ones, making the process cumbersome and time-consuming. Here, we report comparative sequence analyses of putative toxin gene homologs from Russell’s viper (Daboia russelii) using whole-genome sequencing data obtained from shed skin. When compared with the major venom proteins in Russell’s viper studied previously, we found 45–100% sequence similarity between the venom proteins and their putative homologs in the skin. Additionally, comparative analyses of 20 putative toxin gene family homologs provided evidence of unique sequence motifs in nerve growth factor (NGF), platelet derived growth factor (PDGF), Kunitz/Bovine pancreatic trypsin inhibitor (Kunitz BPTI), cysteine-rich secretory proteins, antigen 5, andpathogenesis-related1 proteins (CAP) and cysteine-rich secretory protein (CRISP). In those derived proteins, we identified V11 and T35 in the NGF domain; F23 and A29 in the PDGF domain; N69, K2 and A5 in the CAP domain; and Q17 in the CRISP domain to be responsible for differences in the largest pockets across the protein domain structures in crotalines, viperines and elapids from the in silico structure-based analysis. Similarly, residues F10, Y11 and E20 appear to play an important role in the protein structures across the kunitz protein domain of viperids and elapids. Our study highlights the usefulness of shed skin in obtaining good quality high-molecular weight DNA for comparative genomic studies, and provides evidence towards the unique features and evolution of putative venom gene homologs in vipers.
Collapse
Affiliation(s)
- Neeraja M Krishnan
- Ganit Labs, Bio-IT Centre, Institute of Bioinformatics and Applied Biotechnology, Bangalore, India
| | - Binay Panda
- Ganit Labs, Bio-IT Centre, Institute of Bioinformatics and Applied Biotechnology, Bangalore, India
| |
Collapse
|
37
|
|
38
|
Abstract
The classic model for the evolution of novel gene function is through gene duplication followed by evolution of a new function by one of the copies (neofunctionalization) [1, 2]. However, other modes have also been found, such as novel genes arising from non-coding DNA, chimeric fusions, and lateral gene transfers from other organisms [3-7]. Here we use the rapid turnover of venom genes in parasitoid wasps to study how new gene functions evolve. In contrast to the classic gene duplication model, we find that a common mode of acquisition of new venom genes in parasitoid wasps is co-option of single-copy genes from non-venom progenitors. Transcriptome and proteome sequencing reveal that recruitment and loss of venom genes occur primarily by rapid cis-regulatory expression evolution in the venom gland. Loss of venom genes is primarily due to downregulation of expression in the gland rather than gene death through coding sequence degradation. While the majority of venom genes have specialized expression in the venom gland, recent losses of venom function occur primarily among genes that show broader expression in development, suggesting that they can more readily switch functional roles. We propose that co-option of single-copy genes may be a common but relatively understudied mechanism of evolution for new gene functions, particularly under conditions of rapid evolutionary change.
Collapse
Affiliation(s)
- Ellen O Martinson
- Biology Department, University of Rochester, Rochester, NY 14627, USA
| | | | - Ching-Ho Chang
- Biology Department, University of Rochester, Rochester, NY 14627, USA
| | - John H Werren
- Biology Department, University of Rochester, Rochester, NY 14627, USA.
| |
Collapse
|
39
|
Tan KY, Tan CH, Chanhome L, Tan NH. Comparative venom gland transcriptomics of Naja kaouthia (monocled cobra) from Malaysia and Thailand: elucidating geographical venom variation and insights into sequence novelty. PeerJ 2017; 5:e3142. [PMID: 28392982 PMCID: PMC5384570 DOI: 10.7717/peerj.3142] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 03/03/2017] [Indexed: 11/20/2022] Open
Abstract
Background The monocled cobra (Naja kaouthia) is a medically important venomous snake in Southeast Asia. Its venom has been shown to vary geographically in relation to venom composition and neurotoxic activity, indicating vast diversity of the toxin genes within the species. To investigate the polygenic trait of the venom and its locale-specific variation, we profiled and compared the venom gland transcriptomes of N. kaouthia from Malaysia (NK-M) and Thailand (NK-T) applying next-generation sequencing (NGS) technology. Methods The transcriptomes were sequenced on the Illumina HiSeq platform, assembled and followed by transcript clustering and annotations for gene expression and function. Pairwise or multiple sequence alignments were conducted on the toxin genes expressed. Substitution rates were studied for the major toxins co-expressed in NK-M and NK-T. Results and discussion The toxin transcripts showed high redundancy (41–82% of the total mRNA expression) and comprised 23 gene families expressed in NK-M and NK-T, respectively (22 gene families were co-expressed). Among the venom genes, three-finger toxins (3FTxs) predominated in the expression, with multiple sequences noted. Comparative analysis and selection study revealed that 3FTxs are genetically conserved between the geographical specimens whilst demonstrating distinct differential expression patterns, implying gene up-regulation for selected principal toxins, or alternatively, enhanced transcript degradation or lack of transcription of certain traits. One of the striking features that elucidates the inter-geographical venom variation is the up-regulation of α-neurotoxins (constitutes ∼80.0% of toxin’s fragments per kilobase of exon model per million mapped reads (FPKM)), particularly the long-chain α-elapitoxin-Nk2a (48.3%) in NK-T but only 1.7% was noted in NK-M. Instead, short neurotoxin isoforms were up-regulated in NK-M (46.4%). Another distinct transcriptional pattern observed is the exclusively and abundantly expressed cytotoxin CTX-3 in NK-T. The findings suggested correlation with the geographical variation in proteome and toxicity of the venom, and support the call for optimising antivenom production and use in the region. Besides, the current study uncovered full and partial sequences of numerous toxin genes from N. kaouthia which have not been reported hitherto; these include N. kaouthia-specific l-amino acid oxidase (LAAO), snake venom serine protease (SVSP), cystatin, acetylcholinesterase (AChE), hyaluronidase (HYA), waprin, phospholipase B (PLB), aminopeptidase (AP), neprilysin, etc. Taken together, the findings further enrich the snake toxin database and provide deeper insights into the genetic diversity of cobra venom toxins.
Collapse
Affiliation(s)
- Kae Yi Tan
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya , Kuala Lumpur , Malaysia
| | - Choo Hock Tan
- Department of Pharmacology, Faculty of Medicine, University of Malaya , Kuala Lumpur , Malaysia
| | | | - Nget Hong Tan
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya , Kuala Lumpur , Malaysia
| |
Collapse
|
40
|
Boldrini-França J, Cologna CT, Pucca MB, Bordon KDCF, Amorim FG, Anjolette FAP, Cordeiro FA, Wiezel GA, Cerni FA, Pinheiro-Junior EL, Shibao PYT, Ferreira IG, de Oliveira IS, Cardoso IA, Arantes EC. Minor snake venom proteins: Structure, function and potential applications. Biochim Biophys Acta Gen Subj 2017; 1861:824-838. [DOI: 10.1016/j.bbagen.2016.12.022] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Revised: 12/12/2016] [Accepted: 12/20/2016] [Indexed: 12/20/2022]
|
41
|
Venomics: integrative venom proteomics and beyond*. Biochem J 2017; 474:611-634. [DOI: 10.1042/bcj20160577] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 12/31/2016] [Accepted: 01/03/2017] [Indexed: 01/15/2023]
Abstract
Venoms are integrated phenotypes that evolved independently in, and are used for predatory and defensive purposes by, a wide phylogenetic range of organisms. The same principles that contribute to the evolutionary success of venoms, contribute to making the study of venoms of great interest in such diverse fields as evolutionary ecology and biotechnology. Evolution is profoundly contingent, and nature also reinvents itself continuosly. Changes in a complex phenotypic trait, such as venom, reflect the influences of prior evolutionary history, chance events, and selection. Reconstructing the natural history of venoms, particularly those of snakes, which will be dealt with in more detail in this review, requires the integration of different levels of knowledge into a meaningful and comprehensive evolutionary framework for separating stochastic changes from adaptive evolution. The application of omics technologies and other disciplines have contributed to a qualitative and quantitative advance in the road map towards this goal. In this review we will make a foray into the world of animal venoms, discuss synergies and complementarities of the different approaches used in their study, and identify current bottlenecks that prevent inferring the evolutionary mechanisms and ecological constraints that molded snake venoms to their present-day variability landscape.
Collapse
|
42
|
Pla D, Sanz L, Whiteley G, Wagstaff SC, Harrison RA, Casewell NR, Calvete JJ. What killed Karl Patterson Schmidt? Combined venom gland transcriptomic, venomic and antivenomic analysis of the South African green tree snake (the boomslang), Dispholidus typus. Biochim Biophys Acta Gen Subj 2017; 1861:814-823. [PMID: 28130154 PMCID: PMC5335903 DOI: 10.1016/j.bbagen.2017.01.020] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 12/15/2016] [Accepted: 01/10/2017] [Indexed: 12/13/2022]
Abstract
Background Non-front-fanged colubroid snakes comprise about two-thirds of extant ophidian species. The medical significance of the majority of these snakes is unknown, but at least five species have caused life-threatening or fatal human envenomings. However, the venoms of only a small number of species have been explored. Methods A combined venomic and venom gland transcriptomic approach was employed to characterise of venom of Dispholidus typus (boomslang), the snake that caused the tragic death of Professor Karl Patterson Schmidt. The ability of CroFab™ antivenom to immunocapture boomslang venom proteins was investigated using antivenomics. Results Transcriptomic-assisted proteomic analysis identified venom proteins belonging to seven protein families: three-finger toxin (3FTx); phospholipase A2 (PLA2); cysteine-rich secretory proteins (CRISP); snake venom (SV) serine proteinase (SP); C-type lectin-like (CTL); SV metalloproteinases (SVMPs); and disintegrin-like/cysteine-rich (DC) proteolytic fragments. CroFab™ antivenom efficiently immunodepleted some boomslang SVMPs. Conclusions The present work is the first to address the overall proteomic profile of D. typus venom. This study allowed us to correlate the toxin composition with the toxic activities of the venom. The antivenomic analysis suggested that the antivenom available at the time of the unfortunate accident could have exhibited at least some immunoreactivity against the boomslang SVMPs responsible for the disseminated intravascular coagulation syndrome that caused K.P. Schmidt's fatal outcome. General significance This study may stimulate further research on other non-front-fanged colubroid snake venoms capable of causing life-threatening envenomings to humans, which in turn should contribute to prevent fatal human accidents, such as that unfortunately suffered by K.P. Schmidt. The venom proteome of Dispholidus typus (boomslang) is reported. Transcriptomic-assisted proteomic analysis identified venom proteins belonging to seven protein families. Boomslang venom proteome is dominated (75%) by snake venom PIII-metalloproteinases (PIII-SVMPs). CroFab™ antivenom efficiently immunodepleted some boomslang PIII-SVMPs.
Collapse
Affiliation(s)
- Davinia Pla
- Laboratorio de Venómica Estructural y Funcional, Instituto de Biomedicina de Valencia, CSIC, Valencia, Spain
| | - Libia Sanz
- Laboratorio de Venómica Estructural y Funcional, Instituto de Biomedicina de Valencia, CSIC, Valencia, Spain
| | - Gareth Whiteley
- Alistair Reid Venom Research Unit, Parasitology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Simon C Wagstaff
- Bioinformatics Unit, Parasitology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Robert A Harrison
- Alistair Reid Venom Research Unit, Parasitology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Nicholas R Casewell
- Alistair Reid Venom Research Unit, Parasitology Department, Liverpool School of Tropical Medicine, Liverpool, United Kingdom.
| | - Juan J Calvete
- Laboratorio de Venómica Estructural y Funcional, Instituto de Biomedicina de Valencia, CSIC, Valencia, Spain.
| |
Collapse
|
43
|
Evolution of the Snake Venom Delivery System. EVOLUTION OF VENOMOUS ANIMALS AND THEIR TOXINS 2017. [DOI: 10.1007/978-94-007-6458-3_11] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
|
44
|
Mutation, Duplication, and More in the Evolution of Venomous Animals and Their Toxins. EVOLUTION OF VENOMOUS ANIMALS AND THEIR TOXINS 2017. [DOI: 10.1007/978-94-007-6458-3_5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
45
|
Snake Genome Sequencing: Results and Future Prospects. Toxins (Basel) 2016; 8:toxins8120360. [PMID: 27916957 PMCID: PMC5198554 DOI: 10.3390/toxins8120360] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 11/23/2016] [Accepted: 11/25/2016] [Indexed: 12/16/2022] Open
Abstract
Snake genome sequencing is in its infancy—very much behind the progress made in sequencing the genomes of humans, model organisms and pathogens relevant to biomedical research, and agricultural species. We provide here an overview of some of the snake genome projects in progress, and discuss the biological findings, with special emphasis on toxinology, from the small number of draft snake genomes already published. We discuss the future of snake genomics, pointing out that new sequencing technologies will help overcome the problem of repetitive sequences in assembling snake genomes. Genome sequences are also likely to be valuable in examining the clustering of toxin genes on the chromosomes, in designing recombinant antivenoms and in studying the epigenetic regulation of toxin gene expression.
Collapse
|
46
|
Yang DC, Deuis JR, Dashevsky D, Dobson J, Jackson TNW, Brust A, Xie B, Koludarov I, Debono J, Hendrikx I, Hodgson WC, Josh P, Nouwens A, Baillie GJ, Bruxner TJC, Alewood PF, Lim KKP, Frank N, Vetter I, Fry BG. The Snake with the Scorpion's Sting: Novel Three-Finger Toxin Sodium Channel Activators from the Venom of the Long-Glanded Blue Coral Snake (Calliophis bivirgatus). Toxins (Basel) 2016; 8:E303. [PMID: 27763551 PMCID: PMC5086663 DOI: 10.3390/toxins8100303] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 10/04/2016] [Accepted: 10/10/2016] [Indexed: 02/06/2023] Open
Abstract
Millions of years of evolution have fine-tuned the ability of venom peptides to rapidly incapacitate both prey and potential predators. Toxicofera reptiles are characterized by serous-secreting mandibular or maxillary glands with heightened levels of protein expression. These glands are the core anatomical components of the toxicoferan venom system, which exists in myriad points along an evolutionary continuum. Neofunctionalisation of toxins is facilitated by positive selection at functional hotspots on the ancestral protein and venom proteins have undergone dynamic diversification in helodermatid and varanid lizards as well as advanced snakes. A spectacular point on the venom system continuum is the long-glanded blue coral snake (Calliophis bivirgatus), a specialist feeder that preys on fast moving, venomous snakes which have both a high likelihood of prey escape but also represent significant danger to the predator itself. The maxillary venom glands of C. bivirgatus extend one quarter of the snake's body length and nestle within the rib cavity. Despite the snake's notoriety its venom has remained largely unstudied. Here we show that the venom uniquely produces spastic paralysis, in contrast to the flaccid paralysis typically produced by neurotoxic snake venoms. The toxin responsible, which we have called calliotoxin (δ-elapitoxin-Cb1a), is a three-finger toxin (3FTx). Calliotoxin shifts the voltage-dependence of NaV1.4 activation to more hyperpolarised potentials, inhibits inactivation, and produces large ramp currents, consistent with its profound effects on contractile force in an isolated skeletal muscle preparation. Voltage-gated sodium channels (NaV) are a particularly attractive pharmacological target as they are involved in almost all physiological processes including action potential generation and conduction. Accordingly, venom peptides that interfere with NaV function provide a key defensive and predatory advantage to a range of invertebrate venomous species including cone snails, scorpions, spiders, and anemones. Enhanced activation or delayed inactivation of sodium channels by toxins is associated with the extremely rapid onset of tetanic/excitatory paralysis in envenomed prey animals. A strong selection pressure exists for the evolution of such toxins where there is a high chance of prey escape. However, despite their prevalence in other venomous species, toxins causing delay of sodium channel inhibition have never previously been described in vertebrate venoms. Here we show that NaV modulators, convergent with those of invertebrates, have evolved in the venom of the long-glanded coral snake. Calliotoxin represents a functionally novel class of 3FTx and a structurally novel class of NaV toxins that will provide significant insights into the pharmacology and physiology of NaV. The toxin represents a remarkable case of functional convergence between invertebrate and vertebrate venom systems in response to similar selection pressures. These results underscore the dynamic evolution of the Toxicofera reptile system and reinforces the value of using evolution as a roadmap for biodiscovery.
Collapse
Affiliation(s)
- Daryl C Yang
- Department of Pharmacology, Biomedicine Discovery Institute, Monash University, Clayton 3168, Australia.
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia 4072, Australia.
| | - Jennifer R Deuis
- Institute for Molecular Bioscience, University of Queensland, St. Lucia 4072, Australia.
| | - Daniel Dashevsky
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia 4072, Australia.
| | - James Dobson
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia 4072, Australia.
| | - Timothy N W Jackson
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia 4072, Australia.
| | - Andreas Brust
- Institute for Molecular Bioscience, University of Queensland, St. Lucia 4072, Australia.
| | - Bing Xie
- Bejing Genomics Institute-Shenzhen, Shenzhen 518083, China.
| | - Ivan Koludarov
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia 4072, Australia.
| | - Jordan Debono
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia 4072, Australia.
| | - Iwan Hendrikx
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia 4072, Australia.
| | - Wayne C Hodgson
- Department of Pharmacology, Biomedicine Discovery Institute, Monash University, Clayton 3168, Australia.
| | - Peter Josh
- School of Chemistry and Molecular Biosciences, University of Queensland, St. Lucia 4072, Australia.
| | - Amanda Nouwens
- School of Chemistry and Molecular Biosciences, University of Queensland, St. Lucia 4072, Australia.
| | - Gregory J Baillie
- Institute for Molecular Bioscience, University of Queensland, St. Lucia 4072, Australia.
| | - Timothy J C Bruxner
- Institute for Molecular Bioscience, University of Queensland, St. Lucia 4072, Australia.
| | - Paul F Alewood
- Institute for Molecular Bioscience, University of Queensland, St. Lucia 4072, Australia.
| | - Kelvin Kok Peng Lim
- Lee Kong Chian Natural History Museum, National University of Singapore, 2 Conservatory Drive, Singapore 117377, Singapore.
| | | | - Irina Vetter
- Institute for Molecular Bioscience, University of Queensland, St. Lucia 4072, Australia.
- School of Pharmacy, University of Queensland, Woolloongabba 4102, Australia.
| | - Bryan G Fry
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia 4072, Australia.
| |
Collapse
|
47
|
Integrating Perspectives on Animal Venom Diversity: An Introduction to the Symposium. Integr Comp Biol 2016; 56:934-937. [DOI: 10.1093/icb/icw112] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
|
48
|
Mackessy SP, Saviola AJ. Understanding Biological Roles of Venoms Among the Caenophidia: The Importance of Rear-Fanged Snakes. Integr Comp Biol 2016; 56:1004-1021. [PMID: 27639275 DOI: 10.1093/icb/icw110] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Snake venoms represent an adaptive trophic response to the challenges confronting a limbless predator for overcoming combative prey, and this chemical means of subduing prey shows several dominant phenotypes. Many front-fanged snakes, particularly vipers, feed on various vertebrate and invertebrate prey species, and some of their venom components (e.g., metalloproteinases, cobratoxin) appear to have been selected for "broad-brush" incapacitation of different prey taxa. Using proteomic and genomic techniques, the compositional diversity of front-fanged snakes is becoming well characterized; however, this is not the case for most rear-fanged colubroid snakes. Because these species consume a high diversity of prey, and because venoms are primarily a trophic adaptation, important clues for understanding specific selective pressures favoring venom component composition will be found among rear-fanged snake venoms. Rear-fanged snakes typically (but not always) produce venoms with lower complexity than front-fanged snakes, and there are even fewer dominant (and, arguably, biologically most relevant) venom protein families. We have demonstrated taxon-specific toxic effects, where lizards and birds show high susceptibility while mammals are largely unaffected, for both Old World and New World rear-fanged snakes, strongly indicating a causal link between toxin evolution and prey preference. New data are presented on myotoxin a, showing that the extremely rapid paralysis induced by this rattlesnake toxin is specific for rodents, and that myotoxin a is ineffectual against lizards. Relatively few rear-fanged snake venoms have been characterized, and basic natural history data are largely lacking, but directed sampling of specialized species indicates that novel compounds are likely among these specialists, particularly among those species feeding on invertebrate prey such as scorpions and centipedes. Because many of the more than 2200 species of colubroid snakes are rear-fanged, and many possess a Duvernoy's venom gland, understanding the nature of their venoms is foundational to understanding venom evolution in advanced snakes.
Collapse
Affiliation(s)
- Stephen P Mackessy
- School of Biological Sciences, University of Northern Colorado, 501 20th St, Greeley, CO 80639-0017, USA
| | - Anthony J Saviola
- School of Biological Sciences, University of Northern Colorado, 501 20th St, Greeley, CO 80639-0017, USA
| |
Collapse
|
49
|
|
50
|
Macrander J, Broe M, Daly M. Tissue-Specific Venom Composition and Differential Gene Expression in Sea Anemones. Genome Biol Evol 2016; 8:2358-75. [PMID: 27389690 PMCID: PMC5010892 DOI: 10.1093/gbe/evw155] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/14/2016] [Indexed: 12/19/2022] Open
Abstract
Cnidarians represent one of the few groups of venomous animals that lack a centralized venom transmission system. Instead, they are equipped with stinging capsules collectively known as nematocysts. Nematocysts vary in abundance and type across different tissues; however, the venom composition in most species remains unknown. Depending on the tissue type, the venom composition in sea anemones may be vital for predation, defense, or digestion. Using a tissue-specific RNA-seq approach, we characterize the venom assemblage in the tentacles, mesenterial filaments, and column for three species of sea anemone (Anemonia sulcata, Heteractis crispa, and Megalactis griffithsi). These taxa vary with regard to inferred venom potency, symbiont abundance, and nematocyst diversity. We show that there is significant variation in abundance of toxin-like genes across tissues and species. Although the cumulative toxin abundance for the column was consistently the lowest, contributions to the overall toxin assemblage varied considerably among tissues for different toxin types. Our gene ontology (GO) analyses also show sharp contrasts between conserved GO groups emerging from whole transcriptome analysis and tissue-specific expression among GO groups in our differential expression analysis. This study provides a framework for future characterization of tissue-specific venom and other functionally important genes in this lineage of simple bodied animals.
Collapse
Affiliation(s)
- Jason Macrander
- Department of Evolution, Ecology, and Organismal Biology, The Ohio State University
| | - Michael Broe
- Department of Evolution, Ecology, and Organismal Biology, The Ohio State University
| | - Marymegan Daly
- Department of Evolution, Ecology, and Organismal Biology, The Ohio State University
| |
Collapse
|