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Entiauspe-Neto OM, Nachtigall PG, Borges-Martins M, Junqueira-de-Azevedo ILM, Grazziotin FG. Highly conserved and extremely variable: The paradoxical pattern of toxin expression revealed by comparative venom-gland transcriptomics of Phalotris (Serpentes: Dipsadidae). Toxicon 2024; 244:107740. [PMID: 38705487 DOI: 10.1016/j.toxicon.2024.107740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Revised: 04/11/2024] [Accepted: 04/27/2024] [Indexed: 05/07/2024]
Abstract
Although non-front fanged snakes account for almost two-thirds of snake diversity, most studies on venom composition and evolution focus exclusively on front-fanged species, which comprise most of the clinically relevant accidents. Comprehensive reports on venom composition of non-front fanged snakes are still scarce for several groups. In this study, we address such shortage of knowledge by providing new insights about the venom composition among species of Phalotris, a poorly studied Neotropical dipsadid genus. Phalotris are known for their specialized venom delivery system and toxic venoms, which can cause life-threatening accidents in humans. We evaluate the venom-gland transcriptome of Phalotris, comparing the following three South American species: P. reticulatus for the Araucaria Pine forests, P. lemniscatus for the Pampa grasslands, and P. mertensi for the Brazilian Cerrado. Our results indicate similar venom profiles, in which they share a high expression level of Kunitz-type inhibitors (KUNZ). On the other hand, comparative analyses revealed substantial differences in the expression levels of C-type lectins (CTL) and snake venom metalloproteinases (SVMP). The diverse set of SVMP and CTL isoforms shows signals of positive selection, and we also identified truncated forms of type III SVMPs, which resemble type II and type I SVMPs of viperids. Additionally, we identified a CNP precursor hosting a proline-rich region containing a BPP motif resembling those commonly detected in viperid venoms with hypotensive activity. Altogether, our results suggest an evolutionary history favoring high expression levels of few KUNZ isoforms in Phalotris venoms, contrasting with a highly diverse set of SVMP and CTL isoforms. Such diversity can be comparable with the venom variability observed in some viperids. Our findings highlight the extreme phenotypic diversity of non-front fanged snakes and the importance to allocate greater effort to study neglected groups of Colubroidea.
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Affiliation(s)
- Omar M Entiauspe-Neto
- Laboratório de Coleções Zoológicas, Instituto Butantan, 05503-900, Av. Vital Brazil, 1500, Butantã, São Paulo, SP, Brazil; Programa de Pós-graduação em Biologia Animal, Departamento de Zoologia, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, CEP 91501-970, Porto Alegre, RS, Brazil.
| | - Pedro G Nachtigall
- Laboratório de Toxinologia Aplicada, Instituto Butantan, 05503-900, Av. Vital Brazil, 1500, Butantã, São Paulo, SP, Brazil
| | - Márcio Borges-Martins
- Programa de Pós-graduação em Biologia Animal, Departamento de Zoologia, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, CEP 91501-970, Porto Alegre, RS, Brazil
| | | | - Felipe G Grazziotin
- Laboratório de Coleções Zoológicas, Instituto Butantan, 05503-900, Av. Vital Brazil, 1500, Butantã, São Paulo, SP, Brazil
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2
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Das S, Greenbaum E, Brecko J, Pauwels OSG, Ruane S, Pirro S, Merilä J. Phylogenomics of Psammodynastes and Buhoma (Elapoidea: Serpentes), with the description of a new Asian snake family. Sci Rep 2024; 14:9489. [PMID: 38664489 PMCID: PMC11045840 DOI: 10.1038/s41598-024-60215-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Accepted: 04/19/2024] [Indexed: 04/28/2024] Open
Abstract
Asian mock vipers of the genus Psammodynastes and African forest snakes of the genus Buhoma are two genera belonging to the snake superfamily Elapoidea. The phylogenetic placements of Psammodynastes and Buhoma within Elapoidea has been extremely unstable which has resulted in their uncertain and debated taxonomy. We used ultraconserved elements and traditional nuclear and mitochondrial markers to infer the phylogenetic relationships of these two genera with other elapoids. Psammodynastes, for which a reference genome has been sequenced, were found, with strong branch support, to be a relatively early diverging split within Elapoidea that is sister to a clade consisting of Elapidae, Micrelapidae and Lamprophiidae. Hence, we allocate Psammodynastes to its own family, Psammodynastidae new family. However, the phylogenetic position of Buhoma could not be resolved with a high degree of confidence. Attempts to identify the possible sources of conflict in the rapid radiation of elapoid snakes suggest that both hybridisation/introgression during the rapid diversification, including possible ghost introgression, as well as incomplete lineage sorting likely have had a confounding role. The usual practice of combining mitochondrial loci with nuclear genomic data appears to mislead phylogeny reconstructions in rapid radiation scenarios, especially in the absence of genome scale data.
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Affiliation(s)
- Sunandan Das
- Ecological Genetics Research Unit, Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, 00014, Helsinki, Finland.
| | - Eli Greenbaum
- Department of Biological Sciences, University of Texas at El Paso, 500 W. University Avenue, El Paso, TX, 79968, USA
| | - Jonathan Brecko
- Royal Belgian Institute of Natural Sciences, Rue Vautier 29, 1000, Brussels, Belgium
- Royal Museum for Central Africa, Tervuren, Belgium
| | - Olivier S G Pauwels
- Royal Belgian Institute of Natural Sciences, Rue Vautier 29, 1000, Brussels, Belgium
| | - Sara Ruane
- Life Sciences Section, Negaunee Integrative Research Center, Field Museum, Chicago, IL, USA
| | - Stacy Pirro
- Iridian Genomes Inc., Bethesda, MD, 20817, USA
| | - Juha Merilä
- Ecological Genetics Research Unit, Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, 00014, Helsinki, Finland
- Area of Ecology and Biodiversity, School of Biological Sciences, Kadoorie Biological Sciences Building, The University of Hong Kong, Pokfulam Road, Hong Kong, SAR, China
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3
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Frynta D, Elmi HSA, Janovcová M, Rudolfová V, Štolhoferová I, Rexová K, Král D, Sommer D, Berti DA, Landová E, Frýdlová P. Are vipers prototypic fear-evoking snakes? A cross-cultural comparison of Somalis and Czechs. Front Psychol 2023; 14:1233667. [PMID: 37928591 PMCID: PMC10620321 DOI: 10.3389/fpsyg.2023.1233667] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 09/08/2023] [Indexed: 11/07/2023] Open
Abstract
Snakes are known as highly fear-evoking animals, eliciting preferential attention and fast detection in humans. We examined the human fear response to snakes in the context of both current and evolutionary experiences, conducting our research in the cradle of humankind, the Horn of Africa. This region is characterized by the frequent occurrence of various snake species, including deadly venomous viperids (adders) and elapids (cobras and mambas). We conducted experiments in Somaliland and compared the results with data from Czech respondents to address the still unresolved questions: To which extent is human fear of snakes affected by evolutionary or current experience and local culture? Can people of both nationalities recognize venomous snakes as a category, or are they only afraid of certain species that are most dangerous in a given area? Are respondents of both nationalities equally afraid of deadly snakes from both families (Viperidae, Elapidae)? We employed a well-established picture-sorting approach, consisting of 48 snake species belonging to four distinct groups. Our results revealed significant agreement among Somali as well as Czech respondents. We found a highly significant effect of the stimulus on perceived fear in both populations. Vipers appeared to be the most salient stimuli in both populations, as they occupied the highest positions according to the reported level of subjectively perceived fear. The position of vipers strongly contrasts with the fear ranking of deadly venomous elapids, which were in lower positions. Fear scores of vipers were significantly higher in both populations, and their best predictor was the body width of the snake. The evolutionary, cultural, and cognitive aspects of this phenomenon are discussed.
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Affiliation(s)
- Daniel Frynta
- Department of Zoology, Faculty of Science, Charles University, Prague, Czechia
| | - Hassan Sh Abdirahman Elmi
- Department of Zoology, Faculty of Science, Charles University, Prague, Czechia
- Department of Biology, Faculty of Education, Amoud University, Borama, Somalia
| | - Markéta Janovcová
- Department of Zoology, Faculty of Science, Charles University, Prague, Czechia
| | - Veronika Rudolfová
- Department of Zoology, Faculty of Science, Charles University, Prague, Czechia
| | - Iveta Štolhoferová
- Department of Zoology, Faculty of Science, Charles University, Prague, Czechia
| | - Kateřina Rexová
- Department of Zoology, Faculty of Science, Charles University, Prague, Czechia
| | - David Král
- Department of Zoology, Faculty of Science, Charles University, Prague, Czechia
| | - David Sommer
- Department of Zoology, Faculty of Science, Charles University, Prague, Czechia
| | - Daniel Alex Berti
- Department of Zoology, Faculty of Science, Charles University, Prague, Czechia
| | - Eva Landová
- Department of Zoology, Faculty of Science, Charles University, Prague, Czechia
| | - Petra Frýdlová
- Department of Zoology, Faculty of Science, Charles University, Prague, Czechia
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4
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Gripshover ND, Hennessey P, McBrayer LD, Meik JM, Watson CM, Cox CL. When Food Fights Back: Skull Morphology and Feeding Behavior of Centipede-Eating Snakes. Integr Comp Biol 2023; 63:34-47. [PMID: 37248050 DOI: 10.1093/icb/icad047] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 05/15/2023] [Accepted: 05/24/2023] [Indexed: 05/31/2023] Open
Abstract
Feeding is a complex process that involves an integrated response of multiple functional systems. Animals evolve phenotypic integration of complex morphological traits to covary and maximize performance of feeding behaviors. Specialization, such as feeding on dangerous prey, can further shape the integration of behavior and morphology as traits are expected to evolve and maintain function in parallel. Feeding on centipedes, with their powerful forcipules that pinch and inject venom, has evolved multiple times within snakes, including the genus Tantilla. However, the behavioral and morphological adaptations used to consume this dangerous prey are poorly understood. By studying snakes with varying degrees of dietary specialization, we can test the integration of diet, morphology, and behavior to better understand the evolution of consuming difficult prey. We studied the prey preference and feeding behavior of Tantilla using the flat-headed snake (T. gracilis) and the crowned snake (T. coronata), which differ in the percentage of centipedes in their diet. We then quantified cranial anatomy using geometric morphometric data from CT scans. To test prey preference, we offered multiple types of prey and recorded snake behavior. Both species of snakes showed interest in multiple prey types, but only struck or consumed centipedes. To subdue centipedes, crowned snakes used coiling and holding (envenomation) immediately after striking, while flat-headed snakes used the novel behavior of pausing and holding onto centipedes for a prolonged time prior to the completion of swallowing. Each skull element differed in shape after removing the effects of size, position, and orientation. The rear fang was larger in crowned snakes, but the mechanical advantage of the lower jaw was greater in flat-headed snakes. Our results suggest that the integration of behavioral and morphological adaptations is important for the success of subduing and consuming dangerous prey.
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Affiliation(s)
- Noah D Gripshover
- Department of Biological Sciences, Institute of Environment, Florida International University, Miami, FL 33199, USA
| | - Patrick Hennessey
- School of Biological and Behavioral Sciences, Queen Mary University of London, London, E1 4NS, UK
| | - Lance D McBrayer
- Department of Biology, Georgia Southern University, Statesboro, GA 30458, USA
| | - Jesse M Meik
- Department of Biological Sciences, Tarleton State University, Stephenville, TX 76402, USA
| | - Charles M Watson
- Department of Life Sciences, Texas A&M-San Antonio, San Antonio, TX 78224, USA
| | - Christian L Cox
- Department of Biological Sciences, Institute of Environment, Florida International University, Miami, FL 33199, USA
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5
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Zhao Z, Conradie W, Pietersen DW, Jordaan A, Nicolau G, Edwards S, Riekert S, Heideman N. Diversification of the African legless skinks in the subfamily Acontinae (Family Scincidae). Mol Phylogenet Evol 2023; 182:107747. [PMID: 36849095 DOI: 10.1016/j.ympev.2023.107747] [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: 08/11/2022] [Revised: 02/15/2023] [Accepted: 02/22/2023] [Indexed: 02/27/2023]
Abstract
Cladogenic diversification is often explained by referring to climatic oscillations and geomorphic shifts that cause allopatric speciation. In this regard, southern Africa retains a high level of landscape heterogeneity in vegetation, geology, and rainfall patterns. The legless skink subfamily Acontinae occurs broadly across the southern African subcontinent and therefore provides an ideal model group for investigating biogeographic patterns associated with the region. A robust phylogenetic study of the Acontinae with comprehensive coverage and adequate sampling of each taxon has been lacking up until now, resulting in unresolved questions regarding the subfamily's biogeography and evolution. In this study, we used multi-locus genetic markers (three mitochondrial and two nuclear) with comprehensive taxon coverage (all currently recognized Acontinae species) and adequate sampling (multiple specimens for most taxa) of each taxon to infer a phylogeny for the subfamily. The phylogeny retrieved four well-supported clades in Acontias and supported the monophyly of Typhlosaurus. Following the General Lineage Concept (GLC), many long-standing phylogenetic enigmas within Acontias occidentalis and the A. kgalagadi, A. lineatus and A. meleagris species complexes, and within Typhlosaurus were resolved. Our species delimitation analyses suggest the existence of hidden taxa in the A. occidentalis, A. cregoi and A. meleagris species groups, but also suggest that some currently recognized species in the A. lineatus and A. meleagris species groups, and within Typhlosaurus, should be synonymised. We also possibly encountered "ghost introgression" in A. occidentalis. Our inferred species tree revealed a signal of gene flow, which implies possible cross-over in some groups. Fossil evidence calibration dating results showed that the divergence between Typhlosaurus and Acontias was likely influenced by cooling and increasing aridity along the southwest coast in the mid-Oligocene caused by the opening of the Drake Passage. Further cladogenesis observed in Typhlosaurus and Acontias was likely influenced by Miocene cooling, expansion of open habitat, uplifting of the eastern Great Escarpment (GE), and variation in rainfall patterns, together with the effect of the warm Agulhas Current since the early Miocene, the development of the cold Benguela Current since the late Miocene, and their co-effects. The biogeographic pattern of the Acontinae bears close resemblance to that of other herpetofauna (e.g., rain frogs and African vipers) in southern Africa.
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Affiliation(s)
- Zhongning Zhao
- Department of Zoology and Entomology, University of the Free State, Bloemfontein, South Africa; Department of Genetics, University of the Free State, Bloemfontein, South Africa.
| | - Werner Conradie
- Port Elizabeth Museum (Bayworld), P.O. Box 13147, Humewood, Port Elizabeth 6013, South Africa; Department of Nature Conservation Management, Natural Resource Science and Management Cluster, Faculty of Science, George Campus, Nelson Mandela University, George, South Africa
| | - Darren W Pietersen
- Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
| | - Adriaan Jordaan
- Department of Zoology and Entomology, University of the Free State, Bloemfontein, South Africa
| | - Gary Nicolau
- Zoology & Entomology Molecular Lab, Department of Zoology and Entomology, Rhodes University, Makhanda, South Africa
| | - Shelley Edwards
- Zoology & Entomology Molecular Lab, Department of Zoology and Entomology, Rhodes University, Makhanda, South Africa
| | - Stephanus Riekert
- Department of Information and Communication Technology Services, University of the Free State, Bloemfontein, South Africa
| | - Neil Heideman
- Department of Zoology and Entomology, University of the Free State, Bloemfontein, South Africa
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6
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Das S, Greenbaum E, Meiri S, Bauer AM, Burbrink FT, Raxworthy CJ, Weinell JL, Brown RM, Brecko J, Pauwels OSG, Rabibisoa N, Raselimanana AP, Merilä J. Ultraconserved elements-based phylogenomic systematics of the snake superfamily Elapoidea, with the description of a new Afro-Asian family. Mol Phylogenet Evol 2023; 180:107700. [PMID: 36603697 DOI: 10.1016/j.ympev.2022.107700] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 12/27/2022] [Accepted: 12/29/2022] [Indexed: 01/04/2023]
Abstract
The highly diverse snake superfamily Elapoidea is considered to be a classic example of ancient, rapid radiation. Such radiations are challenging to fully resolve phylogenetically, with the highly diverse Elapoidea a case in point. Previous attempts at inferring a phylogeny of elapoids produced highly incongruent estimates of their evolutionary relationships, often with very low statistical support. We sought to resolve this situation by sequencing over 4,500 ultraconserved element loci from multiple representatives of every elapoid family/subfamily level taxon and inferring their phylogenetic relationships with multiple methods. Concatenation and multispecies coalescent based species trees yielded largely congruent and well-supported topologies. Hypotheses of a hard polytomy were not retained for any deep branches. Our phylogenies recovered Cyclocoridae and Elapidae as diverging early within Elapoidea. The Afro-Malagasy radiation of elapoid snakes, classified as multiple subfamilies of an inclusive Lamprophiidae by some earlier authors, was found to be monophyletic in all analyses. The genus Micrelaps was consistently recovered as sister to Lamprophiidae. We establish a new family, Micrelapidae fam. nov., for Micrelaps and assign Brachyophis to this family based on cranial osteological synapomorphy. We estimate that Elapoidea originated in the early Eocene and rapidly diversified into all the major lineages during this epoch. Ecological opportunities presented by the post-Cretaceous-Paleogene mass extinction event may have promoted the explosive radiation of elapoid snakes.
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Affiliation(s)
- Sunandan Das
- Ecological Genetics Research Unit, Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, FI-00014 University of Helsinki, Finland.
| | - Eli Greenbaum
- Department of Biological Sciences, University of Texas at El Paso, 500 W. University Avenue, El Paso, TX 79968, USA
| | - Shai Meiri
- School of Zoology, Tel Aviv University, Tel Aviv, Israel; The Steinhardt Museum of Natural History, Tel Aviv University, Tel Aviv, Israel
| | - Aaron M Bauer
- Department of Biology and Center for Biodiversity and Ecosystem Stewardship, Villanova University, 800 Lancaster Avenue, Villanova, PA 19085, USA
| | - Frank T Burbrink
- Department of Herpetology, American Museum of Natural History, 200 Central Park West, New York, NY 10024-5192, USA
| | - Christopher J Raxworthy
- Department of Herpetology, American Museum of Natural History, 200 Central Park West, New York, NY 10024-5192, USA
| | - Jeffrey L Weinell
- Department of Herpetology, American Museum of Natural History, 200 Central Park West, New York, NY 10024-5192, USA; Department of Ecology and Evolutionary Biology and Biodiversity Institute, University of Kansas, Lawrence, KS 66045, USA
| | - Rafe M Brown
- Department of Ecology and Evolutionary Biology and Biodiversity Institute, University of Kansas, Lawrence, KS 66045, USA
| | - Jonathan Brecko
- Royal Belgian Institute of Natural Sciences, Rue Vautier 29, B-1000 Brussels, Belgium; Royal Museum for Central Africa, Tervuren, Belgium
| | - Olivier S G Pauwels
- Royal Belgian Institute of Natural Sciences, Rue Vautier 29, B-1000 Brussels, Belgium
| | - Nirhy Rabibisoa
- Sciences de la Vie et de l'Environnement, Faculté des Sciences, de Technologies et de l'Environnement, Université de Mahajanga, Campus Universitaire d'Ambondrona, BP 652, Mahajanga 401, Madagascar
| | - Achille P Raselimanana
- Zoologie et Biodiversité Animale, Faculté des Sciences, Université d'Antananarivo, BP 906, Antananarivo 101, Madagascar
| | - Juha Merilä
- Ecological Genetics Research Unit, Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, FI-00014 University of Helsinki, Finland; Area of Ecology and Biodiversity, School of Biological Sciences, Kadoorie Biological Sciences Building, Pokfulam Road, The University of Hong Kong, Hong Kong Special Administrative Region
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7
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Weldon PJ, Xu S, Attygalle AB. Short-chain carboxylic acids in the scent gland secretions of the eastern small-scaled burrowing asp (Atractaspis fallax: Lamprophiidae, Serpentes, Reptilia). BIOCHEM SYST ECOL 2022. [DOI: 10.1016/j.bse.2022.104548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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8
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Cerebral Complications of Snakebite Envenoming: Case Studies. Toxins (Basel) 2022; 14:toxins14070436. [PMID: 35878174 PMCID: PMC9320586 DOI: 10.3390/toxins14070436] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 06/21/2022] [Accepted: 06/24/2022] [Indexed: 02/01/2023] Open
Abstract
There are an estimated 5.4 million snakebite cases every year. People with snakebite envenoming suffer from severe complications, or even death. Although some review articles cover several topics of snakebite envenoming, a review of the cases regarding cerebral complications, especially rare syndromes, is lacking. Here, we overview 35 cases of snakebite by front-fanged snakes, including Bothrops, Daboia, Cerastes, Deinagkistrodon, Trimeresurus, and Crotalus in the Viperidae family; Bungarus and Naja in the Elapidae family, and Homoroselaps (rare cases) in the Lamprophiidae family. We also review three rare cases of snakebite by rear-fanged snakes, including Oxybelis and Leptodeira in the Colubridae family. In the cases of viper bites, most patients (17/24) were diagnosed with ischemic stroke and intracranial hemorrhage, leading to six deaths. We then discuss the potential underlying molecular mechanisms that cause these complications. In cases of elapid bites, neural, cardiac, and ophthalmic disorders are the main complications. Due to the small amount of venom injection and the inability to deep bite, all the rear-fanged snakebites did not develop any severe complications. To date, antivenom (AV) is the most effective therapy for snakebite envenoming. In the six cases of viper and elapid bites that did not receive AV, three cases (two by viper and one by elapid) resulted in death. This indicates that AV treatment is the key to survival after a venomous snakebite. Lastly, we also discuss several studies of therapeutic agents against snakebite-envenoming-induced complications, which could be potential adjuvants along with AV treatment. This article organizes the diagnosis of hemotoxic and neurotoxic envenoming, which may help ER doctors determine the treatment for unidentified snakebite.
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9
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Das S, Brecko J, Pauwels OSG, Merilä J. Cranial osteology of
Hypoptophis
(Aparallactinae: Atractaspididae: Caenophidia), with a discussion on the evolution of its fossorial adaptations. J Morphol 2022; 283:510-538. [PMID: 35094424 PMCID: PMC9305546 DOI: 10.1002/jmor.21457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 01/10/2022] [Accepted: 01/27/2022] [Indexed: 11/08/2022]
Affiliation(s)
- Sunandan Das
- Ecological Genetics Research Unit, Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, FI‐00014 University of Helsinki Finland
| | - Jonathan Brecko
- Department of Recent Vertebrates Royal Belgian Institute of Natural Sciences (RBINS), Rue Vautier 29, B‐1000 Brussels Belgium
- Royal Museum for Central Africa, Leuvensesteenweg 13, 3080 Tervuren Belgium
| | - Olivier S. G. Pauwels
- Department of Recent Vertebrates Royal Belgian Institute of Natural Sciences (RBINS), Rue Vautier 29, B‐1000 Brussels Belgium
| | - Juha Merilä
- Ecological Genetics Research Unit, Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, FI‐00014 University of Helsinki Finland
- Division of Ecology and Biodiversity, Faculty of Science The University of Hong Kong, KBSB 3N19 Hong Kong SAR
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10
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Maritz B, Barends JM, Mohamed R, Maritz RA, Alexander GJ. Repeated dietary shifts in elapid snakes (Squamata: Elapidae) revealed by ancestral state reconstruction. Biol J Linn Soc Lond 2021. [DOI: 10.1093/biolinnean/blab115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Abstract
Identifying the traits of ancestral organisms can reveal patterns and drivers of organismal diversification. Unfortunately, reconstructing complex multistate traits (such as diet) remains challenging. Adopting a ‘reconstruct, then aggregate’ approach in a maximum likelihood framework, we reconstructed ancestral diets for 298 species of elapid snakes. We tested whether different prey types were correlated with one another, tested for one-way contingency between prey type pairs, and examined the relationship between snake body size and dietary composition. We demonstrate that the evolution of diet was characterized by niche conservation punctuated by repeated dietary shifts. The ancestor of elapids most likely fed on reptiles and possibly amphibians, with deviations from this ancestral diet occurring repeatedly due to shifts into marine environments and changes in body size. Moreover, we demonstrate important patterns of prey use, including one-way dependency—most obviously the inclusion of eggs being dependent on a diet that already included the producers of those eggs. Despite imperfect dietary data, our approach produced a robust overview of dietary evolution. Given the paucity of natural history information for many organisms, our approach has the potential to increase the number of lineages to which ancestral state reconstructions of multistate traits can be robustly applied.
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Affiliation(s)
- Bryan Maritz
- Department of Biodiversity and Conservation Biology, University of the Western Cape, Private Bag X17, Bellville, South Africa
| | - Jody M Barends
- Department of Biodiversity and Conservation Biology, University of the Western Cape, Private Bag X17, Bellville, South Africa
| | - Riaaz Mohamed
- Department of Biodiversity and Conservation Biology, University of the Western Cape, Private Bag X17, Bellville, South Africa
| | - Robin A Maritz
- Department of Biodiversity and Conservation Biology, University of the Western Cape, Private Bag X17, Bellville, South Africa
| | - Graham J Alexander
- School of Animal, Plant & Environmental Sciences, University of the Witwatersrand, Johannesburg, PO Wits, South Africa
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11
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Weinstein SA, Warrell DA, Daoues K, Vidal N. The first reported snakebite by an African snake-eater, Polemon spp. (Atractaspididae, Aparallactinae); Local envenoming by Reinhardt's snake-eater, Polemon acanthias (Reinhardt, 1860). Toxicon 2021; 200:92-95. [PMID: 34280410 DOI: 10.1016/j.toxicon.2021.07.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 07/09/2021] [Accepted: 07/12/2021] [Indexed: 11/19/2022]
Abstract
The first reported snakebite by an African snake-eater, Polemon spp. (Atractaspididae, Aparallactinae); Local envenoming by Reinhardt's snake-eater, Polemon acanthias (Reinhardt, 1860). Toxicon XX, xxx. A 51-yr-old male herpetologist was bitten on the left index finger by a captive male Polemon acanthias while manually removing fragments of incompletely shed skin from the specimen. The snake sustained its bite for approximately 2 mins, advancing its jaws several times. The victim rapidly developed moderate pain, erythema, progressive edema that ultimately extended to the left wrist; a blister later developed in the wound site, as well as joint stiffness in the bitten and adjacent two fingers that limited flexion and extension. These effects regressed during the week following the bite, but recurred thereafter and were similar to the effects that developed immediately post-envenoming. There were no systemic signs or symptoms. The victim sought medical advice and was treated with broad-spectrum antibiotics, antihistamines and wound care; no laboratory investigations were conducted. He improved during the subsequent month with complete resolution in 5 and one-half weeks. This is the first documented bite by a Polemon spp. and the victim's clinical course suggests the development of local effects from venom components. The phylogenetic relationship of Polemon spp. with the burrowing asps (Atractaspis spp.) and the similarity of some of the features of this local envenoming by P. acanthias with mild/moderate envenoming by some Atractaspis spp., suggests that none of these snakes should be handled; they should be considered capable of inflicting potentially serious envenoming.
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Affiliation(s)
- Scott A Weinstein
- Department of Toxinology, Women's and Children's Hospital, North Adelaide, South Australia, 5006, Australia.
| | - David A Warrell
- Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Karim Daoues
- La Ferme Tropicale, 54 rue Jenner, 75013, Paris, France
| | - Nicolas Vidal
- Muséum National d'Histoire Naturelle, UMR 7205, MNHN, CNRS, Sorbonne Université, EPHE, Université des Antilles, Institut de Systématique, Evolution et Biodiversité, CP 30, 57, Rue Cuvier, F-75005, Paris, France
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Allen KE, Greenbaum E, Hime PM, Tapondjou N. WP, Sterkhova VV, Kusamba C, Rödel M, Penner J, Peterson AT, Brown RM. Rivers, not refugia, drove diversification in arboreal, sub-Saharan African snakes. Ecol Evol 2021; 11:6133-6152. [PMID: 34141208 PMCID: PMC8207163 DOI: 10.1002/ece3.7429] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 02/12/2021] [Accepted: 02/18/2021] [Indexed: 12/26/2022] Open
Abstract
The relative roles of rivers versus refugia in shaping the high levels of species diversity in tropical rainforests have been widely debated for decades. Only recently has it become possible to take an integrative approach to test predictions derived from these hypotheses using genomic sequencing and paleo-species distribution modeling. Herein, we tested the predictions of the classic river, refuge, and river-refuge hypotheses on diversification in the arboreal sub-Saharan African snake genus Toxicodryas. We used dated phylogeographic inferences, population clustering analyses, demographic model selection, and paleo-distribution modeling to conduct a phylogenomic and historical demographic analysis of this genus. Our results revealed significant population genetic structure within both Toxicodryas species, corresponding geographically to river barriers and divergence times from the mid-Miocene to Pliocene. Our demographic analyses supported the interpretation that rivers are indications of strong barriers to gene flow among populations since their divergence. Additionally, we found no support for a major contraction of suitable habitat during the last glacial maximum, allowing us to reject both the refuge and river-refuge hypotheses in favor of the river-barrier hypothesis. Based on conservative interpretations of our species delimitation analyses with the Sanger and ddRAD data sets, two new cryptic species are identified from east-central Africa. This study highlights the complexity of diversification dynamics in the African tropics and the advantages of integrative approaches to studying speciation in tropical regions.
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Affiliation(s)
- Kaitlin E. Allen
- Department of Ecology and Evolutionary BiologyUniversity of KansasLawrenceKSUSA
- Biodiversity InstituteUniversity of KansasLawrenceKSUSA
| | - Eli Greenbaum
- Department of Biological SciencesUniversity of Texas at El PasoEl PasoTXUSA
| | - Paul M. Hime
- Biodiversity InstituteUniversity of KansasLawrenceKSUSA
| | - Walter P. Tapondjou N.
- Department of Ecology and Evolutionary BiologyUniversity of KansasLawrenceKSUSA
- Biodiversity InstituteUniversity of KansasLawrenceKSUSA
| | - Viktoria V. Sterkhova
- Department of Ecology and Evolutionary BiologyUniversity of KansasLawrenceKSUSA
- Biodiversity InstituteUniversity of KansasLawrenceKSUSA
| | - Chifundera Kusamba
- Laboratoire d’Hérpétologie, Département de BiologieCentre de Recherche en Sciences NaturellesLwiroDemocratic Republic of Congo
| | - Mark‐Oliver Rödel
- Museum für Naturkunde – Leibniz Institute for Evolution and Biodiversity ScienceBerlinGermany
| | - Johannes Penner
- Museum für Naturkunde – Leibniz Institute for Evolution and Biodiversity ScienceBerlinGermany
- Chair of Wildlife Ecology and ManagementUniversity of FreiburgFreiburgGermany
| | - A. Townsend Peterson
- Department of Ecology and Evolutionary BiologyUniversity of KansasLawrenceKSUSA
- Biodiversity InstituteUniversity of KansasLawrenceKSUSA
| | - Rafe M. Brown
- Department of Ecology and Evolutionary BiologyUniversity of KansasLawrenceKSUSA
- Biodiversity InstituteUniversity of KansasLawrenceKSUSA
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Maritz B, Rawoot A, van Huyssteen R. Testing assertions of dietary specialisation: a case study of the diet of Aparallactus capensis. AFR J HERPETOL 2021. [DOI: 10.1080/21564574.2021.1886185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Bryan Maritz
- Department of Biodiversity and Conservation Biology, University of the Western Cape, Bellville, South Africa
| | - Aadam Rawoot
- Department of Biodiversity and Conservation Biology, University of the Western Cape, Bellville, South Africa
| | - Ryan van Huyssteen
- Department of Biodiversity and Conservation Biology, University of the Western Cape, Bellville, South Africa
- Department of Geography Environmental Studies & Tourism, University of the Western Cape, Bellville, South Africa
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14
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Ancestral Reconstruction of Diet and Fang Condition in the Lamprophiidae: Implications for the Evolution of Venom Systems in Snakes. J HERPETOL 2021. [DOI: 10.1670/19-071] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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15
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Strong CRC, Palci A, Caldwell MW. Insights into skull evolution in fossorial snakes, as revealed by the cranial morphology of Atractaspis irregularis (Serpentes: Colubroidea). J Anat 2021; 238:146-172. [PMID: 32815172 PMCID: PMC7755084 DOI: 10.1111/joa.13295] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 07/20/2020] [Accepted: 07/21/2020] [Indexed: 01/03/2023] Open
Abstract
Comparative osteological analyses of extant organisms provide key insight into major evolutionary transitions and phylogenetic hypotheses. This is especially true for snakes, given their unique morphology relative to other squamates and the persistent controversy regarding their evolutionary origins. However, the osteology of several major snake groups remains undescribed, thus hindering efforts to accurately reconstruct the phylogeny of snakes. One such group is the Atractaspididae, a family of fossorial colubroids. We herein present the first detailed description of the atractaspidid skull, based on fully segmented micro-computed tomography (micro-CT) scans of Atractaspis irregularis. The skull of Atractaspis presents a highly unique morphology influenced by both fossoriality and paedomorphosis. This paedomorphosis is especially evident in the jaws, palate, and suspensorium, the major elements associated with macrostomy (large-gaped feeding in snakes). Comparison to scolecophidians-a group of blind, fossorial, miniaturized snakes-in turn sheds light on current hypotheses of snake phylogeny. Features of both the naso-frontal joint and the morphofunctional system related to macrostomy refute the traditional notion that scolecophidians are fundamentally different from alethinophidians (all other extant snakes). Instead, these features support the controversial hypothesis of scolecophidians as "regressed alethinophidians," in contrast to their traditional placement as the earliest-diverging snake lineage. We propose that Atractaspis and scolecophidians fall along a morphological continuum, characterized by differing degrees of paedomorphosis. Altogether, a combination of heterochrony and miniaturization provides a mechanism for the derivation of the scolecophidian skull from an ancestral fossorial alethinophidian morphotype, exemplified by the nonminiaturized and less extreme paedomorph Atractaspis.
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Affiliation(s)
| | - Alessandro Palci
- Earth Sciences SectionSouth Australian MuseumAdelaideSAAustralia,College of Science and EngineeringFlinders UniversityBedford ParkSAAustralia
| | - Michael W. Caldwell
- Department of Biological SciencesUniversity of AlbertaEdmontonABCanada,Department of Earth and Atmospheric SciencesUniversity of AlbertaEdmontonABCanada
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Widespread Evolution of Molecular Resistance to Snake Venom α-Neurotoxins in Vertebrates. Toxins (Basel) 2020; 12:toxins12100638. [PMID: 33023159 PMCID: PMC7601176 DOI: 10.3390/toxins12100638] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 09/19/2020] [Accepted: 09/22/2020] [Indexed: 02/07/2023] Open
Abstract
Venomous snakes are important subjects of study in evolution, ecology, and biomedicine. Many venomous snakes have alpha-neurotoxins (α-neurotoxins) in their venom. These toxins bind the alpha-1 nicotinic acetylcholine receptor (nAChR) at the neuromuscular junction, causing paralysis and asphyxia. Several venomous snakes and their predators have evolved resistance to α-neurotoxins. The resistance is conferred by steric hindrance from N-glycosylated asparagines at amino acids 187 or 189, by an arginine at position 187 that has been hypothesized to either electrostatically repulse positively charged neurotoxins or sterically interfere with α-neurotoxin binding, or proline replacements at positions 194 or 197 of the nAChR ligand-binding domain to inhibit α-neurotoxin binding through structural changes in the receptor. Here, we analyzed this domain in 148 vertebrate species, and assessed its amino acid sequences for resistance-associated mutations. Of these sequences, 89 were sequenced de novo. We find widespread convergent evolution of the N-glycosylation form of resistance in several taxa including venomous snakes and their lizard prey, but not in the snake-eating birds studied. We also document new lineages with the arginine form of inhibition. Using an in vivo assay in four species, we provide further evidence that N-glycosylation mutations reduce the toxicity of cobra venom. The nAChR is of crucial importance for normal neuromuscular function and is highly conserved throughout the vertebrates as a result. Our research shows that the evolution of α-neurotoxins in snakes may well have prompted arms races and mutations to this ancient receptor across a wide range of sympatric vertebrates. These findings underscore the inter-connectedness of the biosphere and the ripple effects that one adaption can have across global ecosystems.
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Busschau T, Conradie W, Daniels SR. One species hides many: Molecular and morphological evidence for cryptic speciation in a thread snake (Leptotyphlopidae:
Leptotyphlops sylvicolus
Broadley & Wallach, 1997). J ZOOL SYST EVOL RES 2020. [DOI: 10.1111/jzs.12401] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Theo Busschau
- Department of Botany & Zoology University of Stellenbosch Matieland South Africa
| | - Werner Conradie
- Port Elizabeth Museum Humewood South Africa
- School of Natural Resource Management, George Campus Nelson Mandela University George South Africa
| | - Savel R. Daniels
- Department of Botany & Zoology University of Stellenbosch Matieland South Africa
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18
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Keates C, Conradie W, Greenbaum E, Edwards S. A snake in the grass: Genetic structuring of the widespread African grass snake (
Psammophylax
Fitzinger 1843), with the description of a new genus and a new species. J ZOOL SYST EVOL RES 2019. [DOI: 10.1111/jzs.12337] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Chad Keates
- Zoology and Entomology Molecular Lab Department of Zoology and Entomology Rhodes University Grahamstown South Africa
| | - Werner Conradie
- Port Elizabeth Museum (Bayworld) Humewood South Africa
- School of Natural Resource Management Nelson Mandela University George Campus George South Africa
- National Geographic Okavango Wilderness Project, Wild Bird Trust Hogsback South Africa
| | - Eli Greenbaum
- Department of Biological Sciences University of Texas at El Paso El Paso TX USA
| | - Shelley Edwards
- Zoology and Entomology Molecular Lab Department of Zoology and Entomology Rhodes University Grahamstown South Africa
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19
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Jackson TNW, Jouanne H, Vidal N. Snake Venom in Context: Neglected Clades and Concepts. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00332] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
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20
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Correction: Evolutionary history of burrowing asps (Lamprophiidae: Atractaspidinae) with emphasis on fang evolution and prey selection. PLoS One 2019; 14:e0217035. [PMID: 31083679 PMCID: PMC6513269 DOI: 10.1371/journal.pone.0217035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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