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Pontes-Nogueira M, Martins M, Alencar LRV, Sawaya RJ. The role of vicariance and dispersal on the temporal range dynamics of forest vipers in the Neotropical region. PLoS One 2021; 16:e0257519. [PMID: 34534245 PMCID: PMC8448354 DOI: 10.1371/journal.pone.0257519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 09/06/2021] [Indexed: 11/23/2022] Open
Abstract
The emergence of the diagonal of open/dry vegetations, including Chaco, Cerrado and Caatinga, is suggested to have acted as a dispersal barrier for terrestrial organisms by fragmenting a single large forest that existed in South America into the present Atlantic and Amazon forests. Here we tested the hypothesis that the expansion of the South American diagonal of open/dry landscapes acted as a vicariant process for forest lanceheads of the genus Bothrops, by analyzing the temporal range dynamics of those snakes. We estimated ancestral geographic ranges of the focal lancehead clade and its sister clade using a Bayesian dated phylogeny and the BioGeoBEARS package. We compared nine Maximum Likelihood models to infer ancestral range probabilities and their related biogeographic processes. The best fitting models (DECTS and DIVALIKETS) recovered the ancestor of our focal clade in the Amazon biogeographic region of northwestern South America. Vicariant processes in two different subclades resulted in disjunct geographic distributions in the Amazon and the Atlantic Forest. Dispersal processes must have occurred mostly within the Amazon and the Atlantic Forest and not between them. Our results suggest the fragmentation of a single ancient large forest into the Atlantic and Amazon forests acting as a driver of vicariant processes for the snake lineage studied, highlighting the importance of the diagonal of open/dry landscapes in shaping distribution patterns of terrestrial biota in South America.
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Affiliation(s)
| | - Marcio Martins
- Departamento de Ecologia, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
| | - Laura R. V. Alencar
- Department of Biological Sciences, Clemson University, Clemson, South Carolina, United States of America
| | - Ricardo J. Sawaya
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, São Bernardo do Campo, Brazil
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2
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Abstract
Abstract
An increasing problem in the field of health protection is the emergence of drug-resistant and multi-drug-resistant bacterial strains. They cause a number of infections, including hospital infections, which currently available antibiotics are unable to fight. Therefore, many studies are devoted to the search for new therapeutic agents with bactericidal and bacteriostatic properties. One of the latest concepts is to search for this type of substances among toxins produced by venomous animals. In this approach, however, special attention is paid to snake venom because it contains molecules with antibacterial properties. Thorough investigations have shown that the phospholipases A2 (PLA2) and l-amino acids oxidases (LAAO), as well as fragments of these enzymes, are mainly responsible for the bactericidal properties of snake venoms. Some preliminary research studies also suggest that fragments of three-finger toxins (3FTx) are bactericidal. It has also been proven that some snakes produce antibacterial peptides (AMP) homologous to human defensins and cathelicidins. The presence of these proteins and peptides means that snake venoms continue to be an interesting material for researchers and can be perceived as a promising source of antibacterial agents.
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3
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Chretien J, Wang-Claypool CY, Glaw F, Scherz MD. The bizarre skull of Xenotyphlops sheds light on synapomorphies of Typhlopoidea. J Anat 2019; 234:637-655. [PMID: 30740684 DOI: 10.1111/joa.12952] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/11/2019] [Indexed: 11/29/2022] Open
Abstract
The emerging picture of non-monophyly of scolecophidian snakes is increasingly indicative that fossorial lifestyle, myrmecophagous diet, and miniaturisation are powerful drivers of morphological evolution in squamate skulls. We provide a detailed description of the skull of Xenotyphlops grandidieri, with reference to the skulls of other scolecophidian snakes. The skull, which shows dramatic ventral inflection of the snout complex, is remarkably bizarre, and the mouth opening is more ventrally oriented than in other typhlopoids. The eyes are strongly reduced, and the enlarged and rather flat anterior head shield is covered in numerous sensillae. We put forward several potential explanations for the evolution of these unusual modifications. On the other hand, Xenotyphlops shares numerous synapomorphies with other typhlopoid snakes, including the highly specialized jaw mechanism. We argue that the key differences between the jaw mechanisms of Leptotyphlopidae, Anomalepididae, and Typhlopoidea provide compelling evidence for a strong role of convergence in the evolution of the scolecophidian bauplan, and these clades therefore cannot be interpreted as representative of ancestral anatomy or ecology among snakes.
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Affiliation(s)
- Johann Chretien
- Zoologische Staatssammlung München (ZSM-SNSB), Munich, Germany
| | | | - Frank Glaw
- Zoologische Staatssammlung München (ZSM-SNSB), Munich, Germany
| | - Mark D Scherz
- Zoologische Staatssammlung München (ZSM-SNSB), Munich, Germany.,Zoologisches Institut, Technische Universität Braunschweig, Braunschweig, Germany
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Burbrink FT, Lorch JM, Lips KR. Host susceptibility to snake fungal disease is highly dispersed across phylogenetic and functional trait space. SCIENCE ADVANCES 2017; 3:e1701387. [PMID: 29291245 PMCID: PMC5744467 DOI: 10.1126/sciadv.1701387] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 11/20/2017] [Indexed: 05/26/2023]
Abstract
Emerging infectious diseases (EIDs) reduce host population sizes, cause extinction, disassemble communities, and have indirect negative effects on human well-being. Fungal EIDs have reduced population abundances in amphibians and bats across many species over large areas. The recent emergence of snake fungal disease (SFD) may have caused declines in some snake populations in the Eastern United States (EUS), which is home to a phylogenetically and ecologically diverse assembly of 98 taxa. SFD has been documented in only 23 naturally occuring species, although this is likely an underestimate of the number of susceptible taxa. Using several novel methods, including artificial neural networks, we combine phylogenetic and trait-based community estimates from all taxa in this region to show that SFD hosts are both phylogenetically and ecologically randomly dispersed. This might indicate that other species of snakes in the EUS could be currently infected or susceptible to SFD. Our models also indicate that information about key traits that enhance susceptiblity is lacking. Surveillance should consider that all snake species and habitats likely harbor this pathogen.
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Affiliation(s)
- Frank T. Burbrink
- Department of Herpetology, American Museum of Natural History, 79th Street at Central Park West, New York, NY 10024, USA
| | - Jeffrey M. Lorch
- U.S. Geological Survey, National Wildlife Health Center, 6006 Schroeder Road, Madison, WI 53711, USA
| | - Karen R. Lips
- Department of Biology, University of Maryland, College Park, MD 20742, USA
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Blackburn DG, Anderson KE, Lo AR, Marquez EC, Callard IP. Placentation in watersnakes II: Placental ultrastructure in N
erodia erythrogaster
(Colubridae: Natricinae). J Morphol 2017; 278:675-688. [DOI: 10.1002/jmor.20662] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2016] [Revised: 01/05/2017] [Accepted: 01/11/2017] [Indexed: 01/17/2023]
Affiliation(s)
- Daniel G. Blackburn
- Department of Biology, and Electron Microscopy Facility; Trinity College; Hartford Connecticut 06106
| | - Kristie E. Anderson
- Department of Biology, and Electron Microscopy Facility; Trinity College; Hartford Connecticut 06106
| | - Amy R. Lo
- Department of Biology, and Electron Microscopy Facility; Trinity College; Hartford Connecticut 06106
| | - Emily C. Marquez
- Department of Biology; Boston University; Boston Massachusetts 02215
| | - Ian P. Callard
- Department of Biology; Boston University; Boston Massachusetts 02215
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Khedkar T, Sharma R, Tiknaik A, Khedkar G, Naikwade BS, Ron TB, Haymer D. DNA barcoding using skin exuviates can improve identification and biodiversity studies of snakes. Mitochondrial DNA A DNA Mapp Seq Anal 2015; 27:499-507. [PMID: 24724934 DOI: 10.3109/19401736.2014.905830] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Snakes represent a taxonomically underdeveloped group of animals in India with a lack of experts and incomplete taxonomic descriptions being the main deterrents to advances in this area. Molecular taxonomic approaches using DNA barcoding could aid in snake identification as well as studies of biodiversity. Here a non-invasive sampling method using DNA barcoding is tested using skin exuviates. Taxonomically authenticated samples were collected and tested for validation and comparisons to unknown snake exuviate samples. This approach was also used to construct the first comprehensive study targeting the snake species from Maharashtra state in India. A total of 92 skin exuviate samples were collected and tested for this study. Of these, 81 samples were successfully DNA barcoded and compared with unknown samples for assignment of taxonomic identity. Good quality DNA was obtained irrespective of age and quality of the exuviate material, and all unknown samples were successfully identified. A total of 23 species of snakes were identified, six of which were in the list of Endangered species (Red Data Book). Intra- and inter-specific distance values were also calculated, and these were sufficient to allow discrimination among species and between species without ambiguity in most cases. Two samples were suspected to represent cryptic species based on deep K2P divergence values (>3%), and one sample could be identified to the genus level only. Eleven samples failed to amplify COI sequences, suggesting the need for alternative PCR primer pairs. This study clearly documents how snake skin exuviates can be used for DNA barcoding, estimates of diversity and population genetic structuring in a noninvasive manner.
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Affiliation(s)
- Trupti Khedkar
- a Paul Hebert Centre for DNA Barcoding and Biodiversity Studies, Dr. Babasaheb Ambedkar Marathwada University , Aurangabad , Maharashtra , India
| | - Rashmi Sharma
- a Paul Hebert Centre for DNA Barcoding and Biodiversity Studies, Dr. Babasaheb Ambedkar Marathwada University , Aurangabad , Maharashtra , India
| | - Anita Tiknaik
- a Paul Hebert Centre for DNA Barcoding and Biodiversity Studies, Dr. Babasaheb Ambedkar Marathwada University , Aurangabad , Maharashtra , India
| | - Gulab Khedkar
- a Paul Hebert Centre for DNA Barcoding and Biodiversity Studies, Dr. Babasaheb Ambedkar Marathwada University , Aurangabad , Maharashtra , India
| | - Bhagwat S Naikwade
- b Aurangabad Municipal Corporation Siddharth Zoo , Aurangabad , Maharashtra , India , and
| | - Tetsuzan Benny Ron
- c Department of Human Nutrition , Food and Animal Sciences, College of Tropical Agriculture and Human Resources, University of Hawaii , Honolulu , HI , USA , and
| | - David Haymer
- d Department of Cell and Molecular Biology , University of Hawaii , Honolulu , HI , USA
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Johnston P. Homology of the Jaw Muscles in Lizards and Snakes-A Solution from a Comparative Gnathostome Approach. Anat Rec (Hoboken) 2014; 297:574-85. [DOI: 10.1002/ar.22857] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Accepted: 05/27/2013] [Indexed: 11/06/2022]
Affiliation(s)
- Peter Johnston
- Department of Anatomy with Radiology; University of Auckland; Private Bag 92019 Auckland New Zealand
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Polachowski KM, Werneburg I. Late embryos and bony skull development in Bothropoides jararaca (Serpentes, Viperidae). ZOOLOGY 2013; 116:36-63. [DOI: 10.1016/j.zool.2012.07.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Revised: 07/17/2012] [Accepted: 07/18/2012] [Indexed: 12/30/2022]
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Sever DM, Rheubert JL, Gautreaux J, Hill TG, Freeborn LR. Observations on the Sexual Segment of the Kidney of Snakes with Emphasis on Ultrastructure in the Yellow-Bellied Sea Snake, Pelamis platurus. Anat Rec (Hoboken) 2012; 295:872-85. [DOI: 10.1002/ar.22435] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Accepted: 01/26/2012] [Indexed: 11/09/2022]
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Sever DM, Freeborn LR. Observations on the anterior testicular ducts in snakes with emphasis on sea snakes and ultrastructure in the yellow-bellied sea snake, Pelamis platurus. J Morphol 2011; 273:324-36. [DOI: 10.1002/jmor.11025] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Revised: 08/31/2011] [Accepted: 09/01/2011] [Indexed: 11/07/2022]
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Pyron RA, Burbrink FT. Extinction, ecological opportunity, and the origins of global snake diversity. Evolution 2011; 66:163-78. [PMID: 22220872 DOI: 10.1111/j.1558-5646.2011.01437.x] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Snake diversity varies by at least two orders of magnitude among extant lineages, with numerous groups containing only one or two species, and several young clades exhibiting exceptional richness (>700 taxa). With a phylogeny containing all known families and subfamilies, we find that these patterns cannot be explained by background rates of speciation and extinction. The majority of diversity appears to derive from a radiation within the superfamily Colubroidea, potentially stemming from the colonization of new areas and the evolution of advanced venom-delivery systems. In contrast, negative relationships between clade age, clade size, and diversification rate suggest the potential for possible bias in estimated diversification rates, interpreted by some recent authors as support for ecologically mediated limits on diversity. However, evidence from the fossil record indicates that numerous lineages were far more diverse in the past, and that extinction has had an important impact on extant diversity patterns. Thus, failure to adequately account for extinction appears to prevent both rate- and diversity-limited models from fully characterizing richness dynamics in snakes. We suggest that clade-level extinction may provide a key mechanism for explaining negative or hump-shaped relationships between clade age and diversity, and the prevalence of ancient, species-poor lineages in numerous groups.
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Affiliation(s)
- R Alexander Pyron
- Department of Biological Sciences, The George Washington University, 2023 G St. NW, Washington, DC 20052, USA.
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