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Chen ZN, Shi SC, Vogel G, Ding L, Shi JS. Multiple lines of evidence reveal a new species of Krait (Squamata, Elapidae, Bungarus) from Southwestern China and Northern Myanmar. Zookeys 2021; 1025:35-71. [PMID: 33814945 PMCID: PMC7994289 DOI: 10.3897/zookeys.1025.62305] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 02/21/2021] [Indexed: 12/02/2022] Open
Abstract
Kraits of the genus Bungarus Daudin 1803 are widely known venomous snakes distributed from Iran to China and Indonesia. Here, we use a combination of mitochondrial DNA sequence data and morphological data to describe a new species from Yingjiang County, Yunnan Province, China: Bungarussuzhenaesp. nov. Phylogenetically, this species forms a monophyletic lineage sister to the Bungaruscandidus/multicinctus/wanghaotingi complex based on cyt b and ND4 genes but forms a sister species pair with the species B.magnimaculatus Wall & Evans, 1901 based on COI gene fragments. Morphologically, B.suzhenaesp. nov. is similar to the B.candidus/multicinctus/wanghaotingi complex but differs from these taxa by a combination of dental morphology, squamation, coloration pattern, as well as hemipenial morphology. A detailed description of the cranial osteology of the new species is given based on micro-CT tomography images. We revised the morphological characters of B.candidus/multicinctus/wanghaotingi complex and verified the validity of three species in this complex. The distribution of these species was revised; the records of B.candidus in China should be attributed to B.wanghaotingi. We also provide an updated key to species of Bungarus.
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Affiliation(s)
- Ze-Ning Chen
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan 610041, China Chengdu Institute of Biology, Chinese Academy of Sciences Chengdu China.,Guangxi Key Laboratory of Rare and Endangered Animal Ecology, Guangxi Normal University, Guilin, Guangxi 541001, China Guangxi Normal University Guilin China
| | - Sheng-Chao Shi
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan 610041, China Chengdu Institute of Biology, Chinese Academy of Sciences Chengdu China
| | - Gernot Vogel
- Society for Southeast Asian Herpetology, Im Sand 3, Heidelberg D-69115, Germany Society for Southeast Asian Herpetology Heidelberg Germany
| | - Li Ding
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan 610041, China Chengdu Institute of Biology, Chinese Academy of Sciences Chengdu China
| | - Jing-Song Shi
- Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China Origins of Chinese Academy of Sciences Beijing China
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Tsai HY, Wang YM, Tsai IH. Cloning, characterization and phylogenetic analyses of members of three major venom families from a single specimen of Walterinnesia aegyptia. Toxicon 2008; 51:1245-54. [PMID: 18405934 DOI: 10.1016/j.toxicon.2008.02.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2007] [Revised: 02/14/2008] [Accepted: 02/20/2008] [Indexed: 11/18/2022]
Abstract
Walterinnesia aegyptia is a monotypic elapid snake inhabiting in Africa and Mideast. Although its envenoming is known to cause rapid deaths and paralysis, structural data of its venom proteins are rather limited. Using gel filtration and reverse-phase HPLC, phospholipases A(2) (PLAs), three-fingered toxins (3FTxs), and Kunitz-type protease inhibitors (KIns) were purified from the venom of a single specimen of this species caught in northern Egypt. In addition, specific primers were designed and PCR was carried out to amplify the cDNAs encoding members of the three venom families, respectively, using total cDNA prepared from its venom glands. Complete amino acid sequences of two acidic PLAs, three short chain 3FTxs, and four KIns of this venom species were thus deduced after their cDNAs were cloned and sequenced. They are all novel sequences and match the mass data of purified proteins. For members of each toxin family, protein sequences were aligned and subjected to molecular phylogenetic analyses. The results indicated that the PLAs and a Kunitz inhibitor of W. aegyptia are most similar to those of king cobra venom, and its 3FTxs belongs to either Type I alpha-neurotoxins or weak toxins of orphan-II subtype. It is remarkable that both king cobra and W. aegyptia cause rapid deaths of the victims, and a close evolutionary relationship between them is speculated.
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Affiliation(s)
- Hsin-Yu Tsai
- Institute of Biological Chemistry, Academia Sinica, P.O. Box 23-106, Taipei, Taiwan
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Valdez-Cruz NA, Segovia L, Corona M, Possani LD. Sequence analysis and phylogenetic relationship of genes encoding heterodimeric phospholipases A2 from the venom of the scorpion Anuroctonus phaiodactylus. Gene 2007; 396:149-58. [PMID: 17466468 DOI: 10.1016/j.gene.2007.03.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2006] [Revised: 01/25/2007] [Accepted: 03/12/2007] [Indexed: 11/18/2022]
Abstract
Some scorpion venom contain heterodimeric phospholipases A2. They were shown to be toxic to insects and to cause edema and/or hemolysis of mammalian erythrocytes. This manuscript describes the results of cDNA cloning of five different heterodimeric phospholipases from the venomous glands of the Mexican scorpion Anuroctonus phaiodactylus. The amino acid sequence deduced from the heterodimeric phospholipases open reading frames corresponds in each case to a different isoform. The nucleotide sequences corresponding to two of these genes were also obtained by directly sequencing genomic DNA. The cDNA isoforms show high similarity with the heterodimeric phospholipase Phaiodactylipin purified from the same scorpion. However, similar phospholipases were also found in scorpions from other species and the sequences available were used to construct a phylogenetic tree. In order to understand better the gene structure and phylogeny of these enzymes we analyzed their sequences and compared them with secretory phospholipases of other sources from groups I, II and III. The genomic DNA sequence of a similar phospholipase from bee venomous glands was also cloned. The information available on a Drosophila phospholipase was included in this analysis. The phospholipases of groups I and II contain a conserved exon-intron structure (four or five exons of the mature segment of the enzyme are separated by three or four introns). Also, the gene structure of the phospholipases from A. phaiodactylus and that of the bee venom, belonging to group III phospholipases, are interrupted by three introns. The mature peptide of the bee enzyme is a single polypeptide chain, coded by four exons, whereas those from the scorpion studied here although having four exons, showed the presence of two different polypeptides in its native state. The mature protein is processed after synthesis, producing the heterodimeric structure: a long and a short-peptide chain, linked by a disulfide bridge. The small subunit is the one coded by the fourth exon. The human phospholipase A2 and that of Drosophila, also classified into the group III phospholipases, have a considerably different exon-intron organization.
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Affiliation(s)
- Norma A Valdez-Cruz
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad 2001, Apartado Postal 510-3, Cuernavaca 622106221, Mexico
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Tsai IH, Tsai HY, Saha A, Gomes A. Sequences, geographic variations and molecular phylogeny of venom phospholipases and threefinger toxins of eastern India Bungarus fasciatus and kinetic analyses of its Pro31 phospholipases A2. FEBS J 2006; 274:512-25. [PMID: 17166178 DOI: 10.1111/j.1742-4658.2006.05598.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Eight phospholipases A2 (PLAs) and four three-finger-toxins (3FTx) from the pooled venom of Bungarus fasciatus (Bf) were previously studied and sequenced, but their expression pattern in individual Bf venom and possible geographic variations remained to be investigated. We herein analyze the individual venom of two Bf specimens from Kolkata (designated as KBf) to address this question. Seven PLAs and five 3FTx were purified from the KBf venoms, and respective cDNAs were cloned from venom glands of one of the snakes. Comparison of their mass and N-terminal sequence revealed that all the PLAs were conserved in both KBf venoms, but that two of their 3FTx isoforms were variable. When comparing the sequences of these KBf-PLAs with those published, only one was found to be identical to that of Bf Vb-2, and the other five were 94-98% identical to those of Bf II, III, Va, VI and XI-2, respectively. Notably, the most abundant PLA isoforms of Bf and KBf venoms contain Pro31 substitution. They were found to have abnormally low k(cat) values but high affinity for Ca2+. Phylogenetic analysis based on the sequences of venom group IA PLAs showed a close relationship between Bungarus and Australian and marine Elapidae. As the five deduced sequences of KBf-3FTx are only 62-82% identical to the corresponding Bf-3FTx from the pooled venom, the 3FTx apparently have higher degree of individual and geographic variations than the PLAs. None of the KBf-3FTx was found to be neurotoxic or very lethal; phylogenetic analyses of the 3FTx also revealed the unique evolution of Bf as compared with other kraits.
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Affiliation(s)
- Inn-Ho Tsai
- Institute of Biological Chemistry, Academia Sinica, Taiwan.
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Yanoshita R, Ogawa Y, Murayama N, Omori-Satoh T, Saguchi KI, Higuchi S, Khow O, Chanhome L, Samejima Y, Sitprija V. Molecular cloning of the major lethal toxins from two kraits (Bungarus flaviceps and Bungarus candidus). Toxicon 2006; 47:416-24. [PMID: 16458338 DOI: 10.1016/j.toxicon.2005.12.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2005] [Revised: 11/25/2005] [Accepted: 12/06/2005] [Indexed: 11/21/2022]
Abstract
The major lethal toxins present in the venoms of the red-headed krait, Bungarus flaviceps, and the Malayan krait, Bungarus candidus, have both been purified. Each consists of two polypeptide chains, A and B, joined by a disulfide bond. In the present study, primary structures of these toxins were determined by Edman degradation and by nucleotide sequencing of the cDNA clones. Amino acid sequencing of the N-terminus and enzymatically digested peptides revealed that the A and B chains were highly homologous to those of beta-bungarotoxins (beta-Bgts) from Bungarus multicinctus, respectively. We isolated cDNA clones encoding the A and B chains from both B. flaviceps and B. candidus venom gland cDNA libraries using probes designed based on the cDNA sequence of beta-Bgt from B. multicinctus. Two isoforms of the A chain and one isoform of the B chain were obtained from B. flaviceps, and one isoform of the A chain and two isoforms of the B chain were obtained from B. candidus. Both of the two A chains from B. flaviceps are made up of 119 amino acids and comprise 15 cysteine residues, while the A chains of beta-Bgt from other Bungarus species including B. candidus comprise 13 cysteine residues. The B chains from both species are composed of 59 amino acid residues and comprise seven cysteines. In conclusion, the lethal toxin from B. flaviceps is considered to be a novel isoform of beta-Bgt, which has a different pattern of cysteine residues from known beta-Bgts.
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Affiliation(s)
- Ryohei Yanoshita
- Institute of Medicinal Chemistry, Hoshi University, Tokyo 142-8501, Japan
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Kuch U, Molles BE, Omori-Satoh T, Chanhome L, Samejima Y, Mebs D. Identification of alpha-bungarotoxin (A31) as the major postsynaptic neurotoxin, and complete nucleotide identity of a genomic DNA of Bungarus candidus from Java with exons of the Bungarus multicinctus alpha-bungarotoxin (A31) gene. Toxicon 2003; 42:381-90. [PMID: 14505938 DOI: 10.1016/s0041-0101(03)00168-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The Malayan krait (Bungarus candidus) is one of the most medically significant snake species in Southeast Asia. No specific antivenom exists to treat envenoming by this species. Death within 30 min after its bite has been reported from Java, suggesting the presence of highly lethal postsynaptic neurotoxins in the venom of these snakes. We purified and identified the major postsynaptic toxin in the venom of B. candidus from Java. The toxin was indistinguishable from alpha-bungarotoxin (A31), a toxin originally isolated from Bungarus multicinctus, in its mass (7983.75 Da), LD50 (0.23 microg/g in mice i.p.), affinity to nicotinic acetylcholine receptors, and by its 40 N-terminal amino acid residues as determined by Edman degradation. Identity with alpha-bungarotoxin was confirmed by cloning and sequencing a genomic DNA from B. candidus which encodes the 74 amino acid sequence of alpha-bungarotoxin (A31) and part of its signal peptide, revealing complete identity to the alpha-bungarotoxin (A31) gene in exon and 98.9% identity in intron sequences. The entire mitochondrial cytochrome b gene of the krait species B. candidus from Java and B. multicinctus from Taiwan was sequenced for comparison, suggesting that these snakes are phylogenetically closely related. alpha-Bungarotoxin appears to be widely present and conserved in Southeast and East Asian black-and-white kraits across populations and taxa.
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Affiliation(s)
- Ulrich Kuch
- Zentrum der Rechtsmedizan, Klinikum der Johann Wolfgang Goethe-Universität, Kennedyallee 104, 60596 Frankfurt am Main, Germany.
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