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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] [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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Zhao J, Huang M. Characterization and In Vitro Fungicide Sensitivity of Two Fusarium spp. Associated with Stem Rot of Dragon Fruit in Guizhou, China. J Fungi (Basel) 2023; 9:1178. [PMID: 38132778 PMCID: PMC10744873 DOI: 10.3390/jof9121178] [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: 10/26/2023] [Revised: 11/25/2023] [Accepted: 12/06/2023] [Indexed: 12/23/2023] Open
Abstract
Dragon fruit (Hylocereus polyrhizus) constitutes an important economic industry in Guizhou Province, China, and the occurrence of stem rot has become increasingly severe. In this study, we aimed to determine the causative pathogens of stem rot in this region and analyze their sensitivity to fungicides. Twenty-four fungal isolates were obtained from diseased tissues, from which H-4 and H-5 were confirmed as pathogens based on Koch's postulates. Based on the morphological characteristics of macroconidia, microconidia, and colony morphology, the polygenic phylogenetic tree constructed using internal transcribed spacer, elongation factor 1-alpha, and retinol-binding protein-2 gene fragments, and carbon source metabolism analysis using FF microplates, the two pathogens were identified as F. oxysporum and a newly discovered pathogen, F. concentricum. In addition, the in vitro toxicity of eight fungicides against both pathogens was measured based on the mycelial growth rate. The results showed that trifloxystrobin 25%·tebuconazole 50% (75 WG) exhibited the strongest inhibitory effect against both isolates, with EC50 values of 0.13 µg/mL and 0.14 µg/mL, respectively. These findings hold significant potential for guiding the effective treatment of stem rot in dragon fruit in Guizhou, China.
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Affiliation(s)
- Jin Zhao
- College of Agriculture, Guizhou University, Guiyang 550025, China;
- Institute of Pepper Industry and Technology, Guizhou University, Guiyang 550025, China
| | - Miao Huang
- College of Agriculture, Guizhou University, Guiyang 550025, China;
- Institute of Pepper Industry and Technology, Guizhou University, Guiyang 550025, China
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Herrera Y, Fuentes-Retamal S, Kemmerling U, Peichoto ME, Ortiz JC, Urra FA. Shedding Light on the Dentition and Venom Delivery System of the Rear-Fanged Snake, Galvarinus chilensis chilensis (Serpentes: Dipsadidae: Tachymenini) from Chile. BIOLOGY 2022; 11:biology11121788. [PMID: 36552297 PMCID: PMC9775764 DOI: 10.3390/biology11121788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 11/11/2022] [Accepted: 11/18/2022] [Indexed: 12/14/2022]
Abstract
Although the rear-fanged snake Galvarinus chilensis chilensis (formerly named Tachymenis ch. chilensis) causes ophidian accidents with clinical importance in Chile, the anatomical and histological characterizations of the venom delivery system (venom gland and fang) of this species still remain unknown. This study describes the dentition and characteristics of fangs and their ontogenetic variations in G. ch. chilensis. Moreover, histological and histochemistry analyses of the venom glands of this species are presented. Using micro-computed tomography and scanning electron microscopy, the dentitions of neonates, juveniles, and adults were analyzed, and no ontogenetic variations in teeth length and number present in the dentary and maxilla were observed. Moreover, we found three types of basic teeth, with distributional patterns conserved in all ontogenetic categories. The fangs exhibited a groove from the base to the middle. At the end of the groove, prominent ridges are formed. The fang and groove lengths were significantly distinct between ontogenetic categories. No differences between females and males were observed. Histologically, we found that the venom gland is close to the fangs and has a seromucous composition. Our results describe, for the first time, the distributional pattern and characteristics of the dentition and venom delivery system of the poorly studied snake G. ch. chilensis.
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Affiliation(s)
- Yarela Herrera
- Metabolic Plasticity and Bioenergetics Laboratory, Program of Clinical and Molecular Pharmacology, Institute of Biomedical Sciences (ICBM), Faculty of Medicine, University of Chile, Santiago 8380453, Chile
- Network for Snake Venom Research and Drug Discovery, Santiago 8380453, Chile
| | - Sebastián Fuentes-Retamal
- Metabolic Plasticity and Bioenergetics Laboratory, Program of Clinical and Molecular Pharmacology, Institute of Biomedical Sciences (ICBM), Faculty of Medicine, University of Chile, Santiago 8380453, Chile
- Network for Snake Venom Research and Drug Discovery, Santiago 8380453, Chile
| | - Ulrike Kemmerling
- Program of Anatomy and Developmental Biology, Institute of Biomedical Sciences (ICBM), Faculty of Medicine, University of Chile, Santiago 8380453, Chile
| | - María Elisa Peichoto
- National Scientific and Technical Research Council (CONICET), National Institute of Tropical Medicine—National Administration of Laboratories and Health Institutes (ANLIS “Dr. Carlos G Malbrán”), Puerto Iguazú 9C59+8V, Misiones, Argentina
| | - Juan Carlos Ortiz
- Department of Zoology, Faculty of Natural and Oceanographic Sciences, University of Concepcion, Concepción 4070032, Chile
| | - Félix A. Urra
- Metabolic Plasticity and Bioenergetics Laboratory, Program of Clinical and Molecular Pharmacology, Institute of Biomedical Sciences (ICBM), Faculty of Medicine, University of Chile, Santiago 8380453, Chile
- Network for Snake Venom Research and Drug Discovery, Santiago 8380453, Chile
- Correspondence:
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Abegg AD, Santos AP, Costa HC, Battilana J, Graboski R, Vianna FSL, Azevedo WS, Fagundes NJR, Castille CM, Prado PC, Bonatto SL, Zaher H, Grazziotin FG. Increasing taxon sampling suggests a complete taxonomic rearrangement in Echinantherini (Serpentes: Dipsadidae). Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.969263] [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] Open
Abstract
Although the recent advances on the relationship of its major groups, the systematics of the rich fauna of Neotropical snakes is far from being a consensus. In this sense, derived groups presenting continental distributions have represented a main challenge. The taxonomy of the snake tribe Echinantherini is one of the most contentious among the diverse family known as Dipsadidae. The tribe is poorly sampled in phylogenetic studies, resulting in conflicting hypotheses of relationships among its taxa. Moreover, several rare and micro endemic species of Echinantherini have never been evaluated within a comprehensive phylogenetic framework. Here, we assess for the first time the phylogenetic position of the rare Echinanthera amoena within Echinantherini. We based our analyses on a comprehensive multilocus dataset including 14 of the 16 species described for the tribe. Our results support the monophyly of Echinantherini and strongly indicate E. amoena as a unique lineage, phylogenetically positioned apart from all other congeners. From the three current genera (Echinanthera, Taeniophallus, and Sordellina) our results indicate that Echinanthera and Taeniophallus are paraphyletic, since the T. affinis species group is positioned as sister to Echinanthera (except E. amoena) clustering apart from the clade formed by the T. brevirostris and T. occipitalis groups. We describe new genera for the T. affinis and T. occipitalis species groups and an additional monospecific genus for E. amoena. Although we did not evaluate the phylogenetic position of T. nebularis, we described a new genus and removed it from Echinantherini since its morphology strikingly departs from all species now included in the tribe. Finally, we redefine the genera Echinanthera and Taeniophallus and we provide comments about further directions to study the biogeography and the evolution of morphological traits in Echinantherini.
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