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Xie Y, Feng X, Tao J, Gao Q, Li Y, Liu X, Xia M, Wang D. Cloning, characterization and specificity of a new aromatic-L-amino-acid decarboxylases from Bufo bufo gargarizans. Int J Biol Macromol 2024; 260:129539. [PMID: 38244737 DOI: 10.1016/j.ijbiomac.2024.129539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 01/05/2024] [Accepted: 01/14/2024] [Indexed: 01/22/2024]
Abstract
5-Hydroxytryptamine (5-HT) and its derivative bufotenine, which possess important physiological functions, are the primary active components in the secretions of toad parotid and skin gland. However, the biosynthetic pathway of these substances remains unclear in toads. To characterize toad's Aromatic-L-amino-acid decarboxylase (AADC), the key enzyme in the predicted 5-HT derivatives biosynthetic pathway, the full-length cDNA of AADC from Bufo bufo gargarizans (BbgAADC) was cloned from the parotoid gland of B. bufo gargarizans. The recombinant BbgAADC exhibited optimal expression in E. coli BL21 (DE3) containing pCold-BbgAADC after induction for 16 h at 15 °C with 0.3 mM IPTG, resulting in substantial yields of soluble proteins. The enzymological properties of BbgAADC were assessed, and it was determined that the optimal reaction temperature was 37 °C, the optimal pH was 8.6, and the optimum molar ratio of pyridoxal-5'-phosphate (PLP) to BbgAADC was found to be 3.6:1. Additionally, high substrate specificity was observed, as BbgAADC could catalyze the production of 5-HT from 5-hydroxytryptophan (5-HTP) but not dopamine or tryptamine from levodopa or tryptophan, respectively. The Km of the recombinant protein BbgAADC was 0.2918 mM and the maximum reaction rate (Vmax) was 1.182 μM·min-1 when 5-HTP was used as substrate. The Kcat was 0.0545 min-1, and Kcat/Km was 0.1868 mM-1·min-1. To elucidate the mechanism of BbgAADC, molecular docking was performed with PLP and 5-HTP, or the external aldimine formed by 5-HTP and PLP. The results indicated that the active sites for BbgAADC to bind with PLP were K303, H192, N300, A148, F309, T246, A273, and T147. W71, Y79, F80, P81, T82, H192, T246, N300, H302, F309, and R477 served as catalytically active sites for the binding of BbgAADC to 5-HTP. Furthermore, R447, W71, S149, N300, A148, and T147 of BbgAADC were involved in the decarboxylation reaction of the aldimine formed by PLP and 5-HTP.
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Affiliation(s)
- Yancheng Xie
- School of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, Benxi 117004, China
| | - Xue Feng
- School of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, Benxi 117004, China
| | - Jiaqi Tao
- School of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, Benxi 117004, China
| | - Qianhui Gao
- School of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, Benxi 117004, China
| | - Yue Li
- School of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, Benxi 117004, China
| | - Xinyi Liu
- School of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, Benxi 117004, China
| | - Mingyu Xia
- School of Life Science and Biological Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Dong Wang
- School of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, Benxi 117004, China.
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Kowalski K, Marciniak P, Rychlik L. Proteins from toad's parotoid macroglands: do they play a role in gland functioning and chemical defence? Front Zool 2023; 20:21. [PMID: 37328749 DOI: 10.1186/s12983-023-00499-8] [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: 03/02/2023] [Accepted: 06/07/2023] [Indexed: 06/18/2023] Open
Abstract
BACKGROUND Parotoid gland secretion of bufonid toads is a rich source of toxic molecules that are used against predators, parasites and pathogens. Bufadienolides and biogenic amines are the principal compounds responsible for toxicity of parotoid secretion. Many toxicological and pharmacological analyses of parotoid secretions have been performed, but little is known about the processes related to poison production and secretion. Therefore, our aim was to investigate protein content in parotoids of the common toad, Bufo bufo, to understand the processes that regulate synthesis and excretion of toxins as well as functioning of parotoid macroglands. RESULTS Applying a proteomic approach we identified 162 proteins in the extract from toad's parotoids that were classified into 11 categories of biological functions. One-third (34.6%) of the identified molecules, including acyl-CoA-binding protein, actin, catalase, calmodulin, and enolases, were involved in cell metabolism. We found many proteins related to cell division and cell cycle regulation (12.0%; e.g. histone and tubulin), cell structure maintenance (8.4%; e.g. thymosin beta-4, tubulin), intra- and extracellular transport (8.4%), cell aging and apoptosis (7.3%; e.g. catalase and pyruvate kinase) as well as immune (7.0%; e.g. interleukin-24 and UV excision repair protein) and stress (6.3%; including heat shock proteins, peroxiredoxin-6 and superoxide dismutase) response. We also identified two proteins, phosphomevalonate kinase and isopentenyl-diphosphate delta-isomerase 1, that are involved in synthesis of cholesterol which is a precursor for bufadienolides biosynthesis. STRING protein-protein interaction network predicted for identified proteins showed that most proteins are related to metabolic processes, particularly glycolysis, stress response and DNA repair and replication. The results of GO enrichment and KEGG analyses are also consistent with these findings. CONCLUSION This finding indicates that cholesterol may be synthesized in parotoids, and not only in the liver from which is then transferred through the bloodstream to the parotoid macroglands. Presence of proteins that regulate cell cycle, cell division, aging and apoptosis may indicate a high epithelial cell turnover in parotoids. Proteins protecting skin cells from DNA damage may help to minimize the harmful effects of UV radiation. Thus, our work extends our knowledge with new and important functions of parotoids, major glands involved in the bufonid chemical defence.
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Affiliation(s)
- Krzysztof Kowalski
- Department of Vertebrate Zoology and Ecology, Faculty of Biological and Veterinary Sciences, Institute of Biology, Nicolaus Copernicus University, Lwowska 1, 87-100, Toruń, Poland.
| | - Paweł Marciniak
- Department of Animal Physiology and Developmental Biology, Faculty of Biology, Institute of Experimental Biology, Adam Mickiewicz University, Uniwersytetu Poznańskiego 6, 61-614, Poznań, Poland
| | - Leszek Rychlik
- Department of Systematic Zoology, Faculty of Biology, Institute of Environmental Biology, Adam Mickiewicz University, Uniwersytetu Poznańskiego 6, 61-614, Poznań, Poland
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How Diet Leads to Defensive Dynamism: Effect of the Dietary Quality on Autogenous Alkaloid Recovery Rate in a Chemically Defended Beetle. J Chem Ecol 2021; 48:99-107. [PMID: 34799770 DOI: 10.1007/s10886-021-01326-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 09/30/2021] [Accepted: 10/17/2021] [Indexed: 10/19/2022]
Abstract
The impact of different diets on chemical defense has been extensively studied in animals that sequester defensive chemicals from food. However, there are fewer studies of diet-mediated variation in autogenously produced defenses. Ladybird beetles, which use autogenously synthesized defensive alkaloids, are used as models in a wide diversity of studies of chemical defense, specifically in studies of intraspecific variation in color pattern and chemical defense. Many aphidophagous ladybirds consume a wide diversity of aphid prey, which vary in quality and thus could affect the synthesis of chemical defense. We measured alkaloid recovery rate after reflex bleeding by the ladybird Adalia bipunctata on two different aphid diets, the high quality Acyrthosiphon pisum and the lower quality Aphis fabae. Alkaloids reaccumulated in ladybirds more slowly when they were fed A. fabae than when they were fed A. pisum and females generally had more alkaloid than males, but reaccumulated alkaloid more slowly. Recovery times were more than 12 days. There appeared to be a weak positive relationship between alkaloid level and time since reflex bleeding for eggs of A. pisum- but not A. fabae-fed females. Our findings on diet and alkaloid synthesis in ladybirds suggest that chemical defense levels are very dynamic, indicating that studies conducted at a single point in time, such as those focused on ladybird color pattern, fail to consider a wide diversity of temporal variation that occurs in the field. This is likely true for many autogenously produced chemical defense systems in a diversity of other organisms.
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Morphological diversity in the parotoid macroglands of neotropical true toads (Anura: Bufonidae) and its association with the release of glandular secretion. ZOOL ANZ 2021. [DOI: 10.1016/j.jcz.2021.08.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Mailho‐Fontana PL, Titon B, Antoniazzi MM, Gomes FR, Jared C. Skin and poison glands in toads (
Rhinella
) and their role in defence and water balance. ACTA ZOOL-STOCKHOLM 2021. [DOI: 10.1111/azo.12390] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
| | - Braz Titon
- Departamento de Fisiologia Geral Instituto de Biociências, Universidade de São Paulo São Paulo Brazil
| | | | - Fernando Ribeiro Gomes
- Departamento de Fisiologia Geral Instituto de Biociências, Universidade de São Paulo São Paulo Brazil
| | - Carlos Jared
- Laboratório de Biologia Estrutural Instituto Butantan São Paulo Brazil
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Jared C, Luiz Mailho‐Fontana P, Maria Antoniazzi M. Differences between poison and venom: An attempt at an integrative biological approach. ACTA ZOOL-STOCKHOLM 2021. [DOI: 10.1111/azo.12375] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Carlos Jared
- Laboratory of Structural Biology Instituto Butantan São Paulo Brazil
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Oliveira RS, Borges BT, Leal AP, Lailowski MM, Bordon KDCF, de Souza VQ, Vinadé L, dos Santos TG, Hyslop S, Moura S, Arantes EC, Corrado AP, Dal Belo CA. Chemical and Pharmacological Screening of Rhinella icterica (Spix 1824) Toad Parotoid Secretion in Avian Preparations. Toxins (Basel) 2020; 12:toxins12060396. [PMID: 32549266 PMCID: PMC7354542 DOI: 10.3390/toxins12060396] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 05/12/2020] [Accepted: 05/22/2020] [Indexed: 12/15/2022] Open
Abstract
The biological activity of Rhinella icterica parotoid secretion (RIPS) and some of its chromatographic fractions (RI18, RI19, RI23, and RI24) was evaluated in the current study. Mass spectrometry of these fractions indicated the presence of sarmentogenin, argentinogenin, (5β,12β)-12,14-dihydroxy-11-oxobufa-3,20,22-trienolide, marinobufagin, bufogenin B, 11α,19-dihydroxy-telocinobufagin, bufotalin, monohydroxylbufotalin, 19-oxo-cinobufagin, 3α,12β,25,26-tetrahydroxy-7-oxo-5β-cholestane-26-O-sulfate, and cinobufagin-3-hemisuberate that were identified as alkaloid and steroid compounds, in addition to marinoic acid and N-methyl-5-hydroxy-tryptamine. In chick brain slices, all fractions caused a slight decrease in cell viability, as also seen with the highest concentration of RIPS tested. In chick biventer cervicis neuromuscular preparations, RIPS and all four fractions significantly inhibited junctional acetylcholinesterase (AChE) activity. In this preparation, only fraction RI23 completely mimicked the pharmacological profile of RIPS, which included a transient facilitation in the amplitude of muscle twitches followed by progressive and complete neuromuscular blockade. Mass spectrometric analysis showed that RI23 consisted predominantly of bufogenins, a class of steroidal compounds known for their cardiotonic activity mediated by a digoxin- or ouabain-like action and the blockade of voltage-dependent L-type calcium channels. These findings indicate that the pharmacological activities of RI23 (and RIPS) are probably mediated by: (1) inhibition of AChE activity that increases the junctional content of Ach; (2) inhibition of neuronal Na+/K+-ATPase, leading to facilitation followed by neuromuscular blockade; and (3) blockade of voltage-dependent Ca2+ channels, leading to stabilization of the motor endplate membrane.
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Affiliation(s)
- Raquel Soares Oliveira
- Laboratório de Neurobiologia e Toxinologia, Programa de Pós-Graduação em Ciências Biológicas (PPGCB), Universidade Federal do Pampa (UNIPAMPA), Avenida Antônio Trilha 1847, São Gabriel RS 97300-000, Brazil; (R.S.O.); (B.T.B.); (A.P.L.); (V.Q.d.S.)
| | - Bruna Trindade Borges
- Laboratório de Neurobiologia e Toxinologia, Programa de Pós-Graduação em Ciências Biológicas (PPGCB), Universidade Federal do Pampa (UNIPAMPA), Avenida Antônio Trilha 1847, São Gabriel RS 97300-000, Brazil; (R.S.O.); (B.T.B.); (A.P.L.); (V.Q.d.S.)
| | - Allan Pinto Leal
- Laboratório de Neurobiologia e Toxinologia, Programa de Pós-Graduação em Ciências Biológicas (PPGCB), Universidade Federal do Pampa (UNIPAMPA), Avenida Antônio Trilha 1847, São Gabriel RS 97300-000, Brazil; (R.S.O.); (B.T.B.); (A.P.L.); (V.Q.d.S.)
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica Toxicológica (PPGBTox), Universidade Federal de Santa Maria (UFSM), Avenida Roraima 1000, Santa Maria RS 97105-900, Brazil
| | - Manuela Merlin Lailowski
- Laboratório de Biotecnologia de Produtos Naturais e Sintéticos, Instituto de Biotecnologia, Universidade de Caxias do Sul (UCS), Rua Francisco Getúlio Vargas 1130, Caxias do Sul RS 95070-560, Brazil; (M.M.L.); (S.M.)
| | - Karla de Castro Figueiredo Bordon
- Departamento de Ciências BioMoleculares, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo (USP), Avenida do Café, s/n, Ribeirão Preto SP 14.040-903, Brazil; (K.d.C.F.B.); (E.C.A.)
| | - Velci Queiróz de Souza
- Laboratório de Neurobiologia e Toxinologia, Programa de Pós-Graduação em Ciências Biológicas (PPGCB), Universidade Federal do Pampa (UNIPAMPA), Avenida Antônio Trilha 1847, São Gabriel RS 97300-000, Brazil; (R.S.O.); (B.T.B.); (A.P.L.); (V.Q.d.S.)
| | - Lúcia Vinadé
- Laboratório de Neurobiologia e Toxinologia, Programa de Pós-Graduação em Ciências Biológicas (PPGCB), Universidade Federal do Pampa (UNIPAMPA), Avenida Antônio Trilha 1847, São Gabriel RS 97300-000, Brazil; (R.S.O.); (B.T.B.); (A.P.L.); (V.Q.d.S.)
- Correspondence: (L.V.); (C.A.D.B.); Tel.: +55-55-3237-0850 (C.A.D.B.)
| | - Tiago Gomes dos Santos
- Laboratório de Estudos em Biodiversidade Pampiana, Universidade Federal do Pampa (UNIPAMPA), Avenida Antônio Trilha 1847, São Gabriel RS 97300-000, Brazil;
| | - Stephen Hyslop
- Departamento de Farmacologia, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Rua Tessália Vieira de Camargo, 126, Cidade Universitária Zeferino Vaz, Campinas SP 13083-887, Brazil;
| | - Sidnei Moura
- Laboratório de Biotecnologia de Produtos Naturais e Sintéticos, Instituto de Biotecnologia, Universidade de Caxias do Sul (UCS), Rua Francisco Getúlio Vargas 1130, Caxias do Sul RS 95070-560, Brazil; (M.M.L.); (S.M.)
| | - Eliane Candiani Arantes
- Departamento de Ciências BioMoleculares, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo (USP), Avenida do Café, s/n, Ribeirão Preto SP 14.040-903, Brazil; (K.d.C.F.B.); (E.C.A.)
| | - Alexandre Pinto Corrado
- Departamento de Farmacologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo (USP), Avenida Bandeirantes 3900, Ribeirão Preto SP 14040-030, Brazil;
| | - Cháriston A. Dal Belo
- Laboratório de Neurobiologia e Toxinologia, Programa de Pós-Graduação em Ciências Biológicas (PPGCB), Universidade Federal do Pampa (UNIPAMPA), Avenida Antônio Trilha 1847, São Gabriel RS 97300-000, Brazil; (R.S.O.); (B.T.B.); (A.P.L.); (V.Q.d.S.)
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica Toxicológica (PPGBTox), Universidade Federal de Santa Maria (UFSM), Avenida Roraima 1000, Santa Maria RS 97105-900, Brazil
- Correspondence: (L.V.); (C.A.D.B.); Tel.: +55-55-3237-0850 (C.A.D.B.)
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Blennerhassett RA, Bell-Anderson K, Shine R, Brown GP. The cost of chemical defence: the impact of toxin depletion on growth and behaviour of cane toads ( Rhinella marina). Proc Biol Sci 2020; 286:20190867. [PMID: 31088275 DOI: 10.1098/rspb.2019.0867] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Many animals capable of deploying chemical defences are reluctant to use them, suggesting that synthesis of toxins imposes a substantial cost. Typically, such costs have been quantified by measuring the elevation in metabolic rate induced by toxin depletion (i.e. during replenishment of toxin stores). More generally, we might expect that toxin depletion will induce shifts in a broad suite of fitness-relevant traits. In cane toads ( Rhinella marina), toxic compounds that protect against predators and pathogens are stored in large parotoid (shoulder) glands. We used correlational and experimental approaches in field and laboratory settings to investigate impacts of toxin depletion on growth rate and behaviour in cane toads. In free-ranging toads, larger toxin stores were associated with smaller gonads and livers, suggesting energetic trade-offs between toxin production and both reproduction and energy metabolism. Experimental removal of toxin (by manually squeezing parotoid glands) reduced rates of growth in body mass in both captive and free-ranging toads. Radio tracking demonstrated that de-toxined toads dispersed more slowly than did control toads. Given that toxin stores in cane toads take several months to fully replenish, deploying toxin to repel a predator may impose a substantial cost, explaining why toads use toxin only as a final line of defence.
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Affiliation(s)
| | - Kim Bell-Anderson
- 2 School of Life and Environmental Sciences, The University of Sydney , Sydney New South Wales 2006 , Australia
| | - Richard Shine
- 2 School of Life and Environmental Sciences, The University of Sydney , Sydney New South Wales 2006 , Australia
| | - Gregory P Brown
- 2 School of Life and Environmental Sciences, The University of Sydney , Sydney New South Wales 2006 , Australia
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Mariano DO, Prezotto-Neto JP, Spencer PJ, Sciani JM, Pimenta DC. Proteomic analysis of soluble proteins retrieved from Duttaphrynus melanostictus skin secretion by IEx-batch sample preparation. J Proteomics 2019; 209:103525. [DOI: 10.1016/j.jprot.2019.103525] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 08/15/2019] [Accepted: 09/12/2019] [Indexed: 12/18/2022]
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Olea GB, Cheij EO, Curi LM, Cuzziol Boccioni AP, Céspedez JA, Lombardo DM. Histological and immunohistochemical characterization of the integument and parotoids glands Rhinella bergi (Anura: Bufsonidae): Development and differentiation. Acta Histochem 2019; 121:277-283. [PMID: 30678807 DOI: 10.1016/j.acthis.2019.01.004] [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: 06/15/2018] [Revised: 01/10/2019] [Accepted: 01/11/2019] [Indexed: 10/27/2022]
Abstract
A detailed description of the tegument and parotoid glands of pre-metamorphic, post-metamorphic, juvenile and adult individuals of Rhinella bergi is presented to provide an exhaustive analysis of the integumentary characteristics of this species. Fragments of the tegument were fixed in Bouin solution and preserved in buffered Formol 10%. Subsequently, scanning electron microscopy (SEM) was performed to characterize the macroscopic structure of these regions. Microscopic observations were made from histological sections stained with Hematoxylin and Eosin, Alcian Blue (pH 2,5), PAS-H, Coomassie Blue, Oil Red, and Bielschowsky Impregnation.. There were three types of protuberance: warts, tubers, and thorns. These structures became evident from post-metamorphic stages. The ventral surface shows elevations similar to flat warts; however, tubers and spines are absent. Histologically, each structure consists of a spongy dermis of lax connective tissue and dense and compact dermis, associated with granular glands and a keratinized epidermis. The latter, in the dorsal region, forms projections called thorns. The granular glands accumulate, and their alveoli increase in size progressively. This work provides a morphological and histological description of the integument and the parotoid glands during the larval and post-metamorphic stage of the genus Rhinella, with aspects described for the first time in the genus.
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Tóth Z, Kurali A, Móricz ÁM, Hettyey A. Changes in Toxin Quantities Following Experimental Manipulation of Toxin Reserves in Bufo bufo Tadpoles. J Chem Ecol 2019; 45:253-263. [PMID: 30684072 PMCID: PMC6477007 DOI: 10.1007/s10886-019-01045-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 10/25/2018] [Accepted: 01/06/2019] [Indexed: 01/08/2023]
Abstract
Possessing toxins can contribute to an efficient defence against various threats in nature. However, we generally know little about the energy- and time-demands of developing toxicity in animals, which determines the efficiency of chemical defence and its trade-off with other risk-induced phenotypic responses. In this study we examined how immersion into norepinephrine solution inducing the release of stored toxins, administration of mild stress mimicking predator attack or simple handling during experimental procedure affected the quantity and number of toxin compounds present in common toad (Bufo bufo) tadpoles as compared to undisturbed control individuals, and investigated how fast toxin reserves were restored. We found that total bufadienolide quantity (TBQ) significantly decreased only in the norepinephrine treatment group immediately after treatment compared to the control, but this difference disappeared after 12 h; there were no consistent differences in TBQ between treatments at later samplings. Interestingly, in the norepinephrine treatment approximately half of the compounds characterized by >700 m/z values showed the same changes in time as TBQ, but several bufadienolides characterized by <600 m/z values showed the opposite pattern: they were present in higher quantities immediately after treatment. The number of bufadienolide compounds was not affected by any treatments, but was positively related to TBQ. Our study represents the first experimental evidence that toxin quantities returned to the original level following induced toxin release within a very short period of time in common toad tadpoles and provide additional insights into the physiological background of chemical defence in this model vertebrate species.
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Affiliation(s)
- Zoltán Tóth
- Lendület Evolutionary Ecology Research Group, Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Herman Ottó Str. 15, Budapest, H-1022, Hungary.
| | - Anikó Kurali
- Lendület Evolutionary Ecology Research Group, Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Herman Ottó Str. 15, Budapest, H-1022, Hungary
| | - Ágnes M Móricz
- Department of Pathophysiology, Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Herman Ottó Str. 15, Budapest, H-1022, Hungary
| | - Attila Hettyey
- Lendület Evolutionary Ecology Research Group, Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Herman Ottó Str. 15, Budapest, H-1022, Hungary
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Mailho-Fontana PL, Antoniazzi MM, Sciani JM, Pimenta DC, Barbaro KC, Jared C. Morphological and biochemical characterization of the cutaneous poison glands in toads ( Rhinella marina group) from different environments. Front Zool 2018; 15:46. [PMID: 30479646 PMCID: PMC6251109 DOI: 10.1186/s12983-018-0294-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 11/08/2018] [Indexed: 11/10/2022] Open
Abstract
Background Amphibian defence against predators and microorganisms is directly related to cutaneous glands that produce a huge number of different toxins. These glands are distributed throughout the body but can form accumulations in specific regions. When grouped in low numbers, poison glands form structures similar to warts, quite common in the dorsal skin of bufonids (toads). When accumulated in large numbers, the glands constitute protuberant structures known as macroglands, among which the parotoids are the most common ones. This work aimed at the morphological and biochemical characterization of the poison glands composing different glandular accumulations in four species of toads belonging to group Rhinella marina (R. icterica, R. marina, R. schneideri and R. jimi). These species constitute a good model since they possess other glandular accumulations together with the dorsal warts and the parotoids and inhabit environments with different degrees of water availability. Results We have observed that the toads skin has three types of poison glands that can be differentiated from each other through the morphology and the chemical content of their secretion product. The distribution of these different glands throughout the body is peculiar to each toad species, except for the parotoids and the other macroglands, which are composed of an exclusive gland type that is usually different from that composing the dorsal warts. Each type of poison gland presents histochemical and biochemical peculiarities, mainly regarding protein components. Conclusions The distribution, morphology and chemical composition of the different types of poison glands, indicate that they may have different defensive functions in each toad species.
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Affiliation(s)
| | - Marta Maria Antoniazzi
- 1Laboratory of Cell Biology, Instituto Butantan, Av. Vital Brasil 1500, São Paulo, 05503-000 Brazil
| | - Juliana Mozer Sciani
- 2Laboratory of Biochemistry and Biophysics, Instituto Butantan, São Paulo, Brazil
| | | | | | - Carlos Jared
- 1Laboratory of Cell Biology, Instituto Butantan, Av. Vital Brasil 1500, São Paulo, 05503-000 Brazil
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Chen W, Hudson CM, DeVore JL, Shine R. Sex and weaponry: The distribution of toxin-storage glands on the bodies of male and female cane toads ( Rhinella marina). Ecol Evol 2017; 7:8950-8957. [PMID: 29152190 PMCID: PMC5677481 DOI: 10.1002/ece3.2914] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 02/19/2017] [Accepted: 02/21/2017] [Indexed: 11/16/2022] Open
Abstract
The parotoid macroglands of bufonid anurans store (and can expel) large volumes of toxic secretions and have attracted detailed research. However, toxins also are stored in smaller glands that are distributed on the limbs and dorsal surface of the body. Female and male cane toads (Rhinella marina) differ in the location of toxin‐storage glands and the extent of glandular structures. Female toads store a larger proportion of their toxins in the parotoids than males as well as (to a lesser extent) in smaller glands on the forelimbs. Males have smaller and more elongate parotoids than females, but glands cover more of the skin surface on their limbs (especially hindlimbs) and dorsal surface. The delay to toxin exudation in response to electrostimulation varied among glands in various parts of the body, and did so differently in males than in females. The spatial distribution of toxin glands differs between the sexes even in toads that have been raised under standardized conditions in captivity; hence, the sexual dimorphism is due to heritable factors rather than developmentally plastic responses to ecological (e.g., habitat, predation risk) differences between the sexes. The selective advantages of this sexual dimorphism remain unclear. A priori, we might expect to see toxin widely dispersed across any part of the body likely to be contacted by a predator; and a wide distribution also would be expected if the gland secretions have other (e.g., male–male rivalry) functions. Why, then, is toxin concentrated in the parotoids, especially in female toads? That concentration may enhance the effectiveness of frontal displays to deter predation and also may facilitate the transfer of stored toxins to eggs.
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Affiliation(s)
- Wei Chen
- School of Life and Environmental Sciences University of Sydney Sydney NSW 2006 Australia.,Ecological Security and Protection Key Laboratory of Sichuan Province Mianyang Normal University Mianyang 621000 China
| | - Cameron M Hudson
- School of Life and Environmental Sciences University of Sydney Sydney NSW 2006 Australia
| | - Jayna L DeVore
- School of Life and Environmental Sciences University of Sydney Sydney NSW 2006 Australia
| | - Richard Shine
- School of Life and Environmental Sciences University of Sydney Sydney NSW 2006 Australia
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14
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Structural cutaneous adaptations for defense in toad (Rhinella icterica) parotoid macroglands. Toxicon 2017; 137:128-134. [PMID: 28760510 DOI: 10.1016/j.toxicon.2017.07.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2017] [Accepted: 07/26/2017] [Indexed: 11/21/2022]
Abstract
Toads have a pair of glandular accumulations on each side of the dorsal region of the head known as parotoid macroglands. These macroglands consist of secretory units (granular glands), each one capped with an epithelial plug. When threatened, toads point one of the parotoids toward the aggressor, and if the aggressor squeezes the parotoid with its teeth, jets of poison will come out of the secretory units and hit the predator's oral mucosa, thereby causing poisoning. Our study focused on the mechanism of parotoid function by comparing parotoids from toads naturally attacked by dogs with those manually compressed. We verified that the process of glandular emptying in response to dog bites is very similar to that following manual compression. We observed that the structure of the plug plays an essential role in the release of the poison jets. Our results suggest that the parotoids may act as "bulletproof vests," reducing the impact of the force exerted by predator attacks, and thus may function as a passive antipredator mechanism.
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15
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Mailho-Fontana PL, Antoniazzi MM, Rodrigues I, Sciani JM, Pimenta DC, Brodie ED, Rodrigues MT, Jared C. Parotoid, radial, and tibial macroglands of the frog Odontophrynus cultripes: Differences and similarities with toads. Toxicon 2017; 129:123-133. [PMID: 28235580 DOI: 10.1016/j.toxicon.2017.02.022] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 02/16/2017] [Accepted: 02/20/2017] [Indexed: 10/20/2022]
Abstract
Anuran integument is characterized by the presence of glands, some of which are responsible for toxin production. In some species these glands accumulate in parts of the body strategically located against predators, forming structures known as macroglands. This is the case for parotoid macroglands, on the dorsum of the head, tibial macroglands, on the rear limbs, and radial macroglands, on the forelimbs of toads and some other anurans. The toad Rhinella jimi, for example, simultaneously displays all three types of macroglands, which is unusual even among bufonids. Interestingly, considering the phylogenetic distance, the frog Odontophrynus cultripes (Odontophrynidae) also presents these three macroglandular types. In this study we analyze the morphology of O. cultripes macroglands and the chemical composition of their poison using an interdisciplinary approach. In this species, the parotoid, tibial, and radial macroglands consist of aggregates of elongated and juxtaposed poison glands, arranged in a honeycomb style, very similar to that of toads. Comparative analysis of these three macrogland types shows significant differences in both the morphology of secretory granules and biochemical composition. The present work on O. cultripes contributes to the evidence that amphibians, or at least anurans, share a basic design for all cutaneous glandular accumulations. The determinant factor for macroglandular formation may be the selective pressure for defense against predators.
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Affiliation(s)
| | | | | | - Juliana M Sciani
- Laboratory of Biochemistry and Biophysics, Instituto Butantan, São Paulo, Brazil
| | | | - Edmund D Brodie
- Department of Biology, Utah State University, Logan, UT, USA.
| | | | - Carlos Jared
- Laboratory of Cell Biology, Instituto Butantan, São Paulo, Brazil
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16
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Regueira E, Dávila C, Sassone AG, O'Donohoe MEA, Hermida GN. Post-metamorphic development of skin glands in a true toad: Parotoids versus dorsal skin. J Morphol 2017; 278:652-664. [PMID: 28165149 DOI: 10.1002/jmor.20661] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 12/13/2016] [Accepted: 01/07/2017] [Indexed: 01/24/2023]
Abstract
Chemical defenses in amphibians are a common antipredatory and antimicrobial strategy related to the presence of dermal glands that synthesize and store toxic or unpalatable substances. Glands are either distributed throughout the skin or aggregated in multiglandular structures, being the parotoids the most ubiquitous macrogland in toads of Bufonidae. Even though dermal glands begin to develop during late-larval stages, many species, including Rhinella arenarum, have immature glands by the end of metamorphosis, and their post-metamorphic growth is unknown. Herein, we compared the post-metamorphic development of parotoids and dorsal glands by histological and allometric studies in a size series of R. arenarum. Histological and histochemical studies to detect proteins, acidic glycoconjugates, and catecholamines, showed that both, parotoids and dorsal glands, acquire characteristics of adults in individuals larger than 50 mm; that is, a moment in which the cryptic coloration disappears. Parotoid height increased allometrically as a function of body size, whereas the size of small dorsal glands decreased with body size. The number of glands in the dorsum was not linearly related to body size, appearing to be an individual characteristic. Only adult specimens had intraepithelial granular glands in the duct of the largest glands of the parotoids. Since toxic secretions accumulate in the central glands of parotoids, allometric growth of parotoids may translate into greater protection from predators in the largest animals. Conversely, large glands in the dorsum, which produce a proteinaceous secretion of unknown function, grow isometrically to body size. Some characteristics, like intraepithelial glands in the ducts and basophilic glands in the dorsum, are limited to adults.
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Affiliation(s)
- Eleonora Regueira
- Facultad de Ciencias Exactas y Naturales, Departamento de Biodiversidad y Biología Experimental, Laboratorio de Biología de Anfibios-Histología Animal, Universidad de Buenos Aires, Buenos Aires, C1428EGA, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, C1033AAJ, Argentina
| | - Camila Dávila
- Facultad de Ciencias Exactas y Naturales, Departamento de Biodiversidad y Biología Experimental, Laboratorio de Biología de Anfibios-Histología Animal, Universidad de Buenos Aires, Buenos Aires, C1428EGA, Argentina
| | - Alina G Sassone
- Facultad de Ciencias Exactas y Naturales, Departamento de Biodiversidad y Biología Experimental, Laboratorio de Biología de Anfibios-Histología Animal, Universidad de Buenos Aires, Buenos Aires, C1428EGA, Argentina
| | - María E Ailín O'Donohoe
- Facultad de Ciencias Exactas y Naturales, Departamento de Biodiversidad y Biología Experimental, Laboratorio de Biología de Anfibios-Histología Animal, Universidad de Buenos Aires, Buenos Aires, C1428EGA, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, C1033AAJ, Argentina
| | - Gladys N Hermida
- Facultad de Ciencias Exactas y Naturales, Departamento de Biodiversidad y Biología Experimental, Laboratorio de Biología de Anfibios-Histología Animal, Universidad de Buenos Aires, Buenos Aires, C1428EGA, Argentina
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17
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Mailho-Fontana PL, Antoniazzi MM, Barros-Battesti DM, Jared C, Campbell JA, Brodie ED. Toad Parotoid Pores Shelter Tick Larvae. SOUTH AMERICAN JOURNAL OF HERPETOLOGY 2016. [DOI: 10.2994/sajh-d-16-00024.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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