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Yonezawa R, Hayashi K, Oyama H, Yoshitake K, Sato S, Senevirathna JDM, Smith AR, Okabe T, Suo R, Kinoshita S, Takatani T, Arakawa O, Asakawa S, Itoi S. Tissue Localization of Tetrodotoxin in the Flatworm Planocera multitentaculata (Platyhelminthes: Polycladida). MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2024:10.1007/s10126-024-10332-w. [PMID: 38861110 DOI: 10.1007/s10126-024-10332-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2024] [Accepted: 06/03/2024] [Indexed: 06/12/2024]
Abstract
Tetrodotoxin (TTX), a pufferfish toxin, is a highly potent neurotoxin that has been found in a wide variety of animals. The TTX-bearing flatworm Planocera multitentaculata possesses a large amount of TTX and is considered responsible for the toxification of TTX-bearing animals such as pufferfish (Takifugu and Chelonodon) and the toxic goby Yongeichthys criniger. However, the mechanism underlying TTX accumulation in flatworms remains unclear. Previous studies have been limited to identifying the distribution of TTX in multiple organs, such as the digestive organs, genital parts, and the remaining tissues of flatworms. Here, we performed liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis and immunohistochemical staining using a monoclonal anti-TTX antibody to elucidate the detailed localization of TTX in the tissues and organs of the flatworm P. multitentaculata. Immunohistochemical staining for P. multitentaculata showed that TTX-specific signals were detected not only in the ovaries and pharynx but also in many other tissues and organs, whereas no signal was detected in the brain, Lang's vesicle, and genitalia. In addition, combined with LC-MS/MS analysis, it was revealed for the first time that TTX accumulates in high concentrations in the basement membrane and epidermis. These findings robustly support the hypotheses of "TTX utilization protection from predators."
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Affiliation(s)
- Ryo Yonezawa
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Kentaro Hayashi
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Hikaru Oyama
- College of Bioresource Sciences, Nihon University, Kanagawa, Japan
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8566, Japan
| | - Kazutoshi Yoshitake
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Soshi Sato
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Jayan Duminda M Senevirathna
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
- Department of Animal Science, Faculty of Animal Science and Export Agriculture, Uva Wellassa University, Badulla, 90000, Sri Lanka
| | - Ashley R Smith
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Taiki Okabe
- College of Bioresource Sciences, Nihon University, Kanagawa, Japan
- Niigata Prefectural Kaiyo High School, Itoigawa, Niigata, 949-1352, Japan
| | - Rei Suo
- College of Bioresource Sciences, Nihon University, Kanagawa, Japan
| | - Shigeharu Kinoshita
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Tomohiro Takatani
- Graduate School of Integrated Science and Technology, Nagasaki University, Nagasaki, 852-8521, Japan
| | - Osamu Arakawa
- Graduate School of Integrated Science and Technology, Nagasaki University, Nagasaki, 852-8521, Japan
| | - Shuichi Asakawa
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.
| | - Shiro Itoi
- College of Bioresource Sciences, Nihon University, Kanagawa, Japan.
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Robinson KE, Moniz HA, Stokes AN, Feldman CR. Where Does All the Poison Go? Investigating Toxicokinetics of Newt (Taricha) Tetrodotoxin (TTX) in Garter Snakes (Thamnophis). J Chem Ecol 2024:10.1007/s10886-024-01517-7. [PMID: 38842636 DOI: 10.1007/s10886-024-01517-7] [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: 02/20/2024] [Revised: 05/14/2024] [Accepted: 05/22/2024] [Indexed: 06/07/2024]
Abstract
Animals that consume toxic diets provide models for understanding the molecular and physiological adaptations to ecological challenges. Garter snakes (Thamnophis) in western North America prey on Pacific newts (Taricha), which employ tetrodotoxin (TTX) as an antipredator defense. These snakes possess mutations in voltage-gated sodium channels (Nav), the molecular targets of TTX, that decrease the binding ability of TTX to sodium channels (target-site resistance). However, genetic variation at these loci that cannot explain all the phenotypic variation in TTX resistance in Thamnophis. We explored a separate means of resistance, toxin metabolism, to determine if TTX-resistant snakes either rapidly remove TTX or sequester TTX. We examined the metabolism and distribution of TTX in the body (toxicokinetics), to determine differences between TTX-resistant and TTX-sensitive snakes in the rates at which TTX is eliminated from organs and the whole body (using TTX half-life as our metric). We assayed TTX half-life in snakes from TTX-resistant and TTX-sensitive populations of three garter snake species with a coevolutionary history with newts (T. atratus, T. couchii, T. sirtalis), as well as two non-resistant "outgroup" species (T. elegans, Pituophis catenifer) that seldom (if ever) engage newts. We found TTX half-life varied across species, populations, and tissues. Interestingly, TTX half-life was shortest in T. elegans and P. catenifer compared to all other snakes. Furthermore, TTX-resistant populations of T. couchii and T. sirtalis eliminated TTX faster (shorter TTX half-life) than their TTX-sensitive counterparts, while populations of TTX-resistant and TTX-sensitive T. atratus showed no difference rates of TTX removal (same TTX half-life). The ability to rapidly eliminate TTX may have permitted increased prey consumption, which may have promoted the evolution of additional resistance mechanisms. Finally, snakes still retain substantial amounts of TTX, and we projected that snakes could be dangerous to their own predators days to weeks following the ingestion of a single newt. Thus, aspects of toxin metabolism may have been key in driving predator-prey relationships, and important in determining other ecological interactions.
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Affiliation(s)
- Kelly E Robinson
- Department of Biology and Program in Ecology, Evolution and Conservation Biology, University of Nevada, Reno, Reno, NV, USA.
- Program in Ecology, Evolution and Conservation Biology, University of Nevada, Reno, NV, USA.
| | - Haley A Moniz
- Department of Biology and Program in Ecology, Evolution and Conservation Biology, University of Nevada, Reno, Reno, NV, USA
- Program in Ecology, Evolution and Conservation Biology, University of Nevada, Reno, NV, USA
- Department of Biological Sciences, California Polytechnic State University, San Luis Obispo, CA, USA
| | - Amber N Stokes
- Department of Biology, California State University Bakersfield, Bakersfield, CA, USA
| | - Chris R Feldman
- Department of Biology and Program in Ecology, Evolution and Conservation Biology, University of Nevada, Reno, Reno, NV, USA
- Program in Ecology, Evolution and Conservation Biology, University of Nevada, Reno, NV, USA
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Malykin GV, Velansky PV, Melnikova DI, Magarlamov TY. Tetrodotoxins in Larval Development of Ribbon Worm Cephalothrix cf. simula (Palaeonemertea, Nemertea). MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2023; 25:918-934. [PMID: 37672165 DOI: 10.1007/s10126-023-10249-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 08/31/2023] [Indexed: 09/07/2023]
Abstract
The toxic ribbon worm, Cephalothrix cf. simula (Palaeonemertea, Nemertea), possesses extremely high concentrations of tetrodotoxin (TTX). Although TTX has been found in the eggs of this species, the fate of the toxin in the ontogeny of the animal has not been explored. Here, using high performance liquid chromatography with tandem mass spectrometry and immunohistochemistry with anti-TTX antibodies, we examined levels, profile, and localization of TTX and its analogues (TTXs) in larvae of C. cf. simula throughout 41 days post-fertilization. A detailed investigation of cells in sites of TTX-accumulation was performed with light and electron microscopy. Newly hatched larvae possessed weak TTX-like immunoreactivity in all cells. With subsequent development, intensity of TTX-labeling in the ectodermal structures, mesodermal cells and apical cylinder of the apical gland increased. In the ectodermal structures, an intense TTX-labeling was observed in the multiciliated, type II granular, type I mucoid, and basal cells of the epidermis, and in the type III granular cells of the mouth gland. In the mesoderm, TTX was localized in the muscle and unigranular parenchyma-like cells. Eggs and larvae of C. cf. simula contained five TTXs, with two major toxins - TTX and 5,6,11-trideoxyTTX. Level and relative proportion of TTXs did not differ significantly among developmental stages, confirming that larvae obtained toxins from maternal eggs and were able to retain it. The results of this study provide insights into the formation of TTX-bearing apparatus of C. cf. simula through the larval development.
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Affiliation(s)
- Grigorii V Malykin
- A.V. Zhirmunsky National Scientific Center of Marine Biology, Far Eastern Branch, Russian Academy of Sciences, 690041, Vladivostok, Russian Federation
| | - Peter V Velansky
- A.V. Zhirmunsky National Scientific Center of Marine Biology, Far Eastern Branch, Russian Academy of Sciences, 690041, Vladivostok, Russian Federation
| | - Daria I Melnikova
- A.V. Zhirmunsky National Scientific Center of Marine Biology, Far Eastern Branch, Russian Academy of Sciences, 690041, Vladivostok, Russian Federation
| | - Timur Yu Magarlamov
- A.V. Zhirmunsky National Scientific Center of Marine Biology, Far Eastern Branch, Russian Academy of Sciences, 690041, Vladivostok, Russian Federation.
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Anastasiou TI, Kagiampaki E, Kondylatos G, Tselepides A, Peristeraki P, Mandalakis M. Assessing the Toxicity of Lagocephalus sceleratus Pufferfish from the Southeastern Aegean Sea and the Relationship of Tetrodotoxin with Gonadal Hormones. Mar Drugs 2023; 21:520. [PMID: 37888455 PMCID: PMC10608560 DOI: 10.3390/md21100520] [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: 09/03/2023] [Revised: 09/26/2023] [Accepted: 09/27/2023] [Indexed: 10/28/2023] Open
Abstract
Given the dramatic increase in the L. sceleratus population in the southeastern Aegean Sea, there is growing interest in assessing the toxicity of this pufferfish and the factors controlling its tetrodotoxin (TTX) content. In the present study, liver, gonads, muscle and skin of 37 L. sceleratus specimens collected during May and June 2021 from the island of Rhodes, Greece, were subjected to multi-analyte profiling using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in order to quantitate TTX and evaluate whether this biotoxin interrelates with hormones. TTX and its analogues 4-epiTTX, 11-deoxyTTX, 11-norTTX-6-ol, 4,9-anhydroTTX and 5,11/6,11-dideoxyTTX were detected in all tissue types. Liver and gonads were the most toxic tissues, with the highest TTX concentrations being observed in the ovaries of female specimens. Only 22% of the analyzed muscle samples were non-toxic according to the Japanese toxicity threshold (2.2 μg TTX eq g-1), confirming the high poisoning risk from the inadvertent consumption of this species. Four steroid hormones (i.e., cortisol, testosterone, androstenedione and β-estradiol) and the gonadotropin-releasing hormone (GnRH) were detected in the gonads. Androstenedione dominated in female specimens, while GnRH was more abundant in males. A positive correlation of TTX and its analogues with β-estradiol was observed. However, a model incorporating sex rather than β-estradiol as the independent variable proven to be more efficient in predicting TTX concentration, implying that other sex-related characteristics are more important than specific hormone-regulated processes.
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Affiliation(s)
- Thekla I Anastasiou
- Hellenic Centre for Marine Research (HCMR), Institute of Marine Biology, Biotechnology and Aquaculture, 71500 Heraklion, Greece
- Department of Biology, University of Crete, 70013 Heraklion, Greece
| | - Eirini Kagiampaki
- Hellenic Centre for Marine Research (HCMR), Institute of Marine Biology, Biotechnology and Aquaculture, 71500 Heraklion, Greece
| | - Gerasimos Kondylatos
- Hellenic Centre for Marine Research (HCMR), Hydrobiological Station of Rhodes, 85131 Rhodes, Greece
| | | | - Panagiota Peristeraki
- Hellenic Centre for Marine Research (HCMR), Institute of Marine Biological Resources and Inland Waters, 71500 Heraklion, Greece
| | - Manolis Mandalakis
- Hellenic Centre for Marine Research (HCMR), Institute of Marine Biology, Biotechnology and Aquaculture, 71500 Heraklion, Greece
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Alkassar M, Sanchez-Henao A, Reverté J, Barreiro L, Rambla-Alegre M, Leonardo S, Mandalakis M, Peristeraki P, Diogène J, Campàs M. Evaluation of Toxicity Equivalency Factors of Tetrodotoxin Analogues with a Neuro-2a Cell-Based Assay and Application to Puffer Fish from Greece. Mar Drugs 2023; 21:432. [PMID: 37623713 PMCID: PMC10455759 DOI: 10.3390/md21080432] [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: 07/14/2023] [Revised: 07/27/2023] [Accepted: 07/29/2023] [Indexed: 08/26/2023] Open
Abstract
Tetrodotoxin (TTX) is a potent marine neurotoxin involved in poisoning cases, especially through the consumption of puffer fish. Knowledge of the toxicity equivalency factors (TEFs) of TTX analogues is crucial in monitoring programs to estimate the toxicity of samples analyzed with instrumental analysis methods. In this work, TTX analogues were isolated from the liver of a Lagocephalus sceleratus individual caught on South Crete coasts. A cell-based assay (CBA) for TTXs was optimized and applied to the establishment of the TEFs of 5,11-dideoxyTTX, 11-norTTX-6(S)-ol, 11-deoxyTTX and 5,6,11-trideoxyTTX. Results showed that all TTX analogues were less toxic than the parent TTX, their TEFs being in the range of 0.75-0.011. Then, different tissues of three Lagocephalus sceleratus individuals were analyzed with CBA and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The obtained TEFs were applied to the TTX analogues' concentrations obtained by LC-MS/MS analysis, providing an indication of the overall toxicity of the sample. Information about the TEFs of TTX analogues is valuable for food safety control, allowing the estimation of the risk of fish products to consumers.
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Affiliation(s)
- Mounira Alkassar
- Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Ctra. Poble Nou km 5.5, 43540 La Ràpita, Spain; (M.A.); (A.S.-H.); (J.R.); (L.B.); (M.R.-A.); (S.L.); (J.D.)
| | - Andres Sanchez-Henao
- Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Ctra. Poble Nou km 5.5, 43540 La Ràpita, Spain; (M.A.); (A.S.-H.); (J.R.); (L.B.); (M.R.-A.); (S.L.); (J.D.)
| | - Jaume Reverté
- Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Ctra. Poble Nou km 5.5, 43540 La Ràpita, Spain; (M.A.); (A.S.-H.); (J.R.); (L.B.); (M.R.-A.); (S.L.); (J.D.)
| | - Lourdes Barreiro
- Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Ctra. Poble Nou km 5.5, 43540 La Ràpita, Spain; (M.A.); (A.S.-H.); (J.R.); (L.B.); (M.R.-A.); (S.L.); (J.D.)
| | - Maria Rambla-Alegre
- Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Ctra. Poble Nou km 5.5, 43540 La Ràpita, Spain; (M.A.); (A.S.-H.); (J.R.); (L.B.); (M.R.-A.); (S.L.); (J.D.)
| | - Sandra Leonardo
- Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Ctra. Poble Nou km 5.5, 43540 La Ràpita, Spain; (M.A.); (A.S.-H.); (J.R.); (L.B.); (M.R.-A.); (S.L.); (J.D.)
| | - Manolis Mandalakis
- Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, 71003 Heraklion, Greece;
| | - Panagiota Peristeraki
- Institute of Marine Biological Resources and Inland Waters, Hellenic Centre for Marine Research, 71003 Heraklion, Greece;
| | - Jorge Diogène
- Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Ctra. Poble Nou km 5.5, 43540 La Ràpita, Spain; (M.A.); (A.S.-H.); (J.R.); (L.B.); (M.R.-A.); (S.L.); (J.D.)
| | - Mònica Campàs
- Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Ctra. Poble Nou km 5.5, 43540 La Ràpita, Spain; (M.A.); (A.S.-H.); (J.R.); (L.B.); (M.R.-A.); (S.L.); (J.D.)
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Ito M, Shirai K, Oyama H, Yasukawa S, Asano M, Kihara M, Suo R, Sugita H, Nakahigashi R, Adachi M, Nishikawa T, Itoi S. Geographical differences in the composition of tetrodotoxin and 5,6,11-trideoxytetrodotoxin in Japanese pufferfishes and their origins. CHEMOSPHERE 2023; 336:139214. [PMID: 37327821 DOI: 10.1016/j.chemosphere.2023.139214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Revised: 06/02/2023] [Accepted: 06/11/2023] [Indexed: 06/18/2023]
Abstract
Tetrodotoxin (TTX)-bearing fish are thought to accumulate TTXs in their bodies through a food chain that begins with marine bacteria. However, the mechanism of TTXs transfer between prey and predators in the food chain remains unclear and the reasons for regional differences in pufferfish toxicity are also unknown. To investigate these matters, we collected juveniles of four species of pufferfish, Takifugu alboplumbeus, Takifugu flavipterus, Takifugu stictonotus, and Chelonodon patoca, from various locations in the Japanese Islands, and subjected them to liquid chromatography-tandem mass spectrometry analysis for TTX and its analog 5,6,11-trideoxyTTX (TDT). Concentrations of these substances tended to be higher in pufferfish juveniles collected from the Sanriku coastal area (Pacific coast of northern Japan) than in those from other locations. Juveniles had higher concentrations of TTX at all locations than of TDT. Mitochondrial cytochrome c oxidase subunit I (COI) sequences specific to the TTX-bearing flatworm, Planocera multitentaculata, were detected in the intestinal contents of up to 100% of pufferfish juveniles from various sampling sites, suggesting that P. multitentaculata was widely involved in the toxification of the juveniles in the coastal waters of Japan. A toxification experiment was conducted on three species of pufferfish juveniles (T. alboplumbeus, Takifugu rubripes and C. patoca) using TTX-bearing flatworm eggs harboring equal amounts of TTX and TDT. The TTX content of juveniles fed on flatworm eggs was found to be more than twice that of TDT, suggesting that pufferfish preferentially incorporate TTX compared to TDT.
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Affiliation(s)
- Masaaki Ito
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Kyoko Shirai
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Hikaru Oyama
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Shino Yasukawa
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Masaki Asano
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Masato Kihara
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Rei Suo
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Haruo Sugita
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Ryota Nakahigashi
- Laboratory of Organic Chemistry, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, Aichi, 464-8601, Japan
| | - Masaatsu Adachi
- Graduate School of Pharmaceutical Science, Tohoku University, Aoba, Aramaki, Aoba-ku, Sendai, 980-8587, Japan
| | - Toshio Nishikawa
- Laboratory of Organic Chemistry, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, Aichi, 464-8601, Japan
| | - Shiro Itoi
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan.
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Zhou L, Liu F, Chen J, Yang R, Li J, Wang Z, Cai M. Comparative transcriptome analysis reveals sex bias in expression patterns of genes related to sex steroids and immunity in the skin of spinyhead croaker Collichthys lucidus. JOURNAL OF FISH BIOLOGY 2023. [PMID: 37054975 DOI: 10.1111/jfb.15405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Accepted: 04/12/2023] [Indexed: 05/03/2023]
Abstract
Fish skin is the first barrier against external invasion, and also an important interface for communication between males and females during reproduction. Nonetheless, sexual dimorphism in the physiology of fish skins is still poorly understood. Herein, transcriptomes of skin were comparatively analysed between males and females in spinyhead croaker, Collichthys lucidus. Totally, 170 differentially expressed genes (DEG) were detected, including 79 female-biased genes and 91 male-biased genes. Gene ontology (GO) annotation items of the DEGs were mainly enriched in biological process items (86.2%), including regulation of biological processes, responses to chemical and biological stimuli, transport and secretion, movement, immune response, tissue development, etc. In KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway enrichment analysis, the male-biased genes were enriched in pathways including those related to immunity such as the TNF signalling pathway and IL-17 signalling pathway, whereas the female-biased genes were enriched in pathways including those related to female steroids such as ovarian steroidogenesis and oestrogen signalling pathway. In addition, odf3 was found to be a male-specific expression gene, being a candidate marker for phenotypic sex. Thus, the sexual difference in gene expression in fish skin in spawning season was uncovered by transcriptome analysis for the first time, providing new insights into sexual dimorphism in the physiology and functions of fish skin.
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Affiliation(s)
- Li Zhou
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fisheries College, Jimei University, Xiamen, China
| | - Fujiang Liu
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fisheries College, Jimei University, Xiamen, China
| | - Junnan Chen
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fisheries College, Jimei University, Xiamen, China
| | - Ran Yang
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fisheries College, Jimei University, Xiamen, China
| | - Jinshou Li
- College of life science, Ningde Normal University, Ningde, China
| | - Zhiyong Wang
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fisheries College, Jimei University, Xiamen, China
| | - Mingyi Cai
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fisheries College, Jimei University, Xiamen, China
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8
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Asano M, Ishizaki C, Tomonou T, Kihara M, Ito M, Yasukawa S, Shirai K, Oyama H, Izawa S, Kawamura R, Saito K, Suo R, Nakahigashi R, Adachi M, Nishikawa T, Sugita H, Itoi S. Levels of Tetrodotoxins in Spawning Pufferfish, Takifugu alboplumbeus. Mar Drugs 2023; 21:md21040207. [PMID: 37103347 PMCID: PMC10141859 DOI: 10.3390/md21040207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Revised: 03/22/2023] [Accepted: 03/23/2023] [Indexed: 03/29/2023] Open
Abstract
Tetrodotoxin (TTX), also known as pufferfish toxin, is an extremely potent neurotoxin thought to be used as a biological defense compound in organisms bearing it. Although TTX was thought to function as a chemical agent for defense and anti-predation and an attractant for TTX-bearing animals including pufferfish, it has recently been demonstrated that pufferfish were also attracted to 5,6,11-trideoxyTTX, a related compound, rather than TTX alone. In this study, we attempted to estimate the roles of TTXs (TTX and 5,6,11-trideoxyTTX) in the pufferfish, Takifugu alboplumbeus, through examining the location of TTXs in various tissues of spawning pufferfish from Enoshima and Kamogawa, Japan. TTXs levels in the Kamogawa population were higher than those in the Enoshima population, and there was no significant difference in the amount of TTXs between the sexes in either population. Individual differences were greater in females than in males. However, the location of both substances in tissues differed significantly between sexes: male pufferfish accumulated most of their TTX in the skin and liver and most of their 5,6,11-trideoxyTTX in the skin, whereas females accumulated most of their TTX and 5,6,11-trideoxyTTX in the ovaries and skin.
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Zhong Z, Jiang Y, Zhao L, Wang Y, Zhang Z. Establishment and characterization of the ovary cell line derived from two-spot puffer Takifugu bimaculatus and its application for gene editing and marine toxicology. Comp Biochem Physiol C Toxicol Pharmacol 2023; 264:109528. [PMID: 36470397 DOI: 10.1016/j.cbpc.2022.109528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 11/03/2022] [Accepted: 11/23/2022] [Indexed: 12/12/2022]
Abstract
Takifugu bimaculatus is a marine fish with high nutritional value. Its ovary contains tetrodotoxin (TTX) which is a severe neurotoxin that limits its edible value of it. To understand the mechanism of oogenesis and production of TTX in T. bimaculatus, an ovarian cell line named TBO from an adolescent ovary was established. TBO was composed of fibroblast-like cells that expressed the ovarian follicle cells marker gene Foxl2 and highly expressed TTX binding protein 2 (PSTBP2) but did not express the germ cells marker gene Vasa. Therefore, TBO seems to be mainly composed of follicle cells and possibly a small percentage of oocytes. Electroporation was used to successfully transfect the pEGFP-N1 and pNanog-N1 vectors into the TBO cell line with a high transfection efficiency. The morphological changes and survival rates of the exposed cells proved that this cell line was effective for exposure to conotoxins (CTXs), another group of toxins related to food safety. Furthermore, PSTBP2 was knocked out in TBO using CRISPR/Cas9 technology, showing that sgRNA2 could mutate PSTBP2. The results suggested that TBO will be more convenient, efficient, and rapid for reproduction and toxicology investigation, and gene editing. This study laid the groundwork for future research into the fish gonadal cell culture and food-related marine toxins. In conclusion, a cell line has been generated from T. bimaculatus, which might represent a valuable model for fish studies in the fields of toxicology and gene editing.
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Affiliation(s)
- Zhaowei Zhong
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fisheries College, Jimei University, Xiamen 361021, China; College of Ocean and Earth Sciences, Xiamen University, Xiamen, 361005, China.
| | - Yonghua Jiang
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fisheries College, Jimei University, Xiamen 361021, China.
| | - Liping Zhao
- College of Marine Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Yilei Wang
- Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fisheries College, Jimei University, Xiamen 361021, China.
| | - Ziping Zhang
- College of Marine Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Key Laboratory of Marine Biotechnology of Fujian Province, Institute of Oceanology, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
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10
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Oyama H, Ito M, Suo R, Goto-Inoue N, Morisasa M, Mori T, Sugita H, Mori T, Nakahigashi R, Adachi M, Nishikawa T, Itoi S. Changes in Tissue Distribution of Tetrodotoxin and Its Analogues in Association with Maturation in the Toxic Flatworm, Planocera multitentaculata. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2022; 24:1158-1167. [PMID: 36322281 DOI: 10.1007/s10126-022-10179-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 10/20/2022] [Indexed: 06/16/2023]
Abstract
The toxic flatworm, Planocera multitentaculata, possesses highly concentrated tetrodotoxin (TTX), also known as pufferfish toxin, throughout its life cycle, including the egg and larval stages. Additionally, TTX analogues, 5,6,11-trideoxyTTX and 11-norTTX-6(S)-ol, have also been detected in the flatworm. The high concentration of TTX in the eggs and larvae appears to be for protection against predation, and 11-norTTX-6(S)-ol in the pharyngeal tissue in the adults is likely used to sedate or kill prey during predation. However, information on the role of 5,6,11-trideoxyTTX, a potential important biosynthetic intermediate of TTX, in the toxic flatworm is lacking. Here, we aimed to determine the region of localization of TTX and its analogues in the flatworm body, understand their pharmacokinetics during maturation, and speculate on their function. Flatworm specimens in four stages of maturity, namely juvenile, mating, spawning, and late spawning, were subjected to LC-MS/MS analysis, using the pharyngeal tissue, oocytes in seminal receptacle, sperm, and tissue from 12 other sites. Although TTX was consistently high in the pharyngeal tissue throughout maturation, it was extremely high in the oocytes during the spawning period. Meanwhile, 5,6,11-trideoxyTTX was almost undetectable in the pharyngeal part throughout the maturation but was very abundant in the oocytes during spawning. 11-norTTX-6(S)-ol consistently localized in the pharyngeal tissue. Although the localization of TTX and its analogues was approximately consistent with the MS imaging data, TTX and 11-norTTX-6(S)-ol were found to be highly localized in the parenchyma surrounding the pharynx, which suggests the parenchyma is involved in the accumulation and production of TTXs.
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Affiliation(s)
- Hikaru Oyama
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Masaaki Ito
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Rei Suo
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Naoko Goto-Inoue
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Mizuki Morisasa
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Tsukasa Mori
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Haruo Sugita
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Tetsushi Mori
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei, Tokyo, 184-8588, Japan
| | - Ryota Nakahigashi
- Laboratory of Organic Chemistry, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, Aichi, 464-8601, Japan
| | - Masaatsu Adachi
- Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba, Aramaki, Aoba-ku, Sendai, Miyagi, 980-8578, Japan
| | - Toshio Nishikawa
- Laboratory of Organic Chemistry, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, Aichi, 464-8601, Japan
| | - Shiro Itoi
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan.
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11
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An almost nontoxic tetrodotoxin analog, 5,6,11-trideoxytetrodotoxin, as an odorant for the grass puffer. Sci Rep 2022; 12:15087. [PMID: 36064732 PMCID: PMC9445045 DOI: 10.1038/s41598-022-19355-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 08/29/2022] [Indexed: 11/08/2022] Open
Abstract
Toxic puffers contain the potent neurotoxin, tetrodotoxin (TTX). Although TTX is considered to serve as a defense substance, previous behavioral studies have demonstrated that TTX acts as an attractive pheromone for some toxic puffers. To elucidate the physiological mechanism of putative pheromonal action of TTX, we examined whether grass puffers Takifugu alboplumbeus can detect TTX. Electroolfactogram (EOG) results suggest that the olfactory epithelium (OE) of grass puffers responded to a type of TTX analog (5,6,11-trideoxyTTX), although it did not respond to TTX. We also examined the attractive action of 5,6,11-trideoxyTTX on grass puffers by recording their swimming behavior under dark conditions. Grass puffers preferred to stay on the side of the aquarium where 5,6,11-trideoxyTTX was administered, and their swimming speed decreased. Additionally, odorant-induced labeling of olfactory sensory neurons by immunohistochemistry against neural activity marker (phosphorylated extracellular signal regulated kinase; pERK) revealed that labeled olfactory sensory neurons were localized in the region surrounding "islets" where there was considered as nonsensory epithelium. 5,6,11-trideoxyTTX has been known to accumulate in grass puffers, but its toxicity is much lower (almost nontoxic) than TTX. Our results suggest that toxic puffers may positively use this TTX analog, which has been present in their body with TTX but whose function was unknown, as an odorant for chemical communication or effective TTX accumulation.
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12
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Amano M, Takatani T, Sakayauchi F, Oi R, Sakakura Y. The brain of the wild toxic marine pufferfishes accumulates tetrodotoxin. Toxicon 2022; 218:1-7. [PMID: 36041513 DOI: 10.1016/j.toxicon.2022.08.015] [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: 04/22/2022] [Revised: 08/06/2022] [Accepted: 08/21/2022] [Indexed: 10/15/2022]
Abstract
We have previously detected tetrodotoxin (TTX) in the brain of the wild toxic torafugu Takifugu rubripes by immunohistochemistry and LC/MS analysis. We have also indicated that TTX is a stress-relieving substance in the brain and reduces agonistic interactions in torafugu juveniles. Although the toxicity of marine pufferfish in the Japanese waters has been extensively examined for food hygiene, whether wild toxic pufferfish generally possess TTX in the brain has not been investigated. In the present study, we examined the presence of TTX in the brain of several wild toxic marine pufferfishes such as kusafugu T. alboplumbeus, komonfugu T. poecilonotus, shosaifugu T. snyderi, okinawafugu Chelonodon patoca, and in wild non-toxic pufferfishes such as shirosabafugu Lagocephalus spadiceus and yoritofugu Sphoeroides pachygaster. We also examined tsumugihaze Yongeichthys criniger, known to possess TTX in the skin, viscera, and gonad. TTX was extracted from the brain, liver, skin, and muscle and was analyzed by LC/MS. TTX was detected in the brain as well as in the liver, skin, and muscle in kusafugu, komonfugu, shosaifugu, okinawafugu, and tsumugihaze. In shirosabafugu, low level of TTX (0.8 mouse unit/g-brain) was detected in the brain in 1 out of 3 individuals. In yoritofugu, no TTX was detected in any of the tissues. We conclude that the brain is also an organ that contains TTX in the wild toxic marine pufferfishes.
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Affiliation(s)
- Masafumi Amano
- School of Marine Biosciences, Kitasato University, Sagamihara, Kanagawa, 252-0373, Japan.
| | - Tomohiro Takatani
- Graduate School of Fisheries and Environmental Sciences, Institute of Integrated Science and Technology, Nagasaki University, Nagasaki, 852-8521, Japan
| | - Fuka Sakayauchi
- School of Marine Biosciences, Kitasato University, Sagamihara, Kanagawa, 252-0373, Japan
| | - Ryohei Oi
- School of Marine Biosciences, Kitasato University, Sagamihara, Kanagawa, 252-0373, Japan
| | - Yoshitaka Sakakura
- Graduate School of Fisheries and Environmental Sciences, Institute of Integrated Science and Technology, Nagasaki University, Nagasaki, 852-8521, Japan
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13
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Melnikova DI, Magarlamov TY. An Overview of the Anatomical Distribution of Tetrodotoxin in Animals. Toxins (Basel) 2022; 14:toxins14080576. [PMID: 36006238 PMCID: PMC9412668 DOI: 10.3390/toxins14080576] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 08/15/2022] [Accepted: 08/19/2022] [Indexed: 11/23/2022] Open
Abstract
Tetrodotoxin (TTX), a potent paralytic sodium channel blocker, is an intriguing marine toxin. Widely distributed in nature, TTX has attracted attention in various scientific fields, from biomedical studies to environmental safety concerns. Despite a long history of studies, many issues concerning the biosynthesis, origin, and spread of TTX in animals and ecosystems remain. This review aims to summarize the current knowledge on TTX circulation inside TTX-bearing animal bodies. We focus on the advances in TTX detection at the cellular and subcellular levels, providing an expanded picture of intra-organismal TTX migration mechanisms. We believe that this review will help address the gaps in the understanding of the biological function of TTX and facilitate the development of further studies involving TTX-bearing animals.
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14
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He X, Wu H, Ye Y, Gong X, Bao B. Transcriptome analysis revealed gene expression feminization of testis after exogenous tetrodotoxin administration in pufferfish Takifugu flavidus. BMC Genomics 2022; 23:553. [PMID: 35922761 PMCID: PMC9347094 DOI: 10.1186/s12864-022-08787-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 07/22/2022] [Indexed: 11/29/2022] Open
Abstract
Tetrodotoxin (TTX) is a deadly neurotoxin and usually accumulates in large amounts in the ovaries but is non-toxic or low toxic in the testis of pufferfish. The molecular mechanism underlying sexual dimorphism accumulation of TTX in ovary and testis, and the relationship between TTX accumulation with sex related genes expression remain largely unknown. The present study investigated the effects of exogenous TTX treatment on Takifugu flavidus. The results demonstrated that exogenous TTX administration significantly incresed level of TTX concentration in kidney, cholecyst, skin, liver, heart, muscle, ovary and testis of the treatment group (TG) than that of the control group (CG). Transcriptome sequencing and analysis were performed to study differential expression profiles of mRNA and piRNA after TTX administration of the ovary and testis. The results showed that compared with female control group (FCG) and male control group (MCG), TTX administration resulted in 80 and 23 piRNAs, 126 and 223 genes up and down regulated expression in female TTX-treated group (FTG), meanwhile, 286 and 223 piRNAs, 2 and 443 genes up and down regulated expression in male TTX-treated group (MTG). The female dominant genes cyp19a1, gdf9 and foxl2 were found to be up-regulated in MTG. The cyp19a1, whose corresponding target piRNA uniq_554482 was identified as down-regulated in the MTG, indicating the gene expression feminization in testis after exogenous TTX administration. The KEGG enrichment analysis revealed that differentially expressed genes (DEGs) and piRNAs (DEpiRNAs) in MTG vs MCG group were more enriched in metabolism pathways, indicating that the testis produced more metabolic pathways in response to exogenous TTX, which might be a reason for the sexual dimorphism of TTX distribution in gonads. In addition, TdT-mediated dUTP-biotin nick end labeling staining showed that significant apoptosis was detected in the MTG testis, and the role of the cell apoptotic pathways was further confirmed. Overall, our research revealed that the response of the ovary and testis to TTX administration was largely different, the ovary is more tolerant whereas the testis is more sensitive to TTX. These data will deepen our understanding on the accumulation of TTX sexual dimorphism in Takifugu.
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Affiliation(s)
- Xue He
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources (Shanghai Ocean University), Ministry of Education; International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology; National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai, 201306, China
| | - Hexing Wu
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources (Shanghai Ocean University), Ministry of Education; International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology; National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai, 201306, China
| | - Yaping Ye
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources (Shanghai Ocean University), Ministry of Education; International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology; National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai, 201306, China
| | - Xiaolin Gong
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources (Shanghai Ocean University), Ministry of Education; International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology; National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai, 201306, China
| | - Baolong Bao
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources (Shanghai Ocean University), Ministry of Education; International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology; National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai, 201306, China.
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15
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Tetrodotoxin Retention in the Toxic Goby Yongeichthys criniger. JOURNAL OF MARINE SCIENCE AND ENGINEERING 2022. [DOI: 10.3390/jmse10020191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
To investigate tetrodotoxin (TTX) retention by the toxic goby Yongeichthys criniger, rearing experiments feeding nontoxic diets were conducted using 12 (Group I) and 17 (Group II) specimens collected from a natural environment. The specimens were reared in an aquarium with aeration and fed a diet lacking TTX for 60 days. Specimens were removed at 0, 20, 40, and 60 days (Group I) or 0, 30, and 60 days (Group II) after initiation of rearing. Liquid chromatography/mass spectrometry and liquid chromatography-tandem mass spectrometry revealed that whole-body concentrations and amounts of TTX decreased with increasing rearing duration in Group I. There were similar decreases in Group II, but the trend differed among tissues; the concentrations and amounts of TTX in the skin exhibited the greatest decreases. The results imply that Y. criniger has low TTX retention ability.
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16
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Christidis G, Mandalakis M, Anastasiou TI, Tserpes G, Peristeraki P, Somarakis S. Keeping Lagocephalus sceleratus off the Table: Sources of Variation in the Quantity of TTX, TTX Analogues, and Risk of Tetrodotoxication. Toxins (Basel) 2021; 13:toxins13120896. [PMID: 34941733 PMCID: PMC8706384 DOI: 10.3390/toxins13120896] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 12/06/2021] [Accepted: 12/10/2021] [Indexed: 11/16/2022] Open
Abstract
The invasion of the tetrodotoxin (TTX)-bearing silver-cheeked toadfish and potential poisoning due to its consumption (tetrodotoxication) threatens public safety in the Mediterranean Sea. In this study, TTX and TTX analogues of Lagocephalus sceleratus (Gmelin, 1789) were measured using liquid chromatography tandem mass spectrometry (LC-MS/MS) in fish collected off the island of Crete (Southern Mediterranean). We tested the synergistic effect of a suite of factors potentially affecting toxins' levels and tetrodotoxication risk using general and generalized linear models, respectively. The type of tissue, geographic origin (Cretan Sea, Libyan Sea), sex, and fish maturity stage were significant predictors of toxin concentrations. Mean TTX was higher in gonads and lower in muscles, higher in the Libyan Sea and in female fish, and lower in juvenile (virgin) fish. The concentration of TTX was also significantly and positively correlated with the concentration of several TTX analogues (4-epiTTX, 4,9-anhydroTTX, 11-deoxyTTX, 5,11/6,11-dideoxyTTX, 5,6,11-trideoxyTTX, 11-norTTX-6-ol). The analysis showed that fish originating from the Libyan Sea had significantly higher probability to cause tetrodotoxication in case of consumption. The variability explained by the models developed in this study was relatively low, indicating that toxin levels are hard to predict and the consumption of L. sceleratus should therefore be avoided.
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Affiliation(s)
- Georgios Christidis
- Institute of Marine Biological Resources and Inland Waters, Hellenic Centre for Marine Research (HCMR), 71500 Heraklion, Greece; (G.T.); (P.P.); (S.S.)
- Biology Department, University of Crete, 70013 Heraklion, Greece
- Correspondence: (G.C.); (M.M.)
| | - Manolis Mandalakis
- Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Center of Marine Research (HCMR), 71500 Heraklion, Greece;
- Correspondence: (G.C.); (M.M.)
| | - Thekla I. Anastasiou
- Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Center of Marine Research (HCMR), 71500 Heraklion, Greece;
| | - George Tserpes
- Institute of Marine Biological Resources and Inland Waters, Hellenic Centre for Marine Research (HCMR), 71500 Heraklion, Greece; (G.T.); (P.P.); (S.S.)
| | - Panagiota Peristeraki
- Institute of Marine Biological Resources and Inland Waters, Hellenic Centre for Marine Research (HCMR), 71500 Heraklion, Greece; (G.T.); (P.P.); (S.S.)
| | - Stylianos Somarakis
- Institute of Marine Biological Resources and Inland Waters, Hellenic Centre for Marine Research (HCMR), 71500 Heraklion, Greece; (G.T.); (P.P.); (S.S.)
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17
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Dean KJ, Alexander RP, Hatfield RG, Lewis AM, Coates LN, Collin T, Teixeira Alves M, Lee V, Daumich C, Hicks R, White P, Thomas KM, Ellis JR, Turner AD. The Common Sunstar Crossaster papposus-A Neurotoxic Starfish. Mar Drugs 2021; 19:695. [PMID: 34940694 PMCID: PMC8704474 DOI: 10.3390/md19120695] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 12/01/2021] [Accepted: 12/01/2021] [Indexed: 12/21/2022] Open
Abstract
Saxitoxins (STXs) are a family of potent neurotoxins produced naturally by certain species of phytoplankton and cyanobacteria which are extremely toxic to mammalian nervous systems. The accumulation of STXs in bivalve molluscs can significantly impact animal and human health. Recent work conducted in the North Sea highlighted the widespread presence of various saxitoxins in a range of benthic organisms, with the common sunstar (Crossaster papposus) demonstrating high concentrations of saxitoxins. In this study, an extensive sampling program was undertaken across multiple seas surrounding the UK, with 146 starfish and 5 brittlestars of multiple species analysed for STXs. All the common sunstars analysed (n > 70) contained quantifiable levels of STXs, with the total concentrations ranging from 99 to 11,245 µg STX eq/kg. The common sunstars were statistically different in terms of toxin loading to all the other starfish species tested. Two distinct toxic profiles were observed in sunstars, a decarbomylsaxitoxin (dcSTX)-dominant profile which encompassed samples from most of the UK coast and an STX and gonyautoxin2 (GTX2) profile from the North Yorkshire coast of England. Compartmentalisation studies demonstrated that the female gonads exhibited the highest toxin concentrations of all the individual organs tested, with concentrations >40,000 µg STX eq/kg in one sample. All the sunstars, male or female, exhibited the presence of STXs in the skin, digestive glands and gonads. This study highlights that the common sunstar ubiquitously contains STXs, independent of the geographical location around the UK and often at concentrations many times higher than the current regulatory limits for STXs in molluscs; therefore, the common sunstar should be considered toxic hereafter.
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Affiliation(s)
- Karl J. Dean
- Centre for Environment Fisheries and Aquaculture Science (CEFAS), Barrack Road, Weymouth DT4 8UB, UK; (R.P.A.); (R.G.H.); (A.M.L.); (L.N.C.); (T.C.); (M.T.A.); (V.L.); (C.D.); (R.H.); (P.W.); (A.D.T.)
| | - Ryan P. Alexander
- Centre for Environment Fisheries and Aquaculture Science (CEFAS), Barrack Road, Weymouth DT4 8UB, UK; (R.P.A.); (R.G.H.); (A.M.L.); (L.N.C.); (T.C.); (M.T.A.); (V.L.); (C.D.); (R.H.); (P.W.); (A.D.T.)
| | - Robert G. Hatfield
- Centre for Environment Fisheries and Aquaculture Science (CEFAS), Barrack Road, Weymouth DT4 8UB, UK; (R.P.A.); (R.G.H.); (A.M.L.); (L.N.C.); (T.C.); (M.T.A.); (V.L.); (C.D.); (R.H.); (P.W.); (A.D.T.)
| | - Adam M. Lewis
- Centre for Environment Fisheries and Aquaculture Science (CEFAS), Barrack Road, Weymouth DT4 8UB, UK; (R.P.A.); (R.G.H.); (A.M.L.); (L.N.C.); (T.C.); (M.T.A.); (V.L.); (C.D.); (R.H.); (P.W.); (A.D.T.)
| | - Lewis N. Coates
- Centre for Environment Fisheries and Aquaculture Science (CEFAS), Barrack Road, Weymouth DT4 8UB, UK; (R.P.A.); (R.G.H.); (A.M.L.); (L.N.C.); (T.C.); (M.T.A.); (V.L.); (C.D.); (R.H.); (P.W.); (A.D.T.)
| | - Tom Collin
- Centre for Environment Fisheries and Aquaculture Science (CEFAS), Barrack Road, Weymouth DT4 8UB, UK; (R.P.A.); (R.G.H.); (A.M.L.); (L.N.C.); (T.C.); (M.T.A.); (V.L.); (C.D.); (R.H.); (P.W.); (A.D.T.)
- Department of Chemistry, University of Surrey, Guildford GU2 7XH, UK
| | - Mickael Teixeira Alves
- Centre for Environment Fisheries and Aquaculture Science (CEFAS), Barrack Road, Weymouth DT4 8UB, UK; (R.P.A.); (R.G.H.); (A.M.L.); (L.N.C.); (T.C.); (M.T.A.); (V.L.); (C.D.); (R.H.); (P.W.); (A.D.T.)
| | - Vanessa Lee
- Centre for Environment Fisheries and Aquaculture Science (CEFAS), Barrack Road, Weymouth DT4 8UB, UK; (R.P.A.); (R.G.H.); (A.M.L.); (L.N.C.); (T.C.); (M.T.A.); (V.L.); (C.D.); (R.H.); (P.W.); (A.D.T.)
- Department of Chemistry, University of Surrey, Guildford GU2 7XH, UK
| | - Caroline Daumich
- Centre for Environment Fisheries and Aquaculture Science (CEFAS), Barrack Road, Weymouth DT4 8UB, UK; (R.P.A.); (R.G.H.); (A.M.L.); (L.N.C.); (T.C.); (M.T.A.); (V.L.); (C.D.); (R.H.); (P.W.); (A.D.T.)
| | - Ruth Hicks
- Centre for Environment Fisheries and Aquaculture Science (CEFAS), Barrack Road, Weymouth DT4 8UB, UK; (R.P.A.); (R.G.H.); (A.M.L.); (L.N.C.); (T.C.); (M.T.A.); (V.L.); (C.D.); (R.H.); (P.W.); (A.D.T.)
| | - Peter White
- Centre for Environment Fisheries and Aquaculture Science (CEFAS), Barrack Road, Weymouth DT4 8UB, UK; (R.P.A.); (R.G.H.); (A.M.L.); (L.N.C.); (T.C.); (M.T.A.); (V.L.); (C.D.); (R.H.); (P.W.); (A.D.T.)
| | - Krista M. Thomas
- Biotoxin Metrology, National Research Council Canada, Halifax, NS B3Z 3H1, Canada;
| | - Jim R. Ellis
- Centre for Environment Fisheries and Aquaculture Science (CEFAS), Pakefield Road, Lowestoft NR33 0HT, UK;
| | - Andrew D. Turner
- Centre for Environment Fisheries and Aquaculture Science (CEFAS), Barrack Road, Weymouth DT4 8UB, UK; (R.P.A.); (R.G.H.); (A.M.L.); (L.N.C.); (T.C.); (M.T.A.); (V.L.); (C.D.); (R.H.); (P.W.); (A.D.T.)
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De Novo Accumulation of Tetrodotoxin and Its Analogs in Pufferfish and Newt and Dosage-Driven Accumulation of Toxins in Newt: Tissue Distribution and Anatomical Localization. JOURNAL OF MARINE SCIENCE AND ENGINEERING 2021. [DOI: 10.3390/jmse9091004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The present study was undertaken to determine the amounts of tetrodotoxin (TTX) and its analogs (TTXs) in various tissues of toxin-bearing pufferfish (Canthigaster revulata and Takifugu flavipterus) and newt (Cynops pyrrhogaster) using specific polyclonal antibodies against TTXs, and to compare the obtained results with those mainly determined by high-performance liquid chromatography with fluorescence detection (HPLC-FLD). The anatomical localization of TTXs in these animals was also demonstrated immunohistochemically using the above-mentioned antibody. The ratio of the total amount of TTXs determined by ELISA to that determined by HPLC-FLD changed depending on the tissues examined in pufferfish. Such differences were also observed with the newt in tissue- and individual-dependent manners. Furthermore, TTXs, as well as decarbamoylsaxitoxin (dcSTX), an analog of saxitoxin (STX), were traced for their dynamic changes in tissue distribution, when the newt was fed authentic toxins or toxic animal tissues exogenously, demonstrating that a TTX analog, 5,6,11-trideoxyTTX, and dcSTX were not metabolized into TTX or STX. TTXs-immunoreactive (ir) staining was observed in the pancreas region of the hepatopancreas, the oocytes at the perinucleolus stage, the sac-like tissues just outside the serous membrane of the intestine, and the gland-like structure of the skin, but not in the muscles of pufferfish. TTXs-ir staining was also detected in the mature glands in the dermis of the adult and regenerated tail, but not in the liver, intestine, testis and ovary of the adult newt. TTXs-ir staining was detected in the epithelial cells of the intestine, the ovary, the mucous cells, and the dermis of the TTXs-administered newt. These results suggest that TTXs absorbed from the environment are distributed to various organs or tissues in a species-specific manner, regardless of whether or not these are metabolized in the bodies of toxin-bearing animals.
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Battini N, Giachetti CB, Castro KL, Bortolus A, Schwindt E. Predator–prey interactions as key drivers for the invasion success of a potentially neurotoxic sea slug. Biol Invasions 2021. [DOI: 10.1007/s10530-020-02431-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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20
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Vlasenko AE, Magarlamov TY. Tetrodotoxin and Its Analogues in Cephalothrix cf. simula (Nemertea: Palaeonemertea) from the Sea of Japan (Peter the Great Gulf): Intrabody Distribution and Secretions. Toxins (Basel) 2020; 12:toxins12120745. [PMID: 33256088 PMCID: PMC7760002 DOI: 10.3390/toxins12120745] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 11/24/2020] [Accepted: 11/25/2020] [Indexed: 11/16/2022] Open
Abstract
Some nemertean species from the genus Cephalothrix accumulate tetrodotoxin (TTX) in extremely high concentrations. The current study is the first to provide high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) data on tetrodotoxin and its analogues (TTXs) profile and concentration in different regions and organs of Cephalothrix cf. simula, and its secretions produced in response to stimulation. Different specimens of C. cf. simula possessed 7-11 analogues, including nine previously found in this species and two new for nemerteans-4,9-anhydro-8-epi-5,6,11-trideoxyTTX and 1-hydroxy-8-epi-5,6,11-trideoxyTTX. The study of the toxins' distribution in different regions and organs of nemerteans revealed the same qualitative composition of TTXs throughout the body but differences in the total concentration of the toxins. The total concentration of TTXs was highest in the anterior region of the body and decreased towards the posterior; the ratio of the analogues also differed between regions. The data obtained suggest a pathway of TTXs uptake in C. cf. simula and the role of toxins in the life activity of nemerteans.
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Yang S, Wang Y, Wang L, Kamau P, Zhang H, Luo A, Lu X, Lai R. Target switch of centipede toxins for antagonistic switch. SCIENCE ADVANCES 2020; 6:eabb5734. [PMID: 32821839 PMCID: PMC7413724 DOI: 10.1126/sciadv.abb5734] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 06/26/2020] [Indexed: 05/02/2023]
Abstract
Animal venoms are powerful, highly evolved chemical weapons for defense and predation. While venoms are used mainly to lethally antagonize heterospecifics (individuals of a different species), nonlethal envenomation of conspecifics (individuals of the same species) is occasionally observed. Both the venom and target specifications underlying these two forms of envenomation are still poorly understood. Here, we show a target-switching mechanism in centipede (Scolopendra subspinipes) venom. On the basis of this mechanism, a major toxin component [Ssm Spooky Toxin (SsTx)] in centipede venom inhibits the Shal channel in conspecifics but not in heterospecifics to cause short-term, recoverable, and nonlethal envenomation. This same toxin causes fatal heterospecific envenomation, for example, by switching its target to the Shaker channels in heterospecifics without inhibiting the Shaker channel of conspecific S. subspinipes individuals. These findings suggest that venom components exhibit intricate coevolution with their targets in both heterospecifics and conspecifics, which enables a single toxin to develop graded intraspecific and interspecific antagonistic interactions.
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Affiliation(s)
- Shilong Yang
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences/Key Laboratory of bioactive peptides of Yunnan Province, Kunming Institute of Zoology, Kunming, Yunnan 650223, China
- College of Wildlife and Protected Area, Northeast Forestry University, Harbin 150040, China
| | - Yunfei Wang
- College of Wildlife and Protected Area, Northeast Forestry University, Harbin 150040, China
| | - Lu Wang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming, Yunnan 650091, China
| | - Peter Kamau
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences/Key Laboratory of bioactive peptides of Yunnan Province, Kunming Institute of Zoology, Kunming, Yunnan 650223, China
- Kunming College of Life Science, University of Chinese Academy of Sciences, Beijing 100049, China
- Sino-African Joint Research Center, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650223, China
| | - Hao Zhang
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences/Key Laboratory of bioactive peptides of Yunnan Province, Kunming Institute of Zoology, Kunming, Yunnan 650223, China
- Kunming College of Life Science, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Anna Luo
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences/Key Laboratory of bioactive peptides of Yunnan Province, Kunming Institute of Zoology, Kunming, Yunnan 650223, China
- Kunming College of Life Science, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiancui Lu
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences/Key Laboratory of bioactive peptides of Yunnan Province, Kunming Institute of Zoology, Kunming, Yunnan 650223, China
- Kunming College of Life Science, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ren Lai
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences/Key Laboratory of bioactive peptides of Yunnan Province, Kunming Institute of Zoology, Kunming, Yunnan 650223, China
- Kunming College of Life Science, University of Chinese Academy of Sciences, Beijing 100049, China
- Sino-African Joint Research Center, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650223, China
- KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650223, China
- Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, Hubei 430071, China
- Institute for Drug Discovery and Development, Chinese Academy of Sciences, Shanghai 201203, China
- Corresponding author.
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Co-Occurrence of Tetrodotoxin and Saxitoxins and Their Intra-Body Distribution in the Pufferfish Canthigaster valentini. Toxins (Basel) 2020; 12:toxins12070436. [PMID: 32635254 PMCID: PMC7405003 DOI: 10.3390/toxins12070436] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 06/29/2020] [Accepted: 07/02/2020] [Indexed: 12/03/2022] Open
Abstract
Pufferfish of the family Tetraodontidae possess tetrodotoxin (TTX) and/or saxitoxins (STXs), but the toxin ratio differs, depending on the genus or species. In the present study, to clarify the distribution profile of TTX and STXs in Tetraodontidae, we investigated the composition and intra-body distribution of the toxins in Canthigaster valentini. C. valentini specimens (four male and six female) were collected from Amami-Oshima Island, Kagoshima Prefecture, Japan, and the toxins were extracted from the muscle, liver, intestine, gallbladder, gonads, and skin. Analysis of the extracts for TTX by liquid chromatography tandem mass spectrometry and of STXs by high-performance liquid chromatography with post-column fluorescence derivatization revealed TTX, as well as a large amount of STXs, with neoSTX as the main component and dicarbamoylSTX and STX itself as minor components, in the skin and ovary. The toxins were also detected in the other tissues, but in much lower amounts than in the skin and ovary. The TTX/STX ratio varied greatly, depending on the tissue, but TTX was the major toxin component in the whole body, and STXs accounted for 25% and 13% of the total toxin amount in males and females, respectively. Like the marine pufferfish of the genus Arothron, C. valentini should be considered a pufferfish with considerable amounts of both TTX and STXs present simultaneously.
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Itoi S, Sato T, Takei M, Yamada R, Ogata R, Oyama H, Teranishi S, Kishiki A, Wada T, Noguchi K, Abe M, Okabe T, Akagi H, Kashitani M, Suo R, Koito T, Takatani T, Arakawa O, Sugita H. The planocerid flatworm is a main supplier of toxin to tetrodotoxin-bearing fish juveniles. CHEMOSPHERE 2020; 249:126217. [PMID: 32088461 DOI: 10.1016/j.chemosphere.2020.126217] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 02/11/2020] [Accepted: 02/13/2020] [Indexed: 06/10/2023]
Abstract
Tetrodotoxin (TTX), a potent neurotoxin, is found in various phylogenetically diverse taxa. In marine environments, the pufferfish is at the top of the food chain among TTX-bearing organisms. The accumulation of TTX in the body of pufferfish appears to be of the food web that begins with bacteria. It is known that toxic pufferfishes possess TTX from the larval/juvenile stage. However, the source of the TTX is unknown because the maternally sourced TTX is extremely small in quantity. Therefore, the TTX has to be obtained from other organisms or directly from the environment. Here, we report evidence that the source of TTX for toxic fish juveniles including the pufferfish (Chelonodon patoca) and the goby (Yongeichthys criniger) is in the food organisms, as seen in their gut contents. Next generation sequencing analysis for the mitochondrial COI gene showed that the majority of the sequence recovered from intestinal contents of these toxic fishes belonged to the flatworm Planocera multitentaculata, a polyclad flatworm containing highly concentrated TTX from the larval stage. PCR specific to P. multitentaculata also showed that DNA encoding the planocerid COI gene was strongly detected in the intestinal contents of the goby and pufferfish juveniles. Additionally, the planocerid specific COI sequence was detected in the environmental seawater collected from the water around the sampling locations for TTX-bearing fish. These results suggest that planocerid larvae are the major TTX supplier for juveniles of TTX-bearing fish species.
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Affiliation(s)
- Shiro Itoi
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan.
| | - Tatsunori Sato
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Mitsuki Takei
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Riko Yamada
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Ryuya Ogata
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Hikaru Oyama
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Shun Teranishi
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Ayano Kishiki
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Takenori Wada
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Kaede Noguchi
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Misato Abe
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Taiki Okabe
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Hiroyuki Akagi
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Maho Kashitani
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Rei Suo
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Tomoko Koito
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Tomohiro Takatani
- Graduate School of Fisheries Science and Environmental Studies, Nagasaki University, Bunkyo 1-14, Nagasaki, 852-8521, Japan
| | - Osamu Arakawa
- Graduate School of Fisheries Science and Environmental Studies, Nagasaki University, Bunkyo 1-14, Nagasaki, 852-8521, Japan
| | - Haruo Sugita
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
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Zhang X, Zong J, Chen S, Li M, Lu Y, Wang R, Xu H. Accumulation and Elimination of Tetrodotoxin in the Pufferfish Takifugu obscurus by Dietary Administration of the Wild Toxic Gastropod Nassarius semiplicata. Toxins (Basel) 2020; 12:toxins12050278. [PMID: 32344936 PMCID: PMC7290894 DOI: 10.3390/toxins12050278] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 04/23/2020] [Accepted: 04/23/2020] [Indexed: 12/21/2022] Open
Abstract
To investigate pufferfish accumulation, elimination, and distribution of tetrodotoxin (TTX), Takifugu obscurus was fed with wild TTX-containing gastropod Nassarius semiplicata to simulate the natural food chain. Three-month-old non-poisonous T. obscurus was fed with wild toxic N. semiplicata at three exposure dose for 28 days, and later, with toxin-free food until day 67. Three fish individuals from each treatment were sampled, and the distribution of TTX in different tissues was measured. The results showed that the accumulation ratio of TTX in the three exposure dose groups ranged from 35.76% to 40.20%. The accumulation ratio in the skin and liver was the highest amongst all tissues, accounting for more than 85% of the total TTX, whereas that in the kidney and gallbladder was the lowest (0.11–0.78%). Studies on the kinetic of TTX accumulation and elimination revealed that the skin was the tissue with the highest accumulation speed constant (8.06), while the liver, kidney, and intestinal tract showed the highest speed of TTX elimination. The time required for TTX reduction to reach the safety limit could be predicted by using standard elimination equations. Qualitative analysis by UPLC-MS/MS revealed the occurrence of seven TTX derivatives in T. obscurus; of these TTX, 5-deoxy TTX, 11-deoxy TTX, 4,9-anhydro TTX were found in all tested tissues.
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Affiliation(s)
- Xiaojun Zhang
- Laboratory of Aquatic Product Processing and Quality Safety, Marine Fisheries Research Institute of Zhejiang, Zhoushan 316100, China; (X.Z.); (S.C.)
- Zhejiang Province Key Lab of Mariculture & Enhancement, Zhoushan 316100, China
| | - Jingjing Zong
- School of Food and Pharmacy, Zhejiang Ocean University, Zhoushan 316022, China; (J.Z.); (Y.L.); (R.W.)
| | - Si Chen
- Laboratory of Aquatic Product Processing and Quality Safety, Marine Fisheries Research Institute of Zhejiang, Zhoushan 316100, China; (X.Z.); (S.C.)
- Zhejiang Province Key Lab of Mariculture & Enhancement, Zhoushan 316100, China
| | - Menglong Li
- Quality and Standard Research Center, Chinese Academy of Fishery Sciences, Beijing 100141, China;
| | - Yibo Lu
- School of Food and Pharmacy, Zhejiang Ocean University, Zhoushan 316022, China; (J.Z.); (Y.L.); (R.W.)
| | - Ruirui Wang
- School of Food and Pharmacy, Zhejiang Ocean University, Zhoushan 316022, China; (J.Z.); (Y.L.); (R.W.)
| | - Hanxiang Xu
- Laboratory of Aquatic Product Processing and Quality Safety, Marine Fisheries Research Institute of Zhejiang, Zhoushan 316100, China; (X.Z.); (S.C.)
- School of Food and Pharmacy, Zhejiang Ocean University, Zhoushan 316022, China; (J.Z.); (Y.L.); (R.W.)
- Correspondence: ; Tel.: +86-0580-2299-882
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Tetrodotoxin functions as a stress relieving substance in juvenile tiger puffer Takifugu rubripes. Toxicon 2019; 171:54-61. [PMID: 31580836 DOI: 10.1016/j.toxicon.2019.09.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Revised: 08/22/2019] [Accepted: 09/26/2019] [Indexed: 11/24/2022]
Abstract
We tested whether tetrodotoxin (TTX) functions as a stress relieving substance in puffer fish. We orally administered TTX to the juveniles of hatchery-reared non-toxic tiger puffer Takifugu rubripes and measured the effects of TTX on brain corticotropin-releasing hormone (CRH) mRNA expression and plasma cortisol levels in comparison with effects in non-toxic juveniles. Firstly, the reciprocal connections of CRH and adrenocorticotropic hormone (ACTH) were confirmed by dual-label immunohistochemistry. CRH-immunoreactive (ir) cell bodies were detected in the hypothalamus and CRH-ir fibers were observed to project to ACTH-ir cells in the rostral pars distalis of the pituitary. Next, a TTX-containing diet (2.35 mouse units (517 ng)/g diet) or a non-toxic diet were fed to the fish for 28 days under a recirculating system. Standard length and body weight became significantly larger in the TTX-treated group. The degree of loss of the caudal fin, which is an indicator of the degree of agonistic interactions, where high values show a higher loss of caudal fin of a fish due to nipping by other individuals, was significantly lower in the TTX-treated group. Relative CRH mRNA expression levels in the brain and cortisol levels in the plasma were significantly lower in the TTX-treated group. These results indicate that TTX functions as a stress relieving substance by affecting the CRH-ACTH-cortisol axis and reducing agonistic interactions in tiger puffer juveniles.
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Convergent and parallel evolution in a voltage-gated sodium channel underlies TTX-resistance in the Greater Blue-ringed Octopus: Hapalochlaena lunulata. Toxicon 2019; 170:77-84. [DOI: 10.1016/j.toxicon.2019.09.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 09/09/2019] [Accepted: 09/11/2019] [Indexed: 12/24/2022]
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Itoi S, Tabuchi S, Abe M, Ueda H, Oyama H, Ogata R, Okabe T, Kishiki A, Sugita H. Difference in tetrodotoxin content between two sympatric planocerid flatworms, Planocera multitentaculata and Planocera reticulata. Toxicon 2019; 173:57-61. [PMID: 31778684 DOI: 10.1016/j.toxicon.2019.11.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 11/24/2019] [Indexed: 11/20/2022]
Abstract
Planocerid flatworms and the related species (Platyhelminthes: polycladida) are known as tetrodotoxin (TTX)-bearing organisms, and they contribute to toxification of marine organisms at higher trophic levels, such as pufferfish and sea slugs. However, little is known of their biology or ecology. In this study, we therefore investigated the occurrence and toxicity of two sympatric planocerids, Planocera multitentaculata and Planocera reticulata, in intertidal zones of the central region of mainland Honshu, Japanese Islands. Planocera multitentaculata was much more abundant than P. reticulata. Body weight was greater in P. multitentaculata than in P. reticulata. Although a significant difference in TTX concentration was not observed between the two species, total TTX content per individual was greater in P. multitentaculata.
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Affiliation(s)
- Shiro Itoi
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan.
| | - Sora Tabuchi
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Misato Abe
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Hiroyuki Ueda
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Hikaru Oyama
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Ryuya Ogata
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Taiki Okabe
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Ayano Kishiki
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Haruo Sugita
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
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Okabe T, Oyama H, Kashitani M, Ishimaru Y, Suo R, Sugita H, Itoi S. Toxic Flatworm Egg Plates Serve as a Possible Source of Tetrodotoxin for Pufferfish. Toxins (Basel) 2019; 11:E402. [PMID: 31373322 PMCID: PMC6669758 DOI: 10.3390/toxins11070402] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 07/09/2019] [Accepted: 07/10/2019] [Indexed: 11/26/2022] Open
Abstract
The pufferfish Takifugu niphobles (at present Takifugu alboplumbeus) possesses highly concentrated tetrodotoxin (TTX), an extremely potent neurotoxin that provides effective protection from predators, at least at the larval stages. However, the source of the toxin has remained unclear. Recently, DNA from the toxic flatworm Planocera multitentaculata was detected in the intestinal contents of juveniles and young of the pufferfish, suggesting that the flatworm contributes to its toxification at various stages of its life. In this study, we describe the behavior of the pufferfish in the intertidal zone that appears to contribute to its toxification before and during its spawning period: pufferfish were found to aggregate and ingest flatworm egg plates by scraping them off the surface of rocks. DNA analysis based on 28S rRNA and cytochrome c oxidase subunit I (COI) genes identified the egg plates as those of P. multitentaculata. Liquid chromatography with tandem mass spectrometry analysis revealed that the egg plates contain highly concentrated TTX. The feeding behavior of the pufferfish on the flatworm egg plates was also observed in the aquarium. These results suggest that pufferfish feed on the flatworm egg plate, which enables them to acquire toxicity themselves while providing their offspring with the protective shield of TTX.
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Affiliation(s)
- Taiki Okabe
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Hikaru Oyama
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Maho Kashitani
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Yuta Ishimaru
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Rei Suo
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Haruo Sugita
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Shiro Itoi
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan.
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Kudo Y, Yotsu-Yamashita M. Isolation and Biological Activity of 8- Epitetrodotoxin and the Structure of a Possible Biosynthetic Shunt Product of Tetrodotoxin, Cep-226A, from the Newt Cynops ensicauda popei. JOURNAL OF NATURAL PRODUCTS 2019; 82:1656-1663. [PMID: 31117524 DOI: 10.1021/acs.jnatprod.9b00178] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Tetrodotoxin (TTX, 1), a potent neurotoxin, has been found in various animal species in both marine and terrestrial environments. In this study, a new TTX analogue, 8- epiTTX (2), and a possible biosynthetic shunt compound of TTX, Cep-226A (3), were isolated from the newt Cynops ensicauda popei. The voltage-gated sodium ion channel (Nav) blocking activity of 2 and 6- epiTTX (4), a known analogue, were investigated by a colorimetric cell-based assay and compared with that of 1. The EC50 values for 2 and 4 were determined to be 110 ± 40 and 33 ± 11 nM, respectively, which were larger than that of 1 (1.9 ± 0.7 nM). The results indicated that the equatorial hydroxy group at C-8 in TTX significantly contributes to its Nav blocking activity, whereas the 6-epimer of TTX retains substantial activity, consistent with its previously reported toxicity in mice and binding affinity to rat brain membrane preparations. The presence of these epimers of TTX (2 and 4) and Cep-226A (3) in newts supports our hypothesis that TTX is derived from a monoterpene in terrestrial environments.
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Affiliation(s)
- Yuta Kudo
- Graduate School of Agricultural Science , Tohoku University , 468-1 Aramaki-Aza-Aoba, Aoba-ku , Sendai , Miyagi 980-8572 , Japan
- Frontier Research Institute for Interdisciplinary Sciences , Tohoku University , 6-3 Aramaki-Aza-Aoba, Aoba-ku , Sendai , Miyagi 980-8578 , Japan
| | - Mari Yotsu-Yamashita
- Graduate School of Agricultural Science , Tohoku University , 468-1 Aramaki-Aza-Aoba, Aoba-ku , Sendai , Miyagi 980-8572 , Japan
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Duarte M, Gawryszewski FM, Ramineli S, Bessa E. Disruptive coloration and habitat use by seahorses. NEOTROPICAL ICHTHYOLOGY 2019. [DOI: 10.1590/1982-0224-20190064] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
ABSTRACT Predation avoidance is a primary factor influencing survival. Therefore, any trait that affects the risk of predation, such as camouflage, is expected to be under selection pressure. Background matching (homochromy) limits habitat use, especially if the habitat is heterogeneous. Another camouflage mechanism is disruptive coloration, which reduces the probability of detection by masking the prey’s body contours. Here we evaluated if disruptive coloration in the longsnout seahorse, Hippocampus reidi, allows habitat use diversification. We analyzed 82 photographs of animals, comparing animal and background color, and registering anchorage substrate (holdfast). We tested whether the presence (disruptive coloration) or absence of bands (plain coloration) predicted occupation of backgrounds of different colors. We also calculated the connectance between seahorse morph and background color or holdfast, as well as whether color morph differed in their preferences for holdfast. Animals with disruptive coloration were more likely to be found in environments with colors different from their own. Furthermore, animals with disruptive coloration occupied more diversified habitats, but as many holdfasts as plain colored animals. Therefore, animals with disruptive coloration were less selective in habitat use than those lacking disruptive color patterns, which agrees with the disruptive coloration hypothesis.
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Affiliation(s)
| | | | | | - Eduardo Bessa
- Universidade de Brasília, Brazil; Universidade de Brasília, Brazil
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31
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Abstract
Fish mucus layers are the main surface of exchange between fish and the environment, and they possess important biological and ecological functions. Fish mucus research is increasing rapidly, along with the development of high-throughput techniques, which allow the simultaneous study of numerous genes and molecules, enabling a deeper understanding of the fish mucus composition and its functions. Fish mucus plays a major role against fish infections, and research has mostly focused on the study of fish mucus bioactive molecules (e.g., antimicrobial peptides and immune-related molecules) and associated microbiota due to their potential in aquaculture and human medicine. However, external fish mucus surfaces also play important roles in social relationships between conspecifics (fish shoaling, spawning synchronisation, suitable habitat finding, or alarm signals) and in interspecific interactions such as prey-predator relationships, parasite–host interactions, and symbiosis. This article reviews the biological and ecological roles of external (gills and skin) fish mucus, discussing its importance in fish protection against pathogens and in intra and interspecific interactions. We also discuss the advances that “omics” sciences are bringing into the fish mucus research and their importance in studying the fish mucus composition and functions.
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Kato-Unoki Y, Takai Y, Kinoshita M, Mochizuki T, Tatsuno R, Shimasaki Y, Oshima Y. Genome editing of pufferfish saxitoxin- and tetrodotoxin-binding protein type 2 in Takifugu rubripes. Toxicon 2018; 153:58-61. [PMID: 30170168 DOI: 10.1016/j.toxicon.2018.08.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 08/03/2018] [Accepted: 08/19/2018] [Indexed: 01/17/2023]
Abstract
The pufferfish saxitoxin- and tetrodotoxin-binding protein 2 (PSTBP2), which is involved in toxin accumulation, was knocked out in Takifugu rubripes embryos by using clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 genome-editing technology. Treating the embryos with one of two single-guide RNA (sgRNA) resulted in mutation rates of 57.1% and 62.5%, respectively, as estimated using a heteroduplex mobility assay at 3 days postfertilization. Both sgRNAs might induced frameshift mutations that knocked out the T. rubripes PSTBP2.
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Affiliation(s)
- Yoko Kato-Unoki
- Laboratory of Marine Environmental Science, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 819-0395, Japan
| | - Yuki Takai
- Laboratory of Marine Environmental Science, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 819-0395, Japan
| | - Masato Kinoshita
- Department of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
| | | | - Ryohei Tatsuno
- Department of Food Science and Technology, National Fisheries University, Japan Fisheries Research and Education Agency, 2-7-1 Nagata-Honmachi, Shimonoseki, Yamaguchi 759-6595, Japan
| | - Yohei Shimasaki
- Laboratory of Marine Environmental Science, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 819-0395, Japan
| | - Yuji Oshima
- Laboratory of Marine Environmental Science, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 819-0395, Japan.
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Tsutsui S, Suzuki Y, Shibuya K, Nakamura O. Sacciform cells in the epidermis of fugu (Takifugu rubripes) produce and secrete kalliklectin, a novel lectin found in teleosts. FISH & SHELLFISH IMMUNOLOGY 2018; 80:311-318. [PMID: 29902562 DOI: 10.1016/j.fsi.2018.06.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 06/06/2018] [Accepted: 06/08/2018] [Indexed: 06/08/2023]
Abstract
Kalliklectin is a novel lectin identified in the skin mucus and blood plasma of teleosts, including fugu (Takifugu rubripes). It has been found to exhibit sequence similarity to mammalian plasma kallikrein and coagulation factor XI. The objective of the present study was to clarify the cellular localization of kalliklectin using an antiserum specific to fugu kalliklectin. Immunohistochemical analysis showed that positive reactions were observed in the skin and liver, but not in other tested tissues. Several types of epidermal cells were stained by the antiserum; sacciform cells were one of the types of cells most densely stained by the antiserum in adult fugu skin, whereas mucous cells showed negative staining results. RT-PCR demonstrated that the kalliklectin gene was transcribed in the mucous cell-poor region of adult fugu skin, where sacciform cells were present. These results indicated that epidermal cells, including sacciform cells, produce kalliklectin and secrete it into the mucus.
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Affiliation(s)
- Shigeyuki Tsutsui
- School of Marine Biosciences, Kitasato University, 1-15-1 Kitasato, Sagamihara, Kanagawa, 252-0373, Japan.
| | - Yuya Suzuki
- School of Marine Biosciences, Kitasato University, 1-15-1 Kitasato, Sagamihara, Kanagawa, 252-0373, Japan
| | - Ko Shibuya
- School of Marine Biosciences, Kitasato University, 1-15-1 Kitasato, Sagamihara, Kanagawa, 252-0373, Japan
| | - Osamu Nakamura
- School of Marine Biosciences, Kitasato University, 1-15-1 Kitasato, Sagamihara, Kanagawa, 252-0373, Japan
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Itoi S, Ueda H, Yamada R, Takei M, Sato T, Oshikiri S, Wajima Y, Ogata R, Oyama H, Shitto T, Okuhara K, Tsunashima T, Sawayama E, Sugita H. Including planocerid flatworms in the diet effectively toxifies the pufferfish, Takifugu niphobles. Sci Rep 2018; 8:12302. [PMID: 30120305 PMCID: PMC6098040 DOI: 10.1038/s41598-018-30696-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 08/04/2018] [Indexed: 11/26/2022] Open
Abstract
Beginning with the larval stages, marine pufferfish such as Takifugu niphobles contain tetrodotoxin (TTX), an extremely potent neurotoxin. Although highly concentrated TTX has been detected in adults and juveniles of these fish, the source of the toxin has remained unclear. Here we show that TTX in the flatworm Planocera multitentaculata contributes to the toxification of the pufferfish throughout the life cycle of the flatworm. A species-specific PCR method was developed for the flatworm, and the specific DNA fragment was detected in the digesta of wild pufferfish adults. Predation experiments showed that flatworm larvae were eaten by the pufferfish juveniles, and that the two-day postprandial TTX content in these pufferfish was 20–50 μg/g. Predation experiments additionally showed flatworm adults were also eaten by pufferfish young, and after two days of feeding, TTX accumulated in the skin, liver and intestine of the pufferfish.
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Affiliation(s)
- Shiro Itoi
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan.
| | - Hiroyuki Ueda
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Riko Yamada
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Mitsuki Takei
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Tatsunori Sato
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Shotaro Oshikiri
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Yoshiki Wajima
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Ryuya Ogata
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Hikaru Oyama
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Takahiro Shitto
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Kazuya Okuhara
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Tadasuke Tsunashima
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
| | - Eitaro Sawayama
- R&D Division, Marua Suisan Co., Ltd. Kamijima, Ehime, 794-2410, Japan
| | - Haruo Sugita
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan
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35
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Role of maternal tetrodotoxin in survival of larval pufferfish. Toxicon 2018; 148:95-100. [DOI: 10.1016/j.toxicon.2018.04.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 04/03/2018] [Accepted: 04/14/2018] [Indexed: 11/20/2022]
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36
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Morita M, Schmidt EW. Parallel lives of symbionts and hosts: chemical mutualism in marine animals. Nat Prod Rep 2018; 35:357-378. [PMID: 29441375 PMCID: PMC6025756 DOI: 10.1039/c7np00053g] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Covering: up to 2018 Symbiotic microbes interact with animals, often by producing natural products (specialized metabolites; secondary metabolites) that exert a biological role. A major goal is to determine which microbes produce biologically important compounds, a deceptively challenging task that often rests on correlative results, rather than hypothesis testing. Here, we examine the challenges and successes from the perspective of marine animal-bacterial mutualisms. These animals have historically provided a useful model because of their technical accessibility. By comparing biological systems, we suggest a common framework for establishing chemical interactions between animals and microbes.
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Affiliation(s)
- Maho Morita
- Department of Medicinal Chemistry, University of Utah, Salt Lake City, Utah, USA 84112.
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37
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Nagashima Y, Ohta A, Yin X, Ishizaki S, Matsumoto T, Doi H, Ishibashi T. Difference in Uptake of Tetrodotoxin and Saxitoxins into Liver Tissue Slices among Pufferfish, Boxfish and Porcupinefish. Mar Drugs 2018; 16:md16010017. [PMID: 29316695 PMCID: PMC5793065 DOI: 10.3390/md16010017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2017] [Revised: 12/27/2017] [Accepted: 01/04/2018] [Indexed: 11/16/2022] Open
Abstract
Although pufferfish of the family Tetraodontidae contain high levels of tetrodotoxin (TTX) mainly in the liver, some species of pufferfish, boxfish of the family Ostraciidae, and porcupinefish of the family Diodontidae do not. To clarify the mechanisms, uptake of TTX and saxitoxins (STXs) into liver tissue slices of pufferfish, boxfish and porcupinefish was examined. Liver tissue slices of the pufferfish (toxic species Takifugu rubripes and non-toxic species Lagocephalus spadiceus, L. cheesemanii and Sphoeroides pachygaster) incubated with 50 µM TTX accumulated TTX (0.99-1.55 µg TTX/mg protein) after 8 h, regardless of the toxicity of the species. In contrast, in liver tissue slices of boxfish (Ostracion immaculatus) and porcupinefish (Diodon holocanthus, D. liturosus, D. hystrix and Chilomycterus reticulatus), TTX content did not increase with incubation time, and was about 0.1 µg TTX/mg protein. When liver tissue slices were incubated with 50 µM STXs for 8 h, the STXs content was <0.1 µg STXs/mg protein, irrespective of the fish species. These findings indicate that, like the toxic species of pufferfish T. rubripes, non-toxic species such as L. spadiceus, L. cheesemanii and S. pachygaster, potentially take up TTX into the liver, while non-toxic boxfish and porcupinefish do not take up either TTX or STXs.
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Affiliation(s)
- Yuji Nagashima
- Department of Food Science and Technology, Tokyo University of Marine Science and Technology, Minato, Tokyo 108-8477, Japan.
| | - Akira Ohta
- Department of Food Science and Technology, Tokyo University of Marine Science and Technology, Minato, Tokyo 108-8477, Japan.
| | - Xianzhe Yin
- Department of Food Science and Technology, Tokyo University of Marine Science and Technology, Minato, Tokyo 108-8477, Japan.
| | - Shoichiro Ishizaki
- Department of Food Science and Technology, Tokyo University of Marine Science and Technology, Minato, Tokyo 108-8477, Japan.
| | - Takuya Matsumoto
- Department of Environmental Sciences, Faculty of Life and Environmental Science, Prefectural University of Hiroshima, Shobara, Hiroshima 727-0023, Japan.
| | - Hiroyuki Doi
- Shimonoseki Marine Science Museum "Kaikyokan", Shimonoseki, Yamaguchi 750-0036, Japan.
- Osaka Aquarium Kaiyukan NIFREL, Suita, Osaka 565-0826, Japan.
| | - Toshiaki Ishibashi
- Shimonoseki Marine Science Museum "Kaikyokan", Shimonoseki, Yamaguchi 750-0036, Japan.
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38
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Yin X, Kiriake A, Ohta A, Kitani Y, Ishizaki S, Nagashima Y. A novel function of vitellogenin subdomain, vWF type D, as a toxin-binding protein in the pufferfish Takifugu pardalis ovary. Toxicon 2017; 136:56-66. [PMID: 28651990 DOI: 10.1016/j.toxicon.2017.06.006] [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: 04/08/2017] [Revised: 05/25/2017] [Accepted: 06/10/2017] [Indexed: 10/19/2022]
Abstract
Marine pufferfish of the Tetraodontidae family contain high levels of tetrodotoxin (TTX) in the liver and ovary. TTX is suggested to transfer from the liver to the ovary in female pufferfish during maturation. TTX in pufferfish eggs may act as a repellent against predators and as a sexual pheromone to attract male pufferfish. The toxification mechanism of the pufferfish ovary is poorly understood. Here we evaluated the chemical form of TTX and its related substances in the ovary of the panther pufferfish Takifugu pardalis by LC-ESI/MS. TTX and its analogs 4-epi-TTX, 4, 9-anhydroTTX, deoxyTTX, dideoxyTTX, and trideoxyTTX were detected in a low molecular weight fraction by Sephacryl S-400 column chromatography. The finding of an unknown TTX-related substance in a high molecular weight fraction from the Sephacryl S-400 column suggested the occurrence of toxin-binding protein in the ovary. The toxin-binding protein in the ovary was purified by ion-exchange HPLC, gel filtration HPLC, and SDS-PAGE. Amino acid sequencing and cDNA cloning revealed that the toxin-binding protein, TPOBP-10 (Takifugu pardalis ovary toxin-binding protein with a molecular mass of 10 kDa) was homologous with the predicted vitellogenin-1-like protein [Takifugu rubripes] subdomain, a von Willebrand factor type D domain. TPOBP-10 mRNA was highly expressed in the ovary and liver and less in other organs of female individuals based on RT-PCR. These findings reveal a novel function of the vitellogenin subdomain as binding with TTX-related substances, and its involvement in the toxification of the pufferfish ovary.
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Affiliation(s)
- Xianzhe Yin
- Department of Food Science and Technology, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato, Tokyo 108-8477, Japan
| | - Aya Kiriake
- Department of Food Science and Technology, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato, Tokyo 108-8477, Japan
| | - Akira Ohta
- Department of Food Science and Technology, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato, Tokyo 108-8477, Japan
| | - Yoichiro Kitani
- Faculty of Biosciences and Aquaculture, NORD University, Bodø 8049, Norway
| | - Shoichiro Ishizaki
- Department of Food Science and Technology, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato, Tokyo 108-8477, Japan
| | - Yuji Nagashima
- Department of Food Science and Technology, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato, Tokyo 108-8477, Japan.
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39
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Tatsuno R, Gao W, Ibi K, Mine T, Okita K, Nishihara GN, Takatani T, Arakawa O. Profile differences in tetrodotoxin transfer to skin and liver in the pufferfish Takifugu rubripes. Toxicon 2017; 130:73-78. [DOI: 10.1016/j.toxicon.2017.03.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 02/28/2017] [Accepted: 03/01/2017] [Indexed: 10/20/2022]
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40
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Seasonal Changes in the Tetrodotoxin Content of the Flatworm Planocera multitentaculata. Mar Drugs 2017; 15:md15030056. [PMID: 28245608 PMCID: PMC5367013 DOI: 10.3390/md15030056] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 02/15/2017] [Accepted: 02/23/2017] [Indexed: 11/18/2022] Open
Abstract
Tetrodotoxin (TTX) is a potent neurotoxin that acts specifically on voltage-gated sodium channels on excitable membranes of muscle and nerve tissues. The biosynthetic process for TTX is unclear, although marine bacteria are generally thought to be the primary producers. The marine flatworm Planocera multitentaculata is a known TTX-bearing organism, and is suspected to be a TTX supplier to pufferfish. In this study, flatworm specimens were collected from an intertidal zone in Hayama, Kanagawa, Japan, the TTX content of the flatworm was measured using liquid chromatography with tandem mass spectrometry (LC-MS/MS), and seasonal changes in TTX content were investigated. No significant difference in TTX concentration of the flatworm body was found between the spawning period and other periods. However, the TTX content in individual flatworms was significantly higher in the spawning period than at other times. The TTX content rose in association with an increase in the body weight of the flatworm.
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41
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Developmental morphology of granular skin glands in pre-metamorphic egg-eating poison frogs. ZOOMORPHOLOGY 2017. [DOI: 10.1007/s00435-017-0344-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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42
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Itoi S, Ishizuka K, Mitsuoka R, Takimoto N, Yokoyama N, Detake A, Takayanagi C, Yoshikawa S, Sugita H. Seasonal changes in the tetrodotoxin content of the pufferfish Takifugu niphobles. Toxicon 2016; 114:53-8. [PMID: 26923160 DOI: 10.1016/j.toxicon.2016.02.020] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 02/18/2016] [Accepted: 02/23/2016] [Indexed: 11/29/2022]
Abstract
To investigate seasonal changes in the whole body content and tissue distribution of tetrodotoxin (TTX) in the pufferfish Takifugu niphobles, wild individuals were collected from the coastal waters around Miura Peninsula from November 2010 to May 2012, and their tissues were subjected to LC-MS/MS analysis. Fish that were sexually mature were classified as being in the maturation period (April), the spawning period (May-July) or the "ordinary period" (i.e., other months). In both sexes, gonad somatic index rapidly increased during the maturation period and then decreased during the spawning period. Whole body TTX content was significantly higher during the maturation/spawning period than in the ordinary period. Through all seasons, TTX was localized in the skin or ovary in females and in the skin or liver in males: the difference in TTX localization between females and males was particularly evident during the spawning period.
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Affiliation(s)
- Shiro Itoi
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan.
| | - Kento Ishizuka
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Ryoko Mitsuoka
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Narumi Takimoto
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Naoto Yokoyama
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Ayumi Detake
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Chie Takayanagi
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Saori Yoshikawa
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Haruo Sugita
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
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Turner AD, Higgins C, Higman W, Hungerford J. Potential Threats Posed by Tetrodotoxins in UK Waters: Examination of Detection Methodology Used in Their Control. Mar Drugs 2015; 13:7357-76. [PMID: 26690455 PMCID: PMC4699243 DOI: 10.3390/md13127070] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2015] [Revised: 11/30/2015] [Accepted: 12/07/2015] [Indexed: 12/27/2022] Open
Abstract
Tetrodotoxin is a neurotoxin responsible for many human fatalities, most commonly following the consumption of pufferfish. Whilst the source of the toxin has not been conclusively proven, it is thought to be associated with various species of marine bacteria. Whilst the toxins are well studied in fish and gastropods, in recent years, there have been a number of reports of tetrodotoxin occurring in bivalve shellfish, including those harvested from the UK and other parts of Europe. This paper reviews evidence concerning the prevalence of tetrodotoxins in the UK together with methodologies currently available for testing. Biological, biomolecular and chemical methods are reviewed, including recommendations for further work. With the recent development of quantitative chromatographic methods for these and other hydrophilic toxins, as well as the commercial availability of rapid testing kits, there are a number of options available to ensure consumers are protected against this threat.
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Affiliation(s)
- Andrew D Turner
- Centre for Environment Fisheries and Aquaculture Science (Cefas), Barrack Road, The Nothe, Weymouth, Dorset DT4 8UB, UK.
| | - Cowan Higgins
- Agri-food and Biosciences Institute (AFBI), Newforge Lane, Belfast BT9 5PX, UK.
| | - Wendy Higman
- Centre for Environment Fisheries and Aquaculture Science (Cefas), Barrack Road, The Nothe, Weymouth, Dorset DT4 8UB, UK.
| | - James Hungerford
- Pacific Laboratory Northwest, United States Food and Drug Administration (USFDA), 22201 23rd Dr, S.E., Bothell, WA 98021, USA.
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44
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Silva M, Rodriguez I, Barreiro A, Kaufmann M, Isabel Neto A, Hassouani M, Sabour B, Alfonso A, Botana LM, Vasconcelos V. New Invertebrate Vectors of Okadaic Acid from the North Atlantic Waters--Portugal (Azores and Madeira) and Morocco. Toxins (Basel) 2015; 7:5337-47. [PMID: 26670254 PMCID: PMC4690135 DOI: 10.3390/toxins7124885] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Revised: 11/16/2015] [Accepted: 11/16/2015] [Indexed: 11/16/2022] Open
Abstract
Okadaic acid and its analogues are potent phosphatase inhibitors that cause Diarrheic Shellfish Poisoning (DSP) through the ingestion of contaminated shellfish by humans. This group of toxins is transmitted worldwide but the number of poisoning incidents has declined over the last 20 years due to legislation and monitoring programs that were implemented for bivalves. In the summer of 2012 and 2013, we collected a total of 101 samples of 22 different species that were made up of benthic and subtidal organisms such echinoderms, crustaceans, bivalves and gastropods from Madeira, São Miguel Island (Azores archipelago) and the northwestern coast of Morocco. The samples were analyzed by UPLC-MS/MS. Our main objective was to detect new vectors for these biotoxins. We can report nine new vectors for these toxins in the North Atlantic: Astropecten aranciacus, Arbacia lixula, Echinaster sepositus, Holothuria sanctori, Ophidiaster ophidianus, Onchidella celtica, Aplysia depilans, Patella spp., and Stramonita haemostoma. Differences in toxin contents among the species were found. Even though low concentrations were detected, the levels of toxins that were present, especially in edible species, indicate the importance of these types of studies. Routine monitoring should be extended to comprise a wider number of vectors other than for bivalves of okadaic acid and its analogues.
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Affiliation(s)
- Marisa Silva
- Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, 4619-007 Porto, Portugal.
- Interdisciplinary Center of Marine and Environmental Research-CIMAR/CIIMAR, University of Porto, Rua dos Bragas 289, 4050-123 Porto, Portugal.
| | - Inés Rodriguez
- Department of Pharmacology, Faculty of Veterinary, University of Santiago of Compostela, 27002 Lugo, Spain.
| | - Aldo Barreiro
- Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, 4619-007 Porto, Portugal.
- Interdisciplinary Center of Marine and Environmental Research-CIMAR/CIIMAR, University of Porto, Rua dos Bragas 289, 4050-123 Porto, Portugal.
| | - Manfred Kaufmann
- Interdisciplinary Center of Marine and Environmental Research-CIMAR/CIIMAR, University of Porto, Rua dos Bragas 289, 4050-123 Porto, Portugal.
- University of Madeira, Marine Biology Station of Funchal, 9000-107 Funchal, Madeira Island, Portugal.
- Center of Interdisciplinary Marine and Environmental Research of Madeira-CIIMAR-Madeira, Edifício Madeira Tecnopolo, Caminho da Penteada, 9020-105 Funchal, Madeira, Portugal.
| | - Ana Isabel Neto
- Interdisciplinary Center of Marine and Environmental Research-CIMAR/CIIMAR, University of Porto, Rua dos Bragas 289, 4050-123 Porto, Portugal.
- Department of Marine Biology, University of Azores, 9501-801 Ponta Delgada, Azores, Portugal.
| | - Meryem Hassouani
- Phycology Research Unit-Biotechnology, Ecosystems Ecology and Valorization Laboratory, Faculty of Sciences El Jadida, University Chouaib Doukkali, BP20 El Jadida, Morocco.
| | - Brahim Sabour
- Phycology Research Unit-Biotechnology, Ecosystems Ecology and Valorization Laboratory, Faculty of Sciences El Jadida, University Chouaib Doukkali, BP20 El Jadida, Morocco.
| | - Amparo Alfonso
- Department of Pharmacology, Faculty of Veterinary, University of Santiago of Compostela, 27002 Lugo, Spain.
| | - Luis M Botana
- Department of Pharmacology, Faculty of Veterinary, University of Santiago of Compostela, 27002 Lugo, Spain.
| | - Vitor Vasconcelos
- Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, 4619-007 Porto, Portugal.
- Interdisciplinary Center of Marine and Environmental Research-CIMAR/CIIMAR, University of Porto, Rua dos Bragas 289, 4050-123 Porto, Portugal.
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45
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Paul SC, Pell JK, Blount JD. Reproduction in Risky Environments: The Role of Invasive Egg Predators in Ladybird Laying Strategies. PLoS One 2015; 10:e0139404. [PMID: 26488753 PMCID: PMC4619405 DOI: 10.1371/journal.pone.0139404] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 09/12/2015] [Indexed: 12/04/2022] Open
Abstract
Reproductive environments are variable and the resources available for reproduction are finite. If reliable cues about the environment exist, mothers can alter offspring phenotype in a way that increases both offspring and maternal fitness (‘anticipatory maternal effects’—AMEs). Strategic use of AMEs is likely to be important in chemically defended species, where the risk of offspring predation may be modulated by maternal investment in offspring toxin level, albeit at some cost to mothers. Whether mothers adjust offspring toxin levels in response to variation in predation risk is, however, unknown, but is likely to be important when assessing the response of chemically defended species to the recent and pervasive changes in the global predator landscape, driven by the spread of invasive species. Using the chemically defended two-spot ladybird, Adalia bipunctata, we investigated reproductive investment, including egg toxin level, under conditions that varied in the degree of simulated offspring predation risk from larval harlequin ladybirds, Harmonia axyridis. H. axyridis is a highly voracious alien invasive species in the UK and a significant intraguild predator of A. bipunctata. Females laid fewer, larger egg clusters, under conditions of simulated predation risk (P+) than when predator cues were absent (P-), but there was no difference in toxin level between the two treatments. Among P- females, when mean cluster size increased there were concomitant increases in both the mass and toxin concentration of eggs, however when P+ females increased cluster size there was no corresponding increase in egg toxin level. We conclude that, in the face of offspring predation risk, females either withheld toxins or were physiologically constrained, leading to a trade-off between cluster size and egg toxin level. Our results provide the first demonstration that the risk of offspring predation by a novel invasive predator can influence maternal investment in toxins within their offspring.
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Affiliation(s)
- Sarah C. Paul
- Centre for Ecology & Conservation, College of Life & Environmental Sciences, University of Exeter, Penryn Campus, Cornwall, United Kingdom
| | - Judith K. Pell
- J. K. Pell Consulting, Luton, Bedfordshire, United Kingdom
| | - Jonathan D. Blount
- Centre for Ecology & Conservation, College of Life & Environmental Sciences, University of Exeter, Penryn Campus, Cornwall, United Kingdom
- * E-mail:
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Itoi S, Kozaki A, Komori K, Tsunashima T, Noguchi S, Kawane M, Sugita H. Toxic Takifugu pardalis eggs found in Takifugu niphobles gut: Implications for TTX accumulation in the pufferfish. Toxicon 2015; 108:141-6. [PMID: 26485535 DOI: 10.1016/j.toxicon.2015.10.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 09/30/2015] [Accepted: 10/14/2015] [Indexed: 11/30/2022]
Abstract
Pufferfish (Takifugu spp.) possess a potent neurotoxin, tetrodotoxin (TTX). TTX has been detected in various organisms including food animals of pufferfish, and TTX-producing bacteria have been isolated from these animals. TTX in marine pufferfish accumulates in the pufferfish via the food web starting with marine bacteria. However, such accumulation is unlikely to account for the amount of TTX in the pufferfish body because of the minute amounts of TTX produced by marine bacteria. Therefore, the toxification process in pufferfish still remains unclear. In this article we report the presence of numerous Takifugu pardalis eggs in the intestinal contents of another pufferfish, Takifugu niphobles. The identity of T. pardalis being determined by direct sequencing for mitochondrial DNA. LC-MS/MS analysis revealed that the peak detected in the egg samples corresponded to TTX. Toxification experiments in recirculating aquaria demonstrated that cultured Takifugu rubripes quickly became toxic upon being fed toxic (TTX-containing) T. rubripes eggs. These results suggest that T. niphobles ingested the toxic eggs of another pufferfish T. pardalis to toxify themselves more efficiently via a TTX loop consisting of TTX-bearing organisms at a higher trophic level in the food web.
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Affiliation(s)
- Shiro Itoi
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan.
| | - Ao Kozaki
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Keitaro Komori
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Tadasuke Tsunashima
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Shunsuke Noguchi
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Mitsuo Kawane
- Department of Sea-Farming, Aichi Fish Farming Institute, Tahara, Aichi 441-3618, Japan
| | - Haruo Sugita
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
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47
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Vargas RA, Sarmiento K, Vásquez IC. Zebrafish (Danio rerio): A Potential Model for Toxinological Studies. Zebrafish 2015. [DOI: 10.1089/zeb.2015.1102] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Rafael Antonio Vargas
- Departamento de Ciencias Fisiológicas, Facultad de Medicina, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Karen Sarmiento
- Departamento de Ciencias Fisiológicas, Facultad de Medicina, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Isabel Cristina Vásquez
- Departamento de Ciencias Fisiológicas, Facultad de Medicina, Pontificia Universidad Javeriana, Bogotá, Colombia
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48
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Kojima Y, Mori A. Active foraging for toxic prey during gestation in a snake with maternal provisioning of sequestered chemical defences. Proc Biol Sci 2015; 282:20142137. [PMID: 25392472 DOI: 10.1098/rspb.2014.2137] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Many animals sequester dietary defensive compounds and incorporate them into the offspring, which protects the young against predation. One possible but poorly investigated question is whether females of such species actively prey upon toxic diets. The snake Rhabdophis tigrinus sequesters defensive steroids from toads consumed as prey; it also feeds on other amphibians. Females produce chemically armed offspring in direct proportion to their own level of toad-derived toxins by provisioning the toxins to their eggs. Our field observations of movements and stomach contents of radio-tracked R. tigrinus showed that gravid snakes preyed upon toads by actively foraging in the habitat of toads, even though toads were a scarce resource and toad-searching may incur potential costs. Our Y-maze experiments demonstrated that gravid females were more likely to trail the chemical cues of toads than were males or non-gravid females. These results showed behavioural switching in females and active foraging for scarce, toxic prey during gestation. Because exploitation of toads by gravid females results in their offspring being more richly endowed with prey-derived toxins, active foraging for toxic prey is expected to be an adaptive antipredator trait, which may enhance chemical defence in offspring.
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Affiliation(s)
- Yosuke Kojima
- Department of Zoology, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan
| | - Akira Mori
- Department of Zoology, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan
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49
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Liu J, Wei F, Lu Y, Ma T, Zhao J, Gong X, Bao B. Production level of tetrodotoxin in Aeromonas is associated with the copy number of a plasmid. Toxicon 2015; 101:27-34. [PMID: 25911960 DOI: 10.1016/j.toxicon.2015.04.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Revised: 04/09/2015] [Accepted: 04/21/2015] [Indexed: 10/23/2022]
Abstract
Tetrodotoxin (TTX) has been identified from taxonomically diverse organisms. Artificial synthesis of TTX has been reported, but the biosynthetic pathway of TTX remains elusive. In this study, we found TTX producing ability was associated with the copy number of plasmid pNe-1 in Aeromonas strain Ne-1 during fermentation, suggesting that at least one gene encoding a TTX-synthesis enzyme is located on this plasmid. Compared with bacterial genomes, plasmids are small and easier to screen for genes associated with TTX biosynthesis. The approximately 100 kb genome of pNe-1 was sequenced. The plasmid contains 60 complete open reading frames (orfs) of which 32 (53.3%) encode hypothetical proteins. Seven genes are related to the type IV secretion system (T4SS) and 2 genes are related to transposons, indicating that the TTX-producing bacterium Aeromonas might have the ability to transfer the TTX biosynthesis gene via the conjugation and contagion of plasmid pNe-1. In addition, we unexpectedly found that Aeromonas Ne-1 contains unknown TTX-degrading materials, indicating there is a homeostatic mechanism to maintain a stable amount of TTX in the bacterium. These results will help us to better understand TTX biosynthesis, the bacterial origin of TTX, and TTX degradation.
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Affiliation(s)
- Jing Liu
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Shanghai Ocean University, Ministry of Education, Shanghai 201306, China
| | - Fen Wei
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Shanghai Ocean University, Ministry of Education, Shanghai 201306, China
| | - Ying Lu
- College of Food Science & Technology, Shanghai Ocean University, Shanghai 201306, China
| | - Tinglong Ma
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Shanghai Ocean University, Ministry of Education, Shanghai 201306, China
| | - Jing Zhao
- College of Food Science & Technology, Shanghai Ocean University, Shanghai 201306, China
| | - Xiaoling Gong
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Shanghai Ocean University, Ministry of Education, Shanghai 201306, China
| | - Baolong Bao
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Shanghai Ocean University, Ministry of Education, Shanghai 201306, China.
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50
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Salvitti LR, Wood SA, Winsor L, Cary SC. Intracellular immunohistochemical detection of tetrodotoxin in Pleurobranchaea maculata (Gastropoda) and Stylochoplana sp. (Turbellaria). Mar Drugs 2015; 13:756-69. [PMID: 25636158 PMCID: PMC4344600 DOI: 10.3390/md13020756] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 01/06/2015] [Accepted: 01/23/2015] [Indexed: 12/04/2022] Open
Abstract
Tetrodotoxin (TTX), is a potent neurotoxin targeting sodium channels that has been identified in multiple marine and terrestrial organisms. It was recently detected in the Opisthobranch Pleurobranchaea maculata and a Platyhelminthes Stylochoplana sp. from New Zealand. Knowledge on the distribution of TTX within these organisms is important to assist in elucidating the origin and ecological role of this toxin. Intracellular micro-distribution of TTX was investigated using a monoclonal antibody-based immunoenzymatic technique. Tetrodotoxin was strongly localized in neutral mucin cells and the basement membrane of the mantle, the oocytes and follicles of the gonad tissue, and in the digestive tissue of P. maculata. The ova and pharynx were the only two structures to contain TTX in Stylochoplana sp. Using liquid chromatography-mass spectrometry, TTX was identified in the larvae and eggs, but not the gelatinous egg cases of P. maculata. Tetrodotoxin was present in egg masses of Stylochoplana sp. These data suggest that TTX has a defensive function in adult P. maculata, who then invest this in their progeny for protection. Localization in the digestive tissue of P. maculata potentially indicates a dietary source of TTX. Stylochoplana sp. may use TTX in prey capture and for the protection of offspring.
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Affiliation(s)
- Lauren R Salvitti
- Department of Biological Sciences, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand.
| | - Susanna A Wood
- Department of Biological Sciences, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand.
| | - Leigh Winsor
- College of Marine and Environmental Sciences, James Cook University, Townsville QLD 4811, Australia.
| | - Stephen Craig Cary
- Department of Biological Sciences, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand.
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