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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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Zhu H, Sakai T, Doi H, Yamaguchi K, Yamada A, Takatani T, Arakawa O. Tetrodotoxin/Saxitoxin Accumulation Profile in the Euryhaline Marine Pufferfish Chelonodontops patoca. Toxins (Basel) 2023; 16:18. [PMID: 38251235 PMCID: PMC10820246 DOI: 10.3390/toxins16010018] [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: 11/21/2023] [Revised: 12/25/2023] [Accepted: 12/27/2023] [Indexed: 01/23/2024] Open
Abstract
Marine Takifugu pufferfish, which naturally possess tetrodotoxins (TTXs), selectively take up and accumulate TTXs, whereas freshwater Pao pufferfish, which naturally possess saxitoxins (STXs), selectively take up and accumulate STXs. To further clarify the TTXs/STXs selectivity in pufferfish, we conducted a TTX/STX administration experiment using Chelonodontops patoca, a euryhaline marine pufferfish possessing both TTXs and STXs. Forty nontoxic cultured individuals of C. patoca were divided into a seawater group (SW, acclimated/reared at 33‱ salinity; n = 20) and a brackish water group (BW, acclimated/reared at 8‱ salinity; n = 20). An aqueous TTX/STX mixture was intrarectally administered (both at 7.5 nmol/fish), and five individuals/group were analyzed after 1-48 h. Instrumental toxin analyses revealed that both TTX and STX were taken up, transferred, and retained, but more STX than TTX was retained in both groups. TTX gradually decreased and eventually became almost undetectable in the intestinal tissue, while STX was retained at ~5-10% of the dose level, and only STX showed transient transfer in the liver. The BW group showed a faster decrease/disappearance of TTX, greater STX retention in the intestine, and greater STX transient transfer to the liver. Thus, C. patoca appears to more easily accumulate STXs than TTXs, especially under hypoosmotic conditions.
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Affiliation(s)
- Hongchen Zhu
- Graduate School of Fisheries and Environmental Sciences, Nagasaki University, 1-14, Bunkyo-machi, Nagasaki 852-8521, Japan; (H.Z.); (T.S.); (K.Y.); (A.Y.); (T.T.)
| | - Takashi Sakai
- Graduate School of Fisheries and Environmental Sciences, Nagasaki University, 1-14, Bunkyo-machi, Nagasaki 852-8521, Japan; (H.Z.); (T.S.); (K.Y.); (A.Y.); (T.T.)
| | - Hiroyuki Doi
- Nifrel, Osaka Aquarium Kaiyukan, 2-1, Senribanpakukoen, Suita, Osaka 565-0826, Japan;
| | - Kenichi Yamaguchi
- Graduate School of Fisheries and Environmental Sciences, Nagasaki University, 1-14, Bunkyo-machi, Nagasaki 852-8521, Japan; (H.Z.); (T.S.); (K.Y.); (A.Y.); (T.T.)
| | - Akinori Yamada
- Graduate School of Fisheries and Environmental Sciences, Nagasaki University, 1-14, Bunkyo-machi, Nagasaki 852-8521, Japan; (H.Z.); (T.S.); (K.Y.); (A.Y.); (T.T.)
| | - Tomohiro Takatani
- Graduate School of Fisheries and Environmental Sciences, Nagasaki University, 1-14, Bunkyo-machi, Nagasaki 852-8521, Japan; (H.Z.); (T.S.); (K.Y.); (A.Y.); (T.T.)
| | - Osamu Arakawa
- Graduate School of Fisheries and Environmental Sciences, Nagasaki University, 1-14, Bunkyo-machi, Nagasaki 852-8521, Japan; (H.Z.); (T.S.); (K.Y.); (A.Y.); (T.T.)
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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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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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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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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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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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Local Differences in the Toxin Amount and Composition of Tetrodotoxin and Related Compounds in Pufferfish (Chelonodon patoca) and Toxic Goby (Yongeichthys criniger) Juveniles. Toxins (Basel) 2022; 14:toxins14020150. [PMID: 35202177 PMCID: PMC8876675 DOI: 10.3390/toxins14020150] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 02/08/2022] [Accepted: 02/15/2022] [Indexed: 02/04/2023] Open
Abstract
Tetrodotoxin (TTX)-bearing fish ingest TTX from their preys through the food chain and accumulate TTX in their bodies. Although a wide variety of TTX-bearing organisms have been reported, the missing link in the TTX supply chain has not been elucidated completely. Here, we investigated the composition of TTX and 5,6,11-trideoxyTTX in juveniles of the pufferfish, Chelonodon patoca, and toxic goby, Yongeichthys criniger, using LC–MS/MS, to resolve the missing link in the TTX supply chain. The TTX concentration varied among samples from different localities, sampling periods and fish species. In the samples from the same locality, the TTX concentration was significantly higher in the toxic goby juveniles than in the pufferfish juveniles. The concentration of TTX in all the pufferfish juveniles was significantly higher than that of 5,6,11-trideoxyTTX, whereas the compositional ratio of TTX and 5,6,11-trideoxyTTX in the goby was different among sampling localities. However, the TTX/5,6,11-trideoxyTTX ratio in the goby was not different among samples collected from the same locality at different periods. Based on a species-specific PCR, the detection rate of the toxic flatworm (Planocera multitentaculata)-specific sequence (cytochrome c oxidase subunit I) also varied between the intestinal contents of the pufferfish and toxic goby collected at different localities and periods. These results suggest that although the larvae of the toxic flatworm are likely to be responsible for the toxification of the pufferfish and toxic goby juveniles by TTX, these fish juveniles are also likely to feed on other TTX-bearing organisms depending on their habitat, and they also possess different accumulation mechanisms of TTX and 5,6,11-trideoxyTTX.
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Okabe T, Saito R, Yamamoto K, Watanabe R, Kaneko Y, Yanaoka M, Furukoshi S, Yasukawa S, Ito M, Oyama H, Suo R, Suzuki M, Takatani T, Arakawa O, Sugita H, Itoi S. The role of toxic planocerid flatworm larvae on tetrodotoxin accumulation in marine bivalves. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2021; 237:105908. [PMID: 34273772 DOI: 10.1016/j.aquatox.2021.105908] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/29/2021] [Accepted: 06/30/2021] [Indexed: 06/13/2023]
Abstract
Tetrodotoxin (TTX), also known as pufferfish toxin, has been detected in marine edible bivalves worldwide. In this study, several bivalve species, Azumapecten farreri subsp. akazara, Patinopecten yessoensis and Mytilus galloprovincialis, collected from the Pacific side of the northern Japanese Islands, were studied for the accumulation of TTX in the presence of toxic planocerid larvae. LC-MS/MS analysis demonstrated that TTX was detected only in the midgut gland of A. farreri subsp. akazara. Toxic flatworm-specific PCR and direct sequencing of the amplicons showed that the DNA fragments of the Planocera multitentaculata COI gene were detected in the gut contents of the toxified bivalves. The planocerid larvae were also detected in the environmental seawaters. Toxification experiments in the aquarium demonstrated that the mussel M. galloprovincialis was also toxified by feeding on the toxic flatworm larvae. These results suggest that the source of TTX accumulation in edible bivalves is toxic flatworm larvae.
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Affiliation(s)
- Taiki Okabe
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Rion Saito
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Kohei Yamamoto
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Riku Watanabe
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Yoshiki Kaneko
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Mutsumi Yanaoka
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Seika Furukoshi
- 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
| | - Masaaki Ito
- 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
| | - Rei Suo
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan
| | - Miwa Suzuki
- 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
| | - Shiro Itoi
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan.
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11
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First Detection of Tetrodotoxins in the Cotylean Flatworm Prosthiostomum trilineatum. Mar Drugs 2021; 19:md19010040. [PMID: 33477411 PMCID: PMC7830031 DOI: 10.3390/md19010040] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 01/14/2021] [Accepted: 01/15/2021] [Indexed: 12/14/2022] Open
Abstract
Several polyclad flatworm species are known to contain high levels of tetrodotoxin (TTX), but currently TTX-bearing flatworms seem to be restricted to specific Planocera lineages belonging to the suborder Acotylea. During our ongoing study of flatworm toxins, high concentrations of TTXs were detected for the first time in the flatworm Prosthiostomum trilineatum, suborder Cotylea, from the coastal area of Hayama, Kanagawa, Japan. Toxin levels were investigated by high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS), revealing that this species contains comparable concentrations of toxins as seen in planocerid flatworms such as Planocera multitentaculata. This finding indicated that there may be other species with significant levels of TTXs. The distribution of TTXs among other flatworm species is thus of great interest.
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12
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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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13
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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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14
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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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15
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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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16
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Adachi M, Miyasaka T, Kudo Y, Sugimoto K, Yotsu-Yamashita M, Nishikawa T. Total Syntheses and Determination of Absolute Configurations of Cep-212 and Cep-210, Predicted Biosynthetic Intermediates of Tetrodotoxin Isolated from Toxic Newt. Org Lett 2019; 21:780-784. [DOI: 10.1021/acs.orglett.8b04043] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Masaatsu Adachi
- Laboratory of Organic Chemistry, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan
| | - Tadachika Miyasaka
- Laboratory of Organic Chemistry, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan
| | - Yuta Kudo
- Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki-Aza-Aoba, Aoba-ku, Sendai 980-8572, Japan
| | - Keita Sugimoto
- Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki-Aza-Aoba, Aoba-ku, Sendai 980-8572, Japan
| | - Mari Yotsu-Yamashita
- Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki-Aza-Aoba, Aoba-ku, Sendai 980-8572, Japan
| | - Toshio Nishikawa
- Laboratory of Organic Chemistry, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan
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17
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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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18
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Geographic range expansion of tetrodotoxin in amphibians – First record in Atelopus hoogmoedi from the Guiana Shield. Toxicon 2018; 150:175-179. [DOI: 10.1016/j.toxicon.2018.05.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 05/14/2018] [Accepted: 05/15/2018] [Indexed: 11/19/2022]
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19
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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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20
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Ueda H, Itoi S, Sugita H. TTX-Bearing Planocerid Flatworm (Platyhelminthes: Acotylea) in the Ryukyu Islands, Japan. Mar Drugs 2018; 16:E37. [PMID: 29351203 PMCID: PMC5793085 DOI: 10.3390/md16010037] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2017] [Revised: 12/28/2017] [Accepted: 01/17/2018] [Indexed: 12/02/2022] Open
Abstract
Polyclad flatworms comprise a highly diverse and cosmopolitan group of marine turbellarians. Although some species of the genera Planocera and Stylochoplana are known to be tetrodotoxin (TTX)-bearing, there are few new reports. In this study, planocerid-like flatworm specimens were found in the sea bottom off the waters around the Ryukyu Islands, Japan. The bodies were translucent with brown reticulate mottle, contained two conical tentacles with eye spots clustered at the base, and had a slightly frilled-body margin. Each specimen was subjected to TTX extraction followed by liquid chromatography with tandem mass spectrometry analysis. Mass chromatograms were found to be identical to those of the TTX standards. The TTX amounts in the two flatworm specimens were calculated to be 468 and 3634 μg. Their external morphology was found to be identical to that of Planocera heda. Phylogenetic analysis based on the sequences of the 28S rRNA gene and cytochrome-c oxidase subunit I gene also showed that both specimens clustered with the flatworms of the genus Planocera (Planocera multitentaculata and Planocera reticulata). This fact suggests that there might be other Planocera species that also possess highly concentrated TTX, contributing to the toxification of TTX-bearing organisms, including fish.
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Affiliation(s)
- Hiroyuki Ueda
- 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.
| | - Haruo Sugita
- Department of Marine Science and Resources, Nihon University, Fujisawa, Kanagawa 252-0880, Japan.
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21
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Kudo Y, Chiba C, Konoki K, Cho Y, Yotsu-Yamashita M. Dietary administration of tetrodotoxin and its putative biosynthetic intermediates to the captive-reared non-toxic Japanese fire-bellied newt, Cynops pyrrhogaster. Toxicon 2017; 137:78-82. [DOI: 10.1016/j.toxicon.2017.07.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2017] [Revised: 07/10/2017] [Accepted: 07/14/2017] [Indexed: 10/19/2022]
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22
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Gallego V, Yoshida M, Kurokawa D, Asturiano JF, Fraser GJ. Embryonic development of the grass pufferfish (Takifugu niphobles): From egg to larvae. Theriogenology 2017; 90:191-196. [PMID: 28166967 DOI: 10.1016/j.theriogenology.2016.12.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Revised: 11/26/2016] [Accepted: 12/03/2016] [Indexed: 11/29/2022]
Abstract
Tetraodontidae (pufferfish) family members carry the smallest genomes among vertebrates, and these pocket-sized genomes have directly contributed to our understanding of the structure and evolution of higher animals. The grass pufferfish (Takifugu niphobles) could be considered a potential new model organism for comparative genomics and development due to the potential access to embryos, and availability of sequence data for two similar genomes: that of spotted green pufferfish (Tetraodon nigroviridis) and Fugu (Takifugu rubripes). In this study, we provide the first description of the normal embryonic development of T. niphobles, by drawing comparisons with the closely related species cited above. Embryos were obtained by in vitro fertilization of eggs, and subsequent development was monitored at a constant temperature consistent with natural conditions. T. niphobles development was divided into seven periods of embryogenesis: the zygote, cleavage, blastula, gastrula, segmentation, pharyngula, and hatching periods; and stages subdividing these periods are defined based on morphological characteristics. The developmental stage series described in this study aims to provide the utilization of T. niphobles as an experimental model organism for comparative developmental studies.
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Affiliation(s)
- V Gallego
- Grupo de Acuicultura y Biodiversidad, Instituto de Ciencia y Tecnología Animal, Universitat Politècnica de València, Camino de Vera s/n, 46022, Valencia, Spain; Misaki Marine Biological Station, Graduate School of Science, University of Tokyo, Miura, Kanagawa, 238-0225, Japan
| | - M Yoshida
- Misaki Marine Biological Station, Graduate School of Science, University of Tokyo, Miura, Kanagawa, 238-0225, Japan
| | - D Kurokawa
- Misaki Marine Biological Station, Graduate School of Science, University of Tokyo, Miura, Kanagawa, 238-0225, Japan
| | - J F Asturiano
- Grupo de Acuicultura y Biodiversidad, Instituto de Ciencia y Tecnología Animal, Universitat Politècnica de València, Camino de Vera s/n, 46022, Valencia, Spain
| | - G J Fraser
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, United Kingdom.
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23
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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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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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