Epidermal distribution of tetrodotoxin-rich cells in newly hatched larvae of Takifugu spp.

Pufferfish of the genus Takifugu possess tetrodotoxin (TTX), known as "pufferfish toxin" and it is believed that pufferfish eggs and newly hatched larvae utilize TTX as a defensive substance against predators. However, the mechanism for the placement of TTX to specific cells on the larval body surface during the developmental process remains unknown. In this study, we clarify the distribution and characteristics of TTX-rich cells.

The impact of tetrodotoxin (TTX) on the gut microbiome in juvenile tiger pufferfish, Takifugu rubripes.

Tetrodotoxin (TTX) is a potent neurotoxin that accumulates in Takifugu rubripes, commonly known as pufferfish, through the ingestion of TTX-bearing organisms as part of their food chain. Although researchers believe that pufferfish use TTX to relieve stress, data are not currently available on how TTX affects the gut microbiota of pufferfish. To address this gap, our study aimed to investigate whether administering TTX to fish could alter their gut microbiota and overall health under various salinity conditions, including 30.

Tissue Localization of Tetrodotoxin in the Flatworm Planocera multitentaculata (Platyhelminthes: Polycladida).

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.

Distribution of pufferfish saxitoxin- and tetrodotoxin-binding protein homolog and tetrodotoxin in the brain and pituitary of juvenile tiger puffer Takifugu rubripes.

Pufferfish saxitoxin- and tetrodotoxin (TTX)-binding protein (PSTBP) is considered to transfer TTX between tissues. The immunohistochemical distribution of PSTBP-homolog (PSTBPh) and TTX in the brain and pituitary of hatchery-reared juvenile tiger puffer Takifugu rubripes was investigated. PSTBPh was observed mainly in the pars intermedia of the pituitary.

Tetrodotoxin/Saxitoxin Accumulation Profile in the Euryhaline Marine Pufferfish .

Marine pufferfish, which naturally possess tetrodotoxins (TTXs), selectively take up and accumulate TTXs, whereas freshwater 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 , a euryhaline marine pufferfish possessing both TTXs and STXs. Forty nontoxic cultured individuals of were divided into a seawater group (SW, acclimated/reared at 33‱ salinity; = 20) and a brackish water group (BW, acclimated/reared at 8‱ salinity; = 20).

Wheat germ agglutinin affinity chromatography enrichment and glyco-proteomic characterization of tetrodotoxin-binding proteins from the plasma of cultured tiger pufferfish (Takifugu rubripes).

Efficient enrichment of tetrodotoxin (TTX)-binding proteins from the plasma of cultured tiger pufferfish (Takifugu rubripes) was achieved by ammonium sulfate fractionation and wheat germ agglutinin (WGA) affinity chromatography. The enrichment efficiency was validated by ultrafiltration-LC/MS-based TTX-binding assay and proteomics. Major proteins in the WGA-bound fraction were identified as isoform X1 (125 kDa) and X2 variants (88 and 79 kDa) derived from pufferfish saxitoxin and tetrodotoxin-binding protein (PSTBP) 1-like gene (LOC101075943).

Tetrodotoxin Profiles in Xanthid Crab and Blue-Lined Octopus cf. from the Same Site in Nagasaki, Japan.

The xanhid crab and the blue-lined octopus cf. have long been known as TTX-bearing organisms. It has been speculated that the TTX possessed by both organisms is exogenously toxic through the food chain, since they are reported to have geographic and individual differences.

The quite low cross-reactivity of Kawatsu's anti-tetrodotoxin monoclonal antibody to 5,6,11-trideoxytetrodotoxin, 11-nortetrodotoxin-6(S)-ol, and 11-oxotetrodotoxin, the major tetrodotoxin analogues in pufferfish.

The monoclonal antibody against tetrodotoxin (TTX), prepared by Kawatsu et al. (1997), has been used in several TTX-related studies. Herein, we confirmed the quite low cross-reactivity of this antibody to three major TTX analogues in pufferfish using competitive ELISA: 5,6,11-trideoxyTTX (<2.

The brain of the wild toxic marine pufferfishes accumulates tetrodotoxin.

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.

Local Differences in the Toxin Amount and Composition of Tetrodotoxin and Related Compounds in Pufferfish () and Toxic Goby () Juveniles.

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, , and toxic goby, , using LC-MS/MS, to resolve the missing link in the TTX supply chain.

Geographic Variations in the Toxin Profile of the Xanthid Crab in a Single Reef on Ishigaki Island, Okinawa, Japan.

Toxic crabs of the family Xanthidae contain saxitoxins (STXs) and/or tetrodotoxin (TTX), but the toxin ratio differs depending on their habitat. In the present study, to clarify within reef variations in the toxin profile of xanthid crabs, we collected specimens of the toxic xanthid crab and their sampling location within a single reef (Yoshihara reef) on Ishigaki Island, Okinawa Prefecture, Japan, in 2018 and 2019. The STXs/TTX content within the appendages and viscera or stomach contents of each specimen was determined by instrumental analyses.

Tetrodotoxin/Saxitoxins Selectivity of the Euryhaline Freshwater Pufferfish .

The present study evaluated differences in the tetrodotoxin (TTX)/saxitoxins (STXs) selectivity between marine and freshwater pufferfish by performing in vivo and in vitro experiments. In the in vivo experiment, artificially reared nontoxic euryhaline freshwater pufferfish were intrarectally administered a mixture of TTX (24 nmol/fish) and STX (20 nmol/fish). The amount of toxin in the intestine, liver, muscle, gonads, and skin was quantified at 24, 48, and 72 h.

The role of toxic planocerid flatworm larvae on tetrodotoxin accumulation in marine bivalves.

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.

Homophymamide A, Heterodetic Cyclic Tetrapeptide from a sp. Marine Sponge: A Cautionary Note on Configurational Assignment of Peptides That Contain a Ureido Linkage.

A previously unreported heterodetic cyclic peptide, homophymamide A (), was isolated from a sp. marine sponge. The structure of homophymamide A was determined to be a lower homologue of anabaenopeptins by spectroscopic analysis, chemical degradation, and chemical synthesis.

Myrindole A, an Antimicrobial Bis-indole from a Marine Sponge sp.

Myrindole A, a bis-indole alkaloid, was isolated from the deep-sea sponge sp. The high degree of unsaturation of the molecule complicated the assignment of its structure by standard 2D-NMR experiments but was ultimately achieved by a combination of H-N-HMBC and 1,-ADEQUATE experiments as well as the comparison of measured and calculated CD spectra. Myrindole A showed antimicrobial activity against Gram-positive and Gram-negative bacteria.

Phylogeny and Toxin Profile of Freshwater Pufferfish (Genus ) Collected from 2 Different Regions in Cambodia.

The species classification of Cambodian freshwater pufferfish is incomplete and confusing, and scientific information on their toxicity and toxin profile is limited. In the present study, to accumulate information on the phylogeny and toxin profile of freshwater pufferfish, and to contribute to food safety in Cambodia, we conducted simultaneous genetic-based phylogenetic and toxin analyses using freshwater pufferfish individuals collected from Phnom Penh and Kratie (designated PNH and KTI, respectively). Phylogenetic analysis of partial sequences of three mitochondrial genes (cytochrome , 16S rRNA, and cytochrome oxidase subunit I) determined for each fish revealed that PNH and KTI are different species in the genus (designated sp.

Change in Paralytic Shellfish Toxins in the Mussel Depending on Dynamics of Harmful (Group I) in the Geoje Coast (South Korea) during Bloom Season.

Paralytic shellfish toxins (PSTs) produced by (formerly ) in Korean coastal waters caused the deaths of four people (in 1986 and 1996) who consumed contaminated mussels (). This led to more detailed consideration of the risks of PST outbreaks and incidents in Korea, including the introduction of shellfish collection bans. In this study, we investigated the relationships between population dynamics and PST accumulation in the mussel Discharges from the Nakdong River affect the environmental conditions along the Geoje coast, resulting in low salinity and high nutrient levels that trigger blooms of .

Co-Occurrence of Tetrodotoxin and Saxitoxins and Their Intra-Body Distribution in the Pufferfish .

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 . 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.

The planocerid flatworm is a main supplier of toxin to tetrodotoxin-bearing fish juveniles.

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.

Evaluation of the tetrodotoxin uptake ability of pufferfish Takifugu rubripes tissues according to age using an in vitro tissue slice incubation method.

The tetrodotoxin (TTX) uptake ability of pufferfish Takifugu rubripes tissues and its growth-associated changes were investigated using an in vitro tissue slice incubation method. Tissue slices prepared from the liver, skin, and intestine of a non-toxic cultured adult T. rubripes (20 months old) and incubated with incubation buffer containing 25 μg/mL TTX for 1-48 h showed a time-dependent increase in the TTX content in all tissues.

Tetrodotoxin functions as a stress relieving substance in juvenile tiger puffer Takifugu rubripes.

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.

Contrasting Toxin Selectivity between the Marine Pufferfish and the Freshwater Pufferfish .

To clarify the differences in toxin selectivity between marine and freshwater pufferfish, we conducted experiments in artificially reared nontoxic specimens of (marine) and (freshwater) using tetrodotoxin (TTX) and paralytic shellfish poison (PSP; decarbamoylsaxitoxin (dcSTX) or saxitoxin (STX)). specimens were administered feed homogenate containing TTX or dcSTX (dose of toxin, 55.2 nmol/fish) and specimens were administered feed homogenate containing TTX + STX (dose of each toxin, 19.

Role of maternal tetrodotoxin in survival of larval pufferfish.

It is known that tetrodotoxin (TTX), also known as pufferfish toxin, is an extremely potent neurotoxin and had been detected in various taxa. However, the exact function of the toxin in TTX-bearing organisms has remained unclear. In Takifugu pufferfish species, it has been suggested that TTX is utilized to protect larvae from predators but no experimental proof exists.

Profile differences in tetrodotoxin transfer to skin and liver in the pufferfish Takifugu rubripes.

Tetrodotoxin (TTX) was intramuscularly administered to nontoxic cultured specimens of the pufferfish Takifugu rubripes to investigate differences in the toxin transfer and accumulation profiles between the skin and liver. Test fish were administered TTX at doses of 30 (Low dose; LD), 100 (Medium dose; MD), and 300 (High dose; HD) μg/individual, respectively. Liquid chromatography/mass spectrometry analysis for TTX revealed that the TTX concentration in both the skin (0.