Ryohei Tatsuno

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To investigate the effects of growth (organ development) on tetrodotoxin (TTX) dynamics in the pufferfish body, TTX-containing feed homogenate was administered to 6- and 15-month old non-toxic cultured specimens of the pufferfish Takifugu rubripes at a dose of 40 mouse units (MU) (8.8 μg)/20 g body weight by oral gavage. After 24 h, the specimens were(More)
Tetrodotoxin (TTX) was intramuscularly administered to artificially hybridized specimens of the pufferfish Takifugu rubripes and Takifugu niphobles to investigate toxin accumulation in hybrids, and TTX transfer/accumulation profiles in the pufferfish body. In the test fish administered 146 MU TTX in physiologic saline, TTX rapidly transferred from the(More)
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,(More)
In order to understand the sexual differences in TTX-usage in the pufferfish, Takifugu niphobles, localization of TTX and toxin amount in tissues of mature male and female specimens were investigated by immunohistochemical methods using anti-TTX antibody and LC/MS analysis. Subsequently, differences in the immunohistochemical signals were compared with the(More)
Marine pufferfish contain tetrodotoxin (TTX), an extremely potent neurotoxin. All species of the genus Takifugu accumulate TTX in the liver and ovaries, although the tissue(s) in which it is localized can differ among species. TTX is the major defense strategy the pufferfish appears to use against predators. TTX is also used as a male-attracting pheromone(More)
Four genes of Takifugu rubripes, tentatively designated Tr1-Tr4, encoding homologs of pufferfish saxitoxin- and tetrodotoxin-binding protein, were identified by BLAST search and 3'-RACE. RT-PCR and MALDI-TOF mass spectrometry allowed the identification and discrimination of Tr isoforms from the non-toxically cultured specimens. The expression of Tr1 and Tr3(More)
Maturation-associated changes in the internal distribution of tetrodotoxin (TTX) in the goby Yongeichthys criniger were investigated in 29 and 40 female specimens collected from Okinawa, Japan, from August 2008 to June 2009 (Group I), and from November 2009 to August 2010 (Group II), respectively. In Group I, based on changes in the gonadosomatic index(More)
Structure analysis was performed on the antibiotic-resistance-gene region of conjugative plasmids of four fish farm bacteria.The kanamycin resistance gene, IS26, and tetracycline resistance gene (tetA(D)) were flanked by two IS26s in opposite orientation in Citrobacter sp. TA3 and TA6, and Alteromonas sp. TA55 from fish farm A. IS26-Inner was disrupted with(More)
Tetrodotoxin (TTX) was administered to artificially hybridized specimens of the pufferfish Takifugu rubripes and Takifugu porphyreus to investigate toxin accumulation in hybrids and TTX transfer/accumulation profiles in the pufferfish body. In test fish administered TTX-containing feed homogenate at a dose of ∼400 MU/fish by oral gavage using a syringe (OGA(More)
A feeding experiment of TTX-containing diet was conducted using the small scavenging marine snails Pliarcularia globosa and Reticunassa festiva. Seventy-five specimens of each species were divided into 15 groups of 5 individuals, of which 3 groups were directly submitted, without feeding, to toxin quantification as described below. TTX was not detected.(More)