Elucidation on the tetrodotoxin transport mechanism in Takifugu rubripes by analysis of tetrodotoxin-binding protein complexes

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K15915
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 40040:Aquatic life science-related
• Research Institution: Fisheries Research and Education Agency
• Principal Investigator: Tatsuno Ryohei 国立研究開発法人水産研究・教育機構, 水産大学校, 講師 (70771872)
• Project Period (FY): 2019-04-01 – 2024-03-31
• Keywords: トラフグ / テトロドトキシン / 毒結合タンパク質

Outline of Final Research Achievements

Cultured Takifugu rubripes were orally administered TTX-containing feed homogenate (approximately 1,600 g). TTX take up from their digestive tract accumulated in the liver or ovaries. Females accumulated less TTX in their livers than males, and the difference was presumably due to TTX accumulation in the ovaries. Plasma were collected from female and male T. rubripes(approximately 2,000 g) from the natural environment. The plasmad were subjected to Western blotting using an antibody for tetrodotoxin binding protein (PSTBP). The result showed that multiple bands were obtained, with the 70-100 kDa size band being almost the same size as previously reported. On the other hand, one or two more bands were detected at smaller sizes.

Free Research Field

食品衛生

Academic Significance and Societal Importance of the Research Achievements

トラフグ属魚類は特定部位に多量のテトロドトキシン（TTX）を蓄積するが、それを担う分子機構は明らかになっていない。その点を解明するため、トラフグのTTX蓄積部位と毒結合タンパク質（PSTBP）に関する調査を実施した。その結果、成熟個体は肝臓もしくは卵巣が主要な蓄積部位であること、肝臓は雌個体の方が蓄積量が少なくその分は卵巣に蓄積されたことが推察された。トラフグの主要なTTX蓄積部位が成長、成熟段階で異なることは、トラフグを研究する上で重要な基礎知見となる。また、段階の異なる個体でPSTBPの構成に差があることも明らかとなり、今後の研究に貢献しうる知見が得られたことは学術的、社会的意義がある。