Are TTX circulated among TTX-bearing organisms?

• Project/Area Number: 26660177
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Aquatic life science
• Research Institution: Nihon University
• Principal Investigator: ITOI Shiro 日本大学, 生物資源科学部, 准教授 (30385992)
• Research Collaborator: HAGIYA Morio 日本大学, 生物資源科学部, 研究員 ; TSUNASHIMA Tadasuke 日本大学, 大学院・生物資源科学研究科, 大学院生 ; YAMADA Riko 日本大学, 大学院・生物資源科学研究科, 大学院生 ; UEDA Hiroyuki 日本大学, 大学院・生物資源科学研究科, 大学院生 ; ABE Koko 日本大学, 生物資源科学部, 実習助手 ; KAWANE Mitsuo (財)愛知県水産業振興基金, 栽培漁業部
• Project Period (FY): 2014-04-01 – 2017-03-31
• Project Status: Completed (Fiscal Year 2016)
• Budget Amount: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2015: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2014: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
• Keywords: フグ毒 / テトロドトキシン（TTX) / TTXループ / クサフグ / ヒガンフグ / トラフグ / テトロドトキシン / TTX

Outline of Final Research Achievements

The presence of numerous Takifugu pardalis eggs in the intestinal contents of another pufferfish, T 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 T. rubripes quickly became toxic upon being fed toxic T. rubripes eggs. Additionally, next generation sequencing analysis revealed that the sequence of toxic goby Yongeichthys criniger was detected from juveniles of the pufferfish Chelonodon patoca. These results suggest that T. niphobles and C. patoca ingested the toxic eggs of another pufferfish T. pardalis and toxic goby, respectively, to toxify themselves more efficiently via a TTX loop consisting of TTX-bearing organisms at a higher trophic level in the food web.

Research Products

• [Journal Article] Seasonal changes in the tetrodotoxin content of the flatworm Planocera multitentaculata (2017)
  • Author(s): Yamada R, Tsunashima T, Takei M, Sato T, Wajima Y, Kawase M, Oshikiri S, Kajitani Y, Kosoba K, Ueda H, Abe K, Itoi S, Sugita H
  • Journal Title: Marine Drugs Volume: 15 Issue: 3 Pages: 56-56
  • DOI: 10.3390/md15030056
  • Peer Reviewed / Open Access
• [Journal Article] Seasonal changes in the tetrodotoxin content of the pufferfish Takifugu niphobles (2016)
  • Author(s): Itoi S, Ishizuka K, Mitsuoka R, Takimoto N, Yokoyama N, Detake A, Takayanagi C, Yoshikawa S, Sugita H
  • Journal Title: Toxicon Volume: 114 Pages: 53-58
  • DOI: 10.1016/j.toxicon.2016.02.020
  • Peer Reviewed
• [Journal Article] Toxic Takifugu pardalis eggs found in T. niphobles gut: implications for TTX accumulation in the pufferfish (2015)
  • Author(s): Itoi S, Kozaki A, Komori K, Tsunashima T, Noguchi S, Kawane M, Sugita H
  • Journal Title: Toxicon Volume: 108 Pages: 141-146
  • DOI: 10.1016/j.toxicon.2015.10.009
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Presentation] Seasonal changes in TTX content of the toxic flatworm Planocera multitentaculata (2016)
  • Author(s): Riko Yamada, Tadasuke Tsunashima, Yusuke Kajitani, Shiro Itoi, Haruo Sugita
  • Organizer: The joint meeting of the 22nd International Congress of Zoology and the 87th Meeting of the Zoological Society of Japan
  • Place of Presentation: 沖縄コンベンションセンター（沖縄県宜野湾市）
  • Year and Date: 2016-11-17
  • Int'l Joint Research
• [Presentation] Toxification of the Takifugu pufferfish via a TTX loop consisting of TTX-bearing organisms (2016)
  • Author(s): Shiro Itoi, Ao Kozaki, Keitaro Komori, Tadasuke Tsunashima, Shunsuke Noguchi, Mitsuo Kawane, Haruo Sugita
  • Organizer: The 7th World Fisheries Congress in Busan, Korea
  • Place of Presentation: Busan, Korea
  • Year and Date: 2016-05-23
  • Int'l Joint Research
• [Presentation] Toxification of the larval pufferfish Takifugu niphobles by the larval flatworm Planocera multitentaculata (2016)
  • Author(s): Riko Yamada, Tadasuke Tsunashima, Kazuya Okuhara, Shiro Itoi, Haruo Sugita
  • Organizer: The 7th World Fisheries Congress in Busan, Korea
  • Place of Presentation: Busan, Korea
  • Year and Date: 2016-05-23
  • Int'l Joint Research
• [Presentation] フグにおけるTTXの生物学的役割 (2015)
  • Author(s): 糸井史朗
  • Organizer: 新学術領域研究「天然物ケミカルバイオロジー」地区ミニシンポジウム
  • Place of Presentation: 名古屋大学野依記念物質科学研究館（愛知県名古屋市）
  • Year and Date: 2015-05-14
  • Invited
• [Presentation] TTXを保有する多岐腸目ヒラムシ類の系統分類 (2014)
  • Author(s): 綱島忠相、伊澤心、山田理子、糸井史朗、萩谷盛雄、杉田治男
  • Organizer: 平成26年度日本水産学会秋季大会
  • Place of Presentation: 九州大学（福岡市）
  • Year and Date: 2014-09-20
• [Presentation] A molecular framework for the taxonomy of the marine turbellarian flatworms (Platyhelminthes, Polycladida) (2014)
  • Author(s): Tsunashima T, Hagiya M, Tsuyuki N, Itoi S, Sugita H
  • Organizer: The 10th Asia-Pacific Marine Biotechnology Conference (APMBC2014)
  • Place of Presentation: Taipei, Taiwan
  • Year and Date: 2014-05-06