Effects of neonicotinoid pesticides on the development and growth of avian embryos

Research Project

Project/Area Number	17K00575
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Research Field	Risk sciences of radiation and chemicals
Research Institution	National Institute for Environmental Studies
Principal Investigator	Kawashima Takaharu 国立研究開発法人国立環境研究所, 生物・生態系環境研究センター, 主任研究員 (90360362)
Project Period (FY)	2017-04-01 – 2021-03-31
Project Status	Completed (Fiscal Year 2020)
Budget Amount *help	¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000) Fiscal Year 2019: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000) Fiscal Year 2018: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000) Fiscal Year 2017: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Keywords	農薬 / 胚 / ウズラ / 鳥類
Outline of Final Research Achievements	In order to assess the toxicity of neonicotinoid pesticides on avian embryonic development and growth, we have developed a technique for avian embryo culture using quail fertilized eggs, which enabled to expose them to the test substances quantitatively at any developmental stage after newly laid egg. Furthermore, we were able to observe embryonic lethality and developmental status continuously during the whole embryonic period until hatching. As a result of the exposure test of imidacloprid, lethality and growth retardation became apparent in the high concentration test group, and a decrease in survival rate was observed. Furthermore, the morphology of the gonads and paragenital gland (i.e. Mullerian duct and Wolffian duct), sex steroid hormone levels in the blood, and expression levels of genes related to sexual differentiation could be used as toxicological endpoints to elucidate the modes of action in the future.
Academic Significance and Societal Importance of the Research Achievements	鳥類胚培養技術を開発することで、被験物質の胚への定量的かつ直接的な曝露を容易にしたことから、従来法に比べて精緻な解析が可能となった。鳥類は、哺乳類と同じ有羊膜類に属するため、発生・分化に関与する生命原理の相同性と種差を比較しつつ、農薬の安全性に対して、より強固な科学的根拠を付与するものと予想される。今後、本研究成果を発展させ、迅速、簡便かつ低コストの試験法が実用化できれば、高次捕食動物に対する化学物質影響評価の国際標準化に向けた波及効果も期待される。また、鳥類発育卵を利用する点で、母体を傷つけない生殖発生毒性試験の動物実験代替法として新たな研究の道を拓く先駆となった意義は大きい。