Development of quantitative detection techniques on harmful algal cyst for assessment of potential risk of harmful algal blooms

• Project/Area Number: 17K07899
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Aquatic bioproduction science
• Research Institution: Fisheries Research and Education Agency
• Principal Investigator: Sakamoto Setsuko 国立研究開発法人水産研究・教育機構, 水産技術研究所(廿日市), グループ長 (40265723)
• Project Period (FY): 2017-04-01 – 2022-03-31
• Project Status: Completed (Fiscal Year 2021)
• Budget Amount: ¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000); Fiscal Year 2020: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2019: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2018: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2017: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
• Keywords: 海洋環境保全 / 有害有毒プランクトン / シスト / 定量PCR / 赤潮 / 貝毒 / シスト（休眠期細胞） / 発現遺伝子

Outline of Final Research Achievements

This study aimed to establish a method for assessing the potential risk of harmful algal blooms based on cysts of harmful algae in the sediments. An accurate quantitative PCR method was investigated using the cyst of harmful algae such as Chattonella spp. and Gymnodinium catenatum, and a quantitative method was established using the rDNA as a target sequence. In addition, expressed genes that could become molecular markers of cyst-specific physiological phenomena such as dormancy and germination were searched for. As results, light, temperature and oxygen stress-related genes which could be involved in cyst dormancy and germination, and the homology gene which related to the control the dormancy and germination of plant seeds. were extracted.

Academic Significance and Societal Importance of the Research Achievements

本研究の成果は、DNAを用いた正確なシストの計数方法を提案するものであり、顕微鏡観察による形態的な種同定が必要であったChattonellaおよびGymnodinium catenatumシストの検出定量を、rDNAのコピー数を基に推定して赤潮発生リスクを評価することを可能にした。また、シストの休眠や発芽への関与が推定される遺伝子マーカー候補となる配列を複数抽出できたことは、今後、単にシストの数ではなく発芽可能なシスト数といった生理状態を把握するための技術開発の基盤となると考える。