Investigating the mechanisms of attraction, settlement, and boring to the host by pest polychaetes in shellfish aquaculture and their origins

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K15899
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 40030:Aquatic bioproduction science-related
• Research Institution: Ishinomaki Senshu University (2022); Iwate Medical University (2019-2021)
• Principal Investigator: Abe Hirokazu 石巻専修大学, 理工学部, 准教授 (10784192)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 海産環形動物 / 貝類養殖 / スピオ科 / 穿孔性多毛類 / 分子系統 / 発現遺伝子 / ミトゲノム

Outline of Final Research Achievements

This study aims to clarify the mechanisms of "larval attraction and settlement to the host" and " boring" in pest spionid polychaetes in shellfish aquaculture, and to understand the "evolutionary process" in the development of such mechanisms. In this study, the following investigations were conducted: 1) estimation of phylogenetic relationships among 15 genera and 62 species of free-living and symbiotic/boring spionid polychaetes based on molecular phylogenetic analysis; 2) description of two new species of spionid polychaetes showing a novel symbiotic system, and the description and estimation of phylogenetic position of one new species of the enigmatic genus Atherospio; 3) description of the morphology of the planktonic larvae of 41 species in 14 genera of the family Spionidae; 4) interspecific comparison of gene expression profiles in adults and larvae of four free-living and boring species belonging to three genera in the family Spionidae.

Free Research Field

海洋生態学

Academic Significance and Societal Importance of the Research Achievements

厳密に宿主を認識して着底する共生性の海産無脊椎動物では，浮遊幼生の嗅覚受容体が宿主認識に重要な役割を果たしている可能性がある。本研究では，「幼生期の誘引物質に対する嗅覚受容体の変化が着底基質選択性や宿主の転換を駆動する」という仮説のもと，スピオ科多毛類の生息基質や宿主の変化プロセスに合わせた嗅覚受容体の分子的変化を追うことで，基質選択性や宿主の転換が起こる仕組みを解明することを目指したものである。このアイデアは，海産無脊椎動物における着底基質選択や宿主転換を統一的に説明できるモデルとして広く波及効果が期待でき，海洋生物の種分化や多様化のメカニズムの理解につながる可能性を秘めているといえる。