Identifications of the ionocytes functional differentiation factors in fish

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K15912
• 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: University of Miyazaki
• Principal Investigator: Miyanishi Hiroshi 宮崎大学, 農学部, 助教 (30726360)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: メダカ / 浸透圧調節 / 塩類細胞 / 分化 / トランスクリプトーム解析 / １細胞解析

Outline of Final Research Achievements

Osmoregulation in fish is important for maintaining the body fluid homeostasis. The understanding of its mechanism will contribute to improve the aquaculture in fish. Fish live mainly in freshwater and seawater. Osmoregulation, mainly Na+ and Cl-, is essential for fish to adapt to an osmotic environment that differs greatly from that in the body. Ionocytes distributed in gills are essential for osmoregulation. In this study, we identified novel target genes involved in the ionocytes functional differentiation. These results may lead us to answer the question, "Why are fish able to adapt to different saline environments?" In addition, the evaluation of the target genes can be established as markers of freshwater and seawater adaptation, and contribute to the development of technologies to stimulate aquaculture in various saline environments.

Free Research Field

魚類生理学

Academic Significance and Societal Importance of the Research Achievements

塩類細胞分化誘導因子を新規に同定し、そのシグナリング機構の全容を分子レベルで解明することに挑んだ。海洋環境に生息する魚類・爬虫類・鳥類の持つ塩類排出器官におけるイオン排出モデルは共通している。よって、魚類の海水型塩類細胞の分化誘導機構を解明することは、なぜ生物が海水への適応能力を得たかという根源的な疑問に一石を投じるものである。また、ヒト内耳にも魚類の塩類細胞と相同な細胞が哺乳類の内耳におけるリンパ液の浸透圧調節を担う点で共通性があり、メニエール病や内耳性難聴となるペンドレッド症候群の原因遺伝子の解明に寄与できる。本研究課題は、理学・水産学および基礎・臨床医学分野へも学術的波及を生み出せる。