Origin and diversification of the vertebrate telencephalon

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K07059
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Neurophysiology / General neuroscience
• Research Institution: Ehime University
• Principal Investigator: Murakami Yasunori 愛媛大学, 理工学研究科(理学系), 教授 (50342861)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 脳 / 進化 / 遺伝子 / 脊椎動物

Outline of Final Research Achievements

Vertebrate brains have evolved a variety of morphology. Recent studies have revealed that some signaling molecules and transcription factors play a fundamental role in the regionalization of the telencephalon. Our recent study using cyclostomes (lampreys and hagfishes) suggested that combinatory expression of regulatory genes may have been established before the split of cyclostomes and gnathostomes (jawed vertebrates). On the other hand, the size and functions of integrative centers are thought to have been modified in vertebrate lineages. To identify the molecular mechanism underlying brain diversification, we studied the development of catfish facial lobe, a center for the gustatory system. We found that FGF and WNT signal-inhibitor treated embryos resulted in the reduction of the facial lobe. Therefore, the modification of expression domains of signaling molecules may play a key role in the lineage-specific morphological change of the brain regions.

Free Research Field

進化形態学

Academic Significance and Societal Importance of the Research Achievements

我々の意識の源であり、自分自身そのものともいえる脳がどのようにして進化してきたのかは、一般の人々にとってもたいへん興味深いテーマである。本研究では脳の起源と多様化の仕組みを明らかにすることで、一般の人々の興味にも応えられる研究成果を得た。この結果について、その他の動物の脳の知見もまとめつつ、高校生以上を対象にした書籍「遺伝子から解き明かす脳の不思議な世界（一色出版）」として出版することで、国民に脳の進化過程についてわかりやすく紹介することができた。