Neuronal and hormonal mechanisms that coordinate events of animal metamorphosis

2022 Fiscal Year Final Research Report

• Project/Area Number: 19H03262
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 44050:Animal physiological chemistry, physiology and behavioral biology-related
• Research Institution: University of Tsukuba
• Principal Investigator: Sasakura Yasunori 筑波大学, 生命環境系, 教授 (10400649)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 変態 / ホヤ / 神経 / GABA / GnRH / Gタンパク質 / cAMP / 進化

Outline of Final Research Achievements

This study aimed to comprehend the molecular mechanisms of how the various metamorphic events are coordinated in a single body of the ascidian Ciona. Ciona metamorphosis is initiated by the neurotransmitter GABA. GABA signaling uses G-proteins as the downstream factor and induces cAMP accumulation for starting metamorphosis. Ciona larvae sense the mechanical stimulus generated by adhesion for starting metamorphosis. We characterized the TRP channel gene for this sensing. GnRH is involved in initiating metamorphic events such as tail regression. D-serine is a signaling molecule downstream of the neuropeptide signaling. During metamorphosis, Ciona develops adult organs through cell proliferation. TPO, the enzyme synthesizing thyroid hormone in vertebrates, is responsible for this process. TPO is expressed in the mesenchyme in addition to the thyroid gland homologous organ. Both organs regulate cell proliferation during metamorphosis, suggesting the role of TPO in non-thyroid organs.

Free Research Field

発生生理学

Academic Significance and Societal Importance of the Research Achievements

変態は一般の方にも目に付く極めて有名な生物現象であり、またその不思議さ故に生命への興味を惹起しやすいため、この現象の原理を深く解明することは、生物学や科学への興味を深める基盤となる。また、新しい機能を持ったタンパク質の発見や神経系での複雑な分子調節機構は、神経生物学や細胞工学の発展に繋がる。固着により開始されるホヤの変態の特殊性からは、付着動物一般の付着機構の解明と共に、新しい防除策の構築に繋がる。