Elucidation of molecular mechanism for the circadian clock formation during vertebrate development

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K08521
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Environmental physiology(including physical medicine and nutritional physiology)
• Research Institution: Komatsu University (2018); Tokyo Medical and Dental University (2016-2017)
• Principal Investigator: Hirayama Jun 公立小松大学, 保健医療学部, 教授 (90510363)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 体内時計 / 細胞時計 / 光 / ゼブラフィッシュ / 転写 / 翻訳 / 発生 / 恒常性維持

Outline of Final Research Achievements

Circadian clocks regulate various physiological processes with a periodicity of approximately 24 h. The exact timing of this rhythm is established by cell-autonomous oscillators called cellular clock. In vertebrates, cellular clocks in early embryos are gradually set in motion during development. In mammals, it is quite difficult to analyze the processes of cellular clock formation during development because embryogenesis proceeds inside the maternal uterus. Thus, the molecular mechanisms underlying the establishment of cellular clocks during vertebrate development are not well understood. Zebrafish eggs are externally fertilized and are transparent. In addition, embryos rapidly develop from fertilized eggs to larvae that swim, making them an excellent model for studies on the ontology of vertebrate clocks. This study used zebrafish to identify noble light-inducible clock proteins as the factor responsible for the light-dependent synchronization of cellular clocks during development.

Free Research Field

時間生物学

Academic Significance and Societal Importance of the Research Achievements

ヒトならびにマウスなどのモデル生物を用いた解析から、発生期の体内時計の形成不全が乳幼児の発達障害に関連することが報告されている。従って、生物の発生期の体内時計の形成機構の解明を目指す本研究の成果には、小児発達障害の予防や治療ならびに周産期医療の観点から有益な知見を提唱することが期待される。
体内時計は、生物の恒常性維持を担う重要な機構であり、その異常は睡眠障害や代謝異常といった様々な疾患につながる。従って、この機構がどのように形成されるかを解明することは、体内時計の異常と関連する様々な疾患の予防ならびに治療戦略を構築する際に重要になると考えられる。