Molecular mechanisms of semilunar-synchronized spawning rhythm in the grass puffer: Regulation by a novel biological clock and environmental factors

2015 Fiscal Year Final Research Report

• Project/Area Number: 24570069
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Morphology/Structure
• Research Institution: Niigata University
• Principal Investigator: ANDO HIRONORI 新潟大学, 自然科学系, 教授 (60221743)
• Co-Investigator(Kenkyū-buntansha): HATTORI Atsuhiko 東京医科歯科大学, 教養部, 教授 (70183910) ; KUROKAWA Daisuke 東京大学, 理学(系)研究科(研究院), 助教 (40342779)
• Co-Investigator(Renkei-kenkyūsha): NOZAKI Masumi 新潟大学, 自然科学系, 教授 (70136232) ; AWATA Satoshi 新潟大学, 自然科学系, 助教 (60569002)
• Research Collaborator: DOI Hiroyuki
• Project Period (FY): 2012-04-01 – 2016-03-31
• Keywords: 脳・神経 / 生殖リズム / クリプトクローム / メラトニン受容体 / 神経ホルモン / 松果体 / 視床下部 / 月周リズム

Outline of Final Research Achievements

To elucidate molecular mechanisms of a novel clock that produces ultradian rhythm in the MelR gene expression in the brain of grass puffer, a transcriptome analysis was conducted by RNA sequencing to search genes that exhibit ultradian oscillations in expression. In the diencephalon, more than 200 genes were identified as potential ultradian expression genes including genes involved in neural and signal transduction activities. A MelR promoter-EGFP DNA was constructed to be microinjected into single-cell stage of embryos. EGFP expression was detected in some cells in the lateral region along the body at 2-3 dpf, but not in the brain. Further studies will be needed to examine the promoter region responsible for the ultradian gene expression. In 3-4 dph larvae, MelR gene showed daily variations in expression under light/dark condition. In addition, cryptochrome, a circadian clock gene, showed daily, circadian and lunar-synchronized expressions in the diencephalon.

Free Research Field

生殖内分泌学、神経内分泌学