2012 Fiscal Year Final Research Report

Regulation of juvenile hormone biosynthesis by ecdysis triggering hormone

Research Project

Project/Area Number	23658044
Research Category	Grant-in-Aid for Challenging Exploratory Research
Allocation Type	Multi-year Fund
Research Field	Applied entomology
Research Institution	Hirosaki University
Principal Investigator	HIRUMA Kiyoshi 弘前大学, 農学生命科学部, 教授 (70374816)
Project Period (FY)	2011 – 2012
Keywords	昆虫生理学 / 脱皮行動誘導ホルモン / 幼若ホルモン / 変態 / 行動
Research Abstract	Ecdysis triggering hormone (ETH) produced by Inka cells is a peptide hormone that induces insect ecdysis. We found that (1) ETH mRNA expression occurred in the corpora allata (CA) shortly before the last larval ecdysis, (2) EHT stimulated juvenile hormone (JH) biosynthesis by CA, and this stimulative action was observed primarily 6 hr before the last larval ecdysis, which was corresponded with the increase in JH synthesis during the molt. These results indicate that the increase in the JH titer during the last larval molt is due to the ETH action. Thus, a single hormone mediates two different phenomena, behavior and growth; a hormone that is responsible for behavior regulates JH synthesis, a key hormone involved in growth and metamorphosis.