Analysis of photic entrainment mchanisms of hemimetabolous insects

2014 Fiscal Year Final Research Report

• Project/Area Number: 23370033
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Animal physiology/Animal behavior
• Research Institution: Okayama University
• Principal Investigator: TOMIOKA Kenji 岡山大学, 自然科学研究科, 教授 (30136163)
• Project Period (FY): 2011-04-01 – 2015-03-31
• Keywords: 概日リズム / 光同調 / 複眼 / 視物質 / 遺伝子 / RNA干渉

Outline of Final Research Achievements

We have investigated the mechanism for photic entrainment of the circadian clock using crickets that have the circadian photoreceptor in the compound eye. Molecular cloning and in situ hybridization revealed that three opsins, i.e., opsin-UV, opsin-Blue and opsin-LW, are expressed at specific regions of the compound eye. A daily mRNA expression rhythm was detected in opsin-Blue and opsin-LW. Behavioral assay revealed that opsin-LW plays an important role in the photic entrainment because its RNAi substantially disrupted the synchronization of the locomotor rhythm to light cycles as well as light-evoked phase shifts of the rhythm. Cryptochromes are also expressed in the compound eye but have no clear role in the photic entrainment. Results of molecular analysis showed that the light resetting of the clock is regulated at the transcriptional level and Clock and cycle may play a role in a phase delay and an advance shift, respectively.

Free Research Field

時間生物学