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Dr. Elzbieta Pyza 特別セミナー
Dr. Elzbieta Pyza 特別セミナーのご案内です。
Pyza博士はポーランド,Jagiellonian大学細胞学・組織学部助教授で,イエバエ,ショウジョウバエの視覚系の概日リズムの細胞生物学的研究で有名な研究者です.この度の来日の機会にご講演を頂けることになりました.是非多くの会員にご来聴いただきたく,ご案内申し上げます.なお,セミナーの後,時間学研究所研究会(環境と時間グループ)を予定しております.こちらにも興味をお持ちの方はご連絡下さい. - 日 時:2001年2月9日(金)12時45分~14時15分
- 場 所:山口大学理学部24番講義室(2階南棟東端)
山口大学への交通は,新幹線小郡駅下車,山口県庁行きシャトルバスにて山口大学前
下車(所要時間約20分)です.
要 旨Cellular circadian rhythms in the fly's visual system. Dr. Elzbieta Pyza (Jagiellonian University, Krakow, Poland)
The visual system of the flies Musca domestica and Drosophila melanogastershows circadian rhythms in the structure of its cells and their subcellularorganization. These rhythms have been detected in the first opticneuropile, the lamina, in the number of synaptic contacts and the verticalmigration of screening pigment in photoreceptor terminals, and in size andshape changes in two of their interneurons, L1 and L2. These are regulated by the lamina's neurotransmitters and controlled by so-called "clock genes", such as the per gene. Circadian information from "clock neurons"is transmitted by the neuropeptide pigment dispersing factor (PDF) the effect of which on L1 and L2 also depends on serotonin. Lesioning the optic lobe in Musca disrupts L1 and L2's circadian size changes but weak daily oscillations in these cells persist. The input from the clock alone is not sufficient, however, for expression of the lamina's structural circadian rhythms. In the arrhythmic Drosophila mutant per01 insertion of A 7.2: 9 kb fragment of per which induces PER expression in the clock neurons and photoreceptors cannot completely rescue rhythms in L1 and L2. This indicates that there are cells in the lamina which participate in L1 and L2's rhythmic changes, for which the lamina epithelial glia are good candidates. These change their sizes too, but in a reversed pattern to L1 and L2, swelling during the night in the housefly's lamina. In Drosophila they express PER and changes in their metabolism affect the sizes of L1 and L2. Moreover, closing gap junctions between glia stops rhythmic swelling and shrinking in L1 and L2. The glial cells may generate and/or synchronize the lamina's rhythms or mediate between PDF neurons and cells which show structural circadian rhythms. If the size of L1 and L2 depends on the epithelial glia a mechanism of this process is unknown. Recently, we have detected in the brain of Musca and Drosophila a proton V-ATPase which is expressed in glia and shows daily oscillations in immunostaining. Blocking the V-ATPase by bafilomycin affects L1 and L2 in Musca only when applied during the night when the glial cells are more active than neurons. This suggests that the glial cell proton VATP-ase may participate in the mechanism of L1 and L2's shrinkage during the night.
- 問い合わせ先:山口大学理学部自然情報科学科 富岡憲治
- (Tel. 083-933-5714)
- e-mail: tomioka
 po.cc.yamaguchi-u.ac.jp
- 山口大学時間学研究所主催,日本比較生理生化学会後援
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