模拟微重力效应对果蝇运动及睡眠的影响

本研究旨在探讨利用模拟微重力效应研究微重力对果蝇运动及睡眠影响的可行性.通过研制能够在模拟微重力环境下实时监测果蝇行为的随机定位仪,监测短时间(3 d)模拟微重力处理过程中,及长时间(10 d、20 d、30 d)处理后雄蝇运动和睡眠的变化;选取受影响较显著的短时间处理组,研究模拟微重力效应对生物钟核心基因(period (per)、timeless(tim)、clock (clk)、cycle (cyc)、cryptochrome (cry))、神经递质多巴胺(dopamine,DA)和5-羟色胺(5-hydroxytryptamine,5-HT)关键合成酶(多巴脱羧酶、酪氨酸羟化酶、色氨酸羟化酶)的编码基因ddc、pale和trh表达水平及DA和5-HT含量的影响.结果显示:短时间暴露下,雄蝇夜晚的运动量增加、单位时间运动次数增加、睡眠时间和次数减少、生物钟基因tim、clk、cyc、cry及神经递质合成相关编码基因ddc、pale和trh的表达水平均显著上升;长时间处理后对雄蝇运动和睡眠的影响较小.本研究认为利用模拟微重力效应研究微重力对果蝇运动及睡眠的影响是可行的,相关研究结果对航天医学研究具有借鉴意义.

Effects of Simulated Microgravity on Activity and Sleep of Drosophila melanogaster

This study was aimed to investigate the feasibility of using simulated microgravity to study the effects of microgravity on activity and sleep of Drosophila melanogaster. Simulated microgravity experiments performed using the random positioning machine (RPM) and male Drosophila melanogaster, and the activity and sleep of the flies were monitored using the DAM system (Trikinetics, USA). First, flies were exposed to simulated microgravity for a short time (3 days) with DAM system monitoring. Next, after being exposed to simulated microgravity for a long time (10, 20, and 30 days), flies were removed to be monitored for 3 consecutive days under control conditions. Then, the flies after short-term treatment (3 days) with greater impact were sampled to study the effects of simulated microgravity on the major circadian clock genes period (per), timeless (tim), clock (clk), cycle (cyc), cryptochrome (cry), and ddc, pale, trh genes encoding dopa decarboxylase, tyrosine hydroxylase, tryptophan hydroxylase, that involved in synthesis of neurotransmitter dopamine (DA) and 5-hydroxy-tryptamine (5-HT), and the contents of DA and 5-HT. The results showed that during short-term treatment, total activity accounts and activity accounts in wake period both increased, and total sleep and number of sleep episode both decreased at night; after short-term treatment, the relative expression levels of tim, clk, cyc and cry increased, and the relative expression levels of ddc, pale and trh increased; after long-term treatment, overall effect on activity and sleep was slight. This study suggests that it is feasible to study the effects of microgravity on activity and sleep of Drosophila melanogaster by simulated microgravity, and valuable reference can be provided for aerospace medical research.