斑马鱼幼鱼生物钟节律行为方法的建立

Establishment of the Circadian Behavioral Method in Zebrafish Larvae

所有生物体均受到生物钟的调控而产生行为和生理的节律变化,运动行为节律是反应生物节律的最可靠标志。斑马鱼是研究行为学的良好模式动物。为了探讨斑马鱼幼鱼在持续黑暗或者持续光照条件下的行为节律方法,选择发育至5 dpf (受精后天数)的幼鱼,放置于诺达思行为分析仪中,分别采取持续弱光(DD, 30 lux)、持续光照(LL, 300 lux)以及正常光照黑暗(LD, 14小时光:10小时暗)三个光照条件,检测斑马鱼幼鱼连续三天的运动行为变化。结果显示斑马鱼幼鱼在正常光暗条件下显示出明显的昼夜节律,即光照时运动多,黑暗时运动少。而在两个持续条件下均表现出明显的生物钟节律,并且统计算出的周期均在24小时左右。但是持续光照条件(LL)下的平均运动距离要明显高于持续弱光条件(DD)。因此,通过本实验建立起可靠的斑马鱼幼鱼行为节律分析方法,为今后以斑马鱼为模型研究不同光暗条件下生物钟行为提供了良好的实验基础。

All organisms show daily rhythms in behaviour and physiology,and are regulated by the circadian clock.The activity behaviour have been shown to be a reliable marker for ciracdian rhythms.In recent times zebrafish have proven to be a good model system for behavioural studies.In the present study we examined the activity rhythms under different light conditions,such as light-dark cycle(LD)and constant darkness(DD)or light(LL),in zebrafish.For this,5dpf(days after fertilization)larvae were placed into48well plate,continous videos were recorded,tracked and analyzed using Noldus behavioral apparatus under normal light-dark cycle(14h light:10h dark),constant dim light(30lux)and constant bright light(300lux).We measured the changes in locomoter activity for three consecutive days.The results showed that the zebrafish showed synchronised daily rhythms in activity behaviour under light-dark cycle with a diurnal pattern,active during the day and rest during the night.Interestingly,in both LL and DD,the activity behaviour showed circadian pattern with period of^24hours.However,the activity was significantly higher under LL,compared to DD condition,which we reason as a direct effect of bright light on the behaviour.This sets a reliable method for analyzing the activity rhythms of zebrafish and established zebrafish as a good model to study circadian rhythms under different light conditions.