DSC1在果蝇幼虫感觉-中枢神经系统-运动回路中的作用

Function of DSC1 in sensory-central nervous system-motor circuits of Drosophila larva

【目的】探究果蝇钠通道1(Drosophila sodium channel 1,DSC1)在果蝇幼虫感觉-中枢神经系统-运动回路(sensory-central nervous system-motor circuits,S-CNS-MC)中的作用,为果蝇的有效防治提供参考。【方法】以果蝇幼虫的S-CNS-MC为模型,以神经遗传背景不同的4种果蝇品系w^(1118)、para^(ts1)、DSC1^(-/-)和para^(ts1);DSC1^(-/-)幼虫为材料,分别在正常状态和饥饿状态下采用番茄切面觅食活动对其进行行为学研究,通过测定不同品系果蝇幼虫的兴奋性接点电位对其进行电生理学研究。【结果】番茄切面觅食活动行为学观察结果表明,正常状态下在每个观察的时间点,4种果蝇品系在番茄切面果皮中的幼虫数量均无显著差异;但饥饿状态下,随着观察时间的延长,DSC1^(-/-)品系的3龄幼虫停留在番茄中果皮部分的数量显著多于其他品系,表明在饥饿状态下敲除DSC1的果蝇幼虫反应迟钝,觅食行为减缓。电生理试验结果表明,w^(1118)和para^(ts1)品系果蝇幼虫在饥饿状态下神经回路的兴奋性接点电位(EJP)频率与正常状态下差异不显著,但DSC1^(-/-)和para^(ts1);DSC1^(-/-)品系果蝇幼虫在饥饿状态下神经回路的EJP频率均较正常状态显著下降,表明敲除DSC1的DSC1^(-/-)和para^(ts1);DSC1^(-/-)2种品系果蝇幼虫S-CNS-MC的兴奋性在饥饿状态下明显降低,这与上述觅食活动行为学结果一致。【结论】DSC1有助于果蝇幼虫在饥饿逆境条件下维持神经系统的兴奋性传导和神经回路的稳定性。

【Objective】This study investigated the role of Drosophila sodium channel 1(DSC1)in sensory-central nervous system-motor circuit(S-CNS-MC)in Drosophila larva to provide reference for effective control of Drosophila.【Method】Taking S-CNS-MC of Drosophila melanogaster larvae as model,four Drosophila strains of w^(1118),para^(ts1),DSC1^(-/-)and para^(ts1);DSC1^(-/-)larvae with different neurogenetic backgrounds were selected.Their behaviors were studied using foraging activities of tomato slices in normal state and hungry state and the electrophysiology was studied by measuring excitatory contact points.【Result】The behavioral observation of foraging activities with tomato slices showed that there was no significant difference among strains at each observation time point under normal conditions.In hungry state,the number of 3rd larvae in the peel part of the DSC 1^(-/-)strain was significantly larger than that of other strains with the extension of time.These results indicated that the response of Drosophila larvae with DSC1 knocked out in starvation was sluggish and the foraging behavior was slow.The excitatory junction potentials(EJP)frequency of w^(1118) and para^(ts1) larvae during starvation showed no significant difference from normal state,while that of DSC1^(-/-)and para^(ts1);DSC1^(-/-)larvae decreased significantly under starvation condition,indicating that the excitability of S-CNS-MC in the larvae with DSC1 channel knocked out was significantly reduced under starvation condition,which was consistent with the observation of foraging behavior.【Conclusion】The DSC1 channel plays an important role in maintaining excitatory conduction and neural circuit stability of nervous system under starvation stress conditions.