无乳链球菌通过5-HT系统影响吉富罗非鱼行为的机制研究

Pathogen infection has a serious impact on fish behavior. However, the quantitative analysis of behavior changes after infected by pathogen, and the underlying physiological mechanism are scarce. Our previous studies have found that pathogen infection caused changes of fish swimming performance, tail beat frequency and discoloration behavior. And the contents and distribution of serotonin (5-HT), a neurotransmitter involved in the regulation of various mental and physiological activities including rhythm behavior, had significant changes in fish brain, gut and stomach. We suspect that the fish behavior may be affected by 5-HT system after Streptococcus agalactia infection . The study will be performed, based on the behavior disorders of GIFT tilapia caused by Streptococcus agalactia infection. We will investigate the behavior changes by the machine-vision technology, and analyze the expression of 5-HT and its receptors quantitatively. The molecular mechanism underlying behavior changes from the perspective of 5-HT system will be illustrated. This study will not only yield well theoretical significance for quantitative analysis of fish behavior and cognition of behavioral mechanisms, but a guideline for the practical production.

病原侵染对鱼类行为产生影响，但其量化分析及生理机制研究非常匮乏。我们的前期研究发现，病原侵染不仅可导致鱼类游泳能力、摆尾频率以及变色行为异常，而且参与调控包括节律行为在内的多种精神及生理活动的神经递质血清素(5-HT)在鱼类脑、肠道及胃组织中的含量和分布均发生明显变化。因此，我们推测，病原侵染可能通过5-HT系统影响鱼类行为。本项目以无乳链球菌导致的吉富罗非鱼行为失调病症为研究对象，通过机器视觉技术量化分析无乳链球菌侵染引起的吉富罗非鱼异常行为，并采用先进的分子生物学手段定量分析病原侵染后罗非鱼脑组织中5-HT及其受体的表达水平，探究5-HT在无乳链球菌引起的吉富罗非鱼行为异常中发挥的作用，从5-HT系统的角度阐明病原侵染影响鱼类行为的分子机制。本研究不仅对鱼类行为的量化分析以及行为机制的认知具有良好的理论意义，且对生产实践具有指导作用。

行为是动物应对内外环境变化的第一手段，病原感染影响鱼类的行为，但其量化分析及生理机制研究非常匮乏。本项目以无乳链球菌导致的吉富罗非鱼行为失调病症为研究对象，我们通过机器视觉技术量化分析无乳链球菌感染后吉富罗非鱼的运动轨迹、碰壁次数、游泳速度和临界游泳速度，采用定量PCR技术检测了感染后罗非鱼不同组织的病原菌含量以及5-HT受体5-HT1A、5-HT2A的相对表达量，并检测了罗非鱼不同组织中5-HT、DA和NE的含量，结合无乳链球菌感染后罗非鱼行为变化和5-HT系统相关指标的变化，探究5-HT在无乳链球菌引起的吉富罗非鱼行为异常中发挥的作用，从5-HT系统的角度阐明病原感染影响鱼类行为的分子机制。本研究不仅对鱼类行为的量化分析以及行为机制的认知具有良好的理论意义，且对实际生产具有指导作用。