Doublesex调控果蝇习得求偶行为的分子与神经机制研究

Innate behavior and learned behavior are important components of animal behavior and human behavior. Drosophila courtship behavior，which is controlled by a transcription factor Fruitless (FRU), is a perfect model system to study the mechanism of behaviors. We recently found that Drosophila male courtship can be learned through environment, when Drosophila male loses its innate courtship behavior. This learned courtship behavior is regulated by a transcription factor Doublesex (DSX). However, the molecular mechanism underlying how dsx regulates learned courtship is still unknown. We hypothesize, based on previous findings, that social experience induces courtship behavior by changing gene expression and/or neuronal connectivity to allow efficient transduction from sensory perception to motor output. We aim to investigate mainly on the two aspects: (1) Identify the key target genes of DSX and their function in learned courtship behavior; (2) How dsx and its target genes regulate the development of the related neural circuitry. These studies will reveal basic mechanisms of how genes corporate to control a learned behavior. DSX is highly conserved in various species, including nematode, fruit fly and human. Therefore, it is significant to investigate the molecular mechanism of how dsx regulates the learned courtship behavior, which could also be applicable to human.

动物包括人类具有与生俱来的本能行为和后天学习获得的习得行为。果蝇的求偶行为是研究本能行为产生机制的经典模型，其主要受转录因子Fruitless (FRU)调控。本课题组近年的研究发现在本能求偶行为丧失的情况下，果蝇还可以通过后天环境获得习得求偶行为，其主要受转录因子Doublesex (DSX)调控。目前关于DSX如何调控果蝇习得求偶行为形成的分子机制仍不清楚。本项目基于已有发现提出假设：后天环境和经验通过改变基因的表达和神经环路的连接从而使果蝇重新获得求偶行为。我们拟集中解决以下两个问题：一是DSX通过调节哪些靶基因的表达调控习得求偶行为；二是DSX与其靶基因如何通过调节神经环路的发育或是神经元之间的信息传递决定习得求偶行为的输出。由于DSX从线虫、果蝇到人类都具有高度保守性，本项目研究DSX调控习得行为形成的分子与神经机制对理解高等动物后天学习行为的机制具有重大借鉴意义。

动物包括人类具有与生俱来的本能行为和后天获得的习得行为。果蝇的求偶行为是研究本能行为产生机制的经典模型，主要受转录因子Fruitless (FRU)调控。在本能求偶行为丧失的情况下，果蝇还可以从后天环境中获得习得求偶行为，主要受转录因子Doublesex (DSX)调控。目前关于DSX如何调控果蝇习得求偶行为的分子机制仍不清楚。本项目通过两种不同的方法鉴定了多个DSX靶基因，并揭示DSX在雌性果蝇中抑制求偶行为，而在雄性果蝇中促进求偶行为。本项目还在不同发育时期和不同的神经系统部分分别研究了DSX对果蝇求偶行为的调控作用。在果蝇发育阶段中，幼虫到蛹的变态发育时期对于求偶行为的正常形成至关重要；在神经系统功能中，果蝇中枢脑和脑之外的神经系统对于求偶行为同样重要。总之，本项目系统的研究了DSX在时间和空间上对果蝇求偶行为的调控机制，并鉴定了多个DSX可能的靶基因，为揭示DSX调控果蝇习得求偶行为的分子机制提供理论基础。