Dissertation Research: Behavioral and quantitative genetic mechanisms for the development and evolution of individual differences in Drosophila aggression

尽管人们对攻击性有广泛的兴趣，但导致个体攻击性差异的基因、经验和进化力量仍然是个谜。显然，基因和社会经验都对攻击性有贡献；但是，越来越多的研究人员意识到，基因和社会环境对行为的影响可能是相互关联的。果蝇（Drosophila melanogaster）是解决个体差异问题的理想系统，因为具有特定基因集的多个自然个体可以在实验室中反复培养。使用类似于同卵双胞胎研究的设计，实验人员因此可以理清基因和经验的影响。这个项目将会确定那些具有攻击性基因的个体是否也有不同的社会经历。初步数据表明，更具攻击性的苍蝇比不具攻击性的苍蝇更容易被社会孤立，这导致具有攻击性的苍蝇变得更具攻击性，而非攻击性的苍蝇则保持不具攻击性。这种类型的积极反馈可以解释为什么许多物种的个体表现出与动物相似的个性——即行为上持久的个体差异。在许多系统中，可遗传行为类型和情境选择之间的相互作用对于许多问题都是至关重要的。例如，有证据表明，对某些精神疾病有遗传倾向的人——包括酗酒和精神分裂症——患病的风险更大，因为他们经历了危险的环境。这些假设不可能直接在人类身上进行测试，因为系统地操纵基因型和环境是不可行的。因此，对果蝇的研究将使研究人员能够测试和完善这些理论，从而指导未来的研究。最后，果蝇行为研究为对研究实验感兴趣的本科生提供了一个理想的学习环境。学生们将参与研究的每个阶段，要求学生阅读科学文献中的论文，并与他们一起为项目贡献自己的想法。

Despite widespread interest in aggressiveness, the genes, experiences, and evolutionary forces contributing to individual differences in aggression remain mysterious. Clearly, genes and social experience both contribute to aggressiveness; but, increasingly, researchers are aware that genetic and social environmental influences on behavior may be connected. Fruit flies (Drosophila melanogaster) are an ideal system for addressing questions about individual differences because multiple, natural individuals with a particular set of genes can be grown repeatedly in the lab. Using a design similar to studies of identical twins, experimenters can thereby untangle the effects of genes and experience. This project will determine whether individuals with genes that make them more aggressive also have different social experiences. Preliminary data suggests that more aggressive flies are more likely to be socially isolated than non-aggressive flies -causing aggressive flies to become even more aggressive, and non-aggressive flies to remain non-aggressive. This type of positive feedback may explain why individuals in many species show the animal analog of personalities -that is, long-lasting individual differences in behavior. The interaction between heritable behavioral types and situation choice can be critical for many questions in many systems. For example, there is evidence that humans with a hereditary predisposition to certain mental illnesses -including alcoholism and schizophrenia-are at greater risk of illness because they experience risky environments. These hypotheses are impossible to directly test in humans, where systematic manipulation of genotype and environment are not feasible. Thus, work on Drosophila will allow researchers to test and refine these theories, and thus guide future research. Finally, Drosophila behavioral research provides an ideal entrée for undergraduates interested in research experiments. The PIs will involve undergraduates in every stage of the research, requiring students to read papers from the scientific literature and working with them to contribute their own ideas to the project.