DISSERTATION RESEARCH: Natural Genetic Variation and Gene Expression in Male Courtship Behavior of Drosophila Melanogaster

在没有或很少父母照顾的物种中，生殖行为是决定雄性生殖成功的主要因素。然而，求偶行为在种群内表现出很大的遗传变异，尽管潜在的强大选择对其进行了操作。此外，生殖行为是复杂的神经过程的结果，而这些过程在大多数生物体中都没有很好的特征。之前使用人造基因突变的研究已经在果蝇身上发现了许多可以扰乱正常生殖行为的基因。果蝇是一种被广泛应用于遗传学研究的生物，它与包括人类在内的脊椎动物有着许多共同的遗传机制。然而，目前尚不清楚这些相同的基因是否是导致自然(非诱变)种群中求偶行为发生变化的原因。这些基因产生的产物(信使核糖核酸)的细微差异可能会导致行为的自然变化，但这种可能性还没有被研究过。这个项目的目标是使用微阵列分析，这是一种允许同时测量基因组中每个基因产生的mRNA的技术，以发现那些与自然发生的行为变化有关的基因。将测量来自单一自然果蝇种群的不同基因类型的全基因组mRNA表达，这些基因类型在雄性生殖行为模式方面有所不同。这项研究将使发现新的候选基因和分析控制复杂神经过程的途径成为可能。它还将提供对实验室突变筛查中被识别为影响复杂特征的基因的自然变异的一般洞察。广泛影响智力价值本项目将开始剖析复杂行为特征的自然变异背后的遗传和分子机制，并为进化提供原材料。它还将使今后能够对种群内隔离的遗传变异的原因和后果进行调查。最后，对雄性求爱行为变异的遗传基础的理解将对性别选择、配偶选择的进化以及在强选择下维持性状遗传变异的理论产生深远的影响。本科生的教育与发展两名本科生将参与这项研究。这些学生将获得微阵列技术、行为遗传学和进化遗传学的实用知识，这些知识将非常有市场。所有参与该项目的本科生还将参加每周一次的实验室会议，在那里他们了解现代研究的实用性，并接触到主要的研究文献。

Reproductive behavior is a major factor in determining male reproductive success in species with little or no parental care. However, courtship behavior exhibits substantial genetic variation within populations, despite potentially strong selection operating on it. In addition, reproductive behavior is the outcome of complex neural processes that are not well characterized in most organisms. Previous research using man-made genetic mutants has found many genes that can disrupt normal reproductive behavior in the fruit fly Drosophila melanogaster, an organism widely used in genetic research which shares many genetic mechanisms with vertebrates, including humans. However, it is not known if these same genes are the ones causing variation in courtship behavior in natural (non-mutagenized) populations. It is possible that subtle differences in the amount of product these genes are producing (mRNA) contributes to naturally-occurring variation in behavior, but this possibility has not been investigated. The goal of this project is to use microarray analysis, a technology that allows measurement of the mRNA produced from every gene in the genome simultaneously, to discover those genes associated with naturally occurring variation in behavior. Genome-wide mRNA expression will be measured in different genotypes derived from a single natural population of Drosophila, which differ with respect to patterns of male reproductive behavior. This study will allow discovery of new candidate genes and the analysis of pathways that control a complex neural process. It will also provide general insight into the contribution to natural variation of genes identified as affecting a complex trait in laboratory mutation screens.Broader Impact Intellectual meritThis project will begin to dissect genetic and molecular mechanisms that underlie natural variation in a complex behavioral trait, and which provide the raw material for evolution. It will also enable future investigations into the causes and consequences of genetic variation that segregates within populations. Finally, an understanding of the genetic basis of variation in male courtship behavior will have profound implications for theories of sexual selection, the evolution of mate choice, and the maintenance of genetic variation in traits under strong selection. Education and development of undergraduatesTwo undergraduate students will participate in this research. These students will gain working knowledge of microarray technology, behavioral genetics, and evolutionary genetics, and this knowledge will be highly marketable. All undergraduates working on the project will also participate in weekly lab meetings, where they gain an understanding of the practicalities of modern research and also are exposed to the primary research literature.