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

在很少或没有亲代照顾的物种中，繁殖行为是决定雄性繁殖成功的一个主要因素。然而，求偶行为在种群内表现出大量的遗传变异，尽管潜在的强烈选择在其上起作用。此外，生殖行为是复杂的神经过程的结果，在大多数生物体中没有很好地表征。先前使用人造基因突变体的研究发现，许多基因可以破坏果蝇的正常生殖行为。果蝇是一种广泛用于基因研究的生物，与包括人类在内的脊椎动物共享许多遗传机制。然而，目前尚不清楚这些相同的基因是否导致了自然种群（非诱变种群）求偶行为的变化。这些基因产生的产物（mRNA）数量的细微差异可能会导致自然发生的行为变化，但这种可能性尚未得到研究。该项目的目标是使用微阵列分析，一种可以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异相关的基因。全基因组mRNA的表达将在不同的基因型中进行测量，这些基因型来源于单个自然种群的果蝇，它们在雄性生殖行为模式方面存在差异。这项研究将有助于发现新的候选基因，并分析控制复杂神经过程的途径。它还将提供对实验室突变筛选中确定的影响复杂性状的基因自然变异的贡献的一般见解。更广泛的影响智力价值该项目将开始剖析复杂行为特征中自然变异的遗传和分子机制，并为进化提供原料。它还将使未来能够调查种群内分离的遗传变异的原因和后果。最后，了解雄性求偶行为变异的遗传基础将对性选择理论、配偶选择进化和强选择下性状遗传变异的维持具有深远的意义。本研究将有两名本科生参与。这些学生将获得微阵列技术、行为遗传学和进化遗传学的工作知识，这些知识将具有很高的市场价值。所有参与该项目的本科生也将参加每周一次的实验室会议，在那里他们可以了解现代研究的实用性，也可以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.