DISSERTATION RESEARCH: Linking functional evolution of odorant receptors to behavioral adaptations and the emergence of herbivory in drosophilids

论文研究：将气味受体的功能进化与行为适应和果蝇食草性的出现联系起来

• 批准号: 1601355
• 负责人: Noah Whiteman
• 金额: $ 1.98万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-05-01 至 2018-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1601355&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Linking; functional; evolution

This research investigates the role of sensory adaptation of smell in closely related species of flies in transitions from feeding on microbes to feeding on plants. Plant-feeding are the most diverse group of animals, including a quarter of all named species. Yet little is known about how insects evolve to feed on plants from other types of diets, or how insects evolve to target specific kinds of plants. This project will study how the smell receptors and underlying genetics of these flies have changed over evolutionary time as their diet switches from yeast to plants. It will determine the changes in smell receptors that allow the switch to new diets and how the underlying genetics shifts to target new host plants. This increased understanding of the evolution of the sense of smell will inform our general understanding of changes in ecological interactions. This research may furthermore provide insights that allow manipulation of insect food choice. It therefore has the potential to broadly impact society through applications to agriculture, where insects are major crop pests, and human health since insects frequently spread disease.This study will investigate the evolution of olfaction (sense of smell) after a niche change by comparing the olfactory systems of Scaptomyza flava and Scaptomyza pallida. These two fly species are closely related but differ in diet. S. flava is a true herbivore feeding on mustard plants, while S. pallida retains the more ancestral diet of microbes. Gas chromatography (GC) -electroantennographic detection (EAD) will be used to differentiate which volatile compounds (smells) produced by leaves of host species the flies can detect. This technique divides a stream of leaf volatiles into two identical streams. One stream is sent into a GC detector for identification by essentially artificially smelling the compound. The other stream is aimed at a fly where EAD will determine if the compound is detectable naturally by determining if the compound triggers a response in single nerve cell. Leaf volatiles that are detected by herbivorous flies will thereby be identified and compared to those detected by flies that feed on microbes. The volatiles identified by GC-EAD as differentiating the two species will then be used as baits in olfactory assays where four calibrated airstreams containing different volatiles are fed into the corners of a square arena. The attraction to each plant volatile will then measured to determine if the species behavior matches their detection profile. Finally, genes that appear to be important in differentiating these two species will be engineered into a model organism Drosophila melanogaster to test if the genes effect on food choice is fully understood.

这项研究调查了气味在紧密相关的果蝇物种中的感觉适应在从微生物进食到植物进食的过渡中。植物喂养是最多样化的动物，其中包括所有命名物种的四分之一。然而，对于昆虫如何以其他类型的饮食为食，或昆虫如何进化以靶向特定种类的植物的植物，知之甚少。该项目将研究这些苍蝇的气味受体和潜在的遗传学在进化时期如何变化，因为它们的饮食从酵母转向植物。它将确定气味受体的变化，从而使转换为新饮食以及基础遗传学如何转移到靶向新的宿主植物。对气味感的演变的这种越来越多的理解将为我们对生态相互作用变化的一般理解。这项研究可能还提供了允许操纵昆虫食物选择的见解。因此，它具有通过对农业的应用，昆虫是主要作物害虫的应用，并且由于昆虫经常传播疾病而广泛影响社会。这项研究将通过比较Scaptomyza Flava和Scaptomyza Pallida的嗅觉变化后的嗅觉变化后的演变（嗅觉）。这两个蝇物种密切相关，但饮食有所不同。 S. flava是芥末植物的真正草食动物，而S. pallida则保留了更祖先的微生物饮食。气相色谱（GC） - 电原抗学检测（EAD）将用于区分蝇可以检测到的宿主物种产生的挥发性化合物（气味）。该技术将叶挥发物的流分为两个相同的流。通过基本上人为地闻到该化合物，将一个流发送到GC检测器中以识别。另一个流的针对苍蝇，通过确定化合物是否触发单神经细胞中的响应来确定化合物是否可自然检测到该化合物。因此，将鉴定出由草食苍蝇检测到的叶挥发物，并将其与以微生物为食的果蝇检测到的叶片。然后，GC-Aead鉴定为区分这两个物种的挥发物将用作嗅觉测定中的诱饵，其中四个校准的含有不同挥发物的校准气流被送入方形竞技场的角落。然后，将测量对每种植物挥发性的吸引力，以确定物种行为是否与其检测曲线相匹配。最后，在区分这两个物种中似乎很重要的基因将被设计成模型的有机体果蝇，以测试基因对食物选择的影响是否完全了解。