DISSERTATION RESEARCH: Do gut microbiota affect caterpillar herbivory and fitness?

论文研究：肠道微生物群会影响毛毛虫的食草和健康吗？

• 批准号: 1601787
• 负责人: Noah Fierer
• 金额: $ 1.61万
• 依托单位: University of Colorado at Boulder
• 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: 2016-06-01 至 2017-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1601787&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Do; gut; microbiota

Recent studies have shown that some animals, including humans, are heavily dependent on trillions of bacteria and other microorganisms that inhabit their gut ("gut microbiota") to digest food and provide nutrients. Although this microbial partnership likely occurs in all animals, it remains unexplored in most. This project assesses the role of gut microbiota in caterpillars, some of which are globally destructive crop pests and thus of major economic interest. Understanding whether caterpillars are reliant on gut microbiota for feeding and growth could help in designing strategies for controlling them more effectively. Researchers will conduct an experiment using the tobacco hornworm caterpillar, a common pest of tomato and tobacco plants. Findings of this project will advance scientific understanding of how much animals and microbes have evolved to depend on each other. This study will also provide research experience for a community college student and will engage the public through an educational workshop and a museum event.Investigators will experimentally test the hypothesis that gut microbiota in the tobacco hornworm, Manduca sexta, affect host feeding behavior and fitness. The experiment will be based in southeastern Arizona, where a large population of wild M. sexta feed on the plant Datura wright-ii. To manipulate gut microbiota, researchers will use antibiotics to selectively remove microbes from D. wrightii without altering leaf chemical or nutritional properties. Feeding rates and development of the caterpillars, as well as fecundity of the resulting adult moths, will be measured and compared between control and antibiotic-treated groups. In addition, the size and composition of gut microbial communities will be characterized using DNA sequencing and fluorescence microscopy. Previous DNA sequencing data indicate that the number of microbes in the M. sexta gut is extremely low relative to other animals. Further, extreme chemical conditions within the caterpillar gut suggest that the gut microbes detected there are unlikely to be metabolically active. Therefore, the researchers anticipate that gut microbiota will not play a large role in host feeding or fitness. This result would challenge the current paradigm that animal growth and reproduction typically depend heavily upon microbial symbiosis.

最近的研究表明，包括人类在内的一些动物严重依赖肠道(肠道微生物区系)中数以万亿计的细菌和其他微生物来消化食物和提供营养。尽管这种微生物伙伴关系可能在所有动物中都存在，但在大多数动物中仍未被发现。该项目评估肠道微生物区系在毛虫中的作用，毛虫中的一些是全球破坏性的作物害虫，因此具有重大的经济利益。了解毛虫是否依赖肠道微生物区系觅食和生长，有助于设计更有效地控制它们的策略。研究人员将使用烟草角虫毛虫进行一项实验，烟草角虫毛虫是番茄和烟草的常见害虫。该项目的发现将促进对动物和微生物在多大程度上进化到相互依赖的科学理解。这项研究还将为社区大学的学生提供研究经验，并将通过教育研讨会和博物馆活动吸引公众。调查人员将通过实验测试烟草角虫肠道微生物区系影响寄主取食行为和健康的假说。这项实验将在亚利桑那州东南部进行，那里有大量的野生六星鼠以植物曼陀罗·赖特-II为食。为了控制肠道微生物区系，研究人员将使用抗生素来选择性地去除莱特氏菌中的微生物，而不会改变叶片的化学或营养特性。在对照组和抗生素处理组之间，将测量毛虫的取食率和发育，以及由此产生的成虫的繁殖力，并进行比较。此外，肠道微生物群落的大小和组成将使用DNA测序和荧光显微镜进行表征。之前的DNA测序数据表明，与其他动物相比，六分枝杆菌肠道中的微生物数量非常少。此外，毛虫肠道内的极端化学条件表明，在那里检测到的肠道微生物不太可能具有新陈代谢活性。因此，研究人员预计肠道微生物区系在宿主取食或适应方面不会发挥很大作用。这一结果将挑战目前的模式，即动物的生长和繁殖通常严重依赖微生物共生。