DISSERTATION RESEARCH: Competition and cooperation in the honey bee gut microbiota

传粉者的健康对农业和自然生态系统都很重要，其中最重要的传粉者之一，特别是在农业中，是蜜蜂。在这个项目中，研究人员将重点放在蜜蜂肠道中的细菌上，因为肠道细菌会影响动物的健康。他们将研究这些细菌如何相互作用，因为这对肠道细菌群落的稳定程度以及它们与宿主动物的相互作用非常重要。研究人员将继续研究蜜蜂肠道中的两种关键细菌。他们已经展示了这些细菌是如何拥有毒素的，它们可以用这些毒素相互攻击。然而，在某些情况下，这些细菌很可能也会相互帮助。研究人员将使用最近开发的方法来观察这些细菌是否以及如何将营养物质传递给彼此和寄主蜜蜂。这将有助于理解蜜蜂肠道细菌群落如何随着时间的推移保持稳定。这将有助于开发改善蜜蜂健康的新途径。此外，在该项目中，研究生和本科生研究人员将接受最先进的微生物学方法培训。由于昆虫可以吸收和利用碳水化合物发酵的副产品，蜜蜂可能受益于其肠道微生物群落成员的新陈代谢活动，通过降解有毒糖和生产有用的副产品。为了更好地了解合作代谢相互作用在肠道群落中的作用，该项目将追踪蜜蜂肠道中的营养交换。基因组证据表明，蜜蜂肠道微生物Snugrsella Alvi和Gilliamella Apicola在生产营养方面相互依赖。阿皮科拉能代谢阿尔维不能代谢的碳水化合物，也能代谢花蜜中对蜜蜂有毒的糖类。这个项目将使用同位素标记的单糖，这种单糖可以被蜜蜂利用，但不能被阿尔维或寄主利用，以追踪蜜蜂肠道中的新陈代谢相互作用。DNA稳定同位素探测(DNA-SIP)将被用来追踪标记的碳原子进入细菌DNA的情况，而这些原子进入宿主组织的情况将通过元素分析和同位素比质谱仪来测量。这项研究将有助于更基本地了解支配肠道微生物区系成员之间以及微生物区系与宿主之间的合作代谢相互作用的过程，并将展示SIP方法在微生物群落生态学的假设检验中的重要潜在作用，而在微生物群落生态学中，它是一个不常用的框架。

Pollinator health is important for both agricultural and natural ecosystems, and one of the most important pollinators, especially in agriculture, is the honey bee. In this project, researchers will focus on bacteria in honey bee guts, because gut bacteria affect animals' health. They will study how these bacteria interact with one another, because this is important for how stable helpful gut bacterial communities are, and how they interact with the host animal. The researchers will continue working with two critical bacteria in the bee gut. They have already shown how these bacteria have toxins with which they can attack one another. However, it is likely that these bacteria also help one another in some situations. The researchers will use recently developed methods to look at whether and how these bacteria pass nutrients to one another and to the host bee. This will contribute to understanding how bee-gut bacterial communities stay stable through time. It will help to develop new routes to improving bee health. In addition, during the project graduate and undergraduate researchers will be trained in state-of-the-art methods in microbiology.As insects can take up and utilize byproducts of carbohydrate fermentation, honeybees may benefit from the metabolic activities of members of their gut microbial communities through both the degradation of toxic sugars and the production of useful byproducts. To better understand the role of cooperative metabolic interactions in gut communities, this project will trace nutrient exchange in the honeybee gut. Genomic evidence suggests that the bee gut microbes Snodgrassella alvi and Gilliamella apicola depend upon one another for production of nutrients. G. apicola metabolizes carbohydrates that S. alvi cannot, and metabolizes sugars found in nectar that are toxic to honey bees. This project will use isotopically-labeled monosaccharides that can be utilized by G. apicola, but not by S. alvi or the host, to trace metabolic interactions in the bee gut. DNA-stable isotope probing (DNA-SIP) will be used to track incorporation of labeled carbon atoms into bacterial DNA, while incorporation of these atoms into host tissues will be measured through elemental analysis and isotope ratio mass spectrometry. This research will contribute to a greater fundamental understanding of the processes that govern cooperative metabolic interactions among members of the gut microbiota and between the microbiota and the host, and will demonstrate the important potential role of SIP methods in hypothesis testing in microbial community ecology, a framework in which it is uncommonly used.