The hidden power within: Using the simple, specialized bee microbiota to examine host-symbiont interactions and health in honey bees

所有的多细胞生物都与不同的微生物群落密切相关，这些微生物群落对其宿主的生活史有着深远的影响。这一发现彻底改变了我们对动物生物学的理解。充分理解微生物组及其所有相关相互作用的能力将揭示生物生态学和生物进化的新维度。此外，从这种理解中获得的操纵微生物组的能力，可以作为一种自然的改进方法应用于健康或农业等不同的研究领域。然而，微生物组成员之间相互作用的复杂性及其对宿主的影响使得大多数宿主-微生物系统难以研究。蜜蜂的实验易处理系统提供了一个理想的机会，从根本上探索共生体对宿主适应性的功能和相互作用，因为相关的微生物群落很小，专业化，可单独培养。我想确认微生物组的一个关键功能是保护蜜蜂免受环境压力的影响，这也会在入侵新环境时增加宿主的适应性。首先，我将利用一个历史性的、独特的数据集，该数据集由美国和墨西哥十多年来采样的3,800只蜜蜂组成。通过Illumina测序技术对蜜蜂相关的细菌和真菌进行测序，以生成内部微生物群的详细图像。在这段时间里，非洲蜜蜂与野生美欧蜜蜂的杂交事件发生了，导致了已知最迅速，最成功的生物入侵之一。在相同的自然环境中，不同的蜜蜂遗传背景将使我能够研究宿主遗传学如何影响该领域的微生物组。由于非洲化的杂交种比欧洲蜜蜂更能抵抗相同的压力因素，我将确定这些谱系中的微生物组成差异，这可能影响了宿主的适应性。我将通过实验转移微生物组来确认微生物组介导的效应，并在病原体，杀虫剂和农业单一文化导致的不良饮食等重要压力下测量蜜蜂的生活史特征。进一步的控制接种实验，使用单一的和混合的微生物群落将揭示每个共生体的功能和它们之间的相互作用对宿主适合度。这项拟议的研究将为宿主微生物组功能提供基本的见解，这些功能将在生命之树中具有类似物。此外，所获得的知识可能使我们能够改善蜜蜂的健康状况，而蜜蜂的健康状况在全球范围内正在下降。

All multicellular organisms are closely associated with diverse microbial communities, which have profound effects on their host's life history. This insight has revolutionized our understanding of animal biology. The ability to fully understand microbiomes with all the associated interactions would shed light on a new dimension of the ecology and evolution of organisms. Moreover, the from such an understanding derived ability of manipulating microbiomes, could be applied as a natural improvement method to diverse research areas such as health or agriculture. Yet, the complexity of microbiomes with interactions between members, and their consequences for hosts, make most host-microbiota systems difficult to study. The experimentally tractable system of the honey bee offers an ideal opportunity to fundamentally explore functions and interactions of symbionts on host fitness, as the associated microbial communities are small, specialized, and individually cultivable. I want to confirm that a key microbiome function is to protect the honey bee from environmental stressors, which also increases host fitness when invading new environments.First, I will take advantage of a historical, unique data set consisting of 3,800 honey bees sampled for more than a decade in the U.S. and Mexico, to generate a detailed picture of the internal microbiota by Illumina-sequencing of honey bee-associated bacteria and fungi. During this time, a hybridization event from introduced African with wild US-European bee lines occurred, leading to one of the most rapid, successful biological invasions known. Diverse genetic bee backgrounds in the same natural environment will allow me to examine how host genetics affect microbiomes in the field. As Africanized hybrids are more resistant to the same stress factors than European bees, I will identify microbial compositional differences in these lineages, which may have affected host fitness. I will confirm microbiome-mediated effects by experimentally transferring microbiomes and measure bee life history traits under important stressors like pathogens, pesticides and poor diets due to agricultural mono culture. Further controlled inoculation experiments using single and mixed microbe communities will reveal the function of each symbiont and its interactions on host fitness. The proposed study will give fundamental insights into host-microbiome function which will have analogs across the tree of life. Moreover, the knowledge acquired may enable us to improve the health of honey bees, which is declining worldwide.