USDA-ARS Bee Research Laboratory, Building 306, BARC-East, Beltsville, MD 20705, USA.
College of Bee Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
J Exp Biol. 2019 Apr 5;222(Pt 7):jeb202077. doi: 10.1242/jeb.202077.
Nutrition is involved in regulating multiple aspects of honey bee biology such as caste, immunity, lifespan, growth and behavioral development. Deformed wing virus (DWV) is a major pathogenic factor which threatens honey bee populations, and its replication is regulated by the nutrition status and immune response of honey bees. The alimentary canal of the honey bee is home to a diverse microbial community that provides essential nutrients and serves to bolster immune responses. However, to what extent gut bacteria affect honey bee nutrition metabolism and immunity with respect to DWV has not been investigated fully. In this study, newly emerged worker bees were subjected to four diets that contained (1) pollen, (2) pollen and antibiotics, (3) neither pollen nor antibiotics or (4) antibiotics alone. The expression level of two nutrition genes () and (), one nutritional marker gene (), five genes (-), one antimicrobial peptide regulating gene (), and DWV virus titer and its replication intermediate, negative RNA strand, were determined by qRT-PCR from the honey bees at 7 days post-antibiotic treatment. Additionally, honey bee head mass and survival rate were measured. We observed that antibiotics decreased the expression of and , and increased DWV titer and its replication activity. Expression of , - and , and honey bee head mass were also reduced compared with bees on a pollen diet. Antibiotics also caused a significant drop in survivorship, which could be rescued by addition of pollen to the diet. Of importance, pollen could partially rescue the loss of and while also increasing the head mass of antibiotic-treated bees. Our results illuminate the roles of bacteria in honey bee nutrition, metabolism and immunity, which confer the ability to inhibit virus replication, extend honey bee lifespan and improve overall health.
营养物质参与调控蜜蜂生物学的多个方面,如蜂群等级、免疫力、寿命、生长和行为发育。变形翅膀病毒(DWV)是威胁蜜蜂种群的主要致病因素,其复制受到蜜蜂营养状况和免疫反应的调节。蜜蜂的消化道内生活着多样的微生物群落,这些微生物提供必需的营养物质,并增强免疫反应。然而,肠道细菌在多大程度上影响蜜蜂的营养代谢和免疫反应以抵抗 DWV 还没有被充分研究。在这项研究中,新羽化的工蜂被喂食四种不同的食物,分别是(1)花粉、(2)花粉加抗生素、(3)既无花粉也无抗生素或(4)仅抗生素。在抗生素处理后 7 天,通过 qRT-PCR 从蜜蜂中测定了两个营养基因()和()、一个营养标记基因()、五个基因(-)、一个抗菌肽调节基因()以及 DWV 病毒滴度及其复制中间体负 RNA 链的表达水平。此外,还测量了蜜蜂的头部质量和存活率。我们观察到抗生素降低了 和 的表达,并增加了 DWV 的滴度和复制活性。与花粉饮食的蜜蜂相比,蜜蜂的 、-和 表达以及头部质量也有所降低。抗生素处理还导致蜜蜂存活率显著下降,而在饮食中添加花粉可以挽救这种情况。重要的是,花粉可以部分挽救抗生素处理蜜蜂中 和 的损失,同时增加抗生素处理蜜蜂的头部质量。我们的研究结果阐明了细菌在蜜蜂营养、代谢和免疫中的作用,这些作用赋予了抑制病毒复制、延长蜜蜂寿命和提高整体健康水平的能力。