Axenic development data, Fig 5A and 5B.

The intracellular bacterium Wolbachia is a common symbiont of many arthropods and nematodes, well studied for its impacts on host reproductive biology. However, its broad success as a vertically transmitted infection cannot be attributed to manipulations of host reproduction alone. Using the Drosophila melanogaster model and natively associated Wolbachia strain “wMel”, we show that Wolbachia infection supports fly development and buffers against nutritional stress. Wolbachia infection across two fly genotypes and a range of nutrient conditions resulted in reduced pupal mortality, increased adult emergence, and larger size. In parallel, transcriptomic and metabolomic analyses indicated that Wolbachia impacts a wide range of developmental and metabolic processes. Wolbachia-infected larvae had strong signatures of shifts in glutathione and mitochondrial metabolism, plus significant changes in the expression of key developmental regulators including Notch, the insulin receptor (lnR), and the juvenile hormone receptor Methoprene-tolerant (Met). We propose that Wolbachia can enhance host fitness by supporting fly development, especially during periods of nutrient stress.

胞内细菌沃尔巴克氏体（Wolbachia）是许多节肢动物与线虫的常见共生菌，因其对宿主生殖生物学的影响而被广泛研究。然而，这种作为垂直传播感染物的广泛成功，不能仅归因于对宿主生殖的操纵。本研究以黑腹果蝇（Drosophila melanogaster）为模型，结合其本土共生的沃尔巴克氏体菌株"wMel"，证实沃尔巴克氏体感染可促进果蝇发育，并抵御营养胁迫。在两种果蝇基因型与多种营养条件下开展的沃尔巴克氏体感染实验显示，该感染可降低蛹死亡率、提升成虫羽化率，并使果蝇体型更大。与此同时，转录组与代谢组分析表明，沃尔巴克氏体可影响广泛的发育与代谢过程。感染沃尔巴克氏体的幼虫表现出谷胱甘肽（glutathione）与线粒体代谢显著改变的特征，同时包括Notch、胰岛素受体（insulin receptor, lnR）以及保幼激素受体早熟素耐受蛋白（Methoprene-tolerant, Met）在内的关键发育调控因子的表达也发生了显著变化。本研究提出，沃尔巴克氏体可通过促进果蝇发育提升宿主适合度，尤其是在营养胁迫时期。