Department of Biology, Aarhus University, 8000, Aarhus, Denmark.
Department of Biological and Environmental Science, University of Jyväskylä, 40500, Jyväskylä, Finland.
Sci Rep. 2021 Sep 22;11(1):18850. doi: 10.1038/s41598-021-98119-0.
Experiments manipulating the nutritional environment and the associated microbiome of animals have demonstrated their importance for key fitness components. However, there is little information on how macronutrient composition and bacterial communities in natural food sources vary across seasons in nature and on how these factors affect the fitness components of insects. In this study, diet samples from an orchard compost heap, which is a natural habitat for many Drosophila species and other arthropods, were collected over 9 months covering all seasons in a temperate climate. We developed D. melanogaster on diet samples and investigated stress resistance and life-history traits as well as the microbial community of flies and compost. Nutrient and microbial community analysis of the diet samples showed marked differences in macronutrient composition and microbial community across seasons. However, except for the duration of development on these diet samples and Critical Thermal maximum, fly stress resistance and life-history traits were unaffected. The resulting differences in the fly microbial community were also more stable and less diverse than the microbial community of the diet samples. Our study suggests that when D. melanogaster are exposed to a vastly varying nutritional environment with a rich, diverse microbial community, the detrimental consequences of an unfavourable macronutrient composition are offset by the complex interactions between microbes and nutrients.
实验操纵动物的营养环境及其相关微生物群，证明了它们对关键适应成分的重要性。然而，关于自然食物来源中的宏量营养素组成和细菌群落如何随季节变化，以及这些因素如何影响昆虫的适应成分，信息很少。在这项研究中，从果园堆肥堆中收集了饮食样本，这是许多果蝇和其他节肢动物的自然栖息地，并在 9 个月内收集了涵盖温带气候所有季节的样本。我们在饮食样本上培养了黑腹果蝇，并研究了抗逆性和生活史特征以及苍蝇和堆肥的微生物群落。饮食样本的营养和微生物群落分析表明，宏量营养素组成和微生物群落在季节之间存在明显差异。然而，除了在这些饮食样本上的发育持续时间和临界热最大值外，苍蝇的抗逆性和生活史特征不受影响。苍蝇微生物群落的差异也比饮食样本的微生物群落更稳定，多样性更低。我们的研究表明，当黑腹果蝇暴露于营养环境变化很大且微生物群落丰富多样的情况下，不利的宏量营养素组成的不利后果可以通过微生物和营养之间的复杂相互作用来抵消。
