Laboratory of Agrozoology, Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium.
Laboratory of Microbiology, Department of Biochemistry and Microbiology, Faculty of Sciences, Ghent University, Ghent, Belgium.
Insect Mol Biol. 2023 Oct;32(5):544-557. doi: 10.1111/imb.12849. Epub 2023 May 16.
The present study aimed to characterise the bacterial, fungal and parasite gut community of the invasive bee Megachile sculpturalis sampled from native (Japan) and invaded (USA and France) regions via 16S rRNA and ITS2 amplicon sequencing and PCR detection of bee microparasites. The bacterial and fungal gut microbiota communities in bees from invaded regions were highly similar and differed strongly from those obtained in Japan. Core amplicon sequence variants (ASVs) within each population represented environmental micro-organisms commonly present in bee-associated niches that likely provide beneficial functions to their host. Although the overall bacterial and fungal communities of the invasive M. sculpturalis in France and the co-foraging native bees Anthidium florentinum and Halictus scabiosae, were significantly different, five out of eight core ASVs were shared suggesting common environmental sources and potential transmission. None of the 46 M. sculpturalis bees analysed harboured known bee pathogens, while microparasite infections were common in A. florentinum, and rare in H. scabiosae. A common shift in the gut microbiota of M. sculpturalis in invaded regions as a response to changed environmental conditions, or a founder effect coupled to population re-establishment in the invaded regions may explain the observed microbial community profiles and the absence of parasites. While the role of pathogen pressure in shaping biological invasions is still debated, the absence of natural enemies may contribute to the invasion success of M. sculpturalis.
本研究旨在通过 16S rRNA 和 ITS2 扩增子测序以及蜜蜂微寄生虫的 PCR 检测，描述来自日本本土（日本）和入侵（美国和法国）地区的入侵蜜蜂 Megachile sculpturalis 的细菌、真菌和寄生虫肠道群落。来自入侵地区的蜜蜂的细菌和真菌肠道微生物群落高度相似，与在日本获得的群落有很大的不同。每个种群内的核心扩增子序列变异 (ASV) 代表了常见于与蜜蜂相关的生态位中的环境微生物，这些微生物可能对其宿主提供有益的功能。尽管法国入侵的 M. sculpturalis 和共同觅食的本地蜜蜂 Anthidium florentinum 和 Halictus scabiosae 的总体细菌和真菌群落有显著差异，但有 8 个核心 ASV 中有 5 个是共有的，这表明存在共同的环境来源和潜在的传播。在分析的 46 只 M. sculpturalis 蜜蜂中，没有一只携带已知的蜜蜂病原体，而 A. florentinum 中微寄生虫感染很常见，H. scabiosae 中则很少见。入侵地区 M. sculpturalis 肠道微生物群的共同变化可能是对环境条件变化的反应，或者是与入侵地区种群重建相关的奠基者效应，可以解释观察到的微生物群落特征和寄生虫的缺乏。虽然病原体压力在塑造生物入侵中的作用仍存在争议，但缺乏天敌可能有助于 M. sculpturalis 的入侵成功。
