Université de Bourgogne Franche-Comté, CNRS UMR 6249 Chrono-environnement, Besançon, 25030, France.
Fédération Régional de Défense contre Organismes Nuisibles de Bourgogne Franche-Comté, Besançon, 25480, France.
Sci Rep. 2020 Jun 11;10(1):9506. doi: 10.1038/s41598-020-66107-5.
Understanding the driving forces that control vole population dynamics requires identifying bacterial parasites hosted by the voles and describing their dynamics at the community level. To this end, we used high-throughput DNA sequencing to identify bacterial parasites in cyclic populations of montane water voles that exhibited a population outbreak and decline in 2014-2018. An unexpectedly large number of 155 Operational Taxonomic Units (OTUs) representing at least 13 genera in 11 families was detected. Individual bacterial richness was higher during declines, and vole body condition was lower. Richness as estimated by Chao2 at the local population scale did not exhibit clear seasonal or cycle phase-related patterns, but at the vole meta-population scale, exhibited seasonal and phase-related patterns. Moreover, bacterial OTUs that were detected in the low density phase were geographically widespread and detected earlier in the outbreak; some were associated with each other. Our results demonstrate the complexity of bacterial community patterns with regard to host density variations, and indicate that investigations about how parasites interact with host populations must be conducted at several temporal and spatial scales: multiple times per year over multiple years, and at both local and long-distance dispersal scales for the host(s) under consideration.
了解控制田鼠种群动态的驱动因素需要确定田鼠携带的细菌寄生虫，并描述其在群落水平上的动态。为此，我们使用高通量 DNA 测序来识别在 2014-2018 年表现出种群爆发和下降的高山水鼠周期性种群中的细菌寄生虫。检测到数量惊人的 155 个操作分类单元 (OTUs)，代表至少 13 个属和 11 个科。个体细菌丰富度在下降期间较高，而田鼠的身体状况较低。Chao2 估计的本地种群尺度的丰富度没有表现出明显的季节性或周期阶段相关模式，但在田鼠元种群尺度上，表现出季节性和阶段相关模式。此外，在低密度阶段检测到的细菌 OTUs 在地理上广泛分布，并在爆发早期更早被检测到；有些 OTUs 彼此相关。我们的研究结果表明，宿主密度变化与细菌群落模式的复杂性有关，并表明必须在多个时间和空间尺度上进行关于寄生虫如何与宿主种群相互作用的研究：每年多次，多年，并在考虑的宿主的本地和长距离扩散尺度上。
