Parker Erik S, Moczek Armin P
Department of Biology Indiana University Bloomington IN USA.
Ecol Evol. 2020 Nov 19;10(24):13640-13648. doi: 10.1002/ece3.6836. eCollection 2020 Dec.
Microbial symbionts can influence their hosts in stunningly diverse ways. Emerging research suggests that an underappreciated facet of these relationships is the influence microbes can have on their host's responses to novel, or stressful, environmental conditions. We sought to address these and related questions in populations resulting from the recent introduction and subsequent rapid range expansion of dung beetles. Specifically, we manipulated both microbial communities and rearing temperature to detect signatures of developmental and life history differentiation in response to the local thermal conditions in two populations derived from the southern most (Florida) and northern most (Michigan) extremes of the exotic Eastern U.S. range of . We then sought to determine the contributions, if any, of host-associated microbiota to this differentiation. We found that when reared under common garden conditions individuals from Florida and Michigan populations differed significantly in developmental performance measures and life history traits, consistent with population divergence. At the same time, and contrary to our predictions, we failed to find support for the hypothesis that animals perform better if reared at temperatures that match their location of origin and that performance differences may be mediated by host-associated microbiota. Instead, we found that microbiome swapping across host populations improved developmental performance in both populations, consistent with enemy release dynamics. We discuss the implications of our results for our understanding of the rapid spread of exotic through the Eastern United States and the significance of symbiosis in host responses to novel environmental conditions more broadly.
微生物共生体能够以惊人的多样方式影响其宿主。新出现的研究表明，这些关系中一个未得到充分重视的方面是微生物对宿主应对新的或有压力的环境条件的影响。我们试图在蜣螂近期引入并随后迅速扩大分布范围所形成的种群中解决这些及相关问题。具体而言，我们对微生物群落和饲养温度进行了操控，以检测来自美国东部外来分布范围最南端（佛罗里达州）和最北端（密歇根州）的两个种群对当地热条件的发育和生活史分化特征。然后，我们试图确定宿主相关微生物群对这种分化的贡献（如果有的话）。我们发现，在共同园圃条件下饲养时，来自佛罗里达州和密歇根州种群的个体在发育性能指标和生活史特征方面存在显著差异，这与种群分化一致。与此同时，与我们的预测相反，我们没有找到支持以下假设的证据：动物在与其原产地温度相匹配的温度下饲养时表现更好，且性能差异可能由宿主相关微生物群介导。相反，我们发现跨宿主种群交换微生物群落提高了两个种群的发育性能，这与天敌释放动态一致。我们讨论了我们的结果对于理解外来物种在美国东部迅速扩散的意义，以及共生在宿主对新环境条件反应中的更广泛意义。
