Abstract：
The role of species interactions, as well as genetic and environmental factors, all likely contribute to the composition and structure of the gut microbiome; however, disentangling these independent factors under field conditions represents a challenge for a functional understanding of gut microbial ecology. Avian brood parasites provide unique opportunities to investigate these questions, as brood parasitism results in parasite and host nestlings being raised in the same nest, by the same parents. Here we utilized obligate brood parasite brown-headed cowbird nestlings (BHCO; Molothrus ater) raised by several different host passerine species to better understand, via 16S rRNA sequencing, the microbial ecology of brood parasitism. First, we compared faecal microbial communities of prothonotary warbler nestlings (PROW; Protonotaria citrea) that were either parasitized or non-parasitized by BHCO and communities among BHCO nestlings from PROW nests. We found that parasitism by BHCO significantly altered both the community membership and community structure of the PROW nestling microbiota, perhaps due to the stressful nest environment generated by brood parasitism. In a second dataset, we compared faecal microbiotas from BHCO nestlings raised by six different host passerine species. Here, we found that the microbiota of BHCO nestlings was significantly influenced by the parental host species and the presence of an inter-specific nestmate. Thus, early rearing environment is important in determining the microbiota of brood parasite nestlings and their companion nestlings. Future work may aim to understand the functional effects of this microbiota variability on nestling performance and fitness.
摘要：
物种相互作用的作用，以及遗传和环境因素，所有这些都可能有助于肠道微生物组的组成和结构；然而，在野外条件下解开这些独立因素对肠道微生物生态学的功能理解提出了挑战。禽类寄生虫提供了独特的机会来研究这些问题，因为雏鸟寄生导致寄生虫和寄主雏鸟在同一个巢中长大，同样的父母。在这里，我们利用了由几种不同的寄主雀形目物种饲养的专性育卵寄生虫棕色头型牛鸟雏鸟（BHCO；Molothrusater），以更好地了解，通过16SrRNA测序，育巢寄生的微生物生态学。首先,我们比较了被BHCO寄生或未寄生的原野莺雏鸟（PROW；Protonotariacitrea）的粪便微生物群落，以及来自PROW巢的BHCO雏鸟的群落。我们发现BHCO的寄生行为显着改变了PROW雏鸟微生物群的社区成员和社区结构，也许是由于巢穴寄生产生的压力环境。在第二个数据集中，我们比较了由六种不同寄主雀形目动物饲养的BHCO雏鸟的粪便微生物。这里,我们发现BHCO雏鸟的微生物群受亲本寄主物种和种间巢的存在显着影响。因此，早期饲养环境对于确定育卵寄生虫雏鸟及其伴侣雏鸟的微生物群很重要。未来的工作可能旨在了解这种微生物群变异性对雏鸟性能和适应性的功能影响。
