Institute of Biological, Environmental and Rural Sciences, Penglais Campus, Aberystwyth University, Aberystwyth, UK.
Institute of Medical Microbiology, RWTH Aachen University Hospital, Aachen, Germany.
FEMS Microbiol Lett. 2019 Jul 1;366(13). doi: 10.1093/femsle/fnz161.
The rumen is known to contain DNA-based viruses, although it is not known whether RNA-based viruses that infect fungi (mycoviruses) are also present. Analysis of publicly available rumen metatranscriptome sequence data from sheep rumen samples (n = 20) was used to assess whether RNA-based viruses exist within the ovine rumen. A total of 2466 unique RNA viral contigs were identified that had homology to nine viral families. The Partitiviridae was the most consistently observed mycoviral family. High variation in the abundance of each detected mycovirus suggests that rumen mycoviral populations vary greatly between individual sheep. Functional analysis of the genes within the assembled mycoviral contigs suggests that the mycoviruses detected had simple genomes, often only carrying the machinery required for replication. The fungal population of the ovine rumen was also assessed using metagenomics data from the same samples, and was consistently dominated by the phyla Ascomycota and Basidomycota. The strictly anaerobic phyla Neocallimastigomycota were also present in all samples but at a low abundance. This preliminary investigation has provided clear evidence that mycoviruses with RNA genomes exist in the rumen, with further in-depth studies now required to characterise this mycoviral community and determine its role in the rumen.
瘤胃中已知存在基于 DNA 的病毒，尽管尚不清楚是否存在感染真菌的基于 RNA 的病毒（真菌病毒）。分析来自绵羊瘤胃样本的公开可用的瘤胃宏转录组序列数据（n=20），以评估绵羊瘤胃中是否存在基于 RNA 的病毒。总共鉴定出 2466 个具有 9 种病毒科同源性的独特 RNA 病毒连续序列，其中二分病毒科是最常观察到的真菌病毒科。每个检测到的真菌病毒的丰度存在很大差异，表明绵羊瘤胃中的真菌病毒种群在个体之间差异很大。对组装的真菌病毒连续序列中的基因进行功能分析表明，检测到的真菌病毒具有简单的基因组，通常仅携带复制所需的机制。使用相同样本的宏基因组数据还评估了绵羊瘤胃中的真菌种群，其始终以子囊菌门和担子菌门为主。严格厌氧的 Neocallimastigomycota 门也存在于所有样本中，但丰度较低。这项初步研究提供了明确的证据，表明存在具有 RNA 基因组的真菌病毒，现在需要进一步深入研究来描述这个真菌病毒群落，并确定其在瘤胃中的作用。
