High-throughput sequencing technologies have advanced RNA virus genomics, but recovering viral genomes from mammalian tissues remains challenging due to the predominance of host RNA. We evaluated two metatranscriptomic workflows to address these challenges. Our results demonstrate that the methods differed significantly in performance, with Method B achieving a 5-fold increase in RNA yield and improved RNA integrity over Method A. These differences resulted in the recovery of 4 complete hepacivirus genomes with Method B compared to fragmented or incomplete genomes with Method A. Additionally, Method B's library preparation workflow, incorporating rRNA depletion, enhanced viral genome recovery by reducing host RNA background. Our novel approach integrates an optimized RNA purification protocol with a customized bioinformatics strategy for improved viral genome recovery. Overall, our findings highlight the critical role of optimized homogenization, RNA purification, and library preparation in metatranscriptomic workflows, facilitating the more effective RNA virus genome recovery from complex mammalian tissues.

• MeSH
• Genome, Viral * genetics   MeSH
• Gene Library MeSH
• Humans MeSH
• RNA, Viral * genetics   isolation & purification   MeSH
• RNA Viruses * genetics   MeSH
• Mammals virology   MeSH
• Transcriptome * MeSH
• High-Throughput Nucleotide Sequencing * methods   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• RNA, Viral * MeSH

In the search for natural reservoirs of hepatitis C virus (HCV), a broad diversity of non-human viruses within the Hepacivirus genus has been uncovered. However, the evolutionary dynamics that shaped the diversity and timescale of hepaciviruses evolution remain elusive. To gain further insights into the origins and evolution of this genus, we screened a large dataset of wild mammal samples (n = 1,672) from Africa and Asia, and generated 34 full-length hepacivirus genomes. Phylogenetic analysis of these data together with publicly available genomes emphasizes the importance of rodents as hepacivirus hosts and we identify 13 rodent species and 3 rodent genera (in Cricetidae and Muridae families) as novel hosts of hepaciviruses. Through co-phylogenetic analyses, we demonstrate that hepacivirus diversity has been affected by cross-species transmission events against the backdrop of detectable signal of virus-host co-divergence in the deep evolutionary history. Using a Bayesian phylogenetic multidimensional scaling approach, we explore the extent to which host relatedness and geographic distances have structured present-day hepacivirus diversity. Our results provide evidence for a substantial structuring of mammalian hepacivirus diversity by host as well as geography, with a somewhat more irregular diffusion process in geographic space. Finally, using a mechanistic model that accounts for substitution saturation, we provide the first formal estimates of the timescale of hepacivirus evolution and estimate the origin of the genus to be about 22 million years ago. Our results offer a comprehensive overview of the micro- and macroevolutionary processes that have shaped hepacivirus diversity and enhance our understanding of the long-term evolution of the Hepacivirus genus.

• Keywords
• co-divergence, cross-species transmission, hepacivirus, phylogeography, timescale estimation,
• Publication type
• Journal Article MeSH
• Preprint MeSH

Recent years have witnessed the discovery of several new viruses belonging to the family Arteriviridae, expanding the known diversity and host range of this group of complex RNA viruses. Although the pathological relevance of these new viruses is not always clear, several well-studied members of the family Arteriviridae are known to be important animal pathogens. Here, we report the complete genome sequences of four new arterivirus variants, belonging to two putative novel species. These new arteriviruses were discovered in African rodents and were given the names Lopma virus and Praja virus. Their genomes follow the characteristic genome organization of all known arteriviruses, even though they are only distantly related to currently known rodent-borne arteriviruses. Phylogenetic analysis shows that Lopma virus clusters in the subfamily Variarterivirinae, while Praja virus clusters near members of the subfamily Heroarterivirinae: the yet undescribed forest pouched giant rat arterivirus and hedgehog arterivirus 1. A co-divergence analysis of rodent-borne arteriviruses confirms that they share similar phylogenetic patterns with their hosts, with only very few cases of host shifting events throughout their evolutionary history. Overall, the genomes described here and their unique clustering with other arteriviruses further illustrate the existence of multiple rodent-borne arterivirus lineages, expanding our knowledge of the evolutionary origin of these viruses.

• Keywords
• Arteriviridae, cross-species transmission, host spectrum, rodent-borne arteriviruses, virus evolution,
• MeSH
• Arteriviridae classification   genetics   isolation & purification   MeSH
• Biological Evolution MeSH
• Phylogeny MeSH
• Genome, Viral * MeSH
• Rodentia virology   MeSH
• RNA Virus Infections veterinary   virology   MeSH
• Whole Genome Sequencing MeSH
• High-Throughput Nucleotide Sequencing MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Africa South of the Sahara MeSH