Genetic Diversity of CRESS DNA Viruses in Rodent Virome

Abstract

CRESS DNA viruses belong to a widely distributed and highly diverse group of viruses, which are often found during the analysis of viromes. However, data on their genetic diversity are still incomplete. The intestinal viromes of widespread vole species—northern red-backed vole and tundra vole—were sequenced. Based on the Rep protein sequence, 22 sequences of various CRESS DNA viruses and alphasatellites were identified; 14 of them were complete genomes. According to the genome organization ten isolates were assigned to CRESS DNA viruses of known families of the Cressdnaviricota phylum, and one isolate to the Alphasatellitidae family. Three complete genomes were unique and possibly belong to new viral families. Most sequences were assigned to the Vilyaviridae family of the Cirlivirales order. An unusual genome from the clade of regular CRESS DNA viruses but without the cp gene was identified, which suggests that it is a possible alphasatellite. This fact raises the question of revising the current paradigm of dividing Circular Rep-Encoding DNA sequences into viruses and alphasatellites. Two pairs of similar CRESS DNA genomes were detected in different rodent species, which indicates the need for further study of diversity and host specificity of CRESS DNA viruses.