Fig. 3. Ordination of individual freshwater viromes according to their taxonomic profiles.

The figure represents the first two axes of a principal components analysis based on the taxonomic affiliation of assigned reads. (A) Projection of the individual viromes on the model. Viromes from the same environment are represented by equal forms. (B) Projection of the viral groups with a higher contribution to the model. The position of each group represents its association with each virome. The analysis indicates a strong partitioning of the viromes between polar and nonpolar viromes, driven mainly by the relative abundance of small circular ssDNA viruses and phages. U., unclassified; d, distance.