Fig. 5

Small RNA size profiles of novel virus assemblies from Cambodia and Senegal sample pools. Hierarchical clustering of 88 novel virus assemblies based on Pearson correlation of small RNA size profiles. The 88 viruses were the members of the 115 novel virus set meeting the threshold of at least 100 small RNA reads mapped to the viral contig, to assure reliable small RNA size profiling. Small RNA reads that mapped to each of the 88 virus assemblies were extracted, and their size distributions were normalized with a z-score transformation. Heatmaps indicate the frequency of small RNA reads of size 15 to 35 nucleotides that map over the positive strand (left panel) and negative strand (right panel) of the reference sequence indicated on the y-axis. The x-axis indicates the size in nucleotides of the small RNAs mapped. Four main clusters were defined (indicated by numbers on the left of each panel) based on these small RNA size profiles. The profile in Cluster 3 is enriched for 21 nucleotide reads mapping over both positive and negative strands, characteristic of the classical small interacting RNA (siRNA) product size profile