Fig. 5

Ordination plots of viromes based on cross-contig abundance profiles. Normalised cross-contig abundances (RPKM) were used to compute Bray-Curtis dissimilarities (a and b) and Sorensen indexes (c and d) among viromes. a and c Dissimilarity matrices of an unamplified virome (Unamp1) and eight derived randomly amplified viromes (MDA_G1-4, MDA_T1-2 and SISPA1-2) was plotted following the NDMS ordination system. b and d Dissimilarity matrices of the coss-contig obtained with the previous nine viromes, together with two new partially related saliva viromes (Unamp2, an unamplified virome from saliva samples pooled from seven individuals, six of whom also contributed to Unamp1; and Sa101, the GenomiPhi-amplified saliva virome from a single individual who contributed to both Unamp1 and Unamp2 pool samples), and two unrelated samples (GenomiPhi-amplified saliva viromes SaC25 and Sa33 from subjects who did not contribute to either of the pooled viromes tested) was also plotted by NMDS. The NMDS plot at the right of panel b represents dissimilarities among all viromes, excluding S25 and S33 (note the differences in the magnitude of the axes). Symbol shape indicates viromes from different samples; white, blue and red colours indicate viromes obtained without random amplification, or randomly amplified by MDA or SISPA, respectively