Figure 2

%G + C and duplication plots for Experiment 1 metagenomes. Heatmap coloring indicates the relative pairwise correlations (Pearson’s r) in the %G + C distributions (red-to-yellow) and duplicates (blue-to-green) where red and blue colors indicate the lowest levels of correlation, while white represents highly correlated data. The %G + C distribution correlations were UPGMA clustered with 100 bootstrap runs to indicate statistical support (only >60% support shown). Abbreviations are as follows: “Tech” is sequencing technology represented by 4 (454), T (Ion Torrent), I (Illumina), S (Sanger); “Pair” is the forward or reverse paired end sequence data; “Rep” is the arbitrarily labeled replicate ranging from two (A and B) to three (A, B, or C); “ng” is the nanograms of input DNA from which the viral metagenome was derived. The most reliable estimate of the true %G + C distribution is the unamplified 454 metagenomes. Relative to these, fosmid end sequences generated using Sanger sequencing were the most shifted toward high %G + C, while problematic <1000ng input DNA metagenomes were less shifted toward high %G + C, and reliable 1000ng Illumina metagenomes were only slightly shifted toward high %G + C.