Fig. 3: Evolutionary characteristics of representative NCLDV-encoded ARGs.

Phylogenetic trees of (A) dihydrofolate reductase, (B) F-subtype ABC protein, and (C) isoleucyl-tRNA transferase from NCLDVs, eukaryotes, prokaryotes, and phages. Dfr, ABC-F ATP-binding cassette genes, and ileS are the top three most prevalent antimicrobial resistance gene families detected in NCLDVs. Nodes with support values > 70% are labeled with black dots. Information on antibiotic resistance phenotypes are adopted from ref. ⁹⁶ for ABC-F and from ref. ⁵² for ileS genes. Roots of the trees are determined using the midpoint rooting method. Ka/Ks ratio of (D) dfr, (E) ABC-F, and (F) ileS sequences in NCLDVs, phages, eukaryotes, and prokaryotes, respectively. Lower-case letters above the bars in (D) to (F) represent significantly different groups assessed with two-sided Wilcoxon rank-sum test, and P-values indicate the overall difference among all families assessed with Kruskal–Wallis test. The unit of study is one sequence pair. The boxes represent 25th percentile, median and 75th percentile of the data, and the whiskers show the minimum or maximum value of the data. Data points are shown when n ≤ 10. Source data are provided as a Source Data file on Github¹⁰⁷.