Extended Data Fig. 4: Defence system distribution between P-phage and NP-phage MAGs across aquatic ecosystems (freshwater, marine, wastewater).
P-phage MAGs consistently encoded more defence systems (DSs) than NP-phage MAGs, with significant differences detected across all ecosystems (two-sided Wilcoxon rank-sum test; **, p < 0.01; ***, p < 0.001; ****, p < 0.0001). The magnitude of phage–host antagonism decreased along the gradient from freshwater to marine and wastewater environments. Each point represents the number of DSs in an individual host genome. Box plots indicate the median (center line and red point), interquartile range (box), and 1.5 × the interquartile range (whiskers). Sample sizes and exact p values were as follows: Freshwater: NP-phage (n = 432) and P-phage (n = 249), p = 3.12 × 10⁻11; Marine: NP-phage (n = 252) and P-phage (n = 379), p = 6.82 × 10⁻4; Wastewater: NP-phage (n = 203) and P-phage (n = 210), p = 8.26 × 10⁻3.
