Fig 2.

Bayesian phylogenetic tree based on the alignment of 112 homologous amino acid positions of the T4-like portal protein-encoding gene g20 from 616 available g20 sequences. Sequences are from Lake Annecy and Lake Bourget, cyanomyovirus isolates (18, 24, 28, 44, 58, 68), and other different environments as described in Table 1. Values at nodes as shown on the main branches are the Bayesian inference (BI) posterior probability and the maximum likelihood (ML) bootstrap value in the order of BI/ML. The inner ring constituted with color strips aims at distinguishing among g20 sequences of the marine field (violet), freshwater (orange), and the paddy soil (antique bronze). The middle ring, with color strips in green, corresponds to sequences from Lake Annecy. In the outer ring, sequences labeled with color strips are from Lake Bourget, of which those in purple were obtained by this study and those in cyan were obtained by Dorigo et al. (12).