Phylogenetic Tree of <i>psbA</i> Gene Sequences from Cultured Cyanobacteria and Cyanophages

<p>Phages are listed by their name, followed by their original host. Phages that are known to infect both <i>Prochlorococcus</i> and <i>Synechococcus</i> hosts are indicated with a “Δ”; those that infect only one genus are labeled either P (infect only <i>Prochlorococcus</i> hosts) or S (infect only <i>Synechococcus</i> hosts), while those that are unknown are designated with a “?”. Phages shown in italics and bracketed with “**” were isolated on hosts that do not belong to the same cluster and are thus exceptions to the general clustering pattern (see text). Taxa are color coded according to the following biological groupings: myoviruses (red), podoviruses (black), marine <i>Synechococcus</i> hosts (light blue), marine <i>Prochlorococcus</i> hosts (dark green, LL; light green, HL), freshwater cyanobacteria (dark blue). The tree topology was estimated by LogDet analysis of 1st and 2nd codon positions. Sequences where intragenic recombination was detected using other methods (see <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0040234#s3" target="_blank">Materials and Methods</a>) were not included in these phylogenetic analyses. Branch lengths were estimated by maximum likelihood under a model with nonstationary nucleotide frequencies. Numbers at the nodes represent neighbor-joining bootstrapping and maximum likelihood puzzling support. Anab, <i>Anabaena;</i> Gloe, Gleobacter; HL, high-light adapted; LL, low-light adapted; Syncy, <i>Synechocystis;</i> Thermo, <i>Thermosynechococcus</i>.