Genome comparison of S-PM2, P-SSM2, P-SSM4, Syn9 and T4 to cyanophage S-RSM4. The outer circle represents the genome of cyanophage S-RSM4. Genes are shaded in blue, with stop and start codon marked by black lines, tRNAs are coloured green. The inner five rings represent the genomes of S-PM2, P-SSM2, P-SSM4, Syn9 and T4 respectively. For each genome all annotated genes were compared to all genes in S-RSM4 using BLASTp and orthologues identified. The nucleotide sequence of identified orthologues were aligned and the percentage sequence identity calculated. The shading of orthologues is proportional to sequence identity, with the darker the shading proportional to higher sequence identity.