Figure 38-4: Phylogenetic analysis of mycobacteriophage genes.  The mycobacteriophage genomes are highly mosaic and it is not possible to draw aggregate phylogenetic relationships for the phages as whole genomic units that accurately reflect their evolutionary history.  Panels A-D show the phylogenetic relationships of four genes that are present in at least seven of the genomes: A, lysB; B, capsid subunits; C, a putative tail protein and D, a putative D-ala-D-ala carboxypeptidase.  The genes of phages Omega, Cjw1, Che8 and Che9d (shown in boxes) clearly have different evolutionary histories.  Trees were generated using the neighbor-joining method in ClustalX and displayed usingNJPlot.  The results of bootstrap analysis with 1000 reiterations are shown.