Abstract: To reveal the relative synonymous codon usage and base composition
variation in bacteriophages, six mycobacteriophages were used as a model system
here and both parameters in these phages and their host bacteria,
Mycobacterium tuberculosis, have been determined and compared. As expected for
GC-rich genomes, there are predominantly G and C ending codons in all 6 phages.
Both N_{c} plot and correspondence analysis on relative
synonymous codon usage indicate that mutation bias and translation selection
influences codon usage variation in the 6 phages. Further analysis indicates
that among 6 Mycobacterium phages Che9c, Bxz1 and TM4 may be extremely
virulent in nature as most of their genes have high translation efficiency.
Based on our data we suggest that the genes of above three phages are expressed
rapidly by host's translation machinery. The information might be used to
select the extremely virulent Mycobacterium tuberculosis phages suitable for phage therapy.