The evolutionary selective pressures exerted on A3 actinobacteriophages

This study identified evolutionary selective pressures within subcluster A3 actinobacteriophages. These phages are able to infect the clinically important genus Mycobacterium. Understanding the selective pressures on genes in these phage genomes is a step toward understanding the adaptations that result from short-term and long-term associations of phages and bacteria that have been co-evolving for perhaps billions of years. In this study 149 phamilies (phage protein families) of homologous gene sequences were analyzed using Datamonkey. Complete data were obtained for 57 phamilies. Of these, eleven phamilies were affected by recombination, three showed evidence of predominantly diversifying selection, and twenty-four have a function. In the near future, a study investigating the protein structure of qualified phamilies (those with ≥10 sequences in the analysis) would provide further insight into the selection identified in this study. As more actinobacteriophage genomes are sequenced and annotated, analysis with Datamonkey should be repeated with larger and more diverse alignments