Map of mutations in the GP phages. Shown is a schematic representation of the section of the HA-Stf genome, containing the lom, stf, and the tfa genes. Vertical lines indicate the positions of all the mutations listed in [additional file 1], with the missense mutations shown as filled circles, deletion mutations as arrowheads pointing away from the bar, and insertion mutations as arrowheads pointing toward the bar. Also shown were the nucleotide changes. Numbers in the brackets showed the GP strain numbers [additional file 1]. Great majority of the laboratory λ strains have the λPaPa mutation , including our LA-wt strain.