The genome sequence of Synechocystis sp. PCC 6803 substrain GT-T and its implications for the evolution of PCC 6803 substrains.

Synechocystis sp. PCC 6803 is a model cyanobacterium, glucose tolerant substrains of which are commonly used as laboratory strains. In recent years, it has become evident that "wild-type" strains used in different laboratories show some differences in their phenotypes. We report here the chromosome sequence of our Synechocystis sp. PCC 6803 substrain, named substrain GT-T. The chromosome sequence of GT-T was compared to those of two other commonly used laboratory substrains, GT-S and PCC-M. We identified eleven specific mutations in the GT-T substrain, whose physiological consequences are discussed. We also provide an update of evolutionary relationships between different Synechocystis sp. PCC 6803 substrains.