Genome maps of the three Frankia strains. Circles, from the outside in, show (1) gene regions related to symbiosis including shc1, hup2, hup1, and nif; (2) the coordinates in Mb beginning at 0 = oriC; (3) regions of synteny (syntons) calculated as a minimum of five contiguous genes present in all strains with an identity >30% over 80% of the length of the shortest gene (syntons are tagged with a spectrum-based [red-yellow-green] color code standardized on ACN to indicate regions where syntons have moved in the other strains); (4) IS elements and transposases. Circles were drawn using GenVision Software from DNAStar.