Genomic content of three B. burgdorferi strains. The genome of B. burgdorferi strains B31-5A4, B379, or B408 is represented by a concentric circle, and each color-coded individual segment represents a plasmid or the main chromosome, defined by labels provided in the outermost ring. Gaps in the ring represent plasmids that are not present in the genome at the time of sequencing. Gray lines within each segment represent gene annotations, and the plots within each segment represent the number of methylated nucleotides per 1,000 bases.