Thermococcus synteny analyses. Genome pair scatter plots are shown in the upper right. Similar genes (see Materials and methods) between all genome pairs (Tg, T. gammatolerans; Tk, T. kodakaraensis; Ton, T. onnurineus; Pab, P. abyssi; Pf, P. furiosus; Ph, P. horikoshii) were determined and their respective location on both genomes was plotted. Each dot represents a single gene. Coordinates are in nucleotides. Genome pair synteny block length frequency distributions are shown in the bottom left part. Synteny blocks within each genome pair were compiled, and their length frequency distributions were plotted on a log-log graph. In each plot, the equation of the least squares line of best fit is displayed, as well as the determination coefficient (R2) of the linear regression.