Chromosomal position of the genes in cluster 1. Shown are genes at (a) the chromosomal level and (b) at the local level between ORFs. The 16 chromosomes in panel (a) are shown in white and cluster members as vertical black bars on the chromosomes. The length of the chromosomes are scaled according to the number of ORFs on a given chromosome. (b) The distance between ORFs from cluster 1 (x-axis) measured in number of ORFs. The expected distance is shown with a red curve while the actual distance between ORFs is shown with black bars. ORF, open reading frame.