Hybridization analysis of three AD hybrid strains. The chromosome (chr) numbers listed at the bottom of each panel follow those of the reference genomes on the tiling arrays; for example, the chromosome numbers from JEC21 are used for the hybridization of DNA from each strain to the JEC21 array. Note that the JEC21 and H99 genomes are largely co-linear, but some of the homologous chromosomes have been assigned different numbers in the current genome assemblies . Most of the chromosomes of the AD hybrid strains are represented by copies from both A and D genomes. However, the hybridization signals indicate that chromosome 1 is only represented by sequences from a serotype A genome in all three strains. Similarly, chromosomes 5, 6, and 7 (and chromosome 14 in KW5) are represented by sequences from only one of the serotypes (either A or D). The average Log2 ratios and standard deviations for all of the chromosomes are listed in Additional data file 6, and PCR-RFLP confirmation for selected chromosomes is shown in Figure 6.