Orthologous alignment of the BES of a random sample of 61 clones of the SP80-3280 sugarcane BAC library on the 10 sorghum chromosomes. Sequences from the both ends of the sugarcane BAC clones were searched against the sorghum genome using BlastN, and significant hits were annotated and positioned on the corresponding sorghum chromosome. For non-repetitive sequences, positioning was based on the BAC insert size, concordance of the opposite end sequence direction and best hit. For repetitive sequences, alignment utilised only the best hit. The coloured solid lines represent the sorghum chromosomes with their predicted segmental duplication . The coloured rectangles represent the sugarcane BES classes. C1, C2, C3, C4, C5, C6 and C7 refer to BESs classes as defined in Table 2. C8 and C9 classes are not represented in the figure.