Figure 5. The three levels of anchoring used in the construction of the chromosome 1AS physical map.

On level 1, genes were anchored to physical BAC contigs using positive hybridisation probe matches, BAC-end sequences and Illumina contigs. Individual anchoring procedures are indicated by capital letters in circles and described in the text. For level 2 anchoring, all BAC contigs which contain genes which have their homologs in the 1AS syntenic region of Brachypodium, rice or sorghum were anchored to the reference zipper. This means that the order of genes in wheat was assumed to be the same as in Brachypodium, rice or sorghum. In the final step (level 3), data from genetic markers were used to anchor BAC contigs to previously published genetic maps.