Cereal genome evolution: pastoral pursuits with 'Lego' genomes.

The rapid progress in comparative analysis of cereal genomes reveals that they are composed of similar genomic building blocks. It seems that by simply rearranging these blocks and amplifying some of the repetitive sequences contained within them, it is possible to reconstitute the 56 different chromosomes found in wheat, rice, maize, sorghum, millet and sugarcane. Comparison of the orders of blocks in these reconstituted chromosomes reveals that the cleavage of a single chromosome formed from the blocks could give rise to all the combinations found in the chromosomes of the above species. A framework is now in place for collating all the information which has been generated from studying the individual cereals.