Detecting the undetectable:: uncovering duplicated segments in Arabidopsis by comparison with rice

Genome analysis shows that large-scale gene duplications have occurred in fungi, animals and plants, creating genomic regions that show similarity in gene content and order. However the high frequency of gene loss reduces colinearity resulting in duplicated regions that, in the extreme, no longer share homologous genes. Here, we show that by comparison with an appropriate second genome, such paralogous regions can still be identified.