VISION, TODD J1*, DANIEL G BROWN2, and STEVEN D TANKSLEY3. 1USDA-ARS Center for Agricultural Bioinformatics; 2Dept. of Computer Science, University of Waterloo; 3Depts. of Plant Breeding and Plant Biology, Cornell University. - Ancient genome duplications in the angiosperms: lessons from Arabidopsis.
Polyploidy has been a major force in the evolution of plants, but our
ability to detect ancient polyploidy events has limited. Extensive
DNA sequence, such as we now have for a number of model plants, allows
us to detect common ancestry between protien coding genes that
diverged hundreds of millions of years ago. Provided that gene order
rearrangements are not too extensive, one can use this to detect
common ancestry between chromosomal regions. Applying this principle
to the recently completed Arabidopsis thaliana genome sequence, we
have identified extensive regions of putative common ancestry among
all chromosomes. The extent of sequence divergence suggests that there
have been at least four major duplication events, possibly
genome-wide in scale, and that they occurred roughly 100-200 million
years ago. Thus, these duplications are likely to have shaped the
ancestral genome(s) of many plant taxa.
Key words: Arabidopsis thaliana, genome evolution, polyploidy