|La Rota, Mauricio|
|Lapitan, Nora L|
Submitted to: Proceedings of the National Academy of Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/31/2003
Publication Date: 9/5/2003
Citation: Akhunov, E.D., Akhunov, A.R., Linkiewicz, A.M., Dubcovsky, J., Hummel, D., Lazo, G.R., Chao, S., Anderson, O.D., David, J., Qi, L., Echalier, B., Gill, B.S., Miftahudin, Gustafson, J.P., La Rota, M., Sorrells, M.E., Zhang, D., Nguyen, H.T., Kalavacharla, V., Hossain, K., Kianian, S.F., Peng, J., Lapitan, N.V., Wennerlind, E.J., Nduati, V., Anderson, J.A., Sidhu, D., Gill, K.S., Mcguire, P.E., Qualset, C.O., Dvorak, J. 2003. Synteny perturbations between wheat homoeologous chromosomes caused by locus duplications and deletions correlate with recombination rates along chromosome arms. Proceedings of the National Academy of Sciences. 100:10836-10841. Interpretive Summary: A database of 10,000 wheat expressed sequence tag loci were analyzed by a series of wheat deletion stocks to assess their linear order along homoeologous chromosomes of the wheat A, B, and D genomes. The relation of expressed sequences from one end of a chromosome arm to the other was analyzed. Sequence clustering appeared to be negatively correlated with the distance from the centromere. In addition, there appeared to be twice as many loci in the B genome as in the other two hexaploid wheat (A and D) genomes. These differences among the wheat genomes were attributed to differences in the ancestors of wheat genomes. This information will be of use to wheat molecular biologists in their efforts to modify the wheat genome to increase productivity.
Technical Abstract: A database of close to 10,000 wheat loci detected by 3977 expressed sequence tag (EST) unigenes and mapped into 159 bins delineated by breakpoints of a series of overlapping deletions was used to assess synteny along homoeologous chromosomes of the wheat A, B, and D genomes in relation to bin position on the centromere-telomere axis and the gradient of recombination rates along chromosome arms. Synteny was negatively correlated with the distance of a chromosome region from the centromere and recombination rates along chromosome arms. There were twice as many unique loci in the B genome as compared to the A and D genomes, and synteny of the B genome chromosomes with the A- and D-genome homoeologues was lower than synteny between the A- and D-genome homoeologues. These differences among the wheat genomes were attributed to differences in mating systems of diploid ancestors of wheat genomes. Causes of synteny perturbations were studied in 31 paralogous sets of loci with incomplete synteny. Both insertions and deletions of loci were detected and both preferentially occurred in high recombination regions of chromosomes.