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United States Department of Agriculture

Agricultural Research Service

Title: Genome Organization in Dicots. Ii: Arabidopsis As a 'bridging Species' to Resolve Genome Evolution Events among Legumes

Authors
item Lee, Jennifer - IOWA STATE UNIVERSITY
item Grant, David
item Vallejos, C - UNIVERSITY OF FLORIDA
item Shoemaker, Randy

Submitted to: Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 13, 2001
Publication Date: N/A

Interpretive Summary: Much research is being done to completely decode the hereditary materials of some plants. These plants are considered to be 'models' for other genetic systems. Arabidopsis is one of these model plants. If we are able to make inferences about genetics of crop plants based upon what is known about the model then we will make advances in those corps more cheaply and quickly. In this paper the authors compared the genetic organization of Arabidopsis to that of soybean, common bean, and mung bean. They found a large segment of their DNA to be very similar suggesting that information from Arabidopsis can be used to answer questions about these legumes. This will result in more rapid and efficient genetic gains for these crops.

Technical Abstract: Analysis of molecular linkage groups within the soybean (Glycine max L. Merr.) Genome reveals many homoeologous regions, reflecting the ancient polyploidy of the soybean. The fragmented arrangement of the duplicated regions suggests that extensive rearrangements as well as additional duplications have occurred since the initial polyploidization event. In this study we used comparisons between homoeologous regions in soybean and the homologous regions in the related diploids Phaseolus vulgaris and Vigna radiata to elucidate the evolutionary history of the three legume genomes. Our results show that there is not only conversation of large regions of the genomes but that these conserved linkage blocks are also represented twice in the soybean genome. To gain a better understanding of the process of genome evolution in dicots, molecular comparisons have been extended to another well-studied species, Arabidopsis thaliana. Interestingly, the conserved regions we identified in the legume species are also relatively conserved in Arabidopsis. Our results suggest that there is conservation of blocks of DNA between species as distantly related as legumes and brassicas, representing 90 MY of divergence. We also present evidence for an additional, presumably earlier, genome duplication in soybean. These duplicated regions were only recognized by using Arabidopsis as a 'bridging' species in the genome comparisons.

Last Modified: 4/23/2014
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