Submitted to: Genome
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/7/2004
Publication Date: 8/1/2004
Citation: Pagel, J., Walling, J.G., Young, N.D., Shoemaker, R.C., Jackson, S.A. 2004. Segmental duplications within the glycine max genome revealed by fluorescence in situ hybridization of bacterial artificial chromosomes. Genome. v. 47. p. 764-768. Interpretive Summary: The hereditary material of most types of plants has probably undergone some type of duplication in the evolution of the plant. Soybean is one of those plants. The authors used fine-scale microscopy to show that the DNA on the end one chromosome was duplicated onto two other chromosomes. Surprisingly, little repetitive DNA was observed on any of the chromosomes. This information will provide important clues about the organization and structure of the hereditary material of this important legume. This information will be useful in the design of approaches to decode the hereditary material for soybean.
Technical Abstract: Soybean (Glycine max L. Merr.) is presumed to be an ancient polyploid based on chromosome number and multiple RFLP fragments in genetic mapping. Direct cytogenetic observation of duplicated regions within the soybean genome has not heretofore been reported. Employing FISH of genetically anchored BACs in soybean, we were able to observe that the distal ends of molecular linkage group E had duplicated regions on linkage groups A2 and B2. Further, using fiber-FISH, it was possible to elucidate the size and structure of one of the duplicated regions. Unexpectedly, we observed little or no repetitive DNA sequences as seen by FISH on either chromosomes or DNA fibers in the ~200 kb of the genome that was sampled. This observation has implications for genome structure/evolution and the approach used to sequence the soybean genome.