Plant & Animal Genomes XI Conference

January 11-15, 2003
Town & Country Convention Center
San Diego, CA

Poster: Genome Sequencing & ESTs
            

INSIGHTS INTO SOYBEAN GENOME DUPLICATION AND GENE CLUSTERING FROM BAC CONTIGS ANCHORED WITH RFLPS

¹ Department of Plant Pathology, University of Minnesota, St. Paul, Minnesota, 55108

² Department of Agronomy, Iowa State University, Ames, Iowa, 50011

³ Center for Computational Genomics and Bioinformatics, Academic Health Center, University of Minnesota, Minneapolis, MN 55455

⁴ USDA, Corn Insect and Crop Genetics Research Unit and Department of Agronomy, Iowa State University, Ames, Iowa, 50011

Genomic research in many of the world’s most economically important crop species, including soybean (Glycine max (L.) Merrill), remains difficult because of their large genomes and high proportion of repetitive sequences. Recent evidence of gene clustering in crop plants has improved prospects for genome analysis by reducing the effective genome sizes comprising the underlying gene space. Surveying the soybean genome with several hundred bacterial artificial chromosome (BAC) contiguous groups (contigs) anchored by restriction fragment length polymorphisms (RFLPs) enabled us to examine the physical organization of hypomethylated (and presumably gene-rich) genomic regions, as well as to explore microsyntenic relationships among duplicated regions. Numerous cases where unrelated RFLPs hybridized to one or more common BAC clones indicated that RFLPs, and by extension, genes are physically clustered in soybean, apparently in less than 25% of the genome. Similarities in genome organization among homoeologous BAC contigs uncovered by the same RFLP could also be examined. Many interrelated sets of BAC contigs were found to consist of the same physically linked RFLP markers. In cases where two or more homologous sequences were recovered from duplicate contigs, paralogs shared 86-100% sequence identity.