Plant & Animal Genome VI Conference

P16

DEVELOPMENT OF GENOMES INTEGRATED PHYSICAL MAPS FOR GENE GOLFING

1. Department of Plant Soil and General Agriculture, Southern Illinois University at Carbondale, Carbondale, IL 62901-4415
2. Department of Soil and Crop Sciences, Crop Biotechnology Center, Texas A & M University, College Station, TX 77843-2123

DNA marker analysis of genomes has revolutionized genetic studies of organisms in the past 15 years. AFLP, RFLP and SSR genetic maps have been developed for almost all major crops. The recent developement of technologies for large DNA fragment (>100 Kb) cloning, such as bacterial artificial chromosome (BAC), BAC fingerprinting and contig assembly has provided powerful tools to rapidly generate molecular physical maps. A physical map integrated with the developed DNA marker genetic maps will provide a new strategy to clone genes known only by their phenotypes by gene golfing (Zhang and Wing 1997). Practically, using the newly developed BAC DNA isolation and BAC fingerprinting technologies one technicien can fingerprint up to 40,000 clones of 150 kb per year, covering 6 x haploid genomes of 1,000 Mb. Using the integrated physical map, DNA molecular marker identified 10 cM away from a gene of interest can be used to clone the target gene. Genes in regions where repeated sequences are rich can also be cloned with the integrated physical map, whereas it is difficult, if not impossible, to clone the genes in such regions by the currently used map-based cloning strategy. The development of an integrated physical map will provide a "highway" for isolation of large number of genes and for many other genetic and biological studies of plant and animal genomes. Currently, the integrated physical maps of the rice, Arabidopsis and sorghum genomes are under development using the BAC fingerprinting and contigs assembly technlogies. We are using these technologies to develop the integrated physical map of the soybean genome. We will report the progress in construction of the soybean genome integrated physical map. A new approach to isolate microsattelites DNA markers for gene cloning and marker assisted selection will be also presented.