Plant, Animal & Microbe Genomes X Conference

January 12-16, 2002
Town & Country Convention Center
San Diego, CA

Poster: Genome Sequencing & ESTs
            

COMPARATIVE MAPPING OF WHEAT GENOME AND RICE GENOME BASED ON SEQUENCE MATCHING

¹ Department of Plant Breeding, 252 Emerson-Bradfield Hall, Cornell University. Tower Rd, Ithaca, NY, 14853, USA

² USDA-ARS, WRRC, 800 Buchanan Street, Albany, CA 94710, USA

Traditional comparative mapping based on a set of common RFLP probes has been an enormous aid in understanding the conservation of genome structure and organization within the Poaceae. This approach, however was limited to recombination based maps and only a limited set of cross hybridizing probes have been placed in the comparative genetic maps, yielding a very useful yet low resolution set of links (anchors) between the genomes. With the availability of a large set of ESTs in all of the cereal species and with 50% of the rice genome sequenced, a new and very valuable kind of comparative mapping is possible. The wheat genome is unlikely to be fully sequenced in the near future, enhancing the need for bringing information into wheat from its neighbor species. Sequence - based maps can be constructed in which every orthologous block in the rice genome is placed and re-shuffled according to the position of wheat genes in the physical map. More than 4000 non-redundant wheat EST sequences have already been assigned to discrete bin positions in wheat's physical map using a panel of deletion and aneuploid lines with more to be assigned in the next months. Here we present a preliminary view of the wheat chromosomes with large rice genomic clones assigned assigned to locations based on sequence similarity. In addition, wheat EST contigs can be assigned to locations on the rice physical map. Similarities and discrepancies with the existing wheat-rice genetic comparative maps are discussed.