FISH MAPPING CDNAS TO CEREAL CHROMOSOMES

¹ Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, CO 80523

² Department of Soil and Crop Sciences, Colorado State University, Fort Collins, CO 80523

Fluorescent in situ hybridization (FISH) mapping of cDNAs to metaphase chromosomes was undertaken to determine the distribution of genes along the chromosomes. Both standard and ultra–sensensitive FISH (a.k.a. amplified FISH) techniques were used to locate cDNAs to cereal metaphase chromosomes. In addition, a single plasmid was constructed that contained barley FISH landmark sequences. This FISH landmark probe identified and oriented all barley chromosomes. Since the barley FISH landmark probe was also used in all cDNA FISH reactions, the chromosomal identity and location (reported as %FLpter) could be determined for the specific cDNA FISH signal. Our findings provide an initial correlation between genetic linkage distance and physical distance.