title: Dissecting the maize genome by using chromosome addition and radiation hybrid lines.
abstract: We have developed from crosses of oat (Avena sativa L.) and maize (Zea mays L.) 50 fertile lines that are disomic additions of individual maize chromosomes 1-9 and chromosome 10 as a short-arm telosome. The whole chromosome 10 addition is available only in haploid oat background. Most of the maize chromosome disomic addition lines have regular transmission; however, chromosome 5 showed diminished paternal transmission, and chromosome 10 is transmitted to offspring only as a short-arm telosome. To further dissect the maize genome, we irradiated monosomic additions with gamma rays and recovered radiation hybrid (RH) lines providing low- to medium-resolution mapping for most of the maize chromosomes. For maize chromosome 1, mapping 45 simple-sequence repeat markers delineated 10 groups of RH plants reflecting different chromosome breaks. The present chromosome 1 RH panel dissects this chromosome into eight physical segments defined by the 10 groups of RH lines. Genomic in situ hybridization revealed the physical size of a distal region, which is represented by six of the eight physical segments, as being approximately 20% of the length of the short arm, representing approximately one-third of the genetic chromosome 1 map. The distal approximately 20% of the physical length of the long arm of maize chromosome 1 is represented by a single group of RH lines that spans >23% of the total genetic map. These oat-maize RH lines provide valuable tools for physical mapping of the complex highly duplicated maize genome and for unique studies of inter-specific gene interactions.
authors.affiliation: Department of Agronomy and Plant Genetics and Center for Microbial and Plant Genomics, University of Minnesota, 1991 Upper Buford Circle, St. Paul, MN 55108, USA.
authors.forename: Ralf G
authors.initials: RG
authors.lastname: Kynast
authors.forename: Ron J
authors.initials: RJ
authors.lastname: Okagaki
authors.forename: Mark W
authors.initials: MW
authors.lastname: Galatowitsch
authors.forename: Shannon R
authors.initials: SR
authors.lastname: Granath
authors.forename: Morrison S
authors.initials: MS
authors.lastname: Jacobs
authors.forename: Adrian O
authors.initials: AO
authors.lastname: Stec
authors.forename: Howard W
authors.initials: HW
authors.lastname: Rines
authors.forename: Ronald L
authors.initials: RL
authors.lastname: Phillips
mesh_terms: D018554:Avena / Q000235:genetics; D019457:Chromosome Breakage / Q000235:genetics; D032461:Chromosomes, Plant / Q000235:genetics*; D003433:Crosses, Genetic; D005298:Fertility / Q000235:genetics; D018745:Genome, Plant; D023281:Genomics / Q000379:methods*; D005838:Genotype; D006824:Hybridization, Genetic; D017404:In Situ Hybridization, Fluorescence; D009154:Mutation / Q000235:genetics; D016133:Polymerase Chain Reaction; D021101:Radiation Hybrid Mapping; D003313:Zea mays / Q000235:genetics*