title: Genetic correlation of the orf224/atp6 gene region with Polima CMS in Brassica somatic hybrids.
abstract: To identify regions of the mitochondrial genome from the polima or pol male-sterile cytoplasm of Brassica napus that are genetically correlated with cytoplasmic male sterility (CMS) we analyzed mtDNAs of three male-sterile somatic hybrids formed by the fusion of broccoli (B. oleracea L. var. italica) and pol CMS B. napus protoplasts. Fragments characteristic of a 4.5 kb DNA segment that comprises the single organizational difference between sterile pol and fertile cam Brassica mitochondrial genomes were found in all three sterile somatic hybrids. One of these hybrids possessed a mitochondrial genome that was, apart from a limited region around this 4.5 kb CMS-associated segment, collinear with B. oleracea mtDNA. Previous studies have indicated that expression of transcripts spanning the atp6 gene and a chimeric gene, orf24, located on this 4.5 kb DNA segment, is associated with male sterility. The present results indicate that the orf224/atp6 gene region is genetically correlated with male sterility and provide significant additional support for the view that this gene region may be involved in specifying the CMS trait.
authors.affiliation: Department of Biology, McGill University, Montreal, Quebec, Canada.
authors.forename: H M
authors.initials: HM
authors.lastname: Wang
authors.forename: T
authors.initials: T
authors.lastname: Ketela
authors.forename: W A
authors.initials: WA
authors.lastname: Keller
authors.forename: S C
authors.initials: SC
authors.lastname: Gleddie
authors.forename: G G
authors.initials: GG
authors.lastname: Brown
mesh_terms: D001937:Brassica / Q000235:genetics* / Q000502:physiology; D004272:DNA, Mitochondrial; D005298:Fertility / Q000235:genetics; D017343:Genes, Plant; D006822:Hybrid Cells; D010940:Plant Proteins / Q000235:genetics*
chemical_list: D004272:DNA, Mitochondrial; D010940:Plant Proteins; C088163:orf224 protein, Brassica napus