Genetic correlation of the orf224/atp6 gene region with Polima CMS in Brassica somatic hybrids.
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.
Wang
H M
HM
Department of Biology, McGill University, Montreal, Quebec, Canada.
Ketela
T
T
Keller
W A
WA
Gleddie
S C
SC
Brown
G G
GG
D001937:Brassica / Q000235:genetics* / Q000502:physiology; D004272:DNA, Mitochondrial; D005298:Fertility / Q000235:genetics; D017343:Genes, Plant; D006822:Hybrid Cells; D010940:Plant Proteins / Q000235:genetics*
D004272:DNA, Mitochondrial; D010940:Plant Proteins; C088163:orf224 protein, Brassica napus