High-frequency inter-parental recombination between mitochondrial genomes of rice cybrids.
Analyzing more than 100 independent rice cybrids, we found evidence for inter-molecular recombination between parental mitochondrial genomes occurring at high frequency soon after protoplast fusion. The structure of the region around the atp6 gene showed extensive polymorphism among Indica (MTC-5A), Japonica (Nipponbare), and wild abortive (IR58024A) mitochondrial genomes. Recombination between the mitochondrial genomes of IR58024A and MTC-5A around the atp6 gene was detected by Southern-blot analysis of cybrid plants. Such recombinant mitochondrial molecules were also cloned from IR58024A/Nipponbare cybrid callus. PCR analysis around the atp6 gene demonstrated that inter-parental recombination occurs in practically all cybrid calli within 2 weeks after protoplast fusion. At this point, parental and recombinant mitochondrial genomes co-existed within the callus. Over the course of further cultivation, however, mitochondrial genome diversity decreased as parental and/or recombinant genomes segregated out.
Akagi
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H
Plant Biotechnology Laboratory, Life Science Institute, Mitsui Toatsu Chemicals, Inc., Togo 1144, Mobara 297, Japan.
Shimada
H
H
Fujimura
T
T
D001483:Base Sequence; D002678:Chimera / Q000235:genetics*; D003001:Cloning, Molecular; D004272:DNA, Mitochondrial; D008969:Molecular Sequence Data; D012275:Oryza / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D011153:Population; D006180:Proton-Translocating ATPases / Q000235:genetics*; D011995:Recombination, Genetic; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid
D004272:DNA, Mitochondrial; D006180:Proton-Translocating ATPases