Maize mitochondrial DNA rearrangements between the normal type, the Texas male sterile cytoplasm, and a fertile revertant cms-T regenerated plant

The maize mitochondrial DNA (mtDNA) from the cytoplasmic male sterile type T (cms-T) contains a 6.6 kb XhoI fragment not found in the normal type (N) or the fertile revertant (V3). Analysis of the fragment in cms-T mtDNA and homologous regions in N and V3 mtDNAs reveals that a number of events are necessary to explain the formation of the 6.6 kb XhoI fragment in T mtDNA and its subsequent loss in V3 mtDNA. This includes the formation and the loss of a 4 kb repeat and various recombinational events. It is interesting to note that a recombinational event that has occurred in the fertile revertant genome reconstitutes a sequence arrangement identical to one found in the normal genome.