Abstract
S 1 and S 2 are mitochondlial DNA (mt DNA) molecules found in male-sterlie S cytoplasm (cms-S) of maize but not in fertile revertants with the nucleal background of the inbred line M 825. Three male-fertile revertants were recovered from cms-S lines with the background of WF9. MtDNAs were isolated from these revertants and from cms-S lines. Agarose gel electrophoresis of undigested mtDNA revealed that both S 1 and S 2 molecules were present in the revertants. Terminally attached proteins of S 1 and S 2 from revertants were detected by proteinase K treatment. Restriction fragment analyses inclicatecl that the restriction sites of S 1 and S 2 were not altered and that each revertant had alterations in the high-molecular-weight chromosomal mtDNA.
