The integrated forms of the S1 and S2 DNA elements of maize male sterile mitochondrial DNA are flanked by a large repeated sequence

Abstract
The mitochondrial DNA of maize was cloned using the cosmid, Homer I. Recombinants carrying sequences homologous to the S1 and S2 DNA elements of male sterile maize have been analysed. Restriction endonuclease maps for Sac II, Sma I and Bam HI have been constructed.The S1 and S2 sequences are single copy sequences occurring at unique sites; each is flanked by a 26 kb repeated sequence. The repeated sequence hasbeen shown not to contain the mitochondrial ribosomal RNA genes.