COMPARISON OF THE RESTRICTION ENDONUCLEASE DIGESTION PATTERNS OF MITOCHONDRIAL DNA FROM NORMAL AND MALE STERILE CYTOPLASMS OF ZEA MAYS L

[摘要] High resolution gel electrophoresis has allowed the assignment of fragment number and molecular weight to Eco RI, Sal I and Pst I restriction fragments of mitochondrial DNA from B37 normal (N) and B37 T, C and S male sterile cytoplasmic types of maize. A minimum complexity of 450-475 kb has been established. Hybridization of cloned Eco RI fragments to restriction digests of total mitochondrial DNA suggests that at least 80% of the genome is composed of unique sequences. Restriction fragments of identical size in N, T, C and S contain similar sequence information as evidenced by their hybridization behavior.—The total Sal I digest and the larger Pst I fragments representing 80% of the total complexity were used to calculate the fraction of shared fragments of each pairwise combination of cytoplasmic types. The C type mtDNA is most closely allied with the other mtDNAs and shares 67% of fragments with S, 65% with N, and 60% with T. The S type mtDNA is quite divergent from N (53% shared fragments) and T (56% shared fragments). N and T share 59% of the fragments. These results are discussed in terms of the origin of mtDNA diversity in maize.

[学科分类] 医学（综合）