title: Mitochondrial genome diversity in soybean: repeats and rearrangements.
abstract: Mitochondrial (mt) genome organization in soybean was examined at the molecular level. This study builds upon previous reports that four soybean cytoplasmic groups, Bedford, Arksoy, Lincoln, and soja-forage, are differentiated by polymorphisms detected with a 2.3 kb Hind III mtDNA probe [12]. The variation detected results from DNA alterations in a region within and around a 4.8 kb repeat. The Bedford-type cytoplasm is the only cytoplasm that contains copies of a 4.8 kb repeat in four different genomic environments, evidence that it is recombinationally active. The Lincoln- and Arksoy-type cytoplasms each contain two copies of the repeat, as well as unique fragments that appear to result from rare recombination events outside, but near, the repeat. The soja-forage-type cytoplasm contains no complete copies of the repeat, but does contain a unique truncated version of the repeat. Sequence analysis indicates that the truncation is a result of recombination across a 9 bp repeated sequence, CCCCTCCCC. The structural rearrangements that have occurred in the region surrounding the 4.8 kb repeat may provide a means to dissect species relationships and evolution within the subgenus soja.
authors.affiliation: Department of Agronomy, Iowa State University, Ames 50011, USA.
authors.forename: C A
authors.initials: CA
authors.lastname: Moeykens
authors.forename: S A
authors.initials: SA
authors.lastname: Mackenzie
authors.forename: R C
authors.initials: RC
authors.lastname: Shoemaker
mesh_terms: D001483:Base Sequence; D015139:Blotting, Southern; D003001:Cloning, Molecular; D004272:DNA, Mitochondrial / Q000235:genetics*; D018744:DNA, Plant / Q000235:genetics*; D015321:Gene Rearrangement; D016678:Genome; D008928:Mitochondria / Q000235:genetics*; D008957:Models, Genetic; D008969:Molecular Sequence Data; D011110:Polymorphism, Genetic; D011995:Recombination, Genetic; D012091:Repetitive Sequences, Nucleic Acid; D015183:Restriction Mapping; D017422:Sequence Analysis, DNA; D013025:Glycine max / Q000235:genetics*
chemical_list: D004272:DNA, Mitochondrial; D018744:DNA, Plant