Physicochemical Characterization of Mitochondrial DNA from Soybean
Open Access
- 1 March 1978
- journal article
- research article
- Published by Oxford University Press (OUP) in Plant Physiology
- Vol. 61 (3) , 460-464
- https://doi.org/10.1104/pp.61.3.460
Abstract
Mitochondrial DNA (mtDNA) of soybean (Glycine max L.) was isolated and its buoyant density was contrasted with that of nuclear (nDNA) and chloroplast (ctDNA) DNA. Each of the three DNAs banded at a single, characteristic buoyant density when centrifuged to equilibrium in a CsCl gradient. Buoyant densities were 1.694 g/cm3 for nDNA and 1.706 g/cm3 for mtDNA. These values correspond to G-C contents of 34.7 and 46.9%, respectively. Covalently closed, circular mtDNA molecules were isolated from soybean hypocotyls by ethidium bromide-cesium chloride density gradient centrifugation. Considerable variation in mtDNA circle size was observed by electron microscopy. There were seven apparent size classes with mean lengths of 5.9 μm (class 1), 10 μm (class 2), 12.9 μm (class 3), 16.6 μm (class 4), 20.4 μm (class 5), 24.5 μm (class 6), and 29.9 μm (class 7). In addition, minicircles were observed in all preparations. Partially denatured, circular mtDNA molecules with at least one representative from six of the seven observed size classes were mapped. In class 4, there appear to be at least three distinct denaturation patterns, indicating heterogeneity within this class. It is proposed that the mitochondrial genome of soybean is distributed among the different size circular molecules, several copies of the genome are contained within these classes and that the majority of the various size molecules may be a result of recombination events between circular molecules.This publication has 24 references indexed in Scilit:
- Transposable genetic elements and plasmid evolutionNature, 1976
- The molecular size and conformation of the chloroplast DNA from higher plantsBiochimica et Biophysica Acta (BBA) - Nucleic Acids and Protein Synthesis, 1975
- Denaturation map of the circular mitochondrial genome of Neurospora crassaBiochimica et Biophysica Acta (BBA) - Nucleic Acids and Protein Synthesis, 1975
- Denaturation mapping studies on the circular chloroplast deoxyribonucleic acid from pea leaves.Journal of Biological Chemistry, 1975
- Molecular structure of bacterial plasmids.1972
- Physicochemical Characterization of Mitochondrial DNA from Pea LeavesProceedings of the National Academy of Sciences, 1972
- The Constancy of the Buoyant Density of Chloroplast and Mitochondrial Deoxyribonucleic Acids in a Range of Higher PlantsPlant Physiology, 1970
- Mitochondrial DNA. V. A 25 micron closed circular duplex DNA molecule in wild-type yeast mitochondria. Stucture and genetic complexity.1970
- A dye-buoyant-density method for the detection and isolation of closed circular duplex DNA: the closed circular DNA in HeLa cells.Proceedings of the National Academy of Sciences, 1967
- Determination of the base composition of deoxyribonucleic acid from its buoyant density in CsClJournal of Molecular Biology, 1962