title: Heterogeneity, complexity, and repetition of the chloroplast DNA of Chlamydomonas reinhardtii.
abstract: The chloroplast DNA of wild-type Chlamydomonas reinhardtii was isolated in a CsCl density gradient as a single, homogeneous density class with a mean density of 1.695 g/cm(3). Irrespective of sheared size, denatured chloroplast DNA renatured as a single homogeneous species. Compositional heterogeneity, presumably intramolecular, was revealed by the absorbance-temperature profile. The complement of unique nucleotide sequences of the chloroplast DNA, as determined by the rate of renaturation, was 1.94 x 10(8) daltons. This kinetic complexity is 26-fold less than the DNA content of a single gamete chloroplast, and 52-fold less than the chloroplast of a vegetative cell, which indicates that the chloroplast of C. reinhardtii possesses at least 26 copies of a unique nucleotide sequence.
mesh_terms: D001483:Base Sequence; D002499:Centrifugation, Density Gradient; D000460:Chlorophyta / Q000032:analysis*; D002736:Chloroplasts / Q000032:analysis*; D002845:Chromatography; D004247:DNA / Q000032:analysis*; D004269:DNA, Bacterial / Q000032:analysis; D003720:Densitometry; D004926:Escherichia coli; D006358:Hot Temperature; D007700:Kinetics; D009691:Nucleic Acid Denaturation; D009695:Nucleic Acid Renaturation; D013053:Spectrophotometry; D013696:Temperature
chemical_list: D004269:DNA, Bacterial; D004247:DNA