title: Characterization of the genome of Phycomyces blakesleeanus.
abstract: DNA of Phycomyces blakesleeanus was extracted from whole mycelia and from nuclear and mitochondrial organelle fractions obtained from sporangiophores. DNA from all three sources exhibits one symmetrical band at p equals 1.688 g/ml in CsCl buoyant density gradients. Reassociation data are consistent with kinetic division of the DNA into three components: very rapidly renaturing (fraction I), rapidly reassociating (fraction II) and slowly reassociating (fraction III) base sequences. These components comprise approximately 10%, 20% and 64% of total cell DNA. Kinetic fractions were prepared from total cell DNA and reassociated separately. The corrected rate constant is 11.3 M-1-S-1 for the rapidly reassociating component and 0.055 M-1-S-1 for the slowly reassociating component. Based on these data and the data from unfractionated total cell DNA, the genome size of Phycomyces is approximately 1.9-10-10 daltons, 6.7 times that of Escherichia coli.
mesh_terms: D002467:Cell Nucleus / Q000032:analysis; D002499:Centrifugation, Density Gradient; D004247:DNA / Q000032:analysis; D005658:Fungi / Q000032:analysis*; D005796:Genes; D007700:Kinetics; D008928:Mitochondria / Q000032:analysis; D008970:Molecular Weight; D009090:Mucorales / Q000032:analysis*; D009691:Nucleic Acid Denaturation; D009695:Nucleic Acid Renaturation; D013045:Species Specificity; D013696:Temperature
chemical_list: D004247:DNA