| Abstract: | DNA of Schizophyllum commune was isolated both from mycelial cells and from protoplasts. Nuclear DNA was isolated after solubilization of the mitochondria with the detergent Nonidet. The G + C content of the nuclear DNA was 57%, calculated from its buoyant density (1.7165 g/ml) and from the Tm (77.4 degrees C in 15 mM NaCl/1.5 mM trisodium citrate). The buoyant density of the ribosomal cistrons was 1.707 g/ml. DNA isolated from purified mitochondria had a very low G + C content: 22% (rho = 1.6845 g/ml, Tm = 61.8 degrees C in 15 mM NaCl/1.5 mM trisodium citrate). Analysis of CsCl profiles and melting patterns suggested that mitochondrial DNA contains interspersed (A + T)-rich sequences. From reassociation analysis of sheared nuclear DNA the genome size of S. commune was determined to be 22.8 . 10(9) daltons. A small amount of DNA (0.5 . 10(9) daltons) bound to hydroxyapatite at zero time Cot. 7% of the genome (1.6 . 10(9) daltons) represented repetitive DNA. |
