Sequence organization of the nuclear DNA of Schizophyllum commune

Several methods were used to characterize the organization of repetitive DNA in the fungus Schizophyllum commune. They all failed to show interspersion of repetitive sequences among single copy sequences. Saturation hybridization showed that 2.2% of the double-stranded nuclear DNA coded for rRNA. The size of the ribosomal cistron (11.9.10(6) daltons) was determined by restriction enzyme analysis. From these values it was calculated that about 6% of the nuclear DNA consisted of ribosomal cistrons, which approx. equals the amount of repetitive DNA present. Thus, this simple sequence organization in Schizophyllum commune is fundamentally different from organization patterns in higher eukaryotes.