Ribosomal RNA synthesis in the mycelium of Phycomyces blakesleeanus. High molecular weight RNA.
Total RNA was extracted from 24 h old mycelia of Phycomyces blakesleeanus which had been grown in liquid culture. Heavy molecular weight RNA was fractionated on 2.6% polyacrylamide gels. 1. The main cytoplasmic ribosomal RNA fractions had molecular weights of 1.34 and 0.72-16(6). 2. [3H]Uridine pulse labelling of cultures revealed an initial ribosomal RNA precursor of molecular weight 2.5-10(6). 3. An intermediate precursor for the 1.34 - 10(6) dalton peak was found, having a molecular weight of 1.6-10(6). 4. Pulse-chase experiments, using [3H]methionine, showed the flow of synthesis as being (see article). 5. Mature 0.72-10(6) dalton RNA appeared prior to the 1.34-10(6) dalton RNA but no immediate precursor for it was detected.
D004591:Electrophoresis, Polyacrylamide Gel; D005658:Fungi / Q000378:metabolism*; D007700:Kinetics; D008970:Molecular Weight; D010800:Phycomyces / Q000378:metabolism*; D012335:RNA, Ribosomal / Q000096:biosynthesis*; D014158:Transcription, Genetic
D012335:RNA, Ribosomal