HYBRIDIZATION OF MITOCHONDRIAL RIBOSOMAL RNA

Mitochondrial and cytoplasmic ribosomal RNA's of Neurospora crassa were hybridized with mitochondrial or nuclear DNA which was immobilized on nitrocellulose filters. The 25 s and 19 s mitochondrial RNA's were complementary to 6.1% and 2.8% of the mitochondrial DNA, respectively. The 28 s and 18 s cytoplasmic RNA's were complementary to 0.67 and 0.33% of the nuclear DNA. Renaturation kinetics showed that the sequence length molecular weight of Neurospora mitochondrial DNA is more than 66 × 106. Therefore, the genes for 25 s and 19 s RNA are repeated at least four times in the mitochondrial DNA. © 1969.