Plastidial origin of a large ribosomal precursor molecule in the brown alga Pylaiella littoralis (L.) Kjellm

Abstract

The processing of rRNA, in the brown alga Pylaiella littoralis, is slowed up by low temperatures, allowing the accumulation of precursor molecules. The use of antibiotics inhibiting either the cytoplasmic rRNA synthesis or the plastidial rRNA synthesis, as well as DNA-RNA hybridization experiments, demonstrate the plastidial origin of a large precursor RNA species with an apparent molecular weight of 1.88 × 10 6. This species is not nicked. Competition during the hybridization experiments with isolated mature 23 S and 16 S shows that both arise from this large precursor molecule.