Effect of heat shock on the synthesis of low molecular weight RNAs in drosophila: Accumulation of a novel form of 5S RNA

The synthesis and stability of low molecular weight RNAs following heat shock in Drosophila melanogaster cell cultures have been examined. When cultures are raised from 25°C to 37°C, the synthesis of tRNA and at least two other low molecular weight RNAs continues at the 25°C rate. 5.8S ribosomal RNA and most of the low molecular weight nuclear RNAs are not synthesized. The synthesis of 5S ribosomal RNA is greatly reduced. A large amount of an RNA of about 135 nucleotides in length accumulates at 37°C. Nucleotide sequence analysis reveals that this RNA is a novel form of 5S RNA with approximately 15 additional nucleotides at its 3′ end.