Effect of narciclasine and puromycin on the synthesis of rapidly labelled RNA in excised salivary glands of Chironomus thummi

Abstract

The effect on transcription of two protein synthesis inhibitors, narciclasine and puromycin, when applied in short periods of time to explanted salivary glands of Chironomus thummi, has been studied.Narciclasine (6 muM) enhances the uptake of uridine and stimulates the synthesis of giant-heterogeneous, pre-ribosomal (38 S) and low-molecular weight (4-5 S) RNA.However, puromycin (200 muM) inhibits uridine uptake and decrease selectively the synthesis of pre-rRNA, while transcription of low-molecular weight RNA is stimulated.These effects are compared with those previously found to be produced by other inhibitors of translation in this biological system.