Gene transcription in a temperature-sensitive mutant of RNA polymerase II.

We have studied the transcription rates and the steady-state levels of cytoplasmic mRNA of selected genes in tsAF8 cells, a temperature-sensitive mutant of RNA polymerase II. At the restrictive temperature, the transcription rates decrease uniformly for all genes examined, while the corresponding decreases in steady-state levels of cytoplasmic mRNA vary for individual genes. tsAF8 cells can be advantageously used to study the half-line of mRNA without the use of perturbing drugs.