Abstract
Analysis of the tRNA population from chicken cells was performed by means of polyacrylamide gel mapping. About 60 species were detected; most of these were positively identified by their acceptor specificity. The comparison of polysome-bound and overall cellular tRNA gel patterns from normal and Rous sarcoma virus-infected chicken embryo fibroblasts led us to the following observations: some tRNA species were present in the same relative proportions in all the preparations, and within isoaccepting groups the same species was preponderant; however, although about 8% of whole-cell tRNA was recovered in polysomal preparations, amounts ranging from 3 to 30% were found for individual tRNA species. This points to the absence of a direct correlation between the amount of each mature tRNA species produced and the frequency with which it is used in this case of embryonic cells. No significant difference was observed between the whole-cell tRNA patterns from normal and infected cells. Thus, tRNA transcription appears unaltered when cells are transformed and virus producing. No change was observed in the extent of a post-transcriptional modification of tRNAPhe (the base Y). However, viral infection led to some changes in the relative proportions of individual species from polysomal preparations.