Transcriptional activity of nuclei from WI-38 cells at various passages

Transcriptional activity of nuclei from human diploid fibroblast (WI-38) cells at different passage levels was studied with endogenous RNA polymerase. The rate and extent of the RNA synthesis decreased when the nuclei were prepared from senescent cells. The decreased activity of RNA synthesis in senescent cell nuclei was demonstrated from both the transcriptional assay and the estimation of the processing activity, i.e., polyadenylation of the transcripts.