Mechanisms of transcription in nucleoli of amphibian oocytes as visualized by high-resolution autoradiography.

Open Access
Publisher Website
Google Scholar
Abstract
In oocytes of Pleurodeles waltlii, the method of Miller and Beatty was combined with a method of high-resolution autoradiography especially suitable for the study of isolated molecules. In vitro labeling of RNA by tritiated precursors was carried out with increasing incubation times (1, 4, 15, 24, 48 and 72 h). Ag grains were present over ribonucleoprotein fibrils in amounts sufficient for quantitative analysis of nucleolar DNA transcription. Statistical analysis of the data revealed that the units of any one nucleolus exhibited a large degree of heterogeneity in their number of grains and that there was a parallelism between the increasing grain number and the ribonucleoprotein-fibril lengthening as observed along the transcription unit.