FIG. 4.

Intranuclear distribution of RNA polymerase II molecules in cells transiently expressing the Us11 gene, following the use of mAb 7C2. Formaldehyde fixation, Lowicryl embedding, and uranyl acetate staining. Bars represent 0.5 μm. (a) Gold particles accumulate over a roundish focus of intermingled RNP fibrils (star) whereas they are scattered over the surrounding nucleoplasm. IG: cluster of interchromatin granules; NU: nucleolus, (b) The focus of intermingled viral RNP fibrils (star) is located near a cluster of interchromatin granules (IG). Labeling over the focus of RNP fibrils is exactly superimposed to its individual fibrils (arrow).