Figure 5.

Nuclear foci of RNA from replication-dependent histone genes localize to their sites of transcription, not always with CBs. (A–C) Some HIST2 H4 RNA foci (red, A and C) associate with CBs (green, B and C) in HeLa cells and some do not. These RNA foci vary in number and intensity from cell to cell. The cell shown is atypical in that three of the four RNA signals are CB-associated. Note that the weakest RNA focus (arrowhead) contacts a CB, whereas a more intense, nearby focus does not. (D–F) H4 RNA (red, D and F) forms a focus that partially overlaps one HIST2 locus (arrow, green, E and F) in a WI38 diploid fibroblast nucleus. The other homolog of HIST2 has no apparent accumulation of H4 RNA (arrowhead). Bars, 5 μm.