Figure 7.

Decondensation of the HSR is accompanied by the activation of a noninducible promoter. (A, B) HSR-CFP cells were co-transfected with pMS2-YFP and pTet-OFF, cultured for 2.5 h in the absence of Dox for 30 min, and fixed. Among these cells, HSR and BSR RNA were simultaneously detected by FISH using different colors. Compared with the experiments that appear in Figures 1 and 2, many BSR RNA signals were associated with the HSR DNA. (C) HSR-CFP cells were co-transfected with pMACS-LNGFR and pTet-OFF and cultured for 2 days in the presence or absence of Dox, as indicated. Cells expressing LNGFR were isolated by the MACSelect system. From these cells, total RNA and DNA were extracted, and the amount of BSR sequence was determined by real-time PCR. The graph was generated from three independent experiments; error bars represent standard deviations. All bars in images indicate 2 µm.