Figure 7

Chromatin interphase. Transcription occurs at the interface of chromatin. (A) Electron micrograph showing transcription by RNA pol II (gold particles) at the border of condensed chromatin masses. Figure reproduced from reference 52, with permission from Springer. Activation of transcription proceeds with nuclear volume change. The amount of chromatin (blue) is stable and only the dynamic phase (red) can be changed. As a result by increasing the amount of proteins/RNA, the nuclear volume changes and also the interface between DNA and proteins/RNA, where transcription occurs. (B) Cell with low level of activity (small interface). (C) Very active cell (Large interface).