Figure 1.

Morphological changes in nuclear organization upon global disruption of RNA. (A) Classical experiments explored the role of RNA in maintaining the structural core of the nucleus. To do this, Nickerson and colleagues (B) inhibited transcription using actinomycin D or (C) degraded RNA using RNAse A. In both cases, they observed large-scale changes in the overall morphology of the nucleus, including collapse or aggregation of chromatin matrix-associated proteins. (Bottom row of images are reprinted from Nickerson et al. 1989 courtesy of the CC BY-NC-ND license and The National Academy of Sciences.)