(A) Inhibition of RNA transcription by ActD for 4 h results in morphological changes of the nucleolus. Scale bar, 5 μm.
(B) Within a simple shape model (STAR Methods), FC location is sufficient to describe nucleolar shape in HEK, MV, and U2OS (left, middle, right). Scale bar, 1 μm.
(C) RNA (EU; white) is transcribed at the interface of FC (RPA16; cyan) and DFC (fibrillarin; yellow) (Scale bar, 5 μm.
(D) The RDF of nucleolar phases reflects their concentric layering (N = 131 nucleoli).
(E) rRNA is primarily located in the DFC 30 min after addition of EU to the media (N = 198 nucleoli); the DFC RDF fit is from (D). Shaded error region on RDFs are mean prediction bands to spline fits (supplemental information).