Fig. 3
Electron micrographs of SGN nuclei illustrating the structure and organization of PDDF. 45d post-IR. a, b PDDF (asterisks) appeared as cleared areas in the euchromatin landscape associated with the nuclear envelope or with the nucleolus (No). Interchromatin granule clusters (arrows). Scale bar: 5Ā Ī¼m. c, d Detailed fine structure of a PDDF composed of a loosen network of chromatin fibers surrounded by euchromatin. Scale bar: 1Ā Ī¼m. Cytochemical staining for ribonucleoproteins revealed the lack of weak staining of a PDDF, whereas the adjacent euchromatin and, particularly, the interchromatin granule clusters (IGC) appeared intensely contrasted. Scale bar: 1Ā Ī¼m