Related Experiment Video
Updated: Jul 8, 2026

A Multilabel Single Molecule Localization Microscopy Protocol for Investigation of Chromatin in the Dense Nuclear Environment
Published on: June 5, 2026
Relationships between transcription, silver staining, and chromatin organization of nucleolar organizers in Secale
Ana D Caperta1, Nuno Neves, Wanda Viegas
1Centro Botânica Aplicada à Agricultura, Instituto Superior de Agronomia, Technical University of Lisbon, Lisboa. anadelaunay@isay.utl.pt
Abstract:
The nucleolar organizer regions (NORs) are composed of hundreds of rRNA genes, typically spanning several megabases. Cytologically, NORs include regions that are highly condensed and regions that are decondensed, the latter corresponding to regions at which associated proteins stain intensively with silver (Ag-NORs) and where active rRNA gene transcription is thought to occur. To test the relationship between rRNA gene activity, NOR silver staining, and rDNA (genes coding for rRNA) chromatin condensation, we used the DNA methyl-transferase inhibitor 5-azacytidine to evaluate the correlation between the epigenetic regulation of rRNA genes and NOR silver staining in the plant Secale cereale. Following 5-azacytidine treatment, we observed an increase in rRNA gene transcription as well as a reduction in the number of cells showing a significant difference in the size of the silver-stained domains in the two NORs. These transcriptional changes occurred concomitantly with an increase in nuclear and nucleolar size and were associated with the reallocation of most of the rDNA from perinucleolar heterochromatin into the nucleolus. Collectively, these results suggest that rRNA gene transcription, silver staining, and NOR decondensation are interrelated in S. cereale.
More Related Videos
07:16Isolation and Characterization of Mouse Antral Oocytes Based on Nucleolar Chromatin Organization
Published on: January 7, 2016
09:33An Efficient Method for Quantitative, Single-cell Analysis of Chromatin Modification and Nuclear Architecture in Whole-mount Ovules in Arabidopsis
Published on: June 19, 2014
Related Concept Videos
Nucleoid
The Nucleolus
Chromatin Position Affects Gene Expression
Topologically Associated Domains (TADs)
The 3-dimensional positioning of chromatin in the nucleus influences the timing and level of...
Additional Subnuclear Structures
The nucleus contains many membrane-less subnuclear organelles or nuclear bodies, such as nucleoli, Cajal bodies, speckles, paraspeckles, etc. These nuclear...
Chromatin Packaging
The chromatin
In combination with specialized DNA binding protein called Histones, the DNA double helix forms a compact DNA: protein complex called chromatin. The chromatin itself is further compacted into higher-order structures.
Chromatin Packaging