Three-dimensional reconstructions of nucleolus-organizing regions in PHA-stimulated human lymphocytes
Language English Country England, Great Britain Media print
Document type Journal Article
- MeSH
- Lymphocyte Activation drug effects MeSH
- Time Factors MeSH
- Microscopy, Electron MeSH
- Phytohemagglutinins pharmacology MeSH
- Humans MeSH
- Nucleolus Organizer Region ultrastructure MeSH
- T-Lymphocytes drug effects ultrastructure MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Phytohemagglutinins MeSH
Ultrastructure and three-dimensional distribution of nucleolus-organizing regions have been studied on ultrathin serial sections of PHA-stimulated human lymphocytes. During the 48 hr of activation the size of fibrillar centers (FCs) decreased from 0.6-0.9 microns to 0.2-0.3 microns and the number of FCs increased rapidly from one to 75-107 per cell. The number of fibrillar complexes (i.e. associations of a different number of FCs connected by the dense fibrillar component) also increased but did not reach the maximum number of nucleolar organizers presented here. Three-dimensional computer reconstructions of fibrillar complexes showed that lymphocyte activation was accompanied by early (2-4 hr) changes in the shape of the primary fibrillar center. Invagination of the dense fibrillar component on its surface occurred and division into two or more smaller FCs followed. Gradually, the typical structure of the nucleolus with several fibrillar complexes and many FCs was formed. These results confirm the hypothesis of fibrillar complex-nucleolar organizer correlation published recently.
References provided by Crossref.org
Nuclear distribution of actin and myosin I depends on transcriptional activity of the cell
