Dynamics of HP1 transgene loci movement and silencing in living cells
| Authors | |
|---|---|
| Year of publication | 2004 |
| Type | Article in Proceedings |
| Conference | Biophysics of the Genome |
| MU Faculty or unit | |
| Citation | |
| Field | Genetics and molecular biology |
| Keywords | cytometry |
| Description | Intranuclear localization and mobility of Cy3 labelled transgene loci were studied in living cells. Observations showed occurrence of several transgene copies in each cell nucleus. The majority of copies were localized in the centromeric heterochromatin defined by HP1beta-GFP fusion protein, the minority of copies in euchromatin. The tracking of loci showed restricted diffusive motion of these in the short-time range. During long-time observation of HP1beta domains and transgene loci, we have found that in most cases the proximity of these objects decreased within time. The changes of positions of HP1 domains were very small but transgene loci displayed directional movement towards the relevant HP1 domain. Our data records support the idea that the cell nucleus consists of several separated higher-order compartments. The genes relocate within these compartments, which is finally connected with changes of their expression status. In our experiments, the transgene loci were strongly silenced. Three days after the transfection of cells, their expression was reduced dramatically. At that time we found colocalization of transgene loci with HP1beta domains and centromeres. Moreover, the loci were methylated, which was confirmed using antibodies against trimethylated histone H3 at Lys9. |
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