|
|
Cytologická studie modelů DNA metylace a metylace histonů u lidských buněčných linií
Skalníková, M. ; Bártová, Eva ; Kozubek, Stanislav ; Kozubek, Michal
Epigenetic processes are defined as heritable changes in genome function that occur without a change in DNA sequence. Gene expression, chromosome segregation, DNA replication, repair, and recombination all act, not on DNA alone, but on the chromatin template. DNA methylation, along with histone lysine methylation, establishes the framework for long-term epigenetic maintenance. The discovery that enzymes can (re)organise chromatin into accessible and inaccessible configurations revealed epigenetic mechanisms that considerably extend the information potential of the genetic code. In mammals, heterochromatin is characterised by DNA methylation at CpG dinucleotides and methylation at lysine 9 of histone 3 (H3-K9), whereas euchromatin is associated with methylation at lysine 4 of histone 3 (H3-K4).
|
|
|
Klastrování genů s podobným regulačním mechanismem během monocytární a garanulocytární diferenciace buněk HL-60
Koutná, I. ; Faltýsková, E. ; Krontorád, P. ; Svoboda, Z. ; Pavlík, T. ; Bártová, Eva ; Kozubek, Michal ; Kozubek, Stanislav
In the present study, a high density-microarrays of human cDNA containing 19,000 genetic elements were used to search for differences in gene expression of human promyelic leukaemia cell line HL-60 during monocyte (MD) and granulocyte differentiation (GD). For differentiation to monocytes (granulocytes), the TPA, 12-O-tetradecanoylphorbol-D-acetate (DMSO) were used, respectively. A total number of 4625 (4760) genes were found to be regulated during MD (GD). The genes have been divided into groups according to their kinetics of regulation (R-groups). The genes of the same group are not distributed randomly throughout the genome but form clusters on chromosomes (R-clusters). Thus, functionally interconnected genes are frequently localized near to each other on the DNA molecule.
|
|
|
Dynamika pohybu a umlčování transgenních lokusů HP1 v živých buňkách
Ondřej, Vladan ; Kozubek, Stanislav ; Lukášová, Emilie ; Matula, Pa. ; Matula, Pe. ; Kozubek, Michal
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 HPlbeta-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 HPlbeta domains and transgene loci, we have found that in most cases the proximity of these objects decreased within time. The changes of positions of HPl domains were very small but transgene loci displayed directional movement towards the relevant HPl 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.
|
|
| |
guest ::
