Open AccessPositioning of the NOR-bearing chromosomes in relation to nucleoli in daughter cells after mitosis
Author(s) -
Markéta Kalmárová,
Evgeny Smirnov,
Ľubomír Kováčik,
Alexey A. Popov,
Ivan Raška
Publication year - 2008
Publication title -
physiological research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.647
H-Index - 70
eISSN - 1802-9973
pISSN - 0862-8408
DOI - 10.33549/physiolres.931430
Subject(s) - nucleolus , mitosis , biology , nucleolus organizer region , cell division , genetics , cell nucleus , microbiology and biotechnology , cell , nucleus , gene
It is known that chromosomes occupy non-random positions inthe cell nucleus. However, it is not clear to what extent theirnuclear positions, together with their neighborhood, areconserved in daughter cells. To address specific aspects of thisproblem, we used the model of the chromosomes carryingribosomal genes that are organized in clusters termed NucleolusOrganizer Regions (NORs). We compared the association ofchosen NOR-bearing chromosomes (NOR-chromosomes) withnucleoli, as well as the numbers of nucleoli, in the pairs ofdaughter cells, and established how frequently the daughter cellshad equal numbers of the homologs of certain NORchromosomes associated with individual nucleoli. The daughtercells typically had different numbers of nucleoli. At the sametime, using immuno-FISH with probes for chromosomes 14 and15 in HeLa cells, we found that the cell pairs with identicalcombinations appeared significantly more frequently thanpredicted by the random model. Thus, although the total numberof chromosomes associated with nucleoli is variable, our dataindicate that the position of the NOR-bearing chromosomes inrelation to nucleoli is partly conserved through mitosis.