It is known that chromosomes occupy non-random positions in the cell nucleus. However, it is not clear to what extent their nuclear positions, together with their neighborhood, are conserved in daughter cells. To address specific aspects of this problem, we used the model of the chromosomes carrying ribosomal genes that are organized in clusters termed Nucleolus Organizer Regions (NORs). We compared the association of chosen NOR-bearing chromosomes (NOR-chromosomes) with nucleoli, as well as the numbers of nucleoli, in the pairs of daughter cells, and established how frequently the daughter cells had equal numbers of the homologs of certain NOR-chromosomes associated with individual nucleoli. The daughter cells typically had different numbers of nucleoli. At the same time, using immuno-FISH with probes for chromosomes 14 and 15 in HeLa cells, we found that the cell pairs with identical combinations appeared significantly more frequently than predicted by the random model. Thus, although the total number of chromosomes associated with nucleoli is variable, our data indicate that the position of the NOR-bearing chromosomes in relation to nucleoli is partly conserved through mitosis.

Institute of Cellular Biology and Pathology 1st Faculty of Medicine Charles University Albertov 4 Prague 2 Czech Republic

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BICKMORE WA, CHUBB JR. Dispatch. Chromosome position: now, where was I? Curr Biol. 2003;13:357–359. PubMed

BUSCH H, SMETANA K. The Nucleolus. New York: Academic Press; 1970.

CREMER T, CREMER C. Chromosome territories, nuclear architecture and gene regulation in mammalian cells. Nat Rev Genet. 2001;2:292–301. PubMed

CREMER T, CREMER C. Rise, fall and resurrection of chromosome territories: a historical perspective Part II. Fall and resurrection of chromosome territories during the 1950s to 1980s. Part III. Chromosome territories and the functional nuclear architecture: experiments and models from the 1990s to the present. Eur J Histochem. 2006;50:223–272. PubMed

ESSERS J, Van CAPPELLEN WA, THEIL AF, Van DRUNEN E, JASPERS NG, HOEIJMAKERS JH, WYMAN C, VERMEULEN W, KANAAR R. Dynamics of relative chromosome position during the cell cycle. Mol Biol Cell. 2005;16:769–775. PubMed PMC

FOSTER HA, BRIDGER JM. The genome and the nucleus: a marriage made by evolution. Genome organisation and nuclear architecture. Chromosoma. 2005;114:212–229. PubMed

GERLICH D, BEAUDOUIN J, KALBFUSS B, DAIGLE N, EILS R, ELLENBERG J. Global chromosome positions are transmitted through mitosis in mammalian cells. Cell. 2003;112:751–764. PubMed

HARNIČAROVÁ A, KOZUBEK S, PACHERNÍK J, KREJČI J, BÁRTOVÁ E. Distinct nuclear arrangement of active and inactive c-myc genes in control and differentiated colon carcinoma cells. Exp Cell Res. 2006;312:4019–4035. PubMed

KALMÁROVÁ M, SMIRNOV E, MAŠATA M, KOBERNA K, LIGASOVÁ A, POPOV A, RAŠKA I. Positioning of NORs and NOR-bearing chromosomes in relation to nucleoli. J Struct Biol. 2007;160:49–56. PubMed PMC

LEUNG AK, GERLICH D, MILLER G, LYON C, LAM YW, LLERES D, DAIGLE N, ZOMERDIJK J, ELLENBERG J, LAMOND AI. Quantitative kinetic analysis of nucleolar breakdown and reassembly during mitosis in live human cells. J Cell Biol. 2004;166:787–800. PubMed PMC

McCLINTOCK B. The relationship of a particular chromosomal element to the development of the nucleoli in Zea Mays. Z Zellforsch Mikrosk Anat. 1934;21:294–328.

PARADA L, MISTELI T. Chromosome positioning in the interphase nucleus. Trends Cell Biol. 2002;12:425–432. PubMed

PEDERSON T. The spatial organization of the genome in mammalian cells. Curr Opin Genet Dev. 2004;14:203–209. PubMed

PLISS A, KOBERNA K, VEČEŘOVÁ J, MALÍNSKÝ J, MAŠATA M, FIALOVÁ M, RAŠKA I, BEREZNEY R. Spatio-temporal dynamics at rDNA foci: global switching between DNA replication and transcription. J Cell Biochem. 2005;94:554–565. PubMed

RAŠKA I. Oldies but goldies: searching for Christmas trees within the nucleolar architecture. Trends Cell Biol. 2003;13:517–25. PubMed

RAŠKA I, KOBERNA K, MALÍNSKY J, FIDLEROVÁ H, MAŠATA M. The nucleolus and transcription of ribosomal genes. Biol Cell. 2004;96:579–594. PubMed

SMIRNOV E, KALMÁROVÁ M, KOBERNA K, ZEMANOVÁ Z, MALÍNSKÝ J, MAŠATA M, CVAČKOVÁ Z, MICHALOVÁ K, RAŠKA I. NORs and their transcription competence during the cell cycle. Folia Biol. 2006;52:59–70. PubMed PMC

WALTER J, SCHERMELLEH L, CREMER M, TASHIRO S, CREMER T. Chromosome order in HeLa cells changes during mitosis and early G1, but is stably maintained during subsequent interphase stages. J Cell Biol. 2003;160:685–697. PubMed PMC

Structure and epigenetics of nucleoli in comparison with non-nucleolar compartments

Chromatin position in human HepG2 cells: although being non-random, significantly changed in daughter cells

Asymmetrical distribution of the transcriptionally competent NORs in mitosis