AUTO-CATALYZED KARYOTYPE EVOLUTION OF MURINE EMBRYONIC STEM CELL LINE R1
IN VITRO
T. T. Glazko,1 L. M. Mezhevikina,2 A. A. Boiko,1
E. E. Fesenko 2
1 Institute of Agroccology and Biotechnology, Kiev, the Ukraine, and
2 Institute of Cell Biophysics, RAS, Pushchino, Russia;
1 e-mail: glazko@biotech.relc.com
Cytogenetic anomaly frequencies were analysed in three sublines of ES R1 line in its five clonal sublines,
obtained from two cell colonies after transformation of ES Rl cells by plasmid with gene lif Cell transformation did not
increase cytogenic anomalies, however, the initial sublines of ES R1 line, as well as its transformed clonal descendants bore a
redundant quantity of the chromosome 8 material within the structure of various Robertsonian translocations even in cells with
diploid chromosome quantity (2n = 40). In the initial sublines ES R1 and its clonal descendants a common Rb (8; 15) was
revealed. It was supposed that selection for the increase in ES cell sensitivity to cytokines (in particular, LIF) under cultural
conditions was accompanied by an increase in chromosomal copies, carrying genes of mapk and jak/stat, through which
downstream effectors of cytokine signals for preservation of cell pluripotention and propagation are realized. Genes of chromatid
separation and chromosome segregation control (for example, separase gene Espl in chromosome 15) may be passively involved in
this process, thus promoting acceleration of karyotype evolution in ES cells.
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