Telomere Maintenance in Telomerase-Deficient Mouse Embryonic Stem Cells: Characterization of an Amplified Telomeric DNA
AUTOR(ES)
Niida, Hiroyuki
FONTE
American Society for Microbiology
RESUMO
Telomere dynamics, chromosomal instability, and cellular viability were studied in serial passages of mouse embryonic stem (ES) cells in which the telomerase RNA (mTER) gene was deleted. These cells lack detectable telomerase activity, and their growth rate was reduced after more than 300 divisions and almost zero after 450 cell divisions. After this growth crisis, survivor cells with a rapid growth rate did emerge. Such survivors were found to maintain functional telomeres in a telomerase-independent fashion. Although telomerase-independent telomere maintenance has been reported for some immortalized mammalian cells, its molecular mechanism has not been elucidated. Characterization of the telomeric structures in one of the survivor mTER−/− cell lines showed amplification of the same tandem arrays of telomeric and nontelomeric sequences at most of the chromosome ends. This evidence implicates cis/trans amplification as one mechanism for the telomerase-independent maintenance of telomeres in mammalian cells.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=85781Documentos Relacionados
- Mitotic Cyclins Regulate Telomeric Recombination in Telomerase-Deficient Yeast Cells
- G-strand overhangs on telomeres in telomerase-deficient mouse cells.
- Telomere Cap Components Influence the Rate of Senescence in Telomerase-Deficient Yeast Cells
- The Rap1p-Telomere Complex Does Not Determine the Replicative Capacity of Telomerase-Deficient Yeast†
- The Transcriptome of Prematurely Aging Yeast Cells Is Similar to That of Telomerase-deficient Cells