| Literature DB >> 21297579 |
Arnout G Schepers1, Robert Vries, Maaike van den Born, Marc van de Wetering, Hans Clevers.
Abstract
Somatic cells have been proposed to be limited in the number of cell divisions they can undergo. This is thought to be a mechanism by which stem cells retain their integrity preventing disease. However, we have recently discovered intestinal crypt stem cells that persist for the lifetime of a mouse, yet divide every day. We now demonstrate biochemically that primary isolated Lgr5+ve stem cells contain significant telomerase activity. Telomerase activity rapidly decreases in the undifferentiated progeny of these stem cells and is entirely lost in differentiated villus cells. Conversely, asymmetric segregation of chromosomes has been proposed as a mechanism for stem cells to protect their genomes against damage. We determined the average cell cycle length of Lgr5+ve stem cells at 21.5 h and find that Lgr5+ve intestinal stem cells randomly segregate newly synthesized DNA strands, opposing the 'immortal strand' hypothesis.Entities:
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Year: 2011 PMID: 21297579 PMCID: PMC3061032 DOI: 10.1038/emboj.2011.26
Source DB: PubMed Journal: EMBO J ISSN: 0261-4189 Impact factor: 11.598