engleski

Telomere Q-PNA fish: insight into senescence and aging

Telomeres are specialized structures found at the ends of eukaryotic chromosomes serving as guardians of genome stability. Normal mammalian cells demonstrate limited growth capacity. Due to the DNA end replication problem and additional 5'- exonuclease activity, their telomeres are shortening during each subsequent division. When telomeres are critically shortened cell proliferation is permanently stopped, a phenomenon known as cellular senescence. While telomere shortening is a main molecular mechanism that limits growth of normal cells, telomere elongation is crucial for the maintenance of immortalization in tumor cells. Thus, structural and functional analysis of telomeres is very important for understanding of cell growth control, cellular senescence and processes of immortalization. It is very important to monitor a behavior of telomere sister chromatids as indicator of molecular processes on telomeres. Therefore, we monitored these processes during cell senescence using quantitative PNA-FISH method. Observed differences between sister telomeres are larger and more frequent than this could be attributed to creation of -3' single stranded overhangs after the replication of DNA. Sister telomere signals demonstrate high regularity in telomere variations which ensure reproducibility of results using this method. We consider that deficient hybridization and/or complexity of telomere DNA suprastructure result in observed differences in telomere strands labeling.

Telomeres ; Telomere Q-PNA FISH

nije evidentirano