Telomere Repair Mechanisms Linked to Lifespan

One approach to studying regenerative medicine is to learn more about telomeres, the segments of DNA at the ends of eukaryotic chromosomes that form structures with proteins and help regulate cell replication. Most cells use an enzyme called telomerase to rebuild telomeres when they become shortened or damaged, while some organisms use homogenous recombination. Certain human cancer cell lines have been found to have the capacity for homogenous recombination, but for reasons yet unknown, human cells seem to prefer telomerase. Budding yeast are capable of both processes, providing a perfect model for studying how each works. Using this model, Chen et al. (2009) have discovered that while recombination provides stability to the telomeres, it also shortens the replicative lifespan of the cell line, giving a possible selective advantage to cells that utilize telomerase.

The awarding of the Nobel Prize in Medicine last week, to a scientist who pioneered telomere research, exemplifies the importance of research such as this in areas such as epigenetics, cancer, and stem cell research.

_{Source: Chen, X.F. et al. 2009. Telomere recombination accelerates cellular aging in Saccharomyces cerevisiae. PLoS Genetics, June 2009.}