Telomeres and Ageing

Telomeres are repetitive DNA sequence which form a capped structure at the end of a chromosome. In each cell division, chromosome looses a section of base at its ends, but the telomere prevents from losing any bases that a part of genes for coding vital proteins. Telomeres shortens because of the end replication problem that occurs during DNA replication in eukaryotes. Therefore, Cell stops dividing when the telomeres are shorter. In human, a cell divides 50 times before telomeres becomes shorter. This phenomenon of limited cell division was observed by Leonard Hayflick, and is also called the Hayflick limit.

Researchers can use the length of telomeres to find the cell age and how many times it will replicate that results to anti ageing. Therfore, the extension of human life can be resulted by the lengthening of telomere by temporary activation of telomerase, or by gene therapy. However, this is not proven in humans. Scientists also believes that the cancerous cell stops dyeing because the length of telomere is not shortened by an enzyme telomerase. Therefore, Techniques to extend telomeres could be helpful for biomedical engineers, because they might permit healthy noncancerous mammalian cells to be cultured in amounts large enough to be engieering materials for biomedical repairs.

Sources:

http://mbbnet.umn.edu/doric/telomere.html
http://longevity.about.com/od/researchandmedicine/p/telomeres.htm

Sundeep Sharma