How Does Telomere Length Relate to the Hayflick Limit?
In 1988, Calvin Harley and Carol Greider showed that telomere length is strongly correlated with cellular aging: The shorter the telomeres, the fewer times cells would divide before reaching their Hayflick limit (the correlation coefficient is about 75%). Moreover, cells taken from older persons have shorter telomeres than the same types of cells taken from younger persons. In a seminal paper in Nature in 1990, Harley, Greider, and Bruce Futcher suggested that the telomeres acted as the clock for cellular aging How Long are Human Telomeres? It is estimated that at conception, your telomeres are about 10,000 base pairs long. The subtelomeric region, adjacent to the telomeres, includes another 5,000 base pairs, for a total of about 15,000 base pairs in the so-called terminal restriction fragment (TRF). With each cell division, the telomeres are shortened by about 50-100 base pairs. Because of rapid cell division in growth and development, by the time you are born, the TRF is about 10,000
