What Makes Us Age? Ticking of Cellular Clock Promotes Seismic Changes in Chromatin Landscape Associated With Aging

Each time a cell divides, the protective "caps" at the tip of chromosomes (red and green dots) erode a little bit further. As telomeres wear down, their DNA undergoes massive changes in the way it is packaged. These changes likely trigger what we call "aging." (Credit: Image: Courtesy of Dr. Jan Karlseder, Salk Institute for Biological Studies)

From Science Daily:

ScienceDaily (Oct. 4, 2010) — Like cats, human cells have a finite number of lives: once they divide a certain number of times (thankfully, more than nine) they change shape, slow their pace, and eventually stop dividing -- a phenomenon called "cellular senescence."

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