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Hayflick limit

Animation of the structure of a section of DNA. The bases lie horizontally between the two spiraling strands. Nitrogen: blue, oxygen: red, carbon: green, hydrogen: white, phosphorus: orange

The Hayflick limit, or Hayflick phenomenon, is the number of times a normal somatic, differentiated human cell population will divide before cell division stops.[1][2] However, this limit does not apply to stem cells.[citation needed]

The concept of the Hayflick limit was advanced by American anatomist Leonard Hayflick in 1961,[3] at the Wistar Institute in Philadelphia, Pennsylvania. Hayflick demonstrated that a normal human fetal cell population will divide between 40 and 60 times in cell culture before entering a senescence phase. This finding refuted the contention by Alexis Carrel that normal cells are immortal.

Each time a cell undergoes mitosis, the telomeres on the ends of each chromosome shorten slightly. Cell division will cease once telomeres shorten to a critical length. Hayflick interpreted his discovery to be aging at the cellular level. The aging of cell populations appears to correlate with the overall physical aging of an organism.[3][4]

Macfarlane Burnet coined the name "Hayflick limit" in his book Intrinsic Mutagenesis: A Genetic Approach to Ageing, published in 1974.[5]

  1. ^ Rodriguez-Brenes, Ignacio A.; Wodarz, Dominik; Komarova, Natalia L. (December 9, 2015). "Quantifying replicative senescence as a tumor suppressor pathway and a target for cancer therapy". Scientific Reports. 5: 17660. Bibcode:2015NatSR...517660R. doi:10.1038/srep17660. PMC 4673423. PMID 26647820.
  2. ^ Petersen, Thomas; Niklason, Laura (September 2007). "Cellular Lifespan and Regenerative Medicine". Biomaterials. 28 (26): 3751–3756. doi:10.1016/j.biomaterials.2007.05.012. PMC 2706083. PMID 17574669.
  3. ^ a b Hayflick L, Moorhead PS (1961). "The serial cultivation of human diploid cell strains". Exp Cell Res. 25 (3): 585–621. doi:10.1016/0014-4827(61)90192-6. PMID 13905658.
  4. ^ Hayflick L. (1965). "The limited in vitro lifetime of human diploid cell strains". Exp. Cell Res. 37 (3): 614–636. doi:10.1016/0014-4827(65)90211-9. PMID 14315085.
  5. ^ Cite error: The named reference Shay2000 was invoked but never defined (see the help page).

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