Tsung-Jui Yeh (tjyeh at soda.CSUA.Berkeley.EDU) wrote:
: I was wondering about the Hayflick limit for rapid dividing cells like
: ones that line the stomach and also cells of the cornea. Do these cells
: have the same Hayflick limit as fibroblasts? If so, why can these cells
: afford to divide so fast?
: Thanks
Cells from different tissues display different Hayflick limits. This
means that some cells like fibroblasts may go through about 50 to 70
population doublings, in about 150 cell generations. On the other hand,
adult dermal fibroblasts, chondrocytes experience many fewer
generations. Lymphocytes seem in most growth media, to experience only
about 23 population doublings. So, at the moment we do not really know
whether there is one fixed Hayflick limit; the evidence available so far
would suggest that there are specific Hayflick limits for different
tissues. This clearly has important implications for the homeostasis of
each individual tissue.
Moreover, it is very well established that the same cell type from
different animal species show a species-specific Hayflick limit; this is
part of the evidence for the notion that the Hayflick limit is
genetically controlled.
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