Telomerase deficient mice

Aubrey de Grey ag24 at
Mon Apr 12 12:01:31 EST 1999

Tom Mahoney wrote:

> >If you do, then
> >you're no longer contending that "the replicative cells of mice respond
> >in the same manner as human cells when the catalytic component for
> >telomerase is introduced".
> Your reasoning is correct but then I never did say they did.

having, on March 27th, written:

> >1) Has *anyone* been able to "immortalize" a mouse cell by the
> >insertion of a telomerase gene which would cause the cell to produce
> >telomerase?
> Yes, the replicative cells of mice respond in the same manner as human cells 
> when the catalytic component for telomerase is introduced.  They continue 
> normal growth and don't enter senescence so long at the mTRT is active.


Anyway, we seem to have ironed out the confusions now.  Except that:

> If this slow growth stage is similar to [human cell] quiescence then the
> cells would be "normal" both before and after experiencing this slow growth
> stage and that appears to be the case.

No.  A simple way to see this is to consider the reversibility of the cells'
state.  Cells that escape from quiescence on demand, e.g. by removing contact
inhibition, are indeed normal, but they can also be returned to quiescence
on demand by restoring contact inhibition.  This is a totally unambiguous
difference from cells that spontaneously, and irreversibly, escape from
slow growth.  Cells can also escape spontaneously (and irreversibly) from
quiescence, of course, but then they're likewise no longer normal.

Aubrey de Grey

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