William wrote:
> 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?
to which Tom Mahoney replied:
> 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.
to which William replied:
> Thank you *VERY* much for answering that question! :-)
> I really appreciate it. At least now we know that the loss of
> replicative potential in the cells of mice is indeed caused be
> telomere shortening, and not some other mechanism.
> And since we know this is true, then we can be fairly certain that if
> a telomerase knock-in mice is created, then its cells will indeed be
> immortal with an unlimited replicative potential.
Sometimes I wonder why I bother trying to raise the standard of scientific
analysis here. Tom provides no references for his assertion, then William
accepts it utterly uncritically, yet Tom makes no further comment. If such
seasoned participants in the group remain so unable to learn how science
works, I have very little hope for the lurkers.
As it happens, the mouse telomerase catalytic component was cloned much
more recently than the human one (Proc Natl Acad Sci U S A. 1998 Sep 1;
95(18):10471-10476). It has not, to my knowledge, yet been shown to
immortalise mouse cells of any kind. Such a result would be extremely
interesting, since mice's long telomeres but rapid cellular senescence
predict otherwise; thus I would have thought that Tom would have told
us where it was reported if he knows.
Tom and William: please reflect on the above as a basis for my repeated
entreaties to be only as authoritative as one can rigorously justify.
Aubrey de Grey
