Re: Mice without Telomerase

Tony Benjamin Csoka (csoka@itsa.ucsf.edu)
Sat, 17 Jan 1998 14:05:30 -0800 (PST)


On Fri, 16 Jan 1998, John K Clark wrote:

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> Damien Broderick wrote:
>
> >`[Lee M.] Silver [of MOUSE GENETICS (OUP 1995) fame] told me that
> >mouse researchers have even created mice that do not have [telomerase].
> >The mice seemed healthy... are now up their fourth generation [sans
> >telomerase]... yet to find anything wrong...' (p. 205).
>
>
> Tony Benjamin Csoka
>
> >Yes, the telomerase "knockout" mice (to use the jargon) were
> >perfectly normal. They didn't even have increased rates of cancer,
> >which I suppose was unexpected.
>
>
> I don't see anything unexpected in that, if fact, it's hard to see how mice
> without the enzyme telomerase could ever get cancer, unless the mice still
> had a the telomerase gene somewhere and it just wasn't turned on to make the
> enzyme. I'll bet somebody is exposing the mice to very carcinogenic chemicals
> to see what happens.
>
> I must admit that I would also expect the mice to have severe reproductive
> difficulties, but if they really have gone through 4 generations then the
> trouble can't be too bad. This probably means that we really don't understand
> what's going on very well. Lots about this puzzle seem contradictory, but the
> parts must fit together somehow.
>
> John K Clark johnkc@well.com
>
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Sorry, you're correct. I was very tired when I wrote the above. what I
meant to say was that they still got cancer!! What *is* unexpected, I
think, is that they didn't have a reduced lifespan. That's why I pointed
out that mice may have an alternative means of lengthening their
telomeres.

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Tony Benjamin Csoka // Tel: (415) 476 2745 // Fax: (415) 476 9672

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