"Rob Halgren" wrote in message
...
Al wrote:

One of the things I remember about Dolly the cloned sheep is that,
while they able to reset the sequence of events in the genes and grow
her up from cells of her mother, they started with cells of a specific
age, as measured by the telomere length, so dolly, even as a "baby"
sheep, was subject to the same age related problems as her mother,
since her cells were biologically the same age. They were not able to
reset the clock built into the genes but only restart the sequence.



Ok, I'll go there.

Thanks!

This is greatly appreciated!

I'll get you a sundae if, or when, we meet (possibly at a show in Michigan,
if I get a chance to go, or at a SOOS show in Toronto, should you get a
chance to attend that ;-) I'll even throw in a coffee ;-).

There is a critter called telomerase which adds
telomere repeats to the ends of chromosomes. In the real world, it is
only expressed in a very limited set of cells, for a very limited time.
So your germ cells may have this enzyme turned on, but your skin cells
won't. In fact, turning on telomerase activity in somatic (body) cells
has been associated with cancer progression. So, since Dolly was cloned
from a somatic cell (I don't know which kind), the poor little ewe
started out with shorter telomeres than she should have.

Interesting. I wonder if they could have rejuvenated the cell Dolly was
made from, before it began to divide, by turning back on. If so, would it
turn itself off again at the right time, or would an intervention be
required to turn it off later? Or is an exprimental manipulation to
lengthen the telomeres without turning on the gene (perhaps be extracting
the genetic material, manipulating it and then putting it back)?

So, we could turn telomerase back on in all your cells... This
might make your cells 'young' again. However, you would get terrible
cancers and die. So that isn't really the answer now, is it? *grin*

Nope! But then, those who fear death would likely want it examined in
animals to see if the problems associated with turning telomerase on can be
avoided, in an effort to prolong life. Through my own chronic illness (no
safe, effective treatment and uncontrollable pain: less than a 50% chance of
living to age 65 according to the latest stats I've seen), I have learned
not only not to fear death but to see it as a welcome friend. What good is
a prolonged life if you don't have your health?

Cheers,

Ted