Re: Immortal Human Cells

Hal Finney (
Wed, 14 Jan 1998 10:24:52 -0800

John Clark, <>, writes:
> Take a gene for telomerase production and a gene to turn it on and insert
> them into a sheep cell. With present techniques when you insert a gene into a
> cell it almost never finds its way to the correct place on the chromosome and
> gets expressed properly. It may take millions or billions of attempts before
> everything works correctly, but you can put trillions of cells in a test tube
> and if you also include a signaling gene for antibiotic resistance or for
> the production of a small amount of florescent dye, you can find the one
> successful cell out of billions. Then you use that cell to make a clone and
> observe if you get a cancerous sheep, an immortal sheep, or no sheep at all.
> Whatever the results of this experiment it will give us a profound lesson in
> how life works. We live in exciting times.

I think they said that telomerase production was already turned on
in germ cells (e.g. egg cells). These cells are already immortal in
the sense that some of their fission daughters become egg cells too,
ad infinitum. So there must be something in the development process
which turns off telomerase production in most cell lines as they become
specialized. Arranging to keep telomerase being produced throughout the
development process may be harder than just sticking an extra telomerase
gene into the egg cell.