At 07:34 PM 3/7/99 -0700, you wrote:
>BOSTON -- Mice lacking a gene for making telomeres -- chromosomal elements
>with a conjectured but controversial role in aging and cancer -- were found
>to [blah blah]
This actually isn't directly all that interesting to humans. Standard mice have unusually long telomeres, so even without telomerase to top up their germ cells they manage to pass down enough for a few generations. The ones in question are the sixth generation (I think) of a constructed knockout mouse. This breed started running into trouble at gen 3, and was in deep shit by gen 6. My surmise is that the consecutively truncated telomeres finally hit an unviable brevity by then, and there was a cascade of chromosomal damage.
A useful account (but partisan) of the telomeric hypothesis of aging can be found on Tom Mahoney's site