Interviewee: Jim Kent.
Jim Kent talks about telomeres and cell death.
(DNAi Location: Genome > Tour > Genome FISHing > Telomeres > What is Telomere)
There's things on the ends actually, called telomeres, which curiously get a little bit shorter each time a cell divides. And some people think this may be actually the limiting step. So you can only live so long. You know, when you get to the end of your telomere, that's it. The cell, it dies. And, it turns out that the telomere can be regenerated as well, so it's not as clear-cut as that.
Professor Robert Weinberg explains how normal cells can only double a certain limited number of times; and cancer cells have to learn how to proliferate indefinitely, i.e, they have to become immortalized.
Professor Douglas Hanahan, discusses that due to the nature of the replication machinery chromosomes get smaller every time they divide, and that we now appreciate that specialized cells in the body have a way to counteract this telomere shorting.