DO LOBSTERS HOLD THE KEY TO ETERNAL LIFE ??? While the passing years bring arthritis, muscle loss, memory problems and illness to humans, lobsters seem to be immune to the ravages of time Scientists are shedding light on how age affects people and, as a result, developing new treatments for diseases such as cancer Like the lobsters, planarians, a group of flat worms, use telomerase to protect their DNA and prevent cell death. ‘These species of course still die. They get diseases, they are injured or hunted. But unlike humans, they don’t die as a result of their own metabolisms — there doesn’t seem to be a built-in life expectancy in their cells.’ There are many reasons why humans, along with most species on the planet, deteriorate with age. Mutations in DNA and the battering that our 100 trillion cells take every day contribute to the slow, inevitable decline. But scientists have discovered that our cells also have a built-in fixed lifespan — obsolescence if you like. Cells are constantly renewing and replacing themselves at a rate of millions every second. However, most human cells can only copy themselves 50 to 60 times before they die. The reason for programmed cell death lies in our chromosomes, the 46 strands of DNA found at the heart of almost every cell. The ends of every chromosome are protected with a chemical cap called a telomere. They act like the plastic tips on the end of shoelaces and stop the strands of DNA from fraying. But each time a human cell divides, these telomeres get shorter. Eventually — after 50 or so divisions — they are too short to protect the chromosomes, and the cell dies. It’s the same with almost all species —from frogs and goats to zebras and hummingbirds. But, amazingly, lobsters are different. They produce sufficient quantities of a substance called telomerase to renew these protective DNA caps and prevent cells dying.
Posted on: Thu, 12 Sep 2013 11:48:38 +0000
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