JUST what is it that makes the difference between Olympic gold and the agony of defeat? For athletes, it is about training hard, eating right and preparing mentally – and sometimes taking illegal substances. What they cannot do anything about is their genes.
This week researchers announced that they have genetically engineered “marathon mice” that can run almost twice as far as normal mice. The modified mice have been given an extra gene to boost production of a protein called PPAR-delta, which increases the number of slow-twitch muscle fibres that are vital in endurance events (see “Marathon mice can run and run”)…
