Female (left) and male (right) flies lacking (black lines) neuronal p53 live significantly longer.
HELFAND/ELSEVIER
Hyperactivation of p53, which kills DNA-damaged cells, reduces tumor incidence in mammals but also shortens their life span. These earlier findings suggested that reducing p53 activity might increase life span. Helfand's group found that this did not pan out for flies lacking all p53—they died earlier than normal, probably because of the requirement for p53 in developmental apoptosis. But if the authors blocked p53 activity only in neurons, the flies lived longer healthy lives and were also more resistant to DNA-damaging agents.
Loss of p53 only in the fat body or muscle tissue did not extend life span. “Maybe,” says Helfand, “the nervous system is the weak link....
