Iron accumulation during development and ageing of Drosophila

We examined Drosophila melanogaster fruit flies to determine whether iron accumulates with ageing as it does in mice. Iron concentrations were measured by atomic absorption for flies maintained at 11, 20, 25 and 30 degrees C where the average lifespans were 152, 81, 62 and 25 days, respectively. Iron was found to accumulate with ageing during both the adult and developmental stages with an overall increase of 186% at 25 degrees C. A similar increase was found at 20 degrees C and 30 degrees C. At 11 degrees C the increase was less than half that at 25 degrees C. The rate of iron accumulation also varied with environmental temperature with the logarithm of the rate proportional to temperature (log R = 0.0509T-0.384). The rate of iron accumulation with ageing was, thus, found to be proportional to the rate of ageing, suggesting that excess dietary iron may be an initiator of senescence.