More on CR in Fruit Flies

[Guest guest]

Hi folks:

More from Partridge at University College London, England, on

fruit flies.

" Sex differences in the effect of dietary restriction on life span

and mortality rates in female and male Drosophila melanogaster.

Magwere T, Chapman T, Partridge L.

Department of Biology, University College London, Darwin Building,

Gower Street, London WC1E 6BT, United Kingdom.

Dietary restriction (DR) has been shown to increase life span in

taxonomically diverse animal species. In this study we tested for sex

differences in the response of life span to graded severity of DR in

Drosophila melanogaster. In both sexes, life span peaked at an

intermediate food concentration and declined on either side. However,

the magnitude of the response and the food concentration that

minimized adult mortality differed significantly between the sexes.

Female life span peaked at a food concentration 60% of the standard

laboratory diet compared to a concentration of 40% for males.

Moreover, female flies subject to DR lived up to 60% longer than did

starved or fully fed females, whereas males subjected to DR lived

only up to 30% longer. Analysis of age-specific mortality rates

showed that DR extended life span by decreasing baseline mortality

rates in both sexes, and to a greater extent in females. The

differences in the response to DR in female and male Drosophila may

be due to previously documented sex differences in sensitivity of

life span to insulin/insulin-like growth factor-1 signalling or in

nutrient/energy demand and allocation/utilization. "

Rodney.