Behavioral, physical, and demographic changes in Drosophila populations through dietary restriction

Abstract

SummaryDietary restriction (DR) is a valuable experimental tool for studying the aging process. Primary advancement of research in this area has relied on rodent models, but attention has recently turned toward Drosophila melanogaster . However, little is known about the baseline effects of DR on wild-type Drosophila and continued experimentation requires such information. The findings described here survey the effects of DR on inbred, wildtype populations of Canton-S fruit flies and demonstrate a robust effect of diet on longevity. Over a circumscribed range of dietary conditions, healthy lifespan varies by as much as 121% for wild-type Drosophila females. Significant differences are also observed for male flies, but the magnitude of the DR effect is less robust. Mortality analyses of the survivorship data reveal that this variation in lifespan can be attributed to a modulation of the rate parameter for the mortality function -a change in the demographic rate of aging. Since the feeding of fruit flies is less easily controlled than that of rodents, this research also addresses the validity of applying a DR model to Drosophila populations. Feeding and body weight data for flies given the various dietary conditions surveyed indicate that Drosophila on higher-calorie diets consume a similar volume of food to those on a low-calorie diet, resulting in different levels of calorie intake. Fertility and activity levels demonstrate that the diets surveyed are comparable, and that increasing the calorie content of laboratory food up to twice the normal concentration is not pathologic for experimental fly populations.

Interactive effects of sex, social environment, dietary restriction, and methionine on survival and reproduction in fruit flies

“…In fact, males in mixed-sex groups on restricted diets without methionine had lower average lifespan compared to the 1.0 diet. In contrast, other studies have found a positive effect of DR on male lifespan (Magwere et al 2004;Bross et al 2005;Dick et al 2011). As it stands, we Further studies are necessary to confirm this finding, but our results highlight that nutritional effects can be sex-specific and that it is possible for lifespan-extending genetic or environmental manipulations to be only successful in one sex, with a negative or no effect on the other sex.…”

“…Males are rarely used in Drosophila aging studies but see (Magwere et al 2004;Bross et al 2005;Dick et al 2011) and almost never in different social environments. In our study, males on restricted diets did not have higher average lifespan compared to the 1.0 diet.…”

Dietary Restriction and Cold Temperature Both Acutely Reduce Senescence in C. elegans

“…This is in contrast to one study in flies, in which DR only changed the short-term risk/initial mortality rate with no change in age-dependent acceleration of mortality rate [4], but consistent with a different study in flies [5]. While the present manuscript was being prepared, results consistent with the present study were published [8].…”

“…For rats, it is clear that dietary restriction (DR) decreases senescence [3] (Yen et al unpublished) but not initial mortality rate, but for mice and fruit flies, the relationship is more ambiguous. One study has shown that DR in fruit flies decreases initial mortality rate and not the agedependent acceleration of mortality rate [4], but another study in flies suggests the opposite [5]. Studies in mice have also produced conflicting results about the effects of DR on initial mortality rate and age-dependent acceleration of mortality rate (Yen et al unpublished) [6,7].…”

The effect of resveratrol on lifespan depends on both gender and dietary nutrient composition in Drosophila melanogaster

“…1a-d). The base and DR diets used here are routinely employed in aging intervention and DR studies in D. melanogaster (Bross et al 2005;Bass et al 2007a;Zou et al 2007). Our findings suggest that supplementation of resveratrol at up to 200 μM is not sufficient to promote longevity of flies under standard or restricted dietary conditions.…”