Patterns of intraspecific variability in the response to caloric restriction

Abstract

Caloric restriction (CR) is cited as the most robust means of increasing lifespan across a range of taxa, yet there is a high degree of variability in the response to CR, both within and between species. To examine the intraspecific evolutionary conservation of lifespan extension by CR, we tested the effects of chronic caloric restriction (CCR) at multiple food levels and of intermittent fasting (IF) in twelve isolates from the Brachionus plicatilis species complex of monogonont rotifers. While CCR generally increased or did not change lifespan and total fecundity, IF caused increased, unchanged, or decreased lifespan, depending upon the isolate, and decreased total fecundity in all but one isolate. Lifespan under ad libitum (AL) feeding varied among isolates and predicted the lifespan response to CR: longer-lived isolates under AL were less likely to have a significant increase in lifespan under CCR and were more likely to have a significantly shortened lifespan under IF. Lifespan under AL conditions and the response to CR were not correlated with hydroperiodicity of native habitat or with time in culture. Lack of trade-off between lifespan and fecundity under CCR, and differences in lifespan and fecundity under CCR and IF, even when average food intake was similar, suggest that longevity changes are not always directly determined by energy intake and that CCR and IF regimens extend lifespan through diverse genetic mechanisms.

Shifts in rotifer life history in response to stable isotope enrichment: testing theories of isotope effects on organismal growth

“…The animals receiving diets containing 0.4–5 at% 15 N had lifespan extended up to 40% with concomitant changes in the timing of reproduction and decreased lifetime fecundity by 30–40%. The decline in the reproductive output in combination with increased longevity is typically observed in rotifers on low-calorie diets [29] and under exposure to some chemical compounds [30]. However, in this case, both food intake (electronic supplementary material, figure S1) and elemental composition of the algae (at least, %C and %N) were virtually invariable among the treatments.…”

Maternal caloric restriction partially rescues the deleterious effects of advanced maternal age on offspring

“…Female offspring of the closely related rotifer B. plicatilis have increased life span when their mothers are subjected to intermittent fasting (IF) , but differences between sexes are often found in the response to interventions to aging in other species. We subjected mothers to both chronic caloric restriction (CCR) and to IF, as different CR regimens likely work through different mechanisms and may have different outcomes in the same isolate (Anson et al, 2003(Anson et al, , 2005Greer & Brunet, 2009;Cleary & Grossmann, 2011;Gribble & Mark Welch, 2013;Gribble et al 2014).…”

When males outlive females: Sex‐specific effects of temperature on lifespan in a cyclic parthenogen

“…While the intraspecific differences in the response of longevity to temperature manipulations have rarely been studied, other manipulations which possibly share with temperature mechanisms of action have been shown to induce strain‐specific effects. Different genetic isolates of a Brachionus rotifer (Gribble, Kaido, Jarvis, & Mark Welch, ) and D . magna (Pietrzak, Grzesiuk, & Bednarska, ) respond differently to intermittent fasting or caloric restriction, respectively.…”