Reducing insulin/IGF-1 signalling during development in C. elegans accelerated growth, increased early reproduction, individual fitness, and lifespan, overturning the assumption that longevity gains carry an inevitable reproductive penalty. The benefit was conditional on temperature and came with a distinct cost: impaired environmental sensing, inappropriate dauer entry in offspring, and slowed recovery from developmental arrest. Longevity appears constrained less by a simple reproduction trade-off than by the need to interpret environmental conditions accurately during development.
Key Points
- Developmental daf-2 knockdown raised lifespan, fitness, and early reproduction simultaneously
- Lifespan and fitness gains depended on ambient temperature conditions
- Impaired environmental sensing produced inappropriate offspring dauer entry and delayed recovery
Longevity Analysis
Nutrient-sensing pathways are not simply dials to be turned down; their output is the organism's read on its environment, and suppressing them degrades the accuracy of that read. The same intervention that improved somatic maintenance and reproductive output in parents left offspring misinterpreting stress cues, a reminder that signal fidelity and signal strength are separate targets. Timing and context determined whether the manipulation helped or harmed, which argues for age-specific, condition-aware application of insulin-pathway interventions rather than sustained global suppression.
Original published by Wiley Aging Cell, by Sara D. Irish, Annabel Kimberley, Peter Lenart, Hanne Carlsson, Anna Braybrooke, Benjamin Towbin, Simone Immler, Alexei A. Maklakov .