C. elegans ageing is accelerated by a self-destructive reproductive programme

In post-reproductive C. elegans, destructive somatic biomass repurposing supports production of yolk which, it was recently shown, is vented and can serve as a foodstuff for larval progeny. This is reminiscent of the suicidal reproductive effort (reproductive death) typical of semelparous organisms such as Pacific salmon. To explore the possibility that C. elegans exhibits reproductive death, we have compared sibling species pairs of the genera Caenorhabditis and Pristionchus with hermaphrodites and females. We report that yolk venting and constitutive, early pathology involving major anatomical changes occur only in hermaphrodites, which are also shorter lived. Moreover, only in hermaphrodites does germline removal suppress senescent pathology and markedly increase lifespan. This is consistent with the hypothesis that C. elegans exhibit reproductive death that is suppressed by germline ablation. If correct, this would imply a major difference in the ageing process between C. elegans and most higher organisms, and potentially explain the exceptional plasticity in C. elegans ageing.Caenorhabditis elegans is used as a model species to investigate ageing, yet has a very high degree of plasticity in lifespan. This study argues that ageing in C. elegans is driven by suicidal reproductive effort, unlike many other organisms.

Automated summary

The post-reproductive C. elegans exhibits destructive somatic biomass repurposing to produce yolk as food for the offspring, resembling the suicidal reproductive effort typically seen in semelparous organisms. A comparison between Caenorhabditis and Pristionchus species revealed that yolk venting and pathological changes occur only in hermaphrodites, which also have shorter lifespans. Germline removal in hermaphrodites suppresses senescent pathology and significantly increases lifespan, suggesting the presence of reproductive death in C. elegans that is suppressed by germline ablation.