Germline Signals Deploy NHR-49 to Modulate Fatty-Acid β-Oxidation and Desaturation in Somatic Tissues of C. elegans

In c. elegans,removal of the germline extends lifespan significantly. we demonstrate that the nuclear hormone receptor,nhr-49,enables the response to this physiological change by increasing the expression of genes involved in mitochondrial β-oxidation and fatty-acid desaturation. the coordinated augmentation of these processes is critical for germline-less animals to maintain their lipid stores and to sustain de novo fat synthesis during adulthood. following germline ablation,nhr-49 is up-regulated in somatic cells by the conserved longevity determinants daf-16/foxo and tcer-1/tcerg1. accordingly,nhr-49 overexpression in fertile animals extends their lifespan modestly. in fertile adults,nhr-49 expression is daf-16/foxo and tcer-1/tcerg1 independent although its depletion causes age-related lipid abnormalities. our data provide molecular insights into how reproductive stimuli are integrated into global metabolic changes to alter the lifespan of the animal. they suggest that nhr-49 may facilitate the adaptation to loss of reproductive potential through synchronized enhancement of fatty-acid oxidation and desaturation,thus breaking down some fats ordained for reproduction and orchestrating a lipid profile conducive for somatic maintenance and longevity. © 2014 ratnappan et al.