RRC ID 65375
Author Zhao Y, Zhang B, Marcu I, Athar F, Wang H, Galimov ER, Chapman H, Gems D.
Title Mutation of daf-2 extends lifespan via tissue-specific effectors that suppress distinct life-limiting pathologies.
Journal Aging Cell
Abstract In aging Caenorhabditis elegans, as in higher organisms, there is more than one cause of death. C. elegans exhibit early death with a swollen, infected pharynx (P death), and later death with pharyngeal atrophy (p death). Interventions that alter lifespan can differentially affect frequency and timing of each type of death, generating complex survival curve shapes. Here, we use mortality deconvolution analysis to investigate how reduction of insulin/IGF-1 signaling (IIS), which increases lifespan (the Age phenotype), affects different forms of death. All daf-2 insulin/IGF-1 receptor mutants exhibit increased lifespan in the p subpopulation (p Age), while pleiotropic class 2 daf-2 mutants show an additional marked reduction in P death frequency. The latter is promoted by pharyngeal expression of the IIS-regulated DAF-16 FOXO transcription factor, and at higher temperature by reduced pharyngeal pumping rate. Pharyngeal DAF-16 also promotes p Age in class 2 daf-2 mutants, revealing a previously unknown role for the pharynx in the regulation of aging. Necropsy analysis of daf-2 interactions with the daf-12 steroid receptor implies that previously described opposing effects of daf-12 on daf-2 longevity are attributable to internal hatching of larvae, rather than complex interactions between insulin/IGF-1 and steroid signaling. These findings support the view that wild-type IIS acts through multiple distinct mechanisms which promote different life-limiting pathologies, each of which contribute to late-life mortality. This study further demonstrates the utility of mortality deconvolution analysis to better understand the genetics of lifespan.
Volume 20(3)
Pages e13324
Published 2021-3-1
DOI 10.1111/acel.13324
PMID 33609424
PMC PMC7963334
MeSH Alleles Animals Caenorhabditis elegans / genetics* Caenorhabditis elegans / microbiology Caenorhabditis elegans / physiology* Caenorhabditis elegans Proteins / genetics* Feeding Behavior Gain of Function Mutation Insulin / metabolism Insulin-Like Growth Factor I / metabolism Longevity / genetics* Mutation / genetics* Organ Specificity / genetics* Pharynx / pathology Receptor, Insulin / genetics* Signal Transduction Temperature
C.elegans tm5030 tm6659