title: Modulation of aging profiles in isogenic populations of Caenorhabditis elegans by bacteria causing different extrinsic mortality rates.
abstract: It has been postulated that the presence of parasites causing high extrinsic mortality may trigger an inducible acceleration of the host aging. We tested this hypothesis using isogenic populations of Caenorhabditis elegans nematodes and different Escherichia coli strains. When exposed to pathogenic bacteria, nematodes showed up to fourfold higher mortality rates, reproduced earlier, produced more H(2)O(2), and accumulated more autofluorescence, than when exposed to an innocuous strain. We also observed that mortality increased at a slower rate in old animals, a phenomenon known as mortality deceleration. Mortality deceleration started earlier in populations dying faster, likely as a consequence of lifelong heterogeneity between individual tendencies to die. Taken together, our results strongly suggest that the high extrinsic mortality imposed by the pathogens results in the modulation of nematodes' life-history traits, including aging and reproduction. This could be an adaptive response aiming at the maximization of Darwinian fitness.
authors.affiliation: INSERM U571, and Faculté de Médecine Paris Descartes, Université Paris Descartes, Paris, France.
authors.forename: Simon
authors.initials: S
authors.lastname: Baeriswyl
authors.forename: Médéric
authors.initials: M
authors.lastname: Diard
authors.forename: Thomas
authors.initials: T
authors.lastname: Mosser
authors.forename: Magali
authors.initials: M
authors.lastname: Leroy
authors.forename: Xavier
authors.initials: X
authors.lastname: Manière
authors.forename: François
authors.initials: F
authors.lastname: Taddei
authors.forename: Ivan
authors.initials: I
authors.lastname: Matic
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D017173:Caenorhabditis elegans / Q000382:microbiology* / Q000502:physiology*; D004926:Escherichia coli / Q000145:classification / Q000502:physiology*; D006790:Host-Parasite Interactions; D008136:Longevity / Q000502:physiology*; D013045:Species Specificity; D016019:Survival Analysis; D015996:Survival Rate