title: Ageing is reversed, and metabolism is reset to young levels in recovering dauer larvae of C. elegans.
abstract: The nematode Caenorhabditis elegans responds to unfavourable environmental conditions by arresting development and entering diapause as a dauer larva. Dauers can survive several times the normal life span and the duration of the dauer state has no effect on postdauer life span. This led to the suggestion that dauers are non-ageing, and that dauers eventually perish as the consequence of depletion of stored nutrients. We have investigated physiological changes associated with long-term diapause survival, and found that dauer larvae slowly develop senescence-like symptoms, including decrease of metabolic capacity, aconitase enzyme activity, and ATP stores, and increase of lipofuscin- and oxidised flavin-specific fluorescence. However, these changes are reversed when the dauers recover. Thus senescence can occur before attainment of reproductive maturity, and furthermore, is reversible. Other life processes, including respiration rate and heat output, remain unaltered over four weeks of diapause at 24 degrees C. Possible determinants of the enhanced life maintenance include increased resistance to oxidative stress provided by enhanced superoxide dismutase and catalase activities, and a shift to a highly reducing redox status.
authors.affiliation: Department of Biology, Ghent University, K.L. Ledeganckstraat 35, B-9000 Ghent, Belgium.
authors.forename: Koen
authors.initials: K
authors.lastname: Houthoofd
authors.forename: Bart P
authors.initials: BP
authors.lastname: Braeckman
authors.forename: Isabelle
authors.initials: I
authors.lastname: Lenaerts
authors.forename: Kristel
authors.initials: K
authors.lastname: Brys
authors.forename: Annemie
authors.initials: A
authors.lastname: De Vreese
authors.forename: Sylvie
authors.initials: S
authors.lastname: Van Eygen
authors.forename: Jacques R
authors.initials: JR
authors.lastname: Vanfleteren
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000375:Aging / Q000502:physiology*; D000818:Animals; D017173:Caenorhabditis elegans / Q000502:physiology*; D007814:Larva / Q000502:physiology; D008062:Lipofuscin / Q000096:biosynthesis; D008136:Longevity; D010101:Oxygen Consumption; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D008062:Lipofuscin; D000255:Adenosine Triphosphate; D013482:Superoxide Dismutase