Alternate metabolism during the dauer stage of the nematode Caenorhabditis elegans.
When environmental conditions are unsuitable to support nematode reproduction, Caenorhabditis elegans arrests development before the onset of sexual maturity and specialised 'dauer' larvae, adapted for dispersal, and extended diapause are formed. Dauer larvae do not feed and their metabolism is dependent on internal food reserves. Adult worms which express defects in the insulin/insulin-like growth factor receptor DAF-2 also display enhanced longevity. Whole genome mRNA expression profiling has demonstrated that C. elegans dauer larvae and daf-2 adults have similar transcription profiles for a cohort of longevity genes. Important components of this enhanced longevity system are the alpha-crystallin family of small heat shock proteins, anti-ROS defence systems, increased activity of cellular detoxification processes and possibly also increased chromatin stability and decreased protein turnover. Anaerobic fermentation pathways are upregulated in dauer larvae, while long-lived daf-2 adults appear to have normal oxidative metabolism. Anabolic pathways are down regulated in dauer larvae (and possibly in daf-2 adults as well), and energy consumption appears to be diverted to enhanced cellular maintenance and detoxification processes in both systems.
Burnell
Ann M
AM
Department of Biology, Institute of Bioengineering and Agroecology, National University of Ireland Maynooth, Maynooth, Co. Kildare, Ireland. ann.burnell@nuim.ie
Houthoofd
Koen
K
O'Hanlon
Karen
K
Vanfleteren
Jacques R
JR
D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics* / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics* / Q000378:metabolism; D045222:Electron Transport Chain Complex Proteins / Q000378:metabolism; D010065:Embryo Implantation, Delayed / Q000235:genetics; D004734:Energy Metabolism / Q000235:genetics*; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D007328:Insulin / Q000235:genetics; D007814:Larva; D008136:Longevity / Q000235:genetics*; D008928:Mitochondria / Q000378:metabolism; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D017382:Reactive Oxygen Species / Q000378:metabolism; D017526:Receptor, IGF Type 1 / Q000235:genetics; D011972:Receptor, Insulin / Q000235:genetics / Q000378:metabolism
D029742:Caenorhabditis elegans Proteins; D045222:Electron Transport Chain Complex Proteins; D007328:Insulin; D017382:Reactive Oxygen Species; C107483:DAF-2 protein, C elegans; D017526:Receptor, IGF Type 1; D011972:Receptor, Insulin