title: Circadian stress tolerance in adult Caenorhabditis elegans.
abstract: Circadian rhythms control several behaviors through neural networks, hormones and gene expression. One of these outputs in invertebrates, vertebrates and plants is the stress resistance behavior. In this work, we studied the circadian variation in abiotic stress resistance of adult C. elegans as well as the genetic mechanisms that underlie such behavior. Measuring the stress resistance by tap response behavior we found a rhythm in response to osmotic (NaCl LC50 = 340 mM) and oxidative (H2O2 LC50 = 50 mM) shocks, with a minimum at ZT0 (i.e., lights off) and ZT12 (lights on), respectively. In addition, the expression of glutathione peroxidase (C11E4.1) and glycerol-3-phosphate dehydrogenase (gpdh-1) (genes related to the control of stress responses) also showed a circadian fluctuation in basal levels with a peak at night. Moreover, in the mutant osr-1 (AM1 strain), a negative regulator of the gpdh-1 pathway, the osmotic resistance rhythms were masked at 350 mM but reappeared when the strain was treated with a higher NaCl concentration. This work demonstrates for the first time that in the adult nematode, C. elegans stress responses vary daily, and provides evidence of an underlying rhythmic gene expression that governs these behaviors.
authors.affiliation: Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Roque S. Peña 352, (1876), Bernal, Pcia de Buenos Aires, Argentina.
authors.forename: Sergio H
authors.initials: SH
authors.lastname: Simonetta
authors.forename: Andrés
authors.initials: A
authors.lastname: Romanowski
authors.forename: Alicia N
authors.initials: AN
authors.lastname: Minniti
authors.forename: Nibaldo C
authors.initials: NC
authors.lastname: Inestrosa
authors.forename: Diego A
authors.initials: DA
authors.lastname: Golombek
mesh_terms: D000367:Age Factors; D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics* / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism; D002940:Circadian Rhythm / Q000235:genetics*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000235:genetics*; D005979:Glutathione Peroxidase / Q000235:genetics / Q000378:metabolism; D005993:Glycerolphosphate Dehydrogenase / Q000235:genetics / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D009997:Osmotic Pressure; D018384:Oxidative Stress / Q000187:drug effects / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis / Q000187:drug effects / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology; D013312:Stress, Physiological / Q000235:genetics* / Q000378:metabolism*
chemical_list: D029742:Caenorhabditis elegans Proteins; C495117:OSR-1 protein, C elegans; D012333:RNA, Messenger; D012965:Sodium Chloride; D005993:Glycerolphosphate Dehydrogenase; D005979:Glutathione Peroxidase