title: Reproductive fitness and dietary choice behavior of the genetic model organism Caenorhabditis elegans under semi-natural conditions.
abstract: Laboratory breeding conditions of the model organism C. elegans do not correspond with the conditions in its natural soil habitat. To assess the consequences of the differences in environmental conditions, the effects of air composition, medium and bacterial food on reproductive fitness and/or dietary-choice behavior of C. elegans were investigated. The reproductive fitness of C. elegans was maximal under oxygen deficiency and not influenced by a high fractional share of carbon dioxide. In media approximating natural soil structure, reproductive fitness was much lower than in standard laboratory media. In seminatural media, the reproductive fitness of C. elegans was low with the standard laboratory food bacterium E. coli (γ-Proteobacteria), but significantly higher with C. arvensicola (Bacteroidetes) and B. tropica (β-Proteobacteria) as food. Dietary-choice experiments in semi-natural media revealed a low preference of C. elegans for E. coli but significantly higher preferences for C. arvensicola and B. tropica (among other bacteria). Dietary-choice experiments under quasi-natural conditions, which were feasible by fluorescence in situ hybridization (FISH) of bacteria, showed a high preference of C. elegans for Cytophaga-Flexibacter-Bacteroides, Firmicutes, and β-Proteobacteria, but a low preference for γ-Proteobacteria. The results show that data on C. elegans under standard laboratory conditions have to be carefully interpreted with respect to their biological significance.
authors.affiliation: Institute of Zoophysiology, University of Muenster, Muenster, Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Freyth
authors.forename: Tim
authors.initials: T
authors.lastname: Janowitz
authors.forename: Frank
authors.initials: F
authors.lastname: Nunes
authors.forename: Melanie
authors.initials: M
authors.lastname: Voss
authors.forename: Alexander
authors.initials: A
authors.lastname: Heinick
authors.forename: Joanne
authors.initials: J
authors.lastname: Bertaux
authors.forename: Stefan
authors.initials: S
authors.lastname: Scheu
authors.forename: Rüdiger J
authors.initials: RJ
authors.lastname: Paul
mesh_terms: D000399:Air Pressure; D000818:Animals; D001439:Bacteroides; D001522:Behavior, Animal / Q000502:physiology; D020562:Betaproteobacteria; D017173:Caenorhabditis elegans / Q000382:microbiology / Q000502:physiology*; D003589:Cytophaga; D017753:Ecosystem; D045248:Flexibacter; D005502:Food; D020563:Gammaproteobacteria; D056084:Genetic Fitness / Q000502:physiology; D017404:In Situ Hybridization, Fluorescence; D010100:Oxygen / Q000032:analysis; D012987:Soil; D012988:Soil Microbiology
chemical_list: D012987:Soil; D010100:Oxygen