Consequences of a multi-generation exposure to uranium on Caenorhabditis elegans life parameters and sensitivity

• Published in: Ecotoxicology (London) 2013-07, Vol.22 (5), p.869-878
• Main Authors: Goussen, Benoit, Parisot, Florian, Beaudouin, Rémy, Dutilleul, Morgan, Buisset-Goussen, Adeline, Péry, Alexandre R. R., Bonzom, Jean-Marc
• Format: Article
• Language: English
• Subjects: Adaptation, Physiological - drug effects; Adaptation, Physiological - genetics; Animals; Assessments; Biodiversity; Biological effects; Body Size - drug effects; Caenorhabditis elegans; Caenorhabditis elegans - drug effects; Caenorhabditis elegans - embryology; Caenorhabditis elegans - genetics; Computer Science; Differentiation; Dose-Response Relationship, Drug; Earth and Environmental Science; Ecology; Ecosystem protection; Ecosystems; Ecotoxicology; Environment; Environmental assessment; Environmental Management; Environmental Pollutants - toxicity; Environmental risk; Environmental Sciences; Evolutionary; Fecundity; Fertility; Fertility - drug effects; Gene-Environment Interaction; Life Cycle Stages - drug effects; Life Sciences; Longevity - drug effects; Modeling and Simulation; Nematoda; Population differentiation; Populations; Populations and Evolution; Protection and preservation; Reproduction; Reproduction - drug effects; Reproduction - genetics; Risk Assessment; Stress (Psychology); Toxicity; Toxicology; Uranium; Uranium Compounds - toxicity
• ISSN: 0963-9292; 1573-3017
• DOI: 10.1007/s10646-013-1078-5

The assessment of toxic effects at biologically and ecologically relevant scales is an important challenge in ecosystem protection. Indeed, stressors may impact populations at much longer term than the usual timescale of toxicity tests. It is therefore important to study the evolutionary response of a population under chronic stress. We performed a 16-generation study to assess the evolution of two populations of the ubiquitous nematode Caenorhabditis elegans in control conditions or exposed to 1.1 mM of uranium. Several generations were selected to assess growth, reproduction, survival, and dose–responses relationships, through exposure to a range of concentrations (from 0 to 1.2 mM U) with all endpoints measured daily. Our experiment showed an adaptation of individuals to experimental conditions (increase of maximal length and decrease of fecundity) for both populations. We also observed an increase of adverse effects (reduction of growth and fertility) as a function of uranium concentration. We pointed out the emergence of population differentiation for reproduction traits. In contrast, no differentiation was observed on growth traits. Our results confirm the importance of assessing environmental risk related to pollutant through multi-generational studies.