Etude de l'impact des contaminants métalliques et organiques chez l'anguille européenne (Anguilla anguilla) et américaine (Anguilla rostrata) au moyen d'approches transcriptomiques

摘要

In the natural environment, assessing the impact of contaminants on aquatic organisms remains difficult due to many factors (temperature, oxygenation, predation, parasitism, ...) acting on organisms. The purpose of this thesis was then to test the ability to detect and prioritize the effects of various natural and anthropogenic factors on individuals sampled in the natural environment. The models used were the European (Anguilla anguilla) and American (Anguilla rostrata) eels. To understand the effects of pollutants in situ, weat tempted to identify genes for which the transcription level was correlated to a specific pollutant or a natural factor measured in the field with two transcriptomic tools: high through put sequencing and DNA microarray. Transcriptomic profiles obtained from livers of eels taken directly from the field were compared in a second phase to those obtained from individuals exposed in the laboratory to various natural and anthropogenic factors separately. Comparison of these profiles showed a significant difference in responses of individuals exposed in the laboratory and those collected in the field, showing a significant effect induced by captivity mesocosm stress. Conducting a similar study using the tail fin as a non-invasive method was relevant for the ability of this tissue to discriminate different experimental and field conditions. Finally, the use of the microarray on the gonads of artificially matured European eels indicated that the pollution could affect the reproductive capabilities of futures pawners and contribute to massive decline of this species observed in last decades.