GSE173927
Suceptibility of non target crustacean Eurytemora affinis  to endocrine disruptor tebufenozide: a transcriptomic approach
Copepods are zooplanktonic crustaceans ubiquitously widespread in aquatic systems. They are of ecological importance due to their place in the trophic chain. Copepods are exposed to a wide variety of pollutants as insect growth regulators (IGR) acting as endocrine disruptors although they are not the target. The aim of the present work was to investigate the molecular response of a non-targeted organism, the copepod Eurytemora affinis, to an IGR. Adult males and females were exposed at two sub-lethal concentrations of tebufenozide (TEB), an agonist of the ecdysone receptor targeting lepidopteran larvae. Results suggest a gender-specific response with a higher sensitivity in males potentially due to a differential activation of stress response pathways. Indeed, genes coding for proteins involved in stress response were mis-regulated in males while not in females suggesting that detoxification processes are still ongoing in males. In both genders, TEB exposure triggers similar pathways as for its targeted species by modulating the transcription of early and late ecdysone responsive genes. Among them, genes involved in cuticle metabolism, muscle contraction, neurotransmission and gametogenesis whose mis-regulation could lead to moult, locomotor and reproductive impairments. Furthermore, genes coding for proteins playing part in epigenetic processes were found in both genders highlighting the potential impact of TEB exposure on further generations. Beyond the in-depth knowledge of the molecular MoA of an ecdysone agonist on a non-targeted organism, this work provides data allowing the identification of (i) potential biomarkers of ecdysone agonists and (ii) putative physiological responses to be further assessed to characterize the effects of TEB at higher biological levels. The present study reinforces the suitability of the use E. affinis as an ecotoxicological model. Overall design: RNAseq analysis of adult males and females copepods Eurytemora affinis exposed to 0,5 µg/L and 50 µg/L of tebufenozide or non-exposed controls. All treatments were made in triplicates.