Abidi Sondes, Abbaci Khedidja Tair, Geffard Olivier, Boumaiza Moncef, Dumet Adeline, Garric Jeanne, Mondy Nathalie
Milieux aquatiques, Ecologie et pollutions. Equipe Ecotox, irstea, Lyon, Villeurbanne, France.
Unité d'hydrobiologie Littorale et Limnique, Laboratoire de Bio-surveillance de l'environnement, Faculté des Sciences de Bizerte, 7021, Jarzouna, Tunisia.
Ecotoxicology. 2016 Jul;25(5):880-7. doi: 10.1007/s10646-016-1645-7. Epub 2016 Mar 15.
Gammarus fossarum is an important test organism which is currently used as a bio-indicator as well as in ecotoxicological tests. Nevertheless, data on ecdysteroids in endocrine toxicity test are not yet available for these species, despite its crucial role in molting and reproduction. In the present paper, ecdysteroids concentrations were studied during the molt cycle (in females) and embryonic development in G. fossarum (Crustacea, Amphipoda) in order to propose an ecdysteroids toxicity test. Ecdysteroids levels in G. fossarum showed a single peak during premolt at stage Dl-D2. In embryos, ecdysteroids levels progressively increased over stages 3 and 4, with peak levels at stage 4. A Cadmium toxicity test was proposed to examine if the molting and embryogenesis disturbances previously observed after cadmium exposure (Geffard et al. 2010) could be attributed to changes in ecdysteroids titers. Exposure to the different cadmium concentrations (3; 9; 300; 900 µg/l) increased ecdysteroids secretion by Y-organs in vitro, but it had no significant effect on exposed embryos (in vivo). Based on previous findings, we are led to conclude that the molting impairments in cadmium-exposed females of G. fossarum is connected to the changes in ecdysteroids concentrations.
河蚬是一种重要的试验生物，目前用作生物指示物以及用于生态毒理学试验。然而，尽管蜕皮类固醇在蜕皮和繁殖中起着关键作用，但关于这些物种在内分泌毒性试验中的蜕皮类固醇数据仍未可得。在本文中，研究了河蚬（甲壳纲，端足目）雌性蜕皮周期和胚胎发育过程中的蜕皮类固醇浓度，以便提出一种蜕皮类固醇毒性试验。河蚬中的蜕皮类固醇水平在D1-D2阶段的蜕皮前出现单峰。在胚胎中，蜕皮类固醇水平在第3和第4阶段逐渐升高，在第4阶段达到峰值。提出了一项镉毒性试验，以检验先前在镉暴露后观察到的蜕皮和胚胎发生紊乱（Geffard等人，2010年）是否可归因于蜕皮类固醇滴度的变化。暴露于不同镉浓度（3；9；300；900微克/升）会增加体外Y器官的蜕皮类固醇分泌，但对暴露的胚胎（体内）没有显著影响。基于先前的研究结果，我们得出结论，镉暴露的河蚬雌性的蜕皮损伤与蜕皮类固醇浓度的变化有关。
