Early life exposure to PCB126 results in delayed mortality and growth impairment in the zebrafish larvae
Early life exposure to PCB126 results in delayed mortality and growth impairment in the zebrafish larvae
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DOI：
10.1016/j.aquatox.2015.10.014
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发表时间：
2015-12-01
影响因子：
4.5
通讯作者：
Schirmer, Kristin
中科院分区：
文献类型：
--
作者：
Di Paolo, Carolina;Groh, Ksenia J.;Schirmer, Kristin
在环境风险评估中，因接触亚致死浓度的化学品而产生慢性或延迟毒性的问题日益受到关注。用斑马鱼进行的鱼胚胎毒性试验提供了对成鱼急性毒性的可靠预测，但尚不能用于预测慢性或延迟毒性的发生。鉴定亚致死FET终点有助于预测慢性或迟发性毒性的发生。本研究的特点是延迟毒性的发生在斑马鱼幼虫早期暴露于PCB 126，以前描述的原因在共同的唯一的延迟影响。第一个目的是调查延迟毒性的发生和时间分布在斑马鱼幼体发育过程中，并将其与先前描述的唯一的斑马鱼作为延迟毒性评估的模式鱼物种的适用性进行比较。第二个目的是研究在胚胎和早期幼虫发育过程中评估的亚致死终点与在后期幼虫发育过程中观察到的延迟效应之间的相关性。在暴露于PCB 126（3-3000 ng/L）至受精后5天（dpf）后，将幼虫在清洁水中饲养至14或28 dpf。每天记录死亡率和亚致死形态和行为终点，并在28 dpf时评估生长。在生命早期接触多氯联苯126会导致死亡延迟（300纳克/升和3000纳克/升），以及在清洁水时期生长受损和发育延迟（100纳克/升）。在5 dpf内对鱼鳔膨胀和软骨组织的影响最有希望预测延迟死亡和亚致死效应，如标准长度减少，延迟变态，鱼鳔膨胀减少和柱状畸形。在5 dpf时，鱼鳔膨胀的EC 50值（169 ng/L）与8 dpf时的LC 50值（两个实验中分别为188和202 ng/L）相似。有趣的是，延迟死亡的模式和延迟对生长和发育的影响在比目鱼和斑马鱼之间是相似的。这表明不同鱼类物种的关键发育阶段的可比性，如冷水海洋比目鱼和热带淡水鲤科鱼类。此外，在早期胚胎-幼虫阶段的亚致死效应被认为是预测多氯联苯126的延迟致死和亚致死效应的有效方法。因此，拟议的方法与斑马鱼预计提供宝贵的信息延迟死亡率和延迟亚致死的影响的化学品和环境样品，可以外推到其他物种。(C)2015 Elsevier B. V.版权所有。
The occurrence of chronic or delayed toxicity resulting from the exposure to sublethal chemical concentrations is an increasing concern in environmental risk assessment. The Fish Embryo Toxicity (FET) test with zebrafish provides a reliable prediction of acute toxicity in adult fish, but it cannot yet be applied to predict the occurrence of chronic or delayed toxicity. Identification of sublethal FET endpoints that can assist in predicting the occurrence of chronic or delayed toxicity would be advantageous. The present study characterized the occurrence of delayed toxicity in zebrafish larvae following early exposure to PCB126, previously described to cause delayed effects in the common sole. The first aim was to investigate the occurrence and temporal profiles of delayed toxicity during zebrafish larval development and compare them to those previously described for sole to evaluate the suitability of zebrafish as a model fish species for delayed toxicity assessment. The second aim was to examine the correlation between the sublethal endpoints assessed during embryonal and early larval development and the delayed effects observed during later larval development. After exposure to PCB126 (3-3000 ng/L) until 5 days post fertilization (dpf), larvae were reared in clean water until 14 or 28 dpf. Mortality and sublethal morphological and behavioural endpoints were recorded daily, and growth was assessed at 28 dpf. Early life exposure to PCB126 caused delayed mortality (300 ng/L and 3000 ng/L) as well as growth impairment and delayed development (100 ng/L) during the clean water period. Effects on swim bladder inflation and cartilaginous tissues within 5 dpf were the most promising for predicting delayed mortality and sublethal effects, such as decreased standard length, delayed metamorphosis, reduced inflation of swim bladder and column malformations. The EC50 value for swim bladder inflation at 5 dpf (169 ng/L) was similar to the LC50 value at 8 dpf (188 and 202 ng/L in two experiments). Interestingly, the patterns of delayed mortality and delayed effects on growth and development were similar between sole and zebrafish. This indicates the comparability of critical developmental stages across divergent fish species such as a cold water marine flatfish and a tropical freshwater cyprinid. Additionally, sublethal effects in early embryo-larval stages were found promising for predicting delayed lethal and sublethal effects of PCB126. Therefore, the proposed method with zebrafish is expected to provide valuable information on delayed mortality and delayed sublethal effects of chemicals and environmental samples that may be extrapolated to other species. (C) 2015 Elsevier B.V. All rights reserved.