探討三氟敏 (Trifloxystrobin) 對斑馬魚胚胎離子調節、循環系統和感覺行為之影響

Abstract

三氟敏是一種被廣泛使用的甲氧基丙烯酸酯類除真菌劑。在三氟敏的過度使用下，已有研究證明其在環境中的殘留及對水生生物的風險。為了全面了解三氟敏對非目標生物的毒性作用及機制，本研究選擇斑馬魚作為實驗動物，探討其對胚胎之致死性、離子調節功能、感覺系統、循環系統及基因表達的影響。實驗將受精後4小時的胚胎暴露於0、100、200和300 ppb的三氟敏溶液中，持續96或120小時。結果顯示，濃度高於200 ppb會降低胚胎存活率和孵化率。同時，離子細胞數量及胚胎體內的Na+、K+和Ca2+水平顯著減少，表明其對離子調節功能產生了負面影響。在循環系統，除了圍心腔水腫、和心率降低，還造成了心室收縮力增加、心室血液逆流和血流流速變慢等心血管損傷。此外，本研究還揭示了三氟敏的感覺系統毒性，其不僅導致側線毛細胞數量減少，眼睛、耳石和耳石囊變小，通過行為反應實驗，還證實了側線感覺、聽覺、視覺和嗅覺功能亦受到損害。綜上所述，本研究闡明了三氟敏對斑馬魚胚胎的多種毒性作用，並透過RNA定序，從基因層面對其可能機制進行探討。Trifloxystrobin is a widely used strobilurin fungicide. Due to overuse, residues in the environment and risks to aquatic organisms have been identified. In order to comprehensively understand the toxic effects and mechanisms of trifloxystrobin on non-target organisms, zebrafish were selected as experimental animals to investigate basic toxicity, ion regulation, sensory system, circulatory system, and gene expression in this study. In the experiment, embryos were initially exposed at 4 hours post-fertilization to trifloxystrobin solutions at 0, 100, 200, and 300 ppb for 96 or 120 hours. The results showed that concentrations above 200 ppb decreased survival and hatchability. It also reduced the number of ionocytes and the levels of Na+, K+, and Ca2+ in the embryos, indicating a negative effect on ion regulatory function. In the sensory system, a reduction in lateral line hair cells and in the size of eyes, otoliths and otic vesicles was observed. Subsequent behavioral tests confirmed the impairment of lateral line sensory, auditory, visual and olfactory functions by trifloxystrobin. Furthermore, in addition to pericardial edema and decreased heart rate, it also causes cardiovascular damage such as increased ventricular contractility, ventricular blood reflux, and slowed blood flow velocity. In conclusion, this study clarified the various toxic effects of trifloxystrobin on zebrafish embryos and explored its possible mechanisms at the genetic level through RNA sequencing.