节球藻毒素对斑马鱼胚胎发育的毒性效应

Toxic Effects of Nodularin on Zebrafish (Danio rerio) Embryo

研究了节球藻毒素对斑马鱼(Danio rerio)胚胎的急性毒性效应。采用水浴染毒法,将受精后2h的斑马鱼卵分别暴露于含有0、50、100、200、400、800、1600及3200μg·L-1节球藻毒素的试液中,显微观察不同浓度节球藻毒素对斑马鱼受精卵及其胚胎发育过程的影响,并通过累计孵化率、死亡率、发育畸形率的比较,评价节球藻毒素对斑马鱼胚胎的发育毒性。结果显示:随着节球藻毒素浓度的增加,斑马鱼胚胎的孵化率降低、死亡率和畸形率增加。与对照组比较,浓度≥1600μg·L-1的实验组胚胎发育明显迟缓。浓度≥400μg·L-1时,胚胎孵化率显著降低,72hpf的孵化率由对照组的87%降低到高浓度组(3200μg·L-1)的7%。浓度≥800μg·L-1时,斑马鱼的死亡率、畸形率明显升高;144hpf的死亡率由对照组的7%增加到73%;144hpf的畸形率由对照组的0%增加到93%,畸形主要表现为脊柱弯曲,心包囊肿,尾畸弯曲等。节球藻毒素暴露48hpf对斑马鱼半致死浓度LC50为2572.76μg·L-1,暴露144hpf时为1056.33μg·L-1。节球藻毒素对斑马鱼早期生命发育阶段有一定的抑制效应,高浓度亦会导致死亡。

Toxic effects of nodularin on zebrafish （Danio rerio ） embryo were studied in this paper. The fertilized eggs of zebrafish were exposed to eight different concentrations of nodularin （0, 50, 100, 200, 400, 800, 1 600 and 3 200 μg·L-1）. The influence of nodularin on zebrafish fertilized eggs and embryonic development was observed, and toxic effects were assessed by analyzing hatching, mortality and malformation rates. With the increase of nodularin concentration, the hatching rates of zebrafish embryos were reduced, while the malformation rates and mortality rates were increased. Compared with control groups, zebrafish embryonic development was retarded obviously when the concentration of nodularin was equal or greater than 1 600 μg·L-1. When the concentration of nodularin was equal or greater than 400 μg·L-1 zebrafish embryo incubation rates were significantly reduced from 87% of controls to 7% of exposure groups at 72 hpf. When the concentration of nodularin was equal or greater than 800 μg·L-1, the mortality and malformation rates were increased significantly. The mortality rates of 144 hpf embryos increased from 7% of controls to 73% of exposed groups, and the malformation rates of 144 hpf embryos increased from 0% of controls to 93% of exposure groups. The main malformation characteristics included axial malformation, pericardial edema, tail distorted bending, and etc.. 48 hpf-LC50 and 144 hpf-LC50 of nodularin on the zebrafish was 2 572.76 and 1 056.33μg·L-1 , respectively. Nodularin has certain inhibitory toxicity on the embryonic development of zebrafish and high-concentration nodularin can cause death of zebrafish.