氨氮对稀有鮈鲫胚胎及卵黄囊期仔鱼的毒性效应研究

Study on Toxic Effects of Ammonia on Embryonic and Yolk-sac Stage Larvae of Rare minnow

为探究氨氮溶液暴露对鱼类早期发育阶段产生的毒性,本研究选取中国特有种稀有鮈鲫为试验材料,观察并记录了胚胎至卵黄囊期仔鱼发育过程中一些具代表性的毒理学终点,同时选取了氨转运体蛋白Rhbg基因作为毒性指标,反映暴露在氨氮溶液中的稀有鮈鲫胚胎的Rhbg基因表达变化情况.结果表明,本研究所选取的氨氮溶液暴露影响了胚胎及仔鱼的孵化率、死亡率、心率减缓和心律不齐、未形成功能性的鳔、体长体重的降低以及心包、卵黄囊水肿的发生等多种毒性效应,对其它毒理学终点有较为微弱的影响.氨氮溶液的暴露影响了氨转运体蛋白Rhbg基因的表达变化,特别是在72 h时显著性影响了Rhbg基因的表达变化,Rhbg基因在稀有鮈鲫胚胎时期氨氮转运方面可能有着重要的功能.

To investigate the toxicity to fish which were exposed to ammonia during early life stages.This study choose rare minnow which is unique to China for experimental subject.Representative toxicological endpoints were observed and recorded during the development of embryo and yolk-sac stage larvae.Meanwhile,selected ammonia transporter protein Rhbg gene as a toxicity parameter to reflect the changes of rare minnow embryos Rhbg gene expression.The result shows that ammonia we have chosen in this research had an influence on many toxic effects including the hatching rate of fry,mortality rate,the slowing of heart rate and arrhythmia,unformed functional swim bladder,the decreasing of body length and weight and the occurrence of pericardium and yolk-sac edema etc.But other toxicological endpoints have relatively weak effect.The ammonia also affect the Rhbg gene expression changes,especially that of Rhbg gene at 72 hours post-fertilization distinctly.Rhbg may have important functions to facilitate ammonia transport during rare minnow embryo stages.