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环境浓度的丁草胺暴露对雌性褐菖鲉卵巢发育的干扰

Interference of butachlor exposure at environmental concentration on ovarian development of female Sebastiscus marmoratus

  • 摘要: 丁草胺是使用最广泛的酰胺类除草剂之一,目前丁草胺对鱼类的生殖毒性研究集中于淡水种类,近海鱼类鲜有报道。本研究以分布于我国东南海域的近海经济鱼类褐菖鲉(Sebastiscus marmoratus)为受试对象,探讨丁草胺对海洋鱼类卵巢发育的影响及机制。褐菖鲉在以环境相关浓度(2、20、200 ng/L)的丁草胺暴露50 d后,褐菖鮋卵巢生殖细胞发育受到不同程度抑制,卵巢17β-雌二醇(E2)水平下降,Caspase-3活性上升。相对定量PCR分析结果显示,卵巢芳香化酶基因(CYP19s)及雌激素受体基因(ERβ)表达量下降。结果表明:丁草胺对褐菖鮋具有明显的生殖毒性,卵巢CYP19s基因与ERβ基因表达被抑制而导致卵巢雌激素水平的下降引起卵细胞在发育早期的细胞凋亡是主要原因。

     

    Abstract: Butachlor is one of the most widely used amide herbicides. Although the researches on the reproductive toxicity of butachlor to freshwaterfish have been reported extensively, few studies addressing the reproductive toxicity of butachlor on the offshore fishes are available. The present study was conducted to explore the effects of butachlor on ovarian development inSebastiscus marmoratus, a common offshore fish distributes in the southeast coast of China, and to gain insight into its mechanism. After exposing to butachlor at environmental concentrations (2, 20 and 200 ng/L) for 50 d, the development of ovarian germ cell was depressed to different extents. While 17β estradiol (E2) was decreased in the ovaries, the activity of Caspase-3 increased. Realtime PCR showed that the expressions of CYP19s and ERβ were down-regulatedin the ovaries. These results indicated that butachlor can cause significant reproductive toxicity to Sebastiscus marmoratus, and the inhibited expression of CYP19s gene and ERβ in the ovary leads to the decrease of estrogen level and apoptosis of egg cells in early development.