镉对中国林蛙变态和性腺分化的影响  

Effects of Cadmium on Metamorphism and Gonad Differentiation in Rana chensinensis

作　　者：黄敏毅[1,2] 王宏元[1] 张育辉[1] 

机构地区：[1]陕西师范大学生命科学学院,陕西西安710062 [2]安庆师范学院生命科学学院,安徽安庆246011

出　　处：《Zoological Research》2010年第3期275-281,共7页动物学研究（英文）

基　　金：国家自然科学基金资助项目((130770243)

摘　　要：将发育到26-27期的中国林蛙(Rana chensinensis)共200例蝌蚪分别暴露在0.05、0.1、0.2和0.4mg/L Cd2+的水体中直至完全变态。解剖完全变态后的幼蛙,观察其性腺分辨性别,统计雌性比率。用免疫组织化学方法检测雌激素受体(estrogen receptors,ER)在肝细胞的表达定位。结果显示:①Cd2+诱导蝌蚪变态时出现肢体畸形,但畸形率与Cd2+处理浓度相关性较低,0.4mg/L Cd2+组肢体畸形率较高。②Cd2+影响林蛙幼体的性腺分化。与对照组相比,0.05mg/L Cd2+组的雌性比率明显增大,0.1、0.2和0.4mg/L Cd2+组的雌性比率相对降低,其中0.2mg/L Cd2+组差异显著。在0.2和0.4mg/L Cd2+组中出现个别雌雄同体。③ER在Cd2+处理组的肝细胞质和细胞核中均有阳性表达,但ER的表达量与Cd2+浓度不呈现线性相关。以上结果表明,Cd2+可以通过干扰性激素的分泌而影响蝌蚪变态和性腺发育。200 tadpoles of Rana chensinensis at stage 26-27 were exposed to 0.05, 0.1, 0.2 or 0.4 mg/L Cd2＋ in tap water respectively until they’re fully metamorphic after which the heteromorphic young frogs in different treatments were anatomized, females and males were identified through gonad observation, and the female ratio was calculated. Localization of estrogen receptors （ER） in liver cells was investigated in different treatments using immunocytochemistry. The results showed that Cd2＋ might induce limb abnormality, however, there was little correlation between abnormality rate and cadmium concentration in lower Cd2＋ levels except for a higher limb abnormality ratio in the 0.4 mg/L group. On the other hand, Cd2＋ could affect gonad differentiation. Compared to the control group, the proportion of female population increased in the 0.05 mg/L group and decreased in the 0.1, 0.2 and 0.4 mg/L ones. The sex rate in the 0.2 mg/L group is significantly different from that in the control group. Hermaphrodite gonads appeared in the two treatments with 0.2 mg/L and 0.4 mg/L of Cd2＋. Additionally, ER expression was positive in both cytoplasm and nucleolus of liver cells in Cd2＋ treated groups. But, there was no linear relationship between ER expressions levels and the concentration of Cd2＋. These results suggested that cadmium can influence tadpole metamorphosis and gonad development by affecting the secretion of sex hormone.

关 键 词：镉 中国林蛙 肢体畸形 性腺 

分 类 号：X174[环境科学与工程—环境科学] Q959.530.5[生物学—动物学]