三丁基氧化锡(TBTO)对太平洋牡蛎性成熟的影响

Effect of Tributyltin Oxide on Sexual Maturation of the Pacific Oyster, Crassostrea gigas

利用流水饲养法研究了不同浓度的三丁基氧化锡 (0 .5 μg/ L和 1.0 μg/ L TBTO)对太平洋牡蛎卵巢中卵母细胞直径、RNA/ DNA比、蛋白质和卵黄蛋白含量的影响。卵母细胞径的增长在0 .5 μg/ L实验组受到阻碍 ,并随着 TBTO浓度的增大而更加明显。TBTO暴露组的 RNA/ DNA比在精巢中无明显变化 ,但在卵巢中显著低于对照组。 TBTO暴露组的卵巢中蛋白质和卵黄蛋白含量显示了与 RNA/ DNA比相同的变化趋势 ,表明 TBTO的积累阻碍卵黄蛋白的合成。TBTO暴露4 2 d采集的牡蛎样品中出现 3个雌雄同体 ,暗示

Chronic physiological responses (oocyte diameters, R NA/DNA ratio, protein and vitellin content) in the gonad of the Pacific oyster r eared in running seawater were measured following exposure to two different conc entrations of tributyltin oxide (TBTO; 0.5 and 1.0μgL -1 ). The oocyte diam eters in the two TBTO groups were significantly lower than that in the control g roup on 42 days, and the inhibition of oocyte growth depended on the concentrati on of TBTO exposure. In the test the RNA/DNA ratio changed little between the th ree groups, while in the ovary the RNA/DNA ratio in the TBTO groups obviously de creased compared with that in the control group. The protein and vitellin conten t of the ovary in the TBTO groups showed similar changes in the RNA/DNA ratio of the ovary, indicating that the accumulation of TBTO in the ovary inhibited the synthetic activity of vitellin. In the oyster sampled on 42 days, three hermaphr odites occurred in the TBTO groups, suggesting that TBTO may cause sex change of the oyster, and so resulted in the occurrence of hermaphrodites.