Wu S M, Lin H C, Yang W L
Department of Aquatic Biosciences, National Chiayi University, Chiayi 600, Taiwan.
Aquat Toxicol. 2008 May 30;87(4):296-302. doi: 10.1016/j.aquatox.2008.02.012. Epub 2008 Feb 26.
The purpose of this study was to identify the factor(s) which would enhance the Cd resistance as assessed by the metallothionein (MT) expression in tilapia larvae. Larvae were collected from parents that were pretreated respectively with Cd or saline. At the end of the 12-week experiment, the hepatic MT and Cd contents in the breeding female fish were recorded. Our results indicated that a significant relationship between Cd and MT contents can be found in the offspring from the parent fish treated with Cd. However, the higher Cd resistance, Cd contents, and MT expression were limited to those larvae from parent fish bred within 4 weeks of the injection. By week 12, the Cd-treated fish still contained high levels of MT in their hepatic tissues. However, the MT and Cd contents in the larvae from these adult fish were not significantly different from those from the controls. In summary, we suggest that the higher Cd resistance of larvae from the egg stage was a result of the Cd contamination of the parent female, as evidenced by an increase in MT expression induced in tilapia embryos and larvae.
本研究的目的是确定通过罗非鱼幼鱼中金属硫蛋白（MT）表达评估的增强镉抗性的因素。幼鱼取自分别用镉或盐水预处理的亲鱼。在为期12周的实验结束时，记录了繁殖雌鱼肝脏中的MT和镉含量。我们的结果表明，在用镉处理的亲鱼后代中，镉与MT含量之间存在显著关系。然而，更高的镉抗性、镉含量和MT表达仅限于注射后4周内繁殖的亲鱼的幼鱼。到第12周时，经镉处理的鱼肝脏组织中仍含有高水平的MT。然而，这些成年鱼幼鱼中的MT和镉含量与对照组的幼鱼没有显著差异。总之，我们认为卵期幼鱼较高的镉抗性是亲代雌鱼镉污染的结果，罗非鱼胚胎和幼鱼中MT表达的增加证明了这一点。
