Department of Bio- and Environmental Sciences, University of Helsinki, P.O. Box 65, FI-00014 Helsinki, Finland.
Chemosphere. 2010 Apr;79(5):541-6. doi: 10.1016/j.chemosphere.2010.02.019. Epub 2010 Mar 1.
Endocrine disrupting chemicals (EDCs), natural or manmade, are known to interfere with the endocrinology of organisms and also cause behavioural changes. The aim of this study was to test how 1-4weeks exposure to 17alpha-ethinyl estradiol (EE2, 11ngL(-1)) affects nest building, courtship and aggressive behaviour of male fish. Our study species, the sand goby (Pomatoschistus minutus) exhibits a polygynous mating system, in which males compete for females and defend their nest against intruders. Nest takeovers are common in their nest-constrained habitat. In our experiment, control and EE2-exposed males were first allowed to build a nest and mate with non-exposed females. When the males had received eggs in their nest, three rival males were introduced into the test aquarium, and the males were left to compete for the nest site overnight. Courtship and aggressive defence behaviour were recorded using a video camera. In addition to behavioural endpoints we measured the expression of hepatic vitellogenin (Vtg) and zona radiata protein (Zrp) mRNA, and several common somatic indices. Our study showed that exposure to EE2 delays nest building and decreases male courtship and leading behaviour. Additionally, EE2-exposed males were significantly less aggressive than control males. Nest takeover rate was not affected by EE2 exposure: an equal percent of males in both treatments lost their nest to competitors. EE2 exposure also induced Vtg and Zrp mRNA expression in males and decreased the hepatosomatic index. The observed changes in nest building, courtship and aggressive behaviour of EE2-exposed males are likely to have negative implications for male reproductive success.
内分泌干扰化学物质（EDCs），无论是天然的还是人为的，都已知会干扰生物体的内分泌系统，并导致行为变化。本研究的目的是测试 17α-乙炔基雌二醇（EE2，11ng/L）暴露 1-4 周如何影响雄性鱼类的筑巢、求偶和攻击行为。我们的研究物种沙鲷（Pomatoschistus minutus）表现出多配偶制的交配系统，其中雄性为争夺雌性而竞争，并保护自己的巢穴免受入侵者的侵害。在它们受巢穴限制的栖息地中，巢接管很常见。在我们的实验中，对照和 EE2 暴露的雄性首先被允许筑巢并与未暴露的雌性交配。当雄性在巢中收到卵子时，将三只竞争雄性引入测试水族箱中，让雄性在夜间争夺巢位。使用摄像机记录求偶和攻击性防御行为。除了行为终点外，我们还测量了肝脏卵黄蛋白原（Vtg）和卵黄蛋白带蛋白（Zrp）mRNA 的表达，以及几种常见的体指数。我们的研究表明，EE2 暴露会延迟筑巢，并减少雄性求偶和主导行为。此外，EE2 暴露的雄性比对照雄性的攻击性要小得多。巢接管率不受 EE2 暴露的影响：两种处理组中都有相等比例的雄性失去了对竞争对手的巢穴。EE2 暴露还诱导了雄性的 Vtg 和 Zrp mRNA 表达，并降低了肝体指数。EE2 暴露雄性在筑巢、求偶和攻击行为方面的观察到的变化可能对雄性生殖成功产生负面影响。
