BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Nishihara, Okinawa, Japan.
J Hered. 2018 Feb 14;109(2):188-198. doi: 10.1093/jhered/esx012.
The pale grass blue butterfly, Zizeeria maha, has been used to evaluate biological impacts of the Fukushima nuclear accident in March 2011. Here, we examined the possibility that butterflies have adapted to be robust in the contaminated environment. Larvae (n = 2432) were obtained from adult butterflies (n = 20) collected from 7 localities with various contamination levels in May 2012, corresponding to the 7th generation after the accident. When the larvae were reared on non-contaminated host plant leaves from Okinawa, the normality rates of natural exposure without artificial irradiation (as an indication of robustness) were high not only in the least contaminated locality but also in the most contaminated localities. The normality rates were similarly obtained when the larvae were reared on non-contaminated leaves with external irradiation or on contaminated leaves from Fukushima to deliver internal irradiation. The normality rate of natural exposure and that of external or internal exposure were correlated, suggesting that radiation resistance (or susceptibility) likely reflects general state of health. The normality rate of external or internal exposure was divided by the relative normality rate of natural exposure, being defined as the resistance value. The resistance value was the highest in the populations of heavily contaminated localities and was inversely correlated with the distance from the Fukushima Dai-ichi nuclear power plant. These results suggest that the butterfly population might have adapted to the contaminated environment within approximately 1 year after the accident. The present study may partly explain the decrease in mortality and abnormality rates later observed in the contaminated areas.
苍白草蛱蝶（Zizeeria maha）被用于评估 2011 年 3 月福岛核事故对生物的影响。在这里，我们研究了蝴蝶是否已经适应了受污染环境的可能性。2012 年 5 月，从 7 个具有不同污染水平的当地收集了 20 只成年蝴蝶（n = 20），获得了幼虫（n = 2432）。当幼虫在非污染的冲绳地区的寄主植物叶片上饲养时，在没有人工辐射的自然暴露下的正常率（作为健壮性的指示）不仅在污染最少的地方高，而且在污染最严重的地方也很高。当幼虫在非污染的叶片上进行外部照射或在福岛的污染叶片上进行内部照射进行饲养时，也获得了类似的正常率。自然暴露的正常率与外部或内部暴露的正常率相关，表明辐射抗性（或敏感性）可能反映了一般健康状况。外部或内部暴露的正常率除以自然暴露的相对正常率，定义为抗性值。在污染最严重的地区的种群中，抗性值最高，与福岛第一核电站的距离呈反比。这些结果表明，在事故发生后大约 1 年内，蝴蝶种群可能已经适应了受污染的环境。本研究部分解释了后来在污染地区观察到的死亡率和异常率的下降。
