The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa 903-0213, Japan.
BMC Evol Biol. 2013 Aug 12;13:168. doi: 10.1186/1471-2148-13-168.
On August 9th 2012, we published an original research article in Scientific Reports, concluding that artificial radionuclides released from the Fukushima Dai-ichi Nuclear Power Plant exerted genetically and physiologically adverse effects on the pale grass blue butterfly Zizeeria maha in the Fukushima area. Immediately following publication, many questions and comments were generated from all over the world. Here, we have clarified points made in the original paper and answered questions posed by the readers.
The following points were clarified. (1) There are many advantages to using the pale grass blue butterfly as an indicator species. (2) The forewings of the individuals collected in Fukushima were significantly smaller than in the northern and southern localities. (3) We observed growth retardation in the butterflies from the Fukushima area. (4) The aberrant colour patterns in the butterflies obtained in the Fukushima area were different from the colour patterns induced by temperature and sibling crosses but similar to those induced by external and internal exposures to the artificial radionuclides and by a chemical mutagen, suggesting that genetic mutations caused the aberrations. (5) This species of butterfly has been plentiful in Fukushima area for at least half a century. We here present specimens collected from Fukushima Prefecture before the accident. (6) Mutation accumulation was detected by the increase in the abnormality rates from May 2011 to September 2011. (7) The abnormal traits were heritable. (8) Our sampling localities were not affected by the tsunami. (9) We used a high enough number of samples to obtain statistically significant results. (10) The standard rearing method was followed, producing normal adults in the control groups. (11) The exposure experiments successfully reproduced the results of the field work. This species of butterfly is vulnerable to long-term low-dose internal and external exposures; however, insect cells are known to be resistant to short-term high-dose irradiation. This discrepancy is reconcilable based on the differences in the experimental conditions.
We are just beginning to understand the biological effects of long-term low-dose exposures in animals. Further research is necessary to accurately assess the possible biological effects of the accident.
2012 年 8 月 9 日，我们在《Scientific Reports》上发表了一篇原始研究论文，得出福岛第一核电站释放的人工放射性核素对福岛地区的 pale grass blue butterfly Zizeeria maha 产生了遗传和生理上的不利影响。文章发表后，立即引起了来自世界各地的许多质疑和评论。在这里，我们澄清了原始论文中的要点，并回答了读者提出的问题。
以下几点得到了澄清。(1) 使用 pale grass blue butterfly 作为指示物种有很多优点。(2) 在福岛采集的个体前翅明显小于北部和南部的个体。(3) 我们观察到来自福岛地区的蝴蝶生长迟缓。(4) 在福岛获得的蝴蝶出现的异常颜色模式与由温度和同胞杂交引起的颜色模式不同，但与由人工放射性核素和化学诱变剂的外部和内部暴露以及由化学诱变剂引起的颜色模式相似，表明遗传突变导致了这些异常。(5) 这种蝴蝶在福岛地区已经存在了至少半个世纪。我们在此展示了事故发生前从福岛县采集的标本。(6) 从 2011 年 5 月到 2011 年 9 月，异常率的增加检测到了突变积累。(7) 异常特征是可遗传的。(8) 我们的采样地点没有受到海啸的影响。(9) 我们使用了足够多的样本来获得具有统计学意义的结果。(10) 遵循了标准的饲养方法，对照组产生了正常的成虫。(11) 暴露实验成功复制了野外工作的结果。这种蝴蝶对长期低剂量的内外暴露很敏感，但已知昆虫细胞对短期高剂量辐射有抵抗力。这种差异可以根据实验条件的不同而得到协调。
我们才刚刚开始了解动物长期低剂量暴露的生物学效应。为了准确评估事故可能产生的生物学影响，还需要进一步的研究。
