Since the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, we have established an archive system of livestock and wild animals from the surrounding ex‐evacuation zone. Wildlife within the alert zone have been exposed to low‐dose‐rate (LDR) radiation for a long continuous time. In this study, we analysed the morphological characteristics of the testes and in vitro fertilization (IVF) capacity of cryopreserved sperm of racoons from the ex‐evacuation zone of the FDNPP accident. The radioactivity of caesium‐137 (¹³⁷Cs) was measured by gamma‐ray spectrometry, and the measured radioactivity concentration was 300–6,630 Bq/kg in the Fukushima raccoons. Notably, normal spermatogenesis was observed in the seminiferous tubules of the testes, with the germinal epithelium composed of a spermatogenic cell lineage with no evident ultrastructural alterations; freeze‐thawing sperm penetration ability was confirmed using the interspecific zona pellucida‐free mouse oocytes IVF assays. This study revealed that the chronic and LDR radiation exposure associated with the FDNPP accident had no adverse effect on the reproductive characteristics and functions of male raccoons.

中文翻译：

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福岛事故后浣熊睾丸的形态生殖特征和冷冻精子的受精能力（Procyon Lotor）


自福岛第一核电站（FDNPP）事故以来，我们建立了周边疏散区牲畜和野生动物的档案系统。警戒区内的野生动物长期连续暴露于低剂量率（LDR）辐射。在本研究中，我们分析了 FDNPP 事故疏散区浣熊的睾丸形态特征和冷冻精子的体外受精 (IVF) 能力。通过伽马射线光谱法测量铯-137（ ¹³⁷ Cs）的放射性，测得福岛浣熊体内的放射性浓度为300-6,630 Bq/kg。值得注意的是，在睾丸的曲细精管中观察到正常的精子发生，生发上皮由生精细胞谱系组成，没有明显的超微结构改变；使用种间无透明带小鼠卵母细胞 IVF 测定证实了冻融精子的穿透能力。这项研究表明，与 FDNPP 事故相关的慢性和 LDR 辐射暴露对雄性浣熊的生殖特征和功能没有不利影响。