Impacts of ionising radiation on sperm quality, DNA integrity and post-fertilisation development in marine and freshwater crustaceans
Impacts of ionising radiation on sperm quality, DNA integrity and post-fertilisation development in marine and freshwater crustaceans
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DOI：
10.1016/j.ecoenv.2019.109764
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发表时间：
2019-12-30
影响因子：
6.8
通讯作者：
Ford, Alex T.
中科院分区：
文献类型：
--
作者：
Fuller, Neil;Smith, Jim T.;Ford, Alex T.
甲壳类动物已被指定为制定环境辐射防护措施的国际重要模式生物。尽管已知精子对电离辐射的敏感性，但长期辐射暴露对甲壳类动物雄性生育能力的影响尚未被研究。本研究首次评估了慢性辐射暴露对两种片足类甲壳类雄性生育能力、精子DNA损伤以及伴随而来的繁殖的影响。用磷-32以0、0.1、1和10mGyd的剂量率对滨海棘殖吸虫和短尾伽玛吸虫(仅限雄性可育)进行暴露，观察精子参数、DNA损伤和对繁殖的影响。分别用荧光染色和单细胞凝胶电泳法检测精子质量参数和DNA损伤。通过将暴露于磷-32的雄性与未暴露于性成熟的雌性进行配对，确定了辐射对雄性生殖力的伴随影响。在海滨棘球藻中，当剂量率分别为1和10mGyd时，精子质量分别显著下降9%和11%，而对精子数量没有显著影响。相反，在淡水绿藻中，辐射对精子数量或质量没有显著影响。在辐射剂量为10mGyd的情况下，海滨龙虾的DNA损伤在统计学上显著增加，雌性海滨龙虾的繁殖力下降，而雄性海滨龙虾的异常胚胎频率增加。这些发现表明，精子质量可能是无脊椎动物辐射暴露的敏感指标，对未暴露的胚胎有潜在影响，尽管不清楚的剂量反应和两个密切相关物种之间的差异需要进一步研究，才能得出可靠的结论。
Crustaceans have been designated as internationally important model organisms in the development of environmental radioprotection measures. Despite the known sensitivity of sperm to ionizing radiation, the impacts of chronic radiation exposure on male fertility in crustaceans have not been studied. For the first time, the present study aimed to assess the impacts of chronic radiation exposure on male fertility, sperm DNA damage and concomitant impacts on breeding in two amphipod crustaceans. Echinogammarus marinas and Gammarus pulex (male fertility only) were exposed to phosphorus-32 at dose rates of 0, 0.1, 1 and 10 mGy/d and sperm parameters, DNA damage and knock-on impacts on breeding were assessed. Sperm quality parameters and DNA damage were assessed using a fluorescent staining method and single cell gel electrophoresis respectively. Concomitant effects of male exposure to radiation on fecundity were determined by pairing phosphorus-32 exposed males to unexposed sexually mature females. In E. marinas, a statistically significant reduction of 9 and 11% in the quality of sperm was recorded at dose rates of 1 and 10 mGy/d respectively, with no significant effects recorded on sperm counts. Conversely in the freshwater G. pulex, no significant impact of radiation on sperm quantity or quality was recorded. For E. marinas, a statistically significant increase in DNA damage was recorded at doses of 10 mGy/d. Reduced fecundity and an increase in the frequency of abnormal embryos was recorded in female E. marinas breeding with males exposed to radiation. These findings suggest sperm quality may be a sensitive indicator of radiation exposure in invertebrates with potential impacts on the unexposed embryo, though unclear dose-response and differences between two closely related species necessitate further study before robust conclusions can be drawn.