DNA damage in embryos shapes the development of an organism. Understanding life stage-specific differences between fish species is essential for ecological risk assessment measures. We explored DNA damage sensitivity in two nonmodel fish species, sterlet () and common carp (). Embryos of these species were exposed to a model genotoxicant, camptothecin (CPT), during cleavage (2-cell) stage and gastrulation. Results revealed a species-specific DNA damage sensitivity only at cleavage stage. 3 nM CPT caused lethality in sterlet embryos while carp embryos hatched normally. Multiple nuclear abnormalities were observed in sterlet embryos by early gastrula stage. However, carp embryos exhibited nuclear abnormalities and DNA fragmentation at neurula stage only when exposed to 7 nM CPT. Moreover, increased expression of in carp embryos at gastrula stage suggests activation of apoptosis mechanism. These findings suggest that carp embryos activate DNA damage response more efficiently than sterlet embryos at same developmental stage.

中文翻译：

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早期发育阶段 DNA 损伤敏感性的物种特异性差异：黑鲟 (Acipenser ruthenus) 和鲤鱼 (Cyprinus carpio) 的比较研究


胚胎中的 DNA 损伤决定了有机体的发育。了解鱼类之间特定生命阶段的差异对于生态风险评估措施至关重要。我们研究了两种非模式鱼类：小鲟鱼 () 和鲤鱼 () 的 DNA 损伤敏感性。这些物种的胚胎在卵裂（2 细胞）阶段和原肠胚形成期间暴露于模型基因毒剂喜树碱 (CPT)。结果显示，仅在裂解阶段才具有物种特异性 DNA 损伤敏感性。 3 nM CPT 导致小体鱼胚胎死亡，而鲤鱼胚胎正常孵化。在早期原肠胚阶段，在小猴胚胎中观察到多个核异常。然而，鲤鱼​​胚胎仅在暴露于 7 nM CPT 时才在神经胚阶段表现出核异常和 DNA 断裂。此外，鲤鱼胚胎在原肠胚阶段表达增加表明细胞凋亡机制的激活。这些发现表明，在同一发育阶段，鲤鱼胚胎比小体鱼胚胎更有效地激活DNA损伤反应。