Poly- and perfluoroalkyl substances (PFAS) are frequently detected in the environment and are linked to adverse reproductive health outcomes in humans. Although legacy PFAS have been phased out due to their toxicity, alternative PFAS are increasingly used despite the fact that information on their toxic effects on reproductive traits is particularly scarce. Here, we exposed male guppies () for a short period (21 days) to an environmentally realistic concentration (1 ppb) of PFOA, a legacy PFAS, and its replacement compound, GenX, to assess their impact on reproductive traits and gene expression. Exposure to PFAS did not impair survival but instead caused sublethal effects. Overall, PFAS exposure caused changes in male sexual behaviour and had detrimental effects on sperm motility. Sublethal variations were also seen at the transcriptional level, with the modulation of genes involved in immune regulation, spermatogenesis, and oxidative stress. We also observed bioaccumulation of PFAS, which was higher for PFOA than for GenX. Our results offer a comprehensive comparison of these two PFAS and shed light on the toxicity of a newly emerging alternative to legacy PFAS. It is therefore evident that even at low concentrations and with short exposure, PFAS can have subtle yet significant effects on behaviour, fertility, and immunity. These findings underscore the potential ramifications of pollution under natural conditions and their impact on fish populations.

中文翻译：

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雄性孔雀鱼 (Poecilia reticulata) 亚急性暴露于环境相关浓度的 PFOA 和 GenX 会导致睾丸转录组和生殖性状发生显着变化


多氟烷基物质和全氟烷基物质 (PFAS) 经常在环境中检测到，并与人类生殖健康不良结果相关。尽管传统的 PFAS 因其毒性而已被逐步淘汰，但替代 PFAS 的使用却越来越多，尽管有关其对生殖性状的毒性影响的信息特别稀少。在这里，我们将雄性孔雀鱼短时间（21 天）暴露于符合环境实际浓度 (1 ppb) 的 PFOA（一种传统 PFAS）及其替代化合物 GenX 中，以评估它们对生殖性状和基因表达的影响。接触 PFAS 不会损害生存，反而会造成亚致死效应。总体而言，PFAS 暴露会导致男性性行为发生变化，并对精子活力产生不利影响。在转录水平上也发现了亚致死变异，涉及免疫调节、精子发生和氧化应激的基因调节。我们还观察到 PFAS 的生物累积性，其中 PFOA 的生物累积性高于 GenX。我们的结果对这两种 PFAS 进行了全面比较，并揭示了传统 PFAS 的新兴替代品的毒性。因此，很明显，即使在低浓度和短时间接触下，PFAS 也会对行为、生育力和免疫力产生微妙但显着的影响。这些发现强调了自然条件下污染的潜在后果及其对鱼类种群的影响。