Understanding species differences in sensitivity to toxicants is a critical issue in ecotoxicology. We recently established that double-crested cormorant (DCCO) embryos are more sensitive than Japanese quail (JQ) to the developmental effects of ethinylestradiol (EE2). We explored how this difference in sensitivity between species is reflected at a transcriptomic level. The EE2 was dissolved in dimethyl sulfoxide and injected into the air cell of eggs prior to incubation at nominal concentrations of 0, 3.33, and 33.3 µg/g egg weight. At midincubation (JQ 9 days; DCCO 16 days), livers were collected from five embryos/treatment group for RNA sequencing. Data were processed and analyzed using EcoOmicsAnalyst and ExpressAnalyst. The EE2 exposure dysregulated 238 and 1,987 genes in JQ and DCCO, respectively, with 78 genes in common between the two species. These included classic biomarkers of estrogen exposure such as vitellogenin and apovitellenin. We also report DCCO-specific dysregulation of Phase I/II enzyme-coding genes and species-specific transcriptional ontogeny of vitellogenin-2. Twelve Kyoto Encyclopedia of Genes and Genomes pathways and two EcoToxModules were dysregulated in common in both species including the peroxisome proliferator-activated receptor (PPAR) signaling pathway and fatty acid metabolism. Similar to previously reported differences at the organismal level, DCCO were more responsive to EE2 exposure than JQ at the gene expression level. Our description of differences in transcriptional responses to EE2 in early life stage birds may contribute to a better understanding of the molecular basis for species differences. Environ Toxicol Chem 2024;43:772–783. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

中文翻译：

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日本鹌鹑和双冠鸬鹚胚胎对炔雌醇的肝脏转录组反应

了解物种对毒物敏感性的差异是生态毒理学的一个关键问题。我们最近发现双冠鸬鹚 (DCCO) 胚胎比日本鹌鹑 (JQ) 对炔雌醇 (EE2) 的发育影响更敏感。我们探讨了物种间敏感性的差异如何在转录组水平上反映出来。将 EE2 溶解在二甲基亚砜中，然后以 0、3.33 和 33.3 µg/g 蛋重的标称浓度注射到蛋的气室中，然后进行孵化。在孵化中期（JQ 9 天；DCCO 16 天），从五个胚胎/处理组收集肝脏进行 RNA 测序。使用 EcoOmicsAnalyst 和 ExpressAnalyst 处理和分析数据。 EE2 暴露分别使 JQ 和 DCCO 的 238 个基因和 1,987 个基因失调，两个物种之间有 78 个共同基因。其中包括雌激素暴露的经典生物标志物，例如卵黄蛋白原和阿波卵黄素。我们还报告了 I/II 期酶编码基因的 DCCO 特异性失调和卵黄原蛋白-2 的物种特异性转录个体发育。两个物种的十二个京都基因和基因组百科全书通路以及两个 EcoToxModules 均出现失调，包括过氧化物酶体增殖物激活受体 (PPAR) 信号通路和脂肪酸代谢。与之前报道的有机体水平上的差异类似，在基因表达水平上，DCCO 对 EE2 暴露的反应比 JQ 更敏感。我们对早期生命阶段鸟类对 EE2 转录反应差异的描述可能有助于更好地理解物种差异的分子基础。环境毒理学2024；43：772–783。 © 2023 作者。《环境毒理学和化学》由 Wiley periodicals LLC 代表 SETAC 出版。