Laboratory of Aquatic Environment and Animal Safety, College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, Henan, China.
Laboratory of Aquatic Environment and Animal Safety, College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, Henan, China.
Ecotoxicol Environ Saf. 2018 Jul 30;156:18-24. doi: 10.1016/j.ecoenv.2018.02.049. Epub 2018 Mar 7.
The brain of fish displays sexual dimorphisms and exhibits remarkable sexual plasticity throughout their life span. Although reproductive toxicity of tributyltin (TBT) in fish is well documented in fish, it remains unknown whether TBT interrupts sexual dimorphisms of fish brains. In this work, brain transcriptomic profiles of rare minnow (Gobiocypris rarus) was characterized and sex-biased genes were identified using RNA sequencing. Functional annotation and enrichment analysis were performed to reveal differences of gene products and pathways between the brains of male and female fish. Furthermore, transcriptomic responses of male and female brains to TBT at 10 ng/L were also investigated to understand effects of TBT on brain sexual dimorphisms. Only 345 male-biased and 273 female-biased genes were found in the brains. However, significant female-biased pathways of circadian rhythm and phototransduction were identified in the brains by enrichment analysis. Interestingly, following TBT exposure in the female fish, the circadian rhythm pathway was significantly disrupted based on enrichment analysis, while in the male fish, the phototransduction pathway was significantly disrupted. In the female fish, expression of genes (Per, Cry, Rev-Erb α, Ror, Dec and CK1δ/ε) in the circadian rhythm pathway was down-regulated after TBT exposure; while in the male fish, expression of genes (Rec, GNAT1_2, GNGT1, Rh/opsin, PDE and Arr) in the phototransduction pathway was up-regulated after TBT exposure. Overall, our results not only provide key data on the molecular basis of brain sexual dimorphisms in fish, but also offer valuable resources for investigating molecular mechanisms by which environmental chemicals might influence brain sexual plasticity.
鱼类大脑表现出性别二态性，并在其整个生命周期中表现出显著的性可塑性。尽管三丁基锡（TBT）对鱼类的生殖毒性已有充分的文献记载，但目前尚不清楚 TBT 是否会中断鱼类大脑的性别二态性。在这项工作中，使用 RNA 测序对稀有鲫（Gobiocypris rarus）的大脑转录组图谱进行了表征，并鉴定了性别偏向基因。功能注释和富集分析用于揭示雄性和雌性鱼类大脑中基因产物和途径的差异。此外，还研究了雄性和雌性大脑对 10ng/L TBT 的转录组反应，以了解 TBT 对大脑性别二态性的影响。仅在大脑中发现了 345 个雄性偏向和 273 个雌性偏向基因。然而，通过富集分析，在大脑中确定了显著的雌性偏向昼夜节律和光转导途径。有趣的是，在雌性鱼类暴露于 TBT 后，基于富集分析，昼夜节律途径显著受到干扰，而在雄性鱼类中，光转导途径显著受到干扰。在雌性鱼类中，TBT 暴露后，昼夜节律途径中的基因（Per、Cry、Rev-Erbα、Ror、Dec 和 CK1δ/ε）表达下调；而在雄性鱼类中，光转导途径中的基因（Rec、GNAT1_2、GNGT1、Rh/opsin、PDE 和 Arr）表达上调。总的来说，我们的研究结果不仅为鱼类大脑性别二态性的分子基础提供了关键数据，还为研究环境化学物质可能影响大脑性可塑性的分子机制提供了有价值的资源。
