The sex difference under non-stressed and chronic-stressed conditions in C57BL/6 mice

Animal models are important tools in scientific research, whereas the animals used are usually single-sex instead of mixed-sex in the experimental design. To better understand the effect of sex difference, we compared several phenotypes between male and female C57BL/6 mice, including behavioral tests, plasma corticosterone levels, adult neurogenesis, and RNA-seq. The experiments were performed under non-stressed and chronic-stressed conditions, respectively. Overall, our results showed several differences between male and female mice in sensorimotor performance while little difference was found in anxiety, depression, learning, and memory. We did not observe a significant difference in adult neurogenesis. There was a sex difference in plasma corticosterone levels under chronic stress conditions, either in 30 min after the restraint stress or after 60min of the recovery. Yet, the corticosterone levels were equivalent between the sexes under non-stressed conditions at any time point. Furthermore, the results of RNA-seq identified the differential expression genes between male and female mice under non-stressed or chronic-stressed conditions. Comparative gene expression profiling analysis of RNA-seq data for the hippocampus from C57BL/6 mice under non-stressed and chronic-stressed conditions.动物模型是科学研究的重要工具，但现有实验设计中所用实验动物通常仅采用单一性别，而非混合性别群体。为深入解析性别差异的研究影响，本研究对雄性与雌性C57BL/6小鼠（C57BL/6 mice）的多项表型开展了比较分析，涵盖行为学测试、血浆皮质酮水平检测、成体神经发生观测以及RNA测序（RNA-seq）实验。所有实验分别在非应激与慢性应激两种条件下进行。整体结果显示，雌雄小鼠在感觉运动功能方面存在多项差异，但在焦虑、抑郁、学习与记忆相关表型上几乎无显著区别。本研究未观测到成体神经发生存在显著性别差异。在慢性应激条件下，无论是束缚应激后30分钟还是恢复60分钟后，血浆皮质酮水平均存在显著性别差异；而在非应激条件下的任意时间点，雌雄小鼠的血浆皮质酮水平均无显著差异。此外，RNA-seq测序结果鉴定出非应激或慢性应激条件下雌雄小鼠之间的差异表达基因。本研究同时针对非应激与慢性应激条件下C57BL/6小鼠海马体的RNA-seq数据开展了比较基因表达谱分析。