图1. 超高效液相色谱-四极杆静电场轨道阱质谱（UHPLC-QE-MS）分析不同海拔高原鼠兔的肾脏代谢组学
注：A为生活于海拔4 360 m的高原鼠兔（MD组）对生活于海拔2 900 m的高原鼠兔（MY组）的主成分分析（PCA）模型得分散点图；B为全部样本（包括QC样本）的PCA得分散点图。图A~B中横坐标PC［1］和纵坐标PC［2］分别表示第一主成分和第二主成分得分，散点颜色和形状表示样本的实验分组。C为MD组对MY组的正交偏最小二乘判别分析（OPLS-DA）OPLS-DA模型得分散点图（横坐标表示预测主成分得分值，反映组间分离程度。纵坐标表示正交主成分得分值，反映样本组内差异分布）。D为MD组对MY组OPLS-DA模型置换检验（X轴上t［1］P和 Y轴上t［1］O分别代表第一和第二区域的主要成分；R2Y=0.930，Q2=0.655）。

Figure 1. Ultra-high-performance liquid chromatography coupled with quadrupole electrostatic field orbital trap-mass spectrometry （UHPLC-QE-MS） analysis of kidney metabolomics in plateau pikas at different altitudes
Note：A is the scatter plot of principal component analysis （PCA） model between MD group and MY group； B is the scatter plot obtained by PCA for all samples （including QC samples）. In the figure A and B， the horizontal axis （PC［1］） and the vertical axis （PC［2］） represent the scores of the first and second principal components， respectively， and the color and shape of the scatter points indicate the experimental grouping of the samples. C is the scatter plot of the orthogonal partial least squares discriminant analysis （OPLS-DA） model between MD group and MY group （The horizontal axis represents the scores of the predictive principal components， reflecting the separation degree between groups. The vertical axis represents the scores of the orthogonal principal components， reflecting the distribution of differences within groups）； D is the permutation test of the OPLS-DA model of MD group for MY group （X-axis （t［1］P） and Y-axis （t［1］O） represent the principal components of the first and second regions， respectively. R2Y=0.93， Q2=0.655）.