fig3

Figure 3. Volcano plots for screening sex-dependent features. Volcano plots illustrated the perturbed features between females and males in (A) positive mode and (B) negative ion mode; In addition, the volcano plots show the comparison of OF and OM in (C) positive and (D) negative ion modes, and the comparison of YF and YM in (E) positive and (F) negative ion modes. The dark blue spot represents the features displayed with larger magnitude fold changes (x-axis, |log2(elder/younger)| ≥ 1.0) and statistical significance difference (y-axis, -log P-value ≥ 1.33). OF: Old females; OM: old males; YF: young females; YM: young males.