Figure 4. Ratios of AA to DHA and individual PL species stratified by APOE4-TR and E4FAD mice. Mean ± SE (n = 6 per genotype). (A) There was a main effect of APOE genotypes on LPC (F = 10.53, p < 0.001) and PC (F = 33.73, p < 0.001). Relative to APOE2 and APOE3, ratio of AA to DHA containing species within PC and LPC were higher in APOE4 mice. There was also a main effect of the APOE genotypes in PE (F = 89.95, p < 0.001), ratios of AA to DHA were lower in APOE2 and APOE4 relative to APOE3 and ratios of AA to DHA were lowest in E2 FAD followed by E4FAD relative to E3FAD mice. There was also a main effect of the APOE genotypes for PI (F = 99.71, p < 0.001), where ratios were higher in E4 relative to E2 and E3FAD. (B) There were significant differences in various AA and DHA containing PL between the APOE genotypes for the APOE-TR and EFAD mice. While PL species, such as ePC(36:4), PC(38:4), ePE(38:4) and PI(36:4) were decreased in E4 relative to the other isoforms in APOE-TR and EFAD mice. LPC(20:4) and LPC(22:6) were increased in E4 mice relative to the other isoforms in APOE-TR and EFAD mice. *p < 0.05 for the post-hoc analyses.