Fig. 3

Tas1r3 deficiency largely alters gene expression in the hypothalamus of WD-fed mice. A 3-D view of principal component analysis of the WD-fed Tas1r3^−/− group versus the WD-fed WT group. Groups are represented by different colors, and dots show individual strains. Black spots represent the WT WD group and blue spots represent the Tas1r3^−/− WD group. n = 3 mice/group. B Volcano plot of all DEGs between the WT WD group and the Tas1r3^−/− WD group. Red dots indicate high relative expression of genes (n = 762), and blue dots indicate low relative expression of genes (n = 670). Unpaired two-tailed Student t-test: Thresholds of FDR < 0.05 and 1.5-fold change restriction analysis. C Canonical pathway significantly detected in WD-fed Tas1r3^−/− mice compared to WD-fed WT mice: Right-tailed Fisher’s exact test in IPA. Dots represent –log(p-value) and bars represent Z-score. D GSEA related to PKA signaling; genes were ordered by expression fold-changes upon Tas1r3 deficiency in descending order from left to right. DEGs belonging to the enriched hallmark gene sets identified by GSEA. E Transcriptional regulator predicted to regulate DEGs. F (Left) Western blot analysis of phosphorylated CREB protein and CREB protein levels in hypothalamus of WT and Tas1r3^−/− mice fed ND or WD for 12 weeks. (Right) Quantification of the total phosphorylated CREB protein levels in hypothalamus of mice. Two-way ANOVA followed by Tukey’s multiple comparison test: ***p < 0.001. n = 3 mice/group. G qPCR validation of Bdnf mRNA expression. Two-way ANOVA followed by Tukey’s multiple comparison test: **p < 0.01, ***p < 0.001. n = 3 mice/group. H BDNF protein levels in hypothalamus lysates from WT and Tas1r3^−/− mice fed ND or WD for 12 weeks. Two-way ANOVA followed by Tukey’s multiple comparison test: *p < 0.05, **p < 0.01, ***p < 0.001. n = 4 mice/group. All values are presented as mean ± SEM. ANOVA, analysis of variance; BDNF, brain-derived neurotrophic factor; CREB, cAMP response element-binding protein; DEGs, differentially expressed genes; FDR, false discovery rate; GSEA, gene set enrichment analysis; IPA, ingenuity pathway analysis; ND, normal diet; PKA, protein kinas A; WD, western diet; WT, wild-type