Fig. 2

Short-term cold exposure induces gene programs involved in lipid metabolism. Mice were exposed to cold (4 °C, n = 4) or kept at room temperature (RT, n = 5) for 3 days. iWAT was isolated, and RNA was purified for RNA-seq. a Log2 fold changes in exons of RNA-seq gene bodies in cold-treated versus RT mice and the corresponding significance values displayed as log10 (P value). The transverse and vertical dotted lines indicate the cutoff value for differential expression (P < 0.05 & Abs (Log2 fold changes) > 0.585). In total, 205 and 22 genes were identified that had induced (red) or repressed (blue) expression levels by cold exposure. b Heatmap of relative expression of selected thermogenesis-regulated genes from the RNA-seq dataset. Only genes with P < 0.05 are displayed. c Gene Ontology (GO) enrichment analysis. c Functional enrichment analyses using Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. The triangle size indicates significance and corresponding significance values displayed as log10 (P value). d Selected glycerolipid and glycerophospholipid metabolic reactions from KEGG, with indications of quantified lipid classes and acyl chains (circles) and genes (rectangles) significantly regulated in iWAT by short-term cold exposure. Colors indicate increased (red) or decreased (blue) expression of genes (encoding proteins that catalyze the indicated conversions) upon cold exposure or increased (green), decreased (yellow), and undetected (gray) levels of the total concentration of the lipid classes