Fig. 4.

Weighted gene co-expression network analyses (WGCNA) of DEGs identified from differentiation stages. (a) Hierarchical cluster tree showing 8 modules of co-expressed genes. Each of the 3382 DEGs are represented by a tree leaf and each of the modules by a major tree branch. The lower panel shows modules in designated colors. (b) Module–sample correlations and corresponding p-values (in parentheses). The left panel shows the 8 modules and the number of member genes. The color scale on the right shows module–sample correlations from − 1 (blue) to 1 (red). The labels on the bottom panel represent samples at different points in time. (c) mRNA-seq expression patterns of PPARγ and FABP4. (d) Module–trait correlations and corresponding p-values (in parentheses). The left panel shows the 8 modules and the colour scale on the right shows module–trait correlations from − 1 (blue) to 1 (red). The left panel “PPARγ” (bottom) represents the expression changes of PPARγ, which is the key transcription factor activating adipogenic differentiation. The right panel “FABP4” (bottom) represents the expression changes of FABP4, which is important for lipid hydrolysis and transportation of intracellular free fatty acid