Figure 2. CD44 expression defines differentiating adipocyte progenitors. (A–E) FACS analysis of CD44 expression and lipid accumulation in PDGFRα+ cells in gonadal WAT (gWAT) from control mice and mice treated with CL for 3 d. Representative flow profiles (A) and quantification (B) of lipid+CD44+ and lipid+CD44- cells (mean ± SEM; n = 3–4; *P < 0.05, **P < 0.01). (C) Mean fluorescence intensity (MFI) analyses of PDGFRα+ cells demonstrate a positive correlation between CD44 expression levels and cellular lipid content. (D) Images of PDGFRα+ cells collected using ImageStream flow cytometry demonstrate that high CD44 expression predicted intracellular lipid droplet formation as indicated by LipidTox staining and bright field morphology. Intensity values are displayed below each image. Nuclei were counterstained with 7-AAD. (E) Flow profiles of PDGFRα+ cells showing a positive correlation between lipid staining and Bright Detail Intensity (cellular texture feature) or CD44 expression. Linear regression analyses were performed with log-transformed data (intensity values). (F) Quantitative PCR analysis of adipogenic marker expression in FACS-isolated cells from gWAT of control mice or mice treated with CL for 3 d (n = 3–4, mean ± SEM; *P < 0.05, **P < 0.01).