Figure 3. Existing white adipocytes do not contribute to beiging.

(a) Two-month old C57BL/6J mice were maintained at RT or cold temperature for 7 days. Subcutaneous inguinal adipose depots were haematoxylin and eosin (H&E) stained and IHC stained for UCP1. Insets are magnified images. Scale bar, 100 μm (in both images). (b–d) Two-month-old Adiponectin-Cre^ERT2; RFP (b), aP2-Cre^ERT2: RFP (c) or UCP1-Cre^ERT2; RFP (d) male mice were administered one dose of TM for 2 consecutive days and examined (pulse) or mice were maintained at RT for 7 days (TM washout period). Subsequently, mice were cold exposed for 7 days. Subcutaneous inguinal adipose depots were sectioned and immunostained for RFP (red) and UCP1 (green). Cell nuclei were visualized by DAPI staining. Quantification of UCP1+ beige adipocytes that were RFP+ is denoted next to the IHC image. Images are representative from n=3 mice per group replicated twice. Scale bar, 100 μm.