Figure 4. Adipoq-Cre/ER recombines in most adipocytes and in a subset of LepR⁺ stromal cells in the bone marrow.

(a) 0.017±0.008% of bone marrow cells were Tomato⁺ in enzymatically dissociated bone marrow cells from Adipoq-cre/ER; R26^tdTomato mice at 4 weeks after tamoxifen administration.

(b) Adipoq-cre/ER; R26^tdTomato mice exhibited Tomato expression by perilipin⁺ adipocytes (arrowheads) and a subset of perilipin negative stromal cells (arrows) in the bone marrow.

(c) Only 5.9±3.1% of LepR⁺ stromal cells were Tomato⁺ in the bone marrow of Adipoq-cre/ER; R26^tdTomato mice at 4 weeks after tamoxifen administration.

(d) Tomato expression was rarely detected in bone-lining GFP⁺ osteoblasts from Adipoq-cre/ER; R26^tdTomato; Col1a1*2.3-GFP mice.

(e) Tomato expression was not detected in VE-cadherin⁺CD45/Ter119⁻ endothelial cells in the bone marrow of Adipoq-cre/ER; R26^tdTomato mice at 4 weeks after tamoxifen administration.

(f) Only 6.2±2.9% of Scf-GFP⁺ stromal cells were Tomato⁺ in the bone marrow of Adipoq-cre/ER; R26^tdTomato; Scf^GFP mice at 4 weeks after tamoxifen administration.

(g) While not detected by flow cytometry, perilipin⁺ adipocytes in bone marrow sections from Adipoq-cre/ER; R26^tdTomato; Scf^GFP mice were consistently positive for Scf-GFP and Tomato.

(h) Percentages of LepR⁺Tomato⁻ or LepR⁺Tomato⁺ stromal cells from Adipoq-cre/ER; R26^tdTomato mice that formed CFU-F colonies in culture.

(i) Percentage of CFU-F colonies that contained Oil-red-O⁺ adipocytes or Alzarin-red-S⁺ osteoblastic cells.

(j) The average numbers of perilipin⁺ adipocytes or alkaline phosphatase⁺ (ALP⁺) osteogenic cells that spontaneously differentiated per CFU-F colony after 1 week of culture in DMEM plus 20% FBS (n=53 colonies from 3 mice; 3 independent experiments). A two-way ANOVA with Sidak’s multiple comparisons test was used to assess statistical significance. **P<0.01.

All data in Figure 4 represent mean±SD and representative images from n=3 mice in 3 independent experiments.