Figure 1.

Adipocytes are produced from BMP cells in mice. Eight-week-old female C57Bl/6 wild-type mice were transplanted with BM from mice in which luciferase expression was targeted to adipocytes (AdipoQcre^LSLLuciferase). A–C) Luciferase activity (light emission) was measured in the recipients in an IVIS Imaging System 50, and data were acquired and analyzed with Living Image 3.0 software. A) Representative luminescence images of BM-transplant recipients at 2, 8, 14, and 18 wk after transplant. All images are at the same scale. B) Luminescence measured in a transplant-naïve mouse 16 wk after transplant. Scale is the same as in (A). C) At 16 wk, some animals received a second injection of luciferin and were immediately sacrificed so that the abdominal and thoracic cavities could be opened to expose internal organs. Representative image of light emission showing adipose tissue-restricted luciferase activity is shown. SubQ, subcutaneous. D) Adipose and nonadipose tissues were harvested from transplant recipients 8 wk after transplant and digested with Passive Lysis Buffer from the Dual-Luciferase Assay Kit. Luciferase activity was measured in a Turner BioSystems 20/20 luminometer. Luciferase activity in each fraction was corrected for lysate protein concentration (n = 8; data are presented as means ± sd). RLU, relative light unit. E) Gonadal adipose tissue was digested with collagenase, and adipocytes were separated from stromal cells by flotation. CD11b^POS and CD11b^NEG stromal populations were prepared by magnetic bead separation. Luciferase activity was measured in lysates of the 3 fractions as described in (D) (n = 2; data are presented as means ± sd).