Sox6 over-expression maintains luminal differentiation in mammary epithelial cells in vivo. A) Wholemounts of fat pads transplanted with mammary epithelial cells transduced with control virus (left) or Sox6 GFP virus (right). Arrows indicate regions magnified in insets (GFP+ duct and alveolar buds in control gland; cyst-like structure in Sox6 gland). Bar = 225 μm. B) Flow cytometric analysis of GFP expression in non-infected, wild type cells (left), cells prepared from control transplanted fat pads (centre) and cells prepared from Sox6 transplanted fat pads (right). The lower set of histograms are magnifications of the corresponding upper histograms to show the GFP+ cells with greater clarity. C) Anti-CD24 and anti-Sca-1 staining pattern of cells prepared from control transplanted fat pads (upper plots) and Sox6 transplanted fat pads (lower plots). The plots for the total cells isolated from the transplanted fat pads and the GFP- and GFP+ fractions of cells isolated are shown. The CD24+/Low lSca-1-, CD24+/High Sca-1- and CD24+/High Sca-1+ regions are indicated as are the percentages of GFP+ cells in these regions.