Fig. 2

MMTV-Spy1 mice have an increased MaSC population. Limiting dilution assays were performed using primary cells from (a) 8-week-old and (b) 6-month-old littermate control (FVB-Cntl) and MMTV-Spy1 mice. (c) Mammospheres from MMTV-Spy1 and littermate control mammary primary cells were serially passaged. Fold change in sphere forming efficiency is depicted (top panel; n = 3). Representative images depicted in bottom panel. (d) Primary cells were isolated from control and MMTV-Spy1 inguinal mammary glands, stained with PKH26 and cultured and sorted as depicted in schema in top panel. Sphere forming efficiency is graphically represented in middle panel. Representative images depicted in bottom panel. (n = 6); Scale bar = 200 μm; Errors bars represent SE; Student’s T-test. *p < 0.05, **p < 0.01, ***p < 0.001