The Wnt Co-Receptor Lrp6 Is Required for Normal Mouse Mammary Gland Development (original) (raw)
Figure 2
Lrp6 is required for embryonic mammary development.
(A) Carmine-stained skin pads of inguinal mammary glands at E18.5. While in the Lrp6+/+ mammary gland the nipple, rudimentary ductal tree, and fat pad are all normally developed, the Lrp6−/− mammary gland contains a small nipple, a single ductal out-growth, and an abnormally small fat pad. Dashed lines indicate inguinal epithelium. (B) Oil red O staining of mammary fat pads from Lrp6+/+ and Lrp6−/− embryos. The Lrp6−/− fat pad is abnormally small compared to that of the littermate control. Scale bar: 0.5 mm. (C-D) X-gal-stained BAT-gal embryo whole mounts (C) and histology sections of mammary placode (D) at E12.5. Cells expressing BAT-gal are stained blue. (C) X-gal stains the mammary placodes of BAT-gal;Lrp6+/+ embryos dark blue. Arrow heads indicate mammary placodes number 2, 3, 4, and 5. Mammary placodes are not readily visible on X-gal-stained BAT-gal;Lrp6−/− embryo whole mounts. (D) On the histological level, the mammary placodes of BAT-gal;Lrp6−/− embryos are significantly smaller and exhibit fewer cells with BAT-gal expression than the mammary placodes of littermate controls. Dashed lines indicate inguinal placodes.