Lrp5 in Mammary Stem Cells Figure 1. Lrp5 is Expressed in Mouse Mammary Epithelial Cells. A) Western blot of lysates prepared from E10-12 Lrp5 +/+ and 2/2 embryos, primary MECs, and the NMuMG and HC11 cell lines. B) Northern blots of RNA prepared from E18 Lrp5 +/+, +/2, 2/2 embryos, primary virgin (V) and 14 day pregnant (P) MECs, NMuMG and HC11 cell lines were probed for either Lrp5 or Lrp6 mRNA expression. 18S was used as a loading control. C) Immunohistochemistry was used to localize Lrp5-expressing cells in virgin Lrp5 +/+ and 2/2 paraffin embedded mammary glands. Lrp5 (green) was co-localized with K5 or SMA (red), and nuclei stained with ToPro3 (blue) as indicated, scale bars = 20 mm. Insets depict 56enlargements, scale bars = 4 mm. D) Frozen sections of 10 day pregnant mammary glands from Lrp5 +/+ and 2/2 mice were subjected to the same analysis, scale bars = 20 mm. doi:10.1371/journal.pone.0006594.g001 PLoS ONE | www.plosone.org 3 August 2009 | Volume 4 | Issue 8 | e6594