Fig. 4. SMA and PDGFRβ staining demonstrates a reduction of vSMCs in Lkb1^lox/-, Tie1-Cre conceptuses at E11.5 (A-F) Whole-mount immunofluorescence staining of PECAM1 (green) and SMA (red) in wild-type (A,C,E) and Lkb1^lox/-, Tie1-Cre (B,D,F) yolk sacs, demonstrating loss of SMA staining in the mutant. (G,H) Whole-mount immunofluorescence staining of PDGFRβ in wild-type (G) and Lkb1^lox/-, Tie1-Cre (H) yolk sacs, showing loss of PDGFRβ expression in Lkb1^lox/-, Tie1-Cre yolk sacs. (I,J) SMA staining of cross sections of the aorta at the thoracic level of wild-type (I) and Lkb1^lox/-, Tie1-Cre (J) embryos demonstrates reduced SMA staining in the mutant.