Fig. 1. Abnormal development of Lkb1^lox/-, Mox2-Cre conceptuses at E9.5. (A-H) Gross morphology of wild-type (A,E), Lkb1^lox/-, Mox2-Cre (B,C,F,G) and Lkb1^-/- (D,H) embryos and yolk sacs (E-H). (I-L) Higher magnification of E-H, respectively. Defects observed in Lkb1^lox/-, Mox2-Cre embryos vary from mild abnormalities and reduced size (B) to severe developmental retardation (C) resembling the Lkb1^-/- phenotype (D). Similar to Lkb1^-/- yolk sacs (H,L), the yolk sacs of Lkb1^lox/-, Mox2-Cre embryos (F,G,J,K) fail to remodel the primary vascular plexus into large vitelline vessels, as seen in E9.5 wild-type yolk sacs (E,I).