Fig. 5. Expanded anterior neurectoderm in Lrp5^+/-;Lrp6^-/- embryos. Whole-mount RNA in situ analysis of marker gene expression in normal and Lrp5^+/-;Lrp6^-/- mutant embryos. Anterior is towards the left in all panels except D, which shows an anterior view. Embryos in A,B and C-H are at 8.0 dpc and 8.5 dpc, respectively. (A-D) Analysis of Six3 expression. Control embryos (A,C) show expression in anterior neurectoderm that is greatly expanded in mutant embryos (B,D). Inset in D shows a dorsal view of the mutant embryo, dissected out of the yolk sac. (E,F) Analysis of Gbx2 expression. A control embryo (E) shows expression in the anterior hindbrain, which is also evident in the mutant embryo (F), particularly in a dorsal view (inset, arrow) of the anterior region of the embryo. (G,H) Analysis of Pou5f1 expression. A control embryo (G) has no expression, whereas the mutant embryo (H) shows expression in the abnormal posterior region. Photos taken at the same magnification are grouped as follows: A,B; C-H.