Fig. 4.

Expression of Pbx family members and Emx2 in respective single Emx2 homozygous and compound Pbx1-3 mutants via in situ hybridization. A: Compared to WT (black arrowhead): in E10.5 Emx2^−/− mutants, Pbx1 expression (top) is modestly spatially disrupted in its proximal-to-distal domain, but remains in the proximal HL (red arrowhead); and Pbx2 expression (bottom) is unaffected (black arrowhead). B: Compared to WT (black arrowheads): at E11.5, Emx2 expression is slightly reduced in single Pbx1^−/− and compound Pbx1^−/−;Pbx3^+/− mutant proximal HL (red arrowheads), but is severely reduced-to-absent in compound Pbx1^−/−;Pbx2^+/− mutant proximal HL (double red arrowheads).