<i>Creface^T/T</i> embryos exhibit frontonasal placode patterning defects.

<p><i>Eya2</i> (A–F) and <i>Six2</i> (G–J) whole embryo <i>in situ</i> hybridization in E9.5 and E10.5 control (A, C, E, G, I) and <i>Creface^T/T</i> (B, D, F, H, J) embryos showing agenesis of frontonasal mesenchyme (I, J), nasal placode fusion (C, D) and formation of a single nasal slit in mutant embryos (asterisks). Abbreviations: NP, nasal placode. Scale bars: A and G 500 uM; all others 200 uM.