<i>miR-17-92</i> cluster is required for midface and palate morphogenesis.

<p>(A–D) Scanning electron microscopy (SEM) of embryos with the designated genotypes and designated stages (frontal views). <i>miR-17-92</i> mutants and <i>miR-17-92</i>; <i>miR-106b-25</i> compound mutants exhibit broad orofacial morphogenesis defects including cleft lip (black arrows), mandibular hypoplasia (green arrows), and cleft palate (red arrowheads). (E–H) Histologic analysis with Hematoxylin-eosin (HE) staining of embryos with labeled genotypes and stages. Transverse sections of E13.5 mouse embryos (E, F) and coronal sections of E14.5 mouse embryos (G, H). Black arrows designate cleft lip and red arrowheads designate cleft palate. (I–L) Immunofluorescence (coronal sections) shows proliferation defects in E12.5 mutant embryos: proliferating cells (green)-stained with Phospho-Histon3 (PHH3); Nuclei (red)-stained with DAPI.