Fig. 7. Early patterning of arch epithelial tissues appears unaffected in moz mutants. Lateral views of wild-type (A,C,E,G) and moz mutant (B,D,F,H) embryos at 34 hpf (A,B), 41 hpf (C,D), 54 hpf (E,F) and 4 days (G,H). (A,B) pea3 expression marks posterior pharyngeal endodermal epithelia. No inversion of this pattern is seen in moz mutant pouches. First and second pharyngeal pouches are outlined. (C,D) sonic hedgehog (shh) expression marks the posterior ectodermal margin (PEM) of the second arch, a thin line of cells marking the posterior edge of the forming opercular flap. PEM expression persists in moz mutants. (E,F) pitx2c expression strongly labels the mouth in wild type and moz mutant. No ectopic pitx2c expression is seen in the mouth-like openings between the second and third arch in moz mutants. (G,H) rag1 expression labels a reduced but present thymus in moz mutants. pp1, pharyngeal pouch 1; pp2, pharyngeal pouch 2. Scale bars: 50 µm.