Fig. 1

Danio rerio irf6 expression by in situ hybridization. Lateral views, except as indicated, of D. rerio embryos fixed at the indicated stage and processed with an antisense irf6 probe, except B and inset in C. (A) A cleavage stage embryo, revealing high-level maternal expression. (B) A cleavage stage embryo, processed with an irf6 sense probe, revealing very little background staining. (C) Section at shield stage showing low-level expression in deep cells (DEL) and higher level expression in EVL and dorsal frontrunner cells (DFC). Inset, section of a shield stage embryo processed with a sense probe. (D) Diffuse expression throughout the embryo, with increased expression in the nasal and otic placodes (arrowheads). Head is to the left in panels D–F. (E) Decreasing diffuse expression, expression present in nasal and otic placodes and lateral line primordium (arrowhead). (F) Expression as in E but now including putative gut precursor cells (arrowhead). (G) Ventral view, showing expression in pharyngeal pouches (arrowhead). Expression is not detectable in skin at this stage (asterisk) (e, eye). H) Expression in pharyngeal pouches (arrowhead) and ear (asterisk). (I) Horizontal section, showing expression in oral epithelium (arrowhead). (J) Ventral view, expression in pharyngeal pouches (arrowheads). (e, eye).