Retinoic acid is required for endodermal pouch morphogenesis and not for pharyngeal endoderm specification



Lateral view of the head of a 30 hours post fertilization Tg(foxd3:gfp) zebrafish embryo expressing GFP in neural crest cells which will differentiate into pigment cells and cells in the pharyngeal arches (anterior is pointing up). The embryo is double labeled with the antibody Zn8 in red, which labels four endodermal pouches in between neural crest filled pharyngeal arches, as well as sensory ganglia. See Kopinke et al., Developmental Dynamics 235:2695–2709, 2006. © 2006 Wiley-Liss, Inc.