Fig. 5. Expression of fgf3 in pharyngeal pouches. Dorsal (A-C) and lateral (D-G) views of embryos stained for fgf3 expression. Endodermal expression is indicated on one side (arrowheads and labelling). Anterior to the left. (I) The endodermal expression of fgf3 is absent in cas embryos. (J) Section of a 12-somite embryo showing expression of fgf3 in flat cell abbutting the yolk sack, thereby adopting the normal position and shape of endoderm cells. (K) Enlarged lateral view from the otic region. 24 hour-old embryos were double stained for fgf3 (blue) and dlx2 (red). fgf3 is expressed in the posterior part of posterior pharyngeal pouches (white dots) and abuts dlx2-expressing neural crest cells. ov, otic vesicle.