(Downloading may take up to 30 seconds.
If the slide opens in your browser, select File -> Save As to save it.)
Click on image to view larger version.

Fig. 6. Evidence that Fgf10 plays a role in foregut patterning.
(A,C) Wholemount and section of foregut of E10.5
FGF10lacZ embryo after staining for ß-galactosidase.
(A) Ventral view after dissection of the heart. Section in C shows strong
Fgf10 expression in ventral mesenchyme. (B) Ventral epithelium (black
arrowhead) and mesenchyme (white arrowhead) are positive for phosphorylated
ERK1/2 staining. (E-G) Fluorescence microscopy of foreguts from
32-somite stage Sox2EGFP/+ embryo before (E) and after
culture for 36 hours without (F) or with (G) 50 ng/ml Fgf10 in the culture
medium. White arrowhead marks the junction of the esophagus with the foregut
and the white line marks the undivided proximal foregut. The anterior limit
was determined from phase microscopy. Note that in samples incubated with
Fgf10 the region of undivided foregut is longer than in control incubated
without Fgf. (H-O) Section through the esophagus of samples similar to
those shown in F,G, stained with antibodies to Sox2 (H,L), p63 (I,M), merged
(J,N) and haematoxlyin and eosin (K,O). (H-K) Cultured without Fgf10, (L-O)
cultured with Fgf10. The dotted line in K-O outlines the esophageal epithelial
layer. Note the difference in length of the scale bars. (D) RT-PCR of
transcript levels in isolated esophagi from E11 embryos cultured with and
without Fgf10. Primers for p63 were for the transactivating isoform. Scale
bars: 100 µm in E-G; 50 µm in H-O.