Fig. 7. Reduction of second pharyngeal arch delaminating ncc in the Hoxa1-/- and its loss in the Hoxa1-/-/Hoxb1 3'RARE-/- and Hoxa1-/-/Hoxb1-/- mutants. Wild-type (a,b), Hoxa1-/- (c,d), Hoxa1-/-/Hoxb1 3'RARE-/- (e,f) and Hoxa1-/-/Hoxb1-/- (g,h) Haematoxylin/Eosin stained paraffin sections (a,c,e,g) or CRABPI antisense riboprobe stained vibratome sections (b,d,f,h) at the dorsal hindbrain level. Delaminating ncc of the VII and IX ganglia can be seen in the wild-type hindbrains (arrowheads in a,b) anteriorly and posteriorly, respectively, of the otic vesicle (ov). The delaminating population anterior of the otic vesicle is greatly reduced in the Hoxa1-/- mutants (arrowheads in c,d) and completely lost in the Hoxa1-/-/Hoxb1 3'RARE-/- (e,f) and Hoxa1-/-/Hoxb1-/- mutants (g,h) (asterisks). The IXg ncc population still delaminates in all the mutants examined (arrowheads in c-h).
