Fig. 8. Ihh distribution is altered in Kif3a-deficient synchondroses. (A-D) Serial sections of P0 control (A,B) and Kif3a-deficient (C,D) spheno-occipital synchondroses were processed for immunohistochemistry using Ab80 rabbit hedgehog antibodies. Sections were reacted with secondary fluorescent antibodies and counterstained with the nuclear dye DAPI (blue). Positive immunosignal is orange in color. (A,B) In controls, Ihh is present in the pre-hypertrophic zone (phz) and in adjacent proliferative chondrocytes and inner perichondrium (B, single arrowhead), but is undetectable in the upper growth plate zones and flanking perichondrium (B, double arrowhead). (C,D) However, in Kif3a-deficient specimens, Ihh is present in a more extensive and expansive gradient form throughout much of growth plate and all along perichondrium (D, single and double arrowheads). (E,F) Notice that the hedgehog antibodies produced no detectable signal with sections from Ihh-null synchondroses, attesting to their specificity. (B,D,F) Higher-magnification images of the boxed area in A,C and E, respectively. rz/pr/phz, resting/proliferative/pre-hypertrophic growth plate zones. Scale bar: 65 µm in F for B,D,F.