Fig. 4.

Paired fin skeletons in shhb^−/−zebrafish. (A,B) Pectoral fin development in shhb^−/− (A; n=7/10) and WT (B; n=10/10) zebrafish. For shhb^−/− zebrafish, 7/10 larvae exhibited complete fusion of the third and fourth proximal radials in either the left or right pectoral fins. Some shhb^−/− zebrafish exhibited a mild defect in the subdivision between the third and fourth proximal radials (A′,A″). Numbers indicate first to fourth proximal radials. (C,D) Pelvic fin development in shhb^−/− (C; n=7/10) and WT (D; n=10/10) zebrafish. For shhb^−/− zebrafish, 7/10 larvae exhibited pelvic fin loss, with 6/10 larvae exhibiting complete loss of both left and right pelvic fins, and 1/10 larvae exhibiting complete loss of only the left pelvic fin. The white bracket indicates the pre-anal region where the pelvic fins are formed in WT zebrafish. Green fluorescence indicates the endochondral skeleton marked by col2a1a:EGFP. The standard length of individuals (in mm) is shown in the bottom left of each panel. Scale bars: 250 μm (A-A″,B); 500 μm (C,D).