Fig. 1

Characterization of fin defects in unm_t30922 mutants. (A) unm_t30922 mutant embryos are initially identical to their siblings at 35 hpf and form regular median fin folds. (B) Both the minor and major lobes of the MFF have started to collapse at 48 hpf. (C-D‴) At 6 dpf, the MFF of the sibling has extended (C, D, D′) while most of the mutant MFF has collapsed (C, D″, D‴) apart from small remnants visible in the minor lobe (arrowheads in D″) and large parts of the tail fin fold (D‴). (E) Alcian blue stainings reveal that at 6 dpf, the pectoral fins of siblings and mutants are indistinguishable and have regular cleithrum (CL), scapulocoracoid (SC), endoskeletal disc (ED) cartilages, and a regular fin fold (FF). (F, G) Alizarin red stainings of mineralized bones (F) and images of live fish (G) reveal that at the onset of metamorphosis (15 dpf, SL 6 mm) wnt10a mutants only have remnants of caudal fins with disorganized lepidotrichia (F, G), while the minor and all other parts of the major MFF lobes have disappeared (G). Arrows in the wild-type fish point to the forming unpaired anal (af), dorsal (df), and caudal (cf) fin. (H) As juveniles (26 dpf, SL 11 mm; osterix:nuGFP transgenic18 to label bone-forming cells) the mutants lack the unpaired dorsal (df) and anal (af) fin, while the unpaired caudal fin (cf) is strongly reduced, containing only few lepidotrichia. In comparison, the paired pectoral fins (pecf) and pelvic fins (pelf) are little affected. In addition, scales are formed as in their siblings (enlarged inserts with dashed lines). Arrowheads indicate collapsed fin folds and remnants of adult fins. MFF, median fin fold; SL, standard length.