Fig. 4

Increased distance between left and right posterior ceratobranchial cartilages is a specific kus^tr12 phenotype. Aortic arches (bright green) develop in close association with pharyngeal cartilages (red) in WT (A) and kus^tr12 (D). Note the malformed ventral aorta (VA) in kus^tr12. (The darker green staining is background and represents pharyngeal muscle.) Defects in jaw and pharyngeal cartilages in kus^tr12 include shortening of the palatoquadrates (PQ); compression of the basibranchial cartilages (horizontal white line); improper angling of the ceratobranchial (asterisks) and ceratohyal (arrowheads) cartilages; and decreased lateral distance (vertical white lines) between left and right ceratobranchial cartilages in pharyngeal arches 5 and 6 [compare B (WT) to E (kus^tr12)]. Like kus^tr12, vbg^y6 mutants (C) and tnnt2 morphants (F) develop edema and exhibit all described cartilage defects except increased lateral distance between posterior ceratobranchials. Thus, only the latter defect is likely a direct effect of the kus^tr12 mutation. A, D: 2D confocal projections of TG(flk1:GFP^la116; gata1:dsRed) embryos stained with anti-collagen II (red) and anti-GFP (green). B, C, E, F: Macro images of embryos stained with anti-collagen II. All embryos are 4 dpf; ventral views, anterior to the left.