Figure 4

Calcein staining illustrating the impact of foxl1, foxc1a, and foxc1b lone and combined loss on craniofacial development and calcification. (A) foxc1a^-/- embryos have a lack of bone development in all craniofacial bones resulting from the first (blue) and second (yellow) pharyngeal arches and diminished formation of the opercula bones at 6 dpf. foxc1b^-/- embryos exhibit no change. foxl1 panels are included for reference. (B) WT (n = 173); foxc1a^-/-; foxl1^-/- (n = 6); foxc1b^-/-; foxl1^-/- (n = 2); and foxc1a^-/-; foxc1b^-/- (n = 4) embryos at 6 dpf. foxc1a^-/-; foxl1^-/- embryos exhibit a further loss of craniofacial bone formation and calcification with increased size in the cardiac edema present, while foxc1b^-/-; foxl1^-/- embryos exhibit no change from their respective individual knockout models. foxc1a^-/-; foxc1b^-/- double mutants show a similar phenotype as foxc1a^-/-; foxl1^-/- embryos. Red boxes highlight areas of interest. Small red squares highlight the hyomandibula and the large rectangular box isolates the ceratohyal bone. Scale bars are 100 µm.