FIGURE 4

FIGURE 4

Defective jaw movements greatly reduce food intake in olt mutants. (A) A semi-quantitative food intake assay for zebrafish larvae. Lateral views of 7 dpf larvae fed yellow–green fluorescent microspheres coated with fish food for 3 h. The fluorescent contents (arrowheads) in their guts were visualized under GFP epifluorescence, and ranged from no food with a feeding score (FS) of 0, less than 25% of the gut FS = 1, 50% of the gut (FS = 2), to a full gut (FS = 3). e, eye; s, swim bladder. (B) Distribution of feeding scores showing that a population of olt mutants ate significantly less than wildtype siblings. Pooled data from 3 experiments. Chi-square test used for testing significance (**p < 0.01). (C,D) Cartilage morphology at 7 dpf showing that the various elements develop and pattern normally in olt mutants. (E,F) Pooled data from 4 experiments. The pharyngeal arch (numbered) was measured for (E) length (white line in D) and (F) angle (yellow arc in D) in wildtype siblings and olt mutants. There was no difference in cartilage elements’ lengths or the angles subtended by the elements between olt mutants and wildtype siblings. (G,H) Swimming parameters in 6 dpf larvae. (G) distanced moved and (H) moving duration were analyzed and compared between olt mutant and wildtype sibling larvae with the DanioVision and EthoVision locomotion tracking software (Noldus). There was no significant difference in swimming distance or duration between olt mutants and wildtype siblings. Pooled data from 2 experiments. Number of larvae in parenthesis. The two-tailed student t-test was performed to test for significance (E–H).