Fig. 1
Defective swim bladder formation in FD larvae. Embryos of the zebrafish transgenic line Tg( hsp:EGFP-GGH) were heat-shocked at 9- and 24-hpf to induce folate deficiency and observed for swim bladder development at 5 dpf. ( A,B) The clear bubble-like swim bladders (black arrows) were observed in almost all 5 dpf wild-type larvae but were absent in more than 80% of FD larvae. Data are reported as the means ± SD, n = 20 (20 independently conducted repeats with at least a total of 500 larvae for each group), ***p < 0.001. ( C) The inflated chamber of swim bladder (the circled area indicated by arrows) is clearly seen in the elastin/collagen stained cross-sections (dash-line in ( A)) prepared from wild-type control larvae, but not in FD larvae. WT, wild-type; FD, folate deficiency; sb, swim bladder; gi, gastrointestinal tract.