Figure 2

Morphologic characterization of transgenic EWSR1::FLI1 zebrafish. (A) Phenotypic characterization of non-transgenic siblings at 6 dpf. (B,C) Phenotypic characterization of Tg(col2a1a:EWSR1FLI1:pA) at 6 dpf. The white arrows indicate the swim bladder. The bubble characterizing the seim bladder is greatly diminished in panel (C). (D) Quantification of standard length (SL) in transgenic (n = 29) and non-transgenic (n = 25) larvae at 6 dpf. For non-transgenic fish, the SL is 3.82 ± 0.13 mm, and 3.70 ± 0.16 mm for transgenic fish; ** p < 0.01 by unpaired Student’s t-test. (E) Quantification of surface area (SA) of swim bladder in transgenic (n = 29) larvae with swim bladder and non-transgenic (n = 24) larvae at 6 dpf. Only living fish for each condition were studied. For non-transgenic fish, the SA is 0.147 ± 0.027 mm, and 0.143 ± 0.03 for transgenic fish; p = 0.423. The EWSR1::FLI1 transgenic fish were smaller in standard length. Because the immature swim bladders did not statistically differ between the lines at 6 dpf and the gross morphology showed no difference, we conclude that the smaller standard length was not due to a developmental factor.