Fig. 3

Lack of Scxa in adults affects body measurements and swim behavior. A–H) Weight, length, BMI, and standard weight comparison between mutants and sibling adult fish from a scxa^+/− incross (13 siblings and 7 scxa^−/− males, 18 siblings and 6 scxa^−/− females, A–D) and a scxb^+/− incross (21 siblings and 5 scxb^−/− males, 6 siblings and 2 scxb^−/− females, E–H). Males and females are presented separately as were found significantly different. I, J) Contrast-enhanced µCTs to show soft tissue of scxa^−/− mutant (J–J″) and a ^+/+ sibling (I–I″). Magnified scans show lack of ribs (black arrows) in the mutant. I″, J″) Transverse optical sections at indicated positions, where dashed arrows indicate the vertebrae. K) Myotome volume from co-reared similar-length fish are calculated from scans by creating a virtual steak between 2 ribs (red area, see Materials and Methods). L, M) Quantification of muscle volume in scxa^−/− adult mutants (L) and scxb^−/− (M) and their respective siblings. N–P) Swimming performance was calculated from videos taken from above the tank [schematic drawing in panel (N), see also Supplemental Video and Supplemental Fig. S7], and the range of movement (curvature, M) and instantaneous velocity (N) were calculated as detailed in the Materials and Methods. Two-way ANOVA statistics with Sidak’s post hoc tests were performed (A–H). Unpaired t test with Welch’s correction (L, M) and 2-way ANOVA (O, P). Significant P-values indicated on graphs.