FIGURE 8

Functional and structural analysis of adult WT and b3galt6^–/– zebrafish muscle. (A) The critical swimming speed and (B) the endurance performance was determined for b3galt6^–/– and length-matched WT zebrafish. (C) Semi-thin cross sections, stained with toluidine blue, demonstrate the presence of a thicker endomysium (arrowhead), located between the muscle fibers (Mf) at the horizontal myoseptum of b3galt6^–/– zebrafish at the age of 5 months. (D) Transmission electron microscope structure of a sarcomere with indications of the Z and M line and A, I, and H band. The sarcomere length was determined at 5 different loci per semi-thin section, for 6 semi-thin sections origination from 3 different zebrafish per genotype (N = 30). A significant increase in sarcomere length for b3galt6^–/– is noted. Furthermore, both the A and I band show an increase in length for the mutant zebrafish. Data are expressed as box plots with min-to-max whiskers on which each individual data point is plotted. A Mann-Whitney U test was used to determine significance. ****P < 0.0001, **P < 0.01.