Functional performances of wild-type, mdx/utrn +/+, and mdx/utrn +/- mice.

<p>Five-month-old mdx/utrn+/+ and mdx/utrn+/- mice have a significantly lower treadmill completion rate (A), time to first stop (B), total running distance (C), distance travelled at 1 h post-treadmill exercise (D,) and distance travelled at 4 h post-treadmill exercise (E) than WT mice. The maximum speed reached by the three experimental groups was not significantly different during the 4 h open-field observation period (F). Hanging test performance was significantly lower in 1-month-old mdx/utrn+/+ and mdx/utrn+/- mice (G). Four limb grip strength performance was also significantly lower in 1- and 5-month-old mdx/utrn+/+ and mdx/utrn+/- (H). Overall, utrophin haploinsufficiency in mdx mice did not induce a time-related deterioration of functional tasks relative to mdx/utrn+/+ mice. Data are expressed as means ± SEM. * p<0.05, ** p<0.01, and *** p<0.001 for comparisons between WT and mdx/utrn+/+ or mdx/utrn+/- mice; § p<0.05 for comparisons between mdx/utrn+/+ and mdx/utrn+/- mice; analysis of variance using Tukey’s post hoc test. n = 6–9.