Fig. 5.

Slow myosin heavy chain expression. The majority of primary myotubes initially express slow myosin. Double labelling for slow myosin and laminin/perlecan and counts of the entire muscle enabled a comparison of the percentage of primary myotubes that expressed slow myosin in the TA and EDL at E15.5 and P0 (a, b, respectively). These analyses showed no significant differences in the percentage of slow myosin positive fibres between wild type and FKRP^KD indicating that primary myotube maturation was not altered by the reduction in α-dystroglycan glycosylation. The total fibre number was also not significantly altered between wild type and FKRP^KD (c, d). These counts were made on sections taken from the mid-third section of the hindlimb