Fig. 7.

Pax7 positive progenitor cell quantification. a shows double immunolabelling for Pax7 and laminin α2 in the TA, whilst b shows Ki67+ and type IV collagen in the TA. White arrow indicates Pax7⁺ nuclei laying beneath the basal lamina whilst the yellow arrow shows Pax7⁺ nuclei outside of the basal lamina (P0). However, many nuclei were in an ambiguous position and so only, the total number of Pax7⁺ nuclei was counted. These counts expressed as the number of Pax7⁺ nuclei per fibre showed a significant reduction in the TA at E15.5 and P0 (p = 0.0083 and p = 0.0157, respectively) in the FKRP^KD relative to wild type (c). There was however, a significant increase (p = 0.0017) in the number of Ki67 (cell proliferation marker) positive nuclei was observed in the TA of the FKRP^KD at E15.5 but not at P0 (d). The proportion of Pax7 positive nuclei that were also expressing MyoD was not significantly different between WT and FKRP^KD (e). Immunolabelling for Pax7/MyoD is shown in (f). All immunolabelling was carried out on serial transverse sections