Figure 4. A subpopulation of the α7 integrin sorted human muscle cells express the muscle stem cell marker Pax7 and show variable expression of desmin.

(A) Immunostaining for Pax7 and desmin of fetal (top row) and adult (bottom row) muscle cells show that some cells are Pax7⁺/desmin⁺ (arrows) while others are Pax7⁺/desmin⁻ (arrowheads). (B) Quantification of the immunostaining shows that in both fetal and adult muscle cultures ~20% of cells stain positive for Pax7. (C) Immunostaining for Pax7 and desmin shows that within the fetal cultures approximately 20% of the Pax7⁺ cells did not express desmin while in the adult approximately 4% of the Pax7⁺ subpopulation was desmin negative. Asterisk* P <0.002 denotes significant differences between fetal and adult. Scale Bar = 20μM