Figure 2. Heterogeneous expression of MyoD and desmin by α7 integrin sorted human myoblasts in culture suggests variable lineage progression.

Primary muscle cultures from adult and fetal muscle were isolated using FACS for α7 integrin expression. (A) Flow cytometry analysis using mAb 9.1 against human α7 integrin verifies the muscle cell lineage of the established primary cultures. (B) RT-PCR analysis of adult and fetal cells demonstrates the expression of known muscle lineage markers. (C) Immunostaining for c-Met/desmin shows cells that are positive for both (arrow) and cells that express c-Met but not desmin (arrowhead). (D) Immunostaining for MyoD/desmin shows cells that are positive for both (arrow) and cells that express desmin but not MyoD (arrowhead). (E) Percentage of cells expressing desmin and MyoD as measured by immunostaining of fetal and adult myoblast cultures. Asterisk* P<0.005 denotes significant differences between desmin expression levels in fetal compared to adult. Scale Bar = 20μM