At day 5 of culture, the expression of several markers was analyzed using immunocytochemistry to understand whether the two subpopulations showed different expression signatures and how hypoxia could affect it. Alpha7integrin marker was completely maintained in both LPC and HPC (100%) during the culture period, both under normoxia and hypoxia (Fig. 2A and B). A higher proportion of cells expressed MyoD in LPC than in HPC and this difference was maintained at different oxygen concentrations (Fig. 2C and D). Similar results were observed when MyoD gene expression was evaluated at single cell level using RealTime PCR (Fig. 2M). In accordance, expression of Myf5 was higher in LPC than in HPC, but the marker reached a significant difference only in hypoxia condition, both at protein and gene expression level (Fig. 2E, F and N). Moreover, CD34, a typical quiescence SC marker that rapidly decreases after cell activation, showed significantly higher expression both at 20% and 2% O2 on LPC (56% and 55% respectively) when compared to HPC (41% and 40% respectively; Fig. 2G and H). Besides, CD31 was not present at all (0%) in all the conditions confirming the absence of cells from other origin (Fig. 2I and L). Evaluation of hif-1α expression at single cell level with RealTime PCR showed a higher expression of the factor in LPC compared to HPC, both under normoxia or hypoxia conditions (Fig. 2O). When cultured on proliferative medium, several desmin+myotubes were observed both in LPC and HPC clones. Intriguingly, low oxygen cultivation triggered myotube generation in all the clones (Fig. 3; ANOVA analysis showed p