Fig. 2

Principal component analysis of gene expression data from primary cells and immortalized clones of human myoblasts and differentiated myotubes, and from primary non-myogenic (CD56-negative) muscle-resident cells. a Immortalized myoblasts (light green) cluster together with primary myoblasts (dark green) and immortalized myotubes (light red) together with primary myotubes (dark red). Both are separated from non-myogenic cells (cyan). Data-points are projected onto principal components 1, 2, and 3. b and c The same data for myoblasts (b) and myotubes (c) alone, projected onto principal components 1 and 2. For myoblasts, PC1 accounted for 43% and PC2 for 17% of the total variance in the data. For myotubes, PC1 accounted for 32% and PC2 for 22% of total variance. Each population is labelled and colored separately according to the key presented in (b)—immortalized clone populations are colored a darker shade than their respective primaries. Each immortalized clone clustered near to its parent primary population, and clones were not shifted in any particular direction relative to their parent primary population. Each data-point corresponds to a separate culture dish (average n = 4 dishes per cell line)