Figure 2

Single cell transcriptional analysis of young and aged ASCs.

(A) Hierarchical clustering of cells from young (left) and aged (right) mice. Gene expression is presented as fold change from median on a color scale from yellow (high expression, 32-fold above median) to blue (low expression, 32-fold below median). (B) Whisker plots presenting raw qPCR cycle threshold values for each gene across all young and aged ASCs. Individual dots represent single gene/cell qPCR reactions, with increased cycle threshold values corresponding to decreased mRNA content. Cycle threshold values of 40 were assigned to all reactions that failed to achieve detectable levels of amplification within 40 qPCR cycles. (C) Median-centered Gaussian fit curves of selected genes relating to cell stemness and vasculogenesis displaying grossly differential expression profiles between young and aged cells. Non-parametric two-sample Kolmogorov-Smirnov analysis confirmed the differential expression of the anti-oxidative enzyme Sod-2 in aged versus young ASCs (p < 0.01). The left bar for each panel represents the fraction of qPCR reactions that failed to amplify in each group. (D,E) Partitional clustering of young and aged cells based on the expression patterns of all 71 genes (k = 2). (F) Pie charts representing the fraction of ASCs comprising each cluster (Young [red], Aged [green]), with selected cluster 1-defining genes listed below.