Fig. 6
p21 is crucial for the stem cell-like program, p53-mediated response and block in differentiation. a Principle component analysis (PCA) of the gene expression signatures in purified DN3 thymocytes from 6-week-old wild-type (WT), p21−/−, Lmo2Tg and Lmo2Tg;p21−/− mice. b Heat map of Lmo2-associated upregulated gene signature in purified DN3 thymocytes from (a). c Heat map of genes differentially expressed (FDR < 0.05) in DN3 thymocytes from 6-week-old Lmo2Tg, as compared to Lmo2Tg;p21−/− as well as wild-type (WT) and p21−/− controls. Row mean: relative expression of each gene as compared to the average expression for each genotype analyzed. d Gene set enrichment analysis (GSEA) plot of DNA replication, ribosome function (spliceosome) and proteasome genes in DN3 thymocytes from p21-deficient Lmo2Tg mice, as compared to Lmo2Tg mice (top panels), as well as p21−/− DN3 cells compared to wild-type (WT) DN3 thymocytes (bottom panels). FDR false discovery rate, NES normalized enrichment score. e Immunophenotype of co-cultured DN3 thymocytes for 5 days for in vitro differentiation assays. N = 2 independent experiments, mean ± s.e.m., Student’s t-test. f Representative confocal immunofluorescence of undergoing symmetric cell division (SCD, top row) and asymmetric cell division (ACD, bottom row) of DN3 thymocytes from 6-week-old mice in co-culture assays. Sorted DN3-stromal cell conjugates were fixed and co-stained with α-Tubulin (red) and the cell-fate protein Numb (green). N = 2 independent experiments, with specific numbers of cells analyzed indicated. Chi-Square test described for each genotype was performed (Supplementary Fig. 6b); **p < 0.01, ***p < 0.001, as compared to WT; #p < 0.05, as compared to Lmo2Tg cells, respectively
