Fig. 6

Dlk1 is a marker of quiescence and enhanced self-renewal in aged HSCs. a Expression of Dlk1 in the dataset from Hérault et al., 2021 [38] (see Fig. 5). b Differentially expressed genes between Dlk1+ and Dlk1− cells across aged LT-HSCs (batch A, cluster 1 in Fig. 5a). Threshold values: log₂FC > log₂1.25, padj < 0.05. c UMAP representation of mCEL-Seq2 data of Dlk1+ and Dlk1− LT-HSC populations purified by flow cytometry. d As c, but highlighting Dlk1+ and Dlk1− LT-HSC sorted cells. e Differential expression analysis of the Dlk1+ versus Dlk1− sorted cells. Threshold values: log₂FC > log₂1.25, padj < 0.05. f Quantification of Dlk1+ and Dlk1− frequency among LT-HSC by flow cytometry from groups of mice with different ages (see experimental set up in Additional file 1: Figure S6c). Error bars indicate standard deviation. g Comparison between the percentage of Dlk1+ cells in LT-HSCs and the percentage of myeloid cells in bone marrow, corresponding to the experiment in Additional file 1: Figure S6c (see also Additional file 1: Figure S6e). Spearman’s \(\rho\)=0.80. h Single-cell proliferation assay showing the number of cell divisions in LT-HSCs from young (left, 3 months old) and aged (right, 17–18 months old) mice (n = 3). Error bars indicate standard deviation. i Serial colony-forming unit assays (CFUs) with cells isolated from aged mice (17–18 months old, n = 2). Error bars indicate standard deviation. j Percentage of CD45.2 chimerism in bone marrow 16 weeks post transplantation, showing primary (left) and secondary (right) transplantations (see experimental set up in Additional file 1: Figure S6f). Error bars indicate standard deviation. P value: ns > 0.05, * ≤ 0.05 (one sided t-test). k CD42.5 lineage contribution in the bone marrow 16 weeks post transplantation, showing primary (left) and secondary (right) transplantations. Error bars indicate standard deviation. ND: non-differentiated. Statistical tests in f, h, i, and k: two-way ANOVA test; P value: ns > 0.05, * ≤ 0.05, ** ≤ 0.01, *** ≤ 0.001, **** ≤ 0.0001