MDPs, CDPs, and pre-cDC1s were sorted from bone marrow and lysed in ice-cold ATAC-RSB buffer containing 0.1% NP40, 0.1% Tween-20, and 0.01% digitonin. Cells were incubated at 4° C for 3 min, then washed with ATAC-RSB buffer containing only 0.1% Tween-20. Nuclei were spun down by centrifugation and then incubated in 50 µL of transposition buffer (25 µL 2X TD buffer, 22.5 µL dH2O, 2.5 µL Tn5 transposase (Nextera DNA Library Prep Kit, Illumina)) and incubated at 37° C for 30 min. If 10,000 cells could not be obtained for a certain population then the quantity of Tn5 transposase was titrated down proportionately to the number of cells obtained but cells were still incubated in 50 µL total. Transposed DNA was purified with a DNA Clean & Concentrator kit (Zymo Research), eluted in 21 µL of elution buffer, and stored at -20° C until amplification. Nextera DNA Library Prep Kit