Development of clonal HSC pools in vivo. (A) Experimental design. NHP CD34⁺CD90⁺ cells were transduced with lentivirus encoding for GFP and expressed barcodes. After 12 months, GFP⁺CD34⁺ cells were isolated from the BM and analyzed by scRNA-seq. (B) scRNA-seq of GFP⁺CD34⁺ cells. Transcriptionally distinct progenitor subsets were color coded as indicated in the color key. (C) Expression of GFP, representative genes associated with primitive HSCs (MLLT3), lymphoid (DNTT), erythroid (GATA2), and myeloid (ELANE) progenitors, as well as proliferating cells (TYMS). (D) Identification of cells sharing the same expressed barcode for the 6 most abundant clones. (E) Graphical representation of the clone size in CD34⁺ cells (all clusters combined) and the transcriptionally primitive HSC subset. The dot size is proportional to the number of cells sharing the same expressed barcode identified by scRNA-seq.