Baboon SRCs are capable of multilineage engraftment. (A) Displayed is the gating strategy and a representative subset analysis of engrafted baboon SRCs. Overall engraftment of baboon cells (CD11a⁺) was 1.9%. CD13 was expressed in 5.8%, CD20 in 15.7%, and CD34 in 1.8% of engrafted cells. (B) Myeloid precursors make up most engrafted baboon SRCs. Baboon cells from an engrafted NOD/SCID mouse were sorted, and cytospins were performed and stained. Although most engrafted SRCs appeared to be myeloid precursors (top panels, myeloperoxidase stain), mature monocytes (lower left panel) and lymphocytes (lower right panel) were also observed. Lower panels, Wright stain. Original magnification × 1000. (C) Baboon SRCs form colonies in agar. Baboon cells from engrafted NOD/SCID mice were sorted and plated into semisolid media. The percentage EGFP/EYFP-expressing colonies was similar to the percentage of transgene-expressing SRCs, as assessed by flow cytometry. (Left) White light microscopy; (right) fluorescence microscopy. Original magnification × 100.