In vivo engraftment and differentiation of clone-3 SSEA-1⁺ cells into different mesenchymal cell types and endothelial and hematopoietic-like cells. (A-C) FACS analysis and bone histology revealed the presence of GFP⁺ donor-derived cells in only the injected tibiae. Representative bone sections from engrafted mice (D-T). Presence of donor-derived hematopoietic-like cells was verified by the coexpression of CD45 (C-F). Donor-derived endomucin⁺ cells were frequently detected in the blood vessels that irrigate the bones (H-I) and in the marrow's vessels (G). All of the mice that received a transplant showed substantial presence of GFP⁺ bone-lining cells (J), which was confirmed by staining with an osteocalcin antibody (K-M). Donor-derived osteocytes (osteocalcin- and BSP II–positive cells) were also detected in all of the mice analyzed (N-P). Few GFP⁺ cells expressing type II collagen (Col II) were detected only in 1 of the recipients (Q-R). Deposition of Col II in the marrow's cavity (S). An area of cartilage confirming the specificity of Col II staining is shown (Q). An area with concentrated GFP⁺ adipocytes was found in the marrow of the same recipient (T). Immunostainings were performed using appropriate Alexa 594– or HRP-conjugated secondary antibodies. Sections were counterstained either with hematoxylin (B) or DAPI (D-T). Original magnifications: 10×/0.75 NA dry objective (B, J), 20×/0.75 NA dry objective (H-I, K, O, Q, S-T), 40×/0.75 NA dry objective (D-G, L-N, P, R), and 100×/10.4 NA oil objective (D, insert). M# denotes the mouse number. White dotted lines mark the endosteum.