Frequency of CD43⁺, CD49e⁺, CD49d⁺, and CD62L⁺ cells among donor Sca-1⁺ cells in BM, spleen, and PB at 1, 3, 6, and 20 hours following transplantation of low-density BM cells. Mice were irradiated with 950 cGy, underwent transplantation an average of 18.5 hours later with 1 × 10⁷ to 1 × 10⁸ LDBM cells, were killed at the indicated time points, and donor Sca-1⁺ cells in BM and spleen were analyzed for expression of CD43 (A), CD49e (B), CD49d (C), and CD62L (D) by flow cytometry as described in “Materials and methods.” All 4 time points were assayed in every experiment. Data are expressed as the mean ± SEM percent of donor Sca-1⁺ cells with light scatter properties characteristic of primitive hematopoietic cells and that express each adhesion molecule. n = 4; *P < .05 when compared with spleen at the same time points, #P < .05 when compared with earlier time points of same tissue. Data for BM cells are partially reproduced, with permission, from Plett et al.¹⁸