Characteristics of splenic cell populations at week 3 after BMT. Week-3 chimeras were killed, and flow cytometric analysis of spleen cells was performed for forward and side scatter and for Mac1 expression. (A-C) Dot plots showing forward and side scatter of 1 representative week-3 chimera (A), 1 donor-type (B), and 1 host-type (C) animal. The granular cell population is gated in R1, the lymphocyte population in R2. (D-F) Histograms showing expression of the Mac1 surface marker in the cell populations gated in R1 and R2 of the corresponding dot plot above: week-3-chimera (D), donor-type (E), and host-type (F) animal. (G) Bars represent mean ± SE of a total of 23 week-3 chimeras, 22 donor-type (C3H), and 10 host-type (AKR) mice from 6 independent identically designed experiments (^*P < .05 for comparison with “C3H” and “AKR,” as tested by Kruskal-Wallis multiple comparison Z-test).