Chimerism development in secondary hosts after BM transplantation.(A-B) The circles show the experimentally observed peripheral blood leukocyte chimerism in 2 individual primary radiation chimeras (single values) and in corresponding cohorts of secondary host mice (mean ± SD). The solid lines show average simulations (gray shade: simulation SD) for the chimerism development in the secondary chimeras (goodness of fit measures, Δ: (A) 0.56, (B) 0.80). The simulation scenarios in panels A and B differ with respect to transition characteristics (C-D) and the initiating D2/B6 ratio according to the experimental situation. (C-D) Transition characteristics used to generate the simulations in panels A and B, respectively. The zoomed regions represent the regulatory windows responsible for long-term chimerism development in fully reconstituted systems.