Clonal changes in Hone1 and derived MCH #3/Hone1. A. Four-probe FISH determines the chr3 constitution (see explanation to figure 2C) for #3/Hone1 samples taken at 9 weeks of in vitro propagation (c4) and in SCID tumor 2 (c5). B. Chr3 constitution for each clone. N- normal chr3; red specifies the exogenous chromosome; black are endogenous Hone1 derived markers, M1, M2 ... M7. Underlined: RP6-123I13 signal is present. C-E. Percentages of metaphases representing a particular clone at 0, 3, 6 and 9 weeks of propagation and in all SCID tumors analyzed. Orange, yellow and green shading: expanded clones with no, 1 and 2 supernumerary 3p21 copies, respectively, compared to Hone1. The term "expanded clone" refers to a clone that appeared at the given time or its representation was not decreased (ratio >0.8) compared to the previous time point. No shading: decreased representation from previous time point. Empty: clone is not present in the sample. Note that chr3 fragments, which were carried by N, M1, M2 and M3, were lost in more than one clone expanded during growth ("lost chr3 segments"), whereas ones included into M4, M5, M6 and M7 were never lost ("retained chr3 segments").