Reduced growth factor independence of BCR-ABL–transduced SHIP^–/– cells and up-regulated expression of the full-length 145-kDa SHIP in BCR-ABL–transduced +/+ cells. (A) Autonomous growth of 3 expanded clones (nos. 1, 3, and 4) of BCR-ABL–transduced +/+ BM cells (solid symbols) and 3 expanded clones (nos. 2-4) of transduced SHIP^–/– BM cells (open symbols) in the absence of exogenous growth factors. Viable cell numbers were determined by hematocytometer counts of trypan blue–excluding cells. Results are expressed as the mean ± SEM of data from 3 independent experiments. (B) Western blot analyses of cell lysates from control (MIG-transduced) cells (lane 1); 3 clones of BCR-ABL– transduced +/+ cells (lanes 2-4, clones 1-3); and 3 clones of BCR-ABL–transduced SHIP^–/– cells (lanes 5-7, clones 1-3). Lysates of equal numbers of cells were separated on 8% polyacrylamide gradient gels. The filter was first probed with antiphosphotyrosine (4G10) (top panel), then stripped, and reprobed with anti-SHIP antibodies against the SH2 domain and c-terminal region of SHIP and anti-STAT5 (STAT5A) (middle and bottom panels). The positions of prestained molecular weight markers are indicated on the left side of each blot.