Proviral integration in P210 mice. (A through D) Tissues from mice receiving MSCV 210/grb2. (E) Tissues from mice receiving MSCV 210. (F) Tissues from mice receiving Mig210. All DNA preparations were digested with EcoRI except for lanes 1 and 3 in (F), which were digested with BamHI, which also cleaves once in the provirus. Digestion with Xba I showed the presence of intact proviral DNA for all samples (not shown). All samples are from primary mice and labeled with the tissue from which the DNA was derived, except for the following in (B): lane 2, G46A1 spleen-secondary recipient of spleen cells from G46, this mouse developed the myeloproliferative disease; lane 1, G46A1B2 spleen: recipient of spleen cells from G46A1, this mouse developed T-ALL; lanes 9 and 10, G41A1 spleen and peripheral blood, G41A2 spleen, and G41A3 peripheral blood: recipient of spleen cells from G41; these mice developed the myeloproliferative disease. Abbreviations: PB, peripheral blood; B, BamHI; R1,EcoRI. Sizes of the λ HindIII marker are shown.