Summary of serial transplant experiments. The different constructs are MSCV 210 and MSCV 210/grb2. The diseases are listed under each round of transplant. Where there is more than one disease listed in a column, mice in the cohort developed either one or the other disease, but not both diseases. Proviral integration was determined by digestion of genomic DNA with EcoRI and hybridization with either an IRES or neo probe as described in Materials and Methods. All four tumors analyzed showed an identical proviral integration pattern in secondary, tertiary, and quaternary serial transplant recipients.

Abbreviation: ND, not done.

Mice died before workup. For these mice, diagnosis was made by morphology. Integrated proviral DNA was present by Xba digestion and PCR (not shown); however, the proviral integration pattern could not be assessed due to degradation.