To investigate the significance of the C-terminal Abl actin-binding domain within Bcr/Abl p190 in the development of leukemia/lymphoma in vivo, mutant p190 DNA constructs were used to generate transgenic mice.
We conclude that pl90 BCR-ABL transcripts are frequently present at a low level in p210 BCR-ABL-positive leukemias. p190 mRNA may arise through alternative or missplicing and its presence is probably of no pathogenetic significance.
Interestingly, the leukaemia and the derived cell line each displayed different, clonal patterns of immunoglobulin gene rearrangements providing direct evidence that the t(9;22) translocation which results in the expression of the p190 bcr-abl protein must occur before immunoglobulin heavy chain gene rearrangement.