DETECTION OF IMMUNOGLOBULIN C-MYC RECOMBINATIONS IN MICE THAT ARE RESISTANT TO PLASMACYTOMA INDUCTION

Interchromosomal recombinations between c-myc and immunoglobulin seque nces can be found in preneoplastic lesions (oil granulomata) during pr istane-induced plasmacytoma development in susceptible BALB/cAn mice. In this study we used a more sensitive approach, hybridization-enriche d templates with nested PCR, to detect microclones with Ig alpha/c-myc recombinations in oil granulomata of susceptible and resistant mice. Recombinations were detected in as many as 73% (32/44) of plasmacytoma -susceptible BALB/cAn mice 30 days after an injection of pristane. Mic e that are resistant to plasmacytoma induction can also harbor recombi nation-positive cells, but these are less frequent [2/20 DBA/2N, 8/20 (BALB/cAn x DBA/2N)F-1, hereafter called CD2F(1)]. The clones in DBA/2 N mice were small (<400 cells), whereas in BALB/cAn, the oil granuloma harbored up to several thousand of these cells. We conclude that the molecular machinery for generating characteristic interchromosomal rec ombinations can be found in all strains of mice. Both the frequency of generating Ig alpha/c-myc recombinations and the expansion of recombi nation-positive cells are greater in susceptible mice than in resistan t strains.