TIL-1 - A NOVEL PROVIRAL INSERTION LOCUS FOR MOLONEY MURINE LEUKEMIA-VIRUS IN LYMPHOMAS OF CD2-MYC TRANSGENIC MICE

Moloney murine leukaemia virus (MoMLV) markedly accelerates thymic lym phoma development in mice carrying a transgene in which the human c-my c gene is linked to the CD2 locus control region. To investigate the m echanism of synergy and identify the genes which collaborate with myc in these clonal tumours, we analysed the sites of MoMLV insertion. Ana lysis of known viral integration loci revealed only a small number of insertions at bmi-1, pim-1 and ahi-1. Further cloning and hybridizatio n analysis revealed a new common integration locus, designated til-l, which was occupied in 25 out of 77 lymphomas examined, with evidence o f multiple clonal insertions in some cases. Mapping relative to establ ished chromosomal markers in interspecific backcross mice located til- 1 to mouse chromosome 17, distal to pim-1 and tie-1. These results sug gest that the til-1 locus may harbour a novel myc-collaborating gene w hich acts as a target for activation in T cell lymphomas.