A NEW CANDIDATE SITE FOR A TUMOR-SUPPRESSOR GENE INVOLVED IN MOUSE THYMIC LYMPHOMAGENESIS IS LOCATED ON THE DISTAL PART OF CHROMOSOME-4

In a previous work we provided preliminary evidence of the existence o f a putative tumor suppressor gene region on the distal part of chromo some 4 in gamma-radiation-induced T-cell lymphomas of (C57BL/6JxRF/J) Fl hybrid mice. This region, named as TLSR2 (Thymic Lymphoma Suppresso r Region 2), was located centered at D4Mit54. A more detailed alleloty pe analysis in the mentioned tumors with new informative microsatellit es on distal chromosome 4 region, as well as in thymic lymphomas induc ed with gamma-rays in Fl hybrids generated from reciprocal crosses bet ween the strains C57BL/6J and BALB/cJ, and having in mind the new map position of D4Mit205b, allowed us to confirm the existence of TLSR2 an d to define it more precisely as centered at D4Mit205b, In addition, w e identified a new candidate region, named as TLSR3 (Thymic Lymphoma S uppressor Re,Region 3), located between the Mom-l locus and D4Mit68, a s the site of another putative tumor suppressor region involved in thy mic lymphomagenesis.