CHROMOSOME-11 PARTICIPATION IN ACUTE LYMPHOBLASTIC-LEUKEMIA IN SPRAGUE-DAWLEY RATS

Five cases of spontaneous acute lymphoblastic leukaemias (ALL) of Spra gue-Dawley (SD) inbred rats have been studied cytogenetically. Chromos ome studies were performed on direct preparations of the lymphomas usi ng common cytogenetic methods. For detailed karyology, G-banded prepar ations were used. The chromosome numbers of metaphase cells in all leu kaemias were near diploidy, the majority of metaphases being pseudodip loid with 1-2 stable marker chromosomes. The most frequent change invo lved chromosome 11, where the translocation form of trisomy 11 or 11q aberration was observed. Chromosome 11 abnormalities were found in al l five leukaemias studied, suggesting to be a nonrandom change. 11 q11 - q12 is supposed to be the critical region involved in the genesis o r progression of SD ALL. These results are in agreement with our previ ous observations in nine cases of SD ALL (Sladka et al., 1988).