摘要：Allelic loss on the chromosome 2 is associated with radiation-induced murine acute myeloid leukemia. However, the gene, which contributes mainly to the leukemogenesis has not yet been identified. Expecting any predisposition to acute myeloid leukemia, we performed a radiation leukemogenensis experiment with Pax6 Sey3H , one of the small eye mutants carrying a congenital hemizygosity of the chromosome 2 middle region. A deletion mapping of Pax6 Sey3H with 50 STS markers indicated that the deleted segment extended between the 106.00 and 111.47 Mb site from the centromere with a length of 5.47 Mb. In the deleted segment, 6 known and 17 novel genes were located. Pax6 Sey3H mutants that crossed back into C3H/He did not develop myeloid leukemia spontaneously, but they did when exposed to gamma-rays. The final incidence of myeloid leukemia in mutants (25.8%) was as high as that in normal sibs (21.4%). Survival curves of leukemia-bearing mutants shifted toward the left ( p = 0.043 by the Log rank test). F1 hybrids of Pax6 Sey3H with JF1 were less susceptible to radiation than Pax6 Sey3H onto C3H/He in regard to survival ( p = 0.003 and p < 0.00001 for mutants and normal sibs, respectively, by a test of the difference between two proportions). Congenital deletion of the 5.47 Mb segment at the middle region on chromosome 2 alone did not trigger myeloid stem cells to expand clonally in vivo ; however, the deletion shortcut the latency of radiation-induced myeloid leukemia.
关键词：Chromosome deletion; Acute myeloid leukemia; 60 Co gamma rays; Mouse small eye mutant; Pax6 Sey3H
