Host genetic factors influencing the occurrence of leukemoid reaction in BALB/cMk strain mice bearing transplanted tumors were studied. A Mendelian hybridization experiment was performed with BALB/cMk and C57BL/6 strains, and their strain hybrids: the first filial (F1) generation hybrids; the second filial (F2) generation hybrids; and the backcrosses to the two parental strains. The results of these studies suggested a genetic regulation of leukemoid reaction occurrence in BALB/cMk mice bearing transplanted tumors. Genes permissive to the occurrence of the reaction seemed to be dominant to their nonpermissive alleles.
This work was supported by a Grant-in-Aid for Cancer Research from the Ministry of Education, Science and Culture, Japan.