Cytogenetic analyses of somatic chromosomes in a transplantable monomyelocytic leukemia in BALB/c mice.

ABSTRACT

In vivo cytogenetic analyses have been performed using G-, C-, and nuclear organizing region (NOR)-banding techniques, and sister chromatid exchanges (SCE) on a transplantable monomyelocytic leukemia (MML) initially induced in female BALB/c mice by the Rauscher leukemia virus (RLV). Centromeric associations have been found to be greatly increased in MML transplanted mice. Transplantability of the disease has been demonstrated at the cytogenetic level by the presence of female cells in males transplanted with MML cells. G-banding analysis has shown the existence of a marker deleted chromosome 18 in all tissues examined (bone marrow, spleen, and peripheral blood) restricted to female transplanted cells. The NOR-banding analysis has shown a slight increase in the number of Ag-NOR sites per metaphase in MML transplanted mice compared with controls and the existence of an extra chromosome having NOR in MML transplanted mice. No differences were found in C banding between controls and MML transplanted mice. In MML transplanted males, female transformed cells showed a significant reduction in SCE frequency compared with host male cells or controls.