Chromosomal banding and karyotype analysis in an Ehrlich mouse ascites tumor cell line

The karyotype and the banding pattern of chromosomes through different techniques following Giemsa staining have been worked out in an Ehrlich mouse ascites tumour cell line. The stemline cells show a mode at 74-76. A metacentric chromosome is present in almost all the cells. Some cells show a long telocentric chromosome with a possible secondary constriction. C-bands are restricted at the telomeric regions of the chromosomes excepting in the metacentric one. From the banding pattern it seems that the nucleolar organizers are located at the telomeric region. No band is associated with the second constriction of the long telocentric chromosome. It is suggested that the long metacentric chromosome has arisen out of a Robertsonian translocation involving end to end centromeric fusion of two non-homologue chromosomes.