Translocations involving chromosome 1 in hormone-independent GR mouse mammary tumors

Large marker chromosomes were found in 2 hormone-independent (HI) GR mouse mammary tumors, i.e. a tumor (TSl 75) that was already HI at the first transplantation, and a tumor (TSl 66) that became HI at the 19th passage. These marker chromosomes appear to be translocations to distal and proximal ends of chromosome 1, respectively. The translocation in tumor TSl 66 may be t(15:1).