Cytogenetic observations on the canine venereal tumor in long-term culture.

Cytogenetic observations are reported on five canine venereal tumor tissue culture cell lines maintained over periods of 13 to 30 months. In all instances, a karyotype was observed that is strikingly similar to those reported elsewhere for spontaneous or transplanted venereal tumors. The modal number in all lines was close to 59, containing 17 to 19 abnormal metacentric chromosomes. Three of the metacentric chromosomes were identified as markers. Assays for oncogenic properties were undertake in heterologous and homologous hosts. Attempts to induce tumor formation in homologous hosts using the cultured venereal tumor cell were uniformly unsuccessful.