Chromosome fragility in New Zealand black mice: effect of ultraviolet and gamma radiations on fetal fibroblasts in vitro.

The sensitivity of fibroblasts cultured from New Zealand Black (NZB) and BALB/c mouse fetuses to UV and gamma radiations was tested with two methods: 1) colony-forming ability and 2) chromosome abnormalities. When compared with BALB/c cells, NZB cells had reduced colony-forming ability and increased chromosome abnormalities after UV irradiation. However, no differences were seen in colony formation or frequency of chromosome abnormalities between NZB and BALB/c cells after exposure to gamma radiation. This apparent UV specificity strengthens the suggestion that NZB mice might be used as a model to study the relationship between chromosome abnormalities and cancer in human syndromes such as xeroderma pigmentosum, which is characterized by chromosome instability.