The level of sister chromatid exchanges, both spontaneous and induced by UV light or ethylmethanesulphonate (EMS), in Chinese hamster V79/AP4 cell line, is partially reduced upon cocultivation with human cells. Normal and xeroderma pigmentosum (XP) cells are equally effective. On the basis of these observations, cocultivation may represent a good tool for investigating the SCE's formation processes.
