Pluripotent stem cells of the mouse as a potential in vitro model for mammalian germ cells. Sister chromatid exchanges induced by MMC and ENU in undifferentiated cell lines compared to differentiated cell lines

We tried to develop an in-vitro test system which could serve as a model fo r mammalian germ cells in vivo. Two pluripotent cell types were used, becau se they express some germ cell specific immunological and biochemical marke rs: (1) Embryonal carcinoma cells (ECC) of the line P19 had been isolated f rom a teratocarcinoma of murine primordial germ cells (PGC). (2) Embryonal stem cells (ESC) are obtained from the inner cell mass of mouse blastocysts . Sister chromatid exchanges (SCE) induced by mitomycin C and ethylnitrosou rea (ENU) were analysed in the two undifferentiated cell lines, ECC and ESC , to detect differences in their sensitivity compared with differentiated c ell lines of the mouse. Neither of the model cell lines have shown a greate r sensibility after exposure to MMC and ENU. In contrary, the carcinoma cel l line was able to tolerate higher concentrations of these genotoxicants. T herefore, SCE analysis in the ECC and ESC lines used does not provide a sui table model for genotoxicty testing on mammalian germ cells. (C) 1999 Elsev ier Science B.V. All rights reserved.