CHANGES IN ALKYLATION DAMAGE REMOVAL DURING IN-VITRO NEURONAL DIFFERENTIATION

Mouse teratocarcinoma cell lines allow the analysis of very early comm itment and differentiation events, that are likely to be similar to th ose operating in the early mouse embryo. We have previously characteri sed the excision repair capabilities of these cells after ultraviolet light irradiation and found that differentiation is accompanied by red uction of excision repair. In the present study we examine the operati on of an other DNA repair pathway participating in the removal of alky lation damage. O-6-alkylguanine-DNA alkyltransferase (ATase) activity was determined in undifferentiated and differentiated mouse P19 terato carcinoma cell line. To obtain more information about regulation of AT ase we transfected P19 cells with constructs harbouring a human ATase cDNA driven by a housekeeping promoter.