Changes in alkylation damage removal during in vitro neuronal differentiation.

Mouse teratocarcinoma cell lines allow the analysis of very early commitment and differentiation events, that are likely to be similar to those operating in the early mouse embryo. We have previously characterised the excision repair capabilities of these cells after ultraviolet light irradiation and found that differentiation is accompanied by reduction of excision repair. In the present study we examine the operation of an other DNA repair pathway participating in the removal of alkylation damage. O6-alkylguanine-DNA alkyltransferase (ATase) activity was determined in undifferentiated and differentiated mouse P19 teratocarcinoma cell line. To obtain more information about regulation of ATase we transfected P19 cells with constructs harbouring a human ATase cDNA driven by a housekeeping promoter.