Base excision repair in early zebrafish development: evidence for DNA polymerase switching and standby AP endonuclease activity

The first three steps of base excision repair (BER) in zebrafish extracts from unfertilized eggs, embryos at different developmental stages, and adults were characterized to gain insight into (BER) pathway involved in recognition and repairs of most nonbulky lesions, uracil and abasic (AP) sites in DNA during embryogenesis. The results indicated that switch to normal, adult BER occured fully when the embryos hatched from the chorionic membrane and encountered normal oxidative stress.