To gain insight into the role of AP endonucleases a er embryogenesis, we measured the temporal change in the mRNA expression level of
exo-3 or
apn-1. At 0, 24 and 48 hours, when most N2 worms are in the egg stage, L1 stage and L4 stage, respectively, no di erence in mRNA expression level was found for both
exo-3 and
apn-1. At 60 hours, when most N2 worms are in the young adult stage, the
exo-3 and
apn-1 expression levels were approximately 13-fold and 2.3- fold higher than those at 0 hours, respectively. e expression level at 72 hours, when most N2 worms are in the gravid adult stage, was the same at 60 hours. These results suggest that AP endonucleases are required after embryogenesis, especially a er the L4 stage.