Drosophila ATM and Mre11 are essential for the G2/M checkpoint induced by low-dose irradiation

Others have suggested recently that the conserved ATM checkpoint kinase is minimally involved in controlling the G(2)/M checkpoint in Drosophila that serves to prevent mitotic entry in the presence of DNA damage. Our data indicate that both ATM and its regulator Mre11 are important for the checkpoint and that their roles become essential when animals are challenged with a low dose of X rays or when they have compromised checkpoint function of the ATM-related ATR kinase.