DNA demethylation, a process involving DNA repair, is critical for reprogramming of the paternal genome during the oocyte-to-zygote transition. A new study by Ladstätter and Tachibana-Konwalski shows that a Chk1-mediated zygotic checkpoint monitors the cohesin-dependent repair of DNA lesions arising from DNA demethylation, which prevents zygotes carrying unrepaired lesions from entering mitosis.
Zou, L. (2016, December 15). A Zygotic Checkpoint for Unrepaired Lesions. Cell. Cell Press. https://doi.org/10.1016/j.cell.2016.11.049