The homologous recombination component EEPD1 is required for genome stability in response to developmental stress of vertebrate embryogenesis

ABSTRACTStressed replication forks can be conservatively repaired and restarted using homologous recombination (HR), initiated by nuclease cleavage of branched structures at stalled forks. We previously reported that the 5′ nuclease EEPD1 is recruited to stressed replication forks, where it plays critical early roles in HR initiation by promoting fork cleavage and end resection. HR repair of stressed replication forks prevents their repair by non-homologous end-joining (NHEJ), which would cause genome instability. Rapid cell division during vertebrate embryonic development generates enormous pressure to maintain replication speed and accuracy. To determine the role of EEPD1 in maintaining replication fork integrity and genome stability during rapid cell division in embryonic development, we assessed the role of EEPD1 during zebrafish embryogenesis. We show here that when EEPD1 is depleted, zebrafish embryos fail to develop normally and have a marked increase in death rate. Zebrafish embryos depleted of EE...