DPPA2 and DPPA4 are dispensable for mouse zygotic genome activation and preimplantation development

How maternal factors in oocytes initiate zygotic genome activation (ZGA) remains elusive. Recent studies indicate that DPPA2 and DPPA4 are required for establishing a 2-cell embryo-like (2C-like) state in mouse embryonic stem cells (ESCs) in a DUX-dependent manner. These results suggest that DPPA2 and DPPA4 are essential maternal factors that regulate Dux and ZGA in embryos. By analyzing maternal knockout and maternal-zygotic knockout embryos, we unexpectedly found that Dux activation, ZGA, and preimplantation development are normal in embryos without DPPA2 or DPPA4. Thus, unlike in ESCs/2C-like cells, DPPA2 and DPPA4 are dispensable for ZGA and preimplantation development.