Maternal SMC2 Is Essential for Embryonic Development via Participating in Chromosome Condensation in Mice

During oocyte growth, maturation and zygote development, chromatin structure undergoes continuous changes to regulate different nuclear activities. Condensin plays an essential role in chromatin configuration. Here, through oocyte-specific conditional knockout of SMC2, a core component of the condensin complex, we showed that SMC2 is essential for the production of healthy eggs and early embryo development. Maternal SMC2 knockout caused chromosome condensation defects in oocytes, and subsequently inhibited proper pronuclear organization in zygotes. As a result, pronuclear function was impaired and DNA damage was accumulated, which prevented the development of embryos beyond the zygote stage.