YSL nuclei movement in MZnanog embryos is impaired. Embryos were injected with SYTOX Green at 1-cell stage to visualize YSL. The movie was started when the control wild type embryos reached oblong stage, frames were taken every 3 min. Embryo below is in animal view, embryo above is in lateral view. Note that no nuclei movement or doming is visible until the yolk lysis.