An international research team led by Helmholtz Munich has, for the first time, provided a detailed insight into how the spatial organization of genetic material is established in the cell nucleus of early embryos within the first hours after fertilization. Surprisingly, embryos demonstrate a high degree of flexibility in responding to disruptions in this process. The study, now published in Cell, reveals that no single master regulator controls this nuclear organization. Instead, multiple redundant mechanisms ensure a robust and adaptable nuclear architecture, allowing embryos to correct errors in the initial organization of their nucleus.