It happens in the first hours after fertilization: The cells of the early embryo begin to independently produce proteins, the building blocks for cells and organs. Their own, uniquely composed genetic material serves as the blueprint. In vertebrates, the starting signal for this process comes from three maternal proteins that bind to the DNA of the offspring. New findings now show, using a zebrafish model, how two of these three start proteins of the egg cell elicit their roles and how they act in further development.