The stage during insect embryogenesis in which the cleavage nuclei lie at the surface of the egg in a common cytoplasm. Subsequently the cellularization of the blastoderm occurs. In Drosophila there are 13 rapid synchronous divisions resulting in about 8,000 nuclei which migrate to the cortical ooplasm and then cellularize. The transition from the syncytial blastoderm to the cellular blastoderm corresponds to the time the control of embryogenesis by maternal genes switches to control by the zygotic genome.
Subjects: Genetics and Genomics.