The strategy employed to provide food for an early embryo influences cleavage pattern During early development, there is a transition from maternal control to embryonic control of development. The mid-blastula transition is characterized by a switch to longer cell cycles and increased embryonic transcription.
Gastrulation is the process by which presumptive endoderm and mesoderm are internalized.
This involves active and coordinated cell movements. Distinct types of cell movements are employed during gastrulation. The egg and early embryo may contain localized cytoplasmic determinants. Cleavage proceeds gastrulation. The cleavage pattern of the embryo is influenced by the amount of yolk in the egg.