#Id: 7157
#Unit 5. Developmental Biology
Gray Crescent
The region opposite the point of sperm entry, where the greatest displacement of cytoplasm occurs (Gastrulation will begin)
Vegetal rotation: Vegetal cells asymmetrically press up against the inner blastocoel roof on the dorsal side.
Bottle cell formation and invagination: Localized apical constriction at the dorsal blastopore lip creates anisotropic forces that foster invagination.
Involution and cell migration: The leading edge of invaginating cells crawls up onto the blastocoel roof.
Convergence and extension: The targeted medial-to-lateral intercalation of cells on the midline (convergence) drives anterior-posterior axis elongation (extension).
