Drosophila Embryo Morphogenesis

Drosophila embryo morphogenesis is the process from which a fertilized single cell egg becomes a multicellular embryo with structured tissues and specialized cells/organs. This process occurs through many complex cell shape changes and movements, called gastrulation.

Initially, the fertilized egg divides many times and becomes a hollow ball of cells (called cellular blastoderm). The posterior end of the embryo (to the right) migrates up and over the top (dorsal surface) of the embryo in a process called germband extension, which is responsible for delivery of specific cell types to the interior of the embryo. After this is accomplished, the reverse process (called germband retraction) occurs leaving a large open hole on the dorsal surface of the embryo. Dorsal closure then takes place to close the hole by zipping up the surrounding epidermis over the amnioserosa cells, which overlays the dorsal hole. At this point, the embryo has completed embryogenesis and is ready to proceed with hatching.

Kaufman and colleagues have generated a movie of fly embryo morphogenesis using similar scanning EMs. It is a 'must see': FLY MORPH-O-GENESIS. For other morphogenesis images, visit: The Interactive Fly.