Ingression (biology)

Ingression is a biological process that plays a crucial role in embryogenesis, the process by which an embryo forms and develops. It is a type of cell migration that occurs during the formation of the gastrula, a stage in embryonic development.

Overview

Ingression involves individual cells detaching from the epithelium, the outer layer of cells, and migrating into the interior of the embryo. This process is essential for the formation of the three primary germ layers: the ectoderm, mesoderm, and endoderm. These layers give rise to all the tissues and organs of the organism.

Mechanism

The mechanism of ingression is complex and involves changes in cell shape, cell adhesion, and cell motility. Cells undergoing ingression first change their shape from columnar to bottle-shaped. This is followed by a reduction in cell adhesion, allowing the cells to detach from the epithelium. The cells then increase their motility, enabling them to migrate into the interior of the embryo.

Role in Development

Ingression is a critical process in the formation of the gastrula. It allows cells to move to their correct positions within the embryo, where they can differentiate into the appropriate cell types. Ingression is also involved in the formation of the neural crest, a group of cells that give rise to many different tissues and organs, including the nervous system, skeletal system, and cardiovascular system.

See Also

• Cell migration
• Gastrulation
• Embryogenesis
• Germ layers