Gastrulation
Gastrulation is a stage in early animal development marked by extensive cell migration[1]. When cells are reorganised in the gastrula they develop into distinct germ layers: the mesoderm, ectoderm and endoderm. Together they give the body the basis of its organs and create the external form of developing animals[2]. This positioning is controlled by morphogens, secreted proteins which determine differentiation and result in a change in the cell shape.
Gastrulation can be divided into three main processes, which are morphogenetic and have been conserved evolutionarily: Ingression, Epiboly, and Convergence and Extension.
Ingression
Mesodermal and endodermal cells move via the primitive streak, a hollow sphere of cells which form early in development[3].
References
- ↑ Hartl, D. and Ruvolo, M. (2012) Genetics: Analysis of Genes and Genomes. pp 482-483 8th Edition. United States: Jones and Bartlett Publishers, Inc.
- ↑ Solnica-Krezel, L. and Sepich, D. (2012) ‘Gastrulation: Making and Shaping Germ Layers’, Annual Review of Cell and Developmental Biology, 28(1)
- ↑ (Hartl and Ruvolo, 2012, pp. 482–483)