Modeling gastrulation in the chick embryo: formation of the primitive streak

• Published in: PloS one Vol. 5; no. 5; p. e10571
• Main Authors: Vasiev, Bakhtier, Balter, Ariel, Chaplain, Mark, Glazier, James A, Weijer, Cornelis J
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 11.05.2010; Public Library of Science (PLoS)
• Subjects: Analysis; Animals; Biology; Cell Differentiation; Cell division; Cell migration; Cell Polarity; Cell Proliferation; Chemotaxis; Chick Embryo; Cloning; Computational Biology; Computational Biology/Evolutionary Modeling; Computational Biology/Systems Biology; Computer Simulation; Developmental Biology/Embryology; Embryo; Embryonic development; Endoderm; Endoderm - cytology; Gastrulation; Gastrulation - physiology; Germ Layers - cytology; Growth factors; Mathematical models; Mathematics; Mesoderm; Models, Biological; Primitive streak; Primitive Streak - cytology; Primitive Streak - embryology; Trends; Indiana; United Kingdom > UK; United States > US
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0010571

The body plan of all higher organisms develops during gastrulation. Gastrulation results from the integration of cell proliferation, differentiation and migration of thousands of cells. In the chick embryo gastrulation starts with the formation of the primitive streak, the site of invagination of mesoderm and endoderm cells, from cells overlaying Koller's Sickle. Streak formation is associated with large-scale cell flows that carry the mesoderm cells overlying Koller's sickle into the central midline region of the embryo. We use multi-cell computer simulations to investigate possible mechanisms underlying the formation of the primitive streak in the chick embryo. Our simulations suggest that the formation of the primitive streak employs chemotactic movement of a subpopulation of streak cells, as well as differential adhesion between the mesoderm cells and the other cells in the epiblast. Both chemo-attraction and chemo-repulsion between various combinations of cell types can create a streak. However, only one combination successfully reproduces experimental observations of the manner in which two streaks in the same embryo interact. This finding supports a mechanism in which streak tip cells produce a diffusible morphogen which repels cells in the surrounding epiblast. On the other hand, chemotactic interaction alone does not reproduce the experimental observation that the large-scale vortical cell flows develop simultaneously with streak initiation. In our model the formation of large scale cell flows requires an additional mechanism that coordinates and aligns the motion of neighboring cells.