Gastrulation: Difference between revisions
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This process occurs at the primitive streak where epiblast cells undergo an epithelial to mesenchymal transition in order to delaminate and migrate. | This process occurs at the primitive streak where epiblast cells undergo an epithelial to mesenchymal transition in order to delaminate and migrate. | ||
==Some Recent Findings== | |||
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* '''Zebrafish eve1 regulates the lateral and ventral fates of mesodermal progenitor cells at the onset of gastrulation'''<ref><pubmed>20950598</pubmed></ref> "Our data show that Eve1 functions together with Ved, Vent and Vox in a transcriptional network to prevent the spread of anti-Bmp gene activity from the dorsal side, leading to the establishment of the Bmp gradient activity along the dorsoventral axis to induce distinct transcriptional outputs in mesodermal progenitor cells (MPCs) to maintain the lateral and ventral MPC fates during gastrulation." | |||
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== Human Gastrulation == | == Human Gastrulation == |
Revision as of 13:39, 29 November 2010
Introduction
Gastrulation means the formation of gut (Greek, gastrula = belly), but has now a more broad sense to to describe the formation of the trilaminar embryo. The epiblast layer, consisting of totipotential cells, derives all 3 embryo layers: endoderm, mesoderm and ectoderm. The primitive streak is the visible feature which represents the site of cell migration to form the additional layers.
Historically, gastrulation was one of the earliest observable morphological event occurring in the frog embryo. Currently, the molecular and physical mechanisms that regulate patterning and migration during this key event are being investigated in several different animal models. In humans, it is proposed that similar mechanisms regulate gastrulation to those found in other vertebrates.
- primitive node - region in the middle of the early embryonic disc epiblast from which the primitive streak extends caudally (tail)
- nodal cilia establish the embryo left/right axis
- axial process extends from the nodal epiblast
- primitive streak - region of cell migration from the epiblast layer forming sequentially the two germ cell layers (endoderm and mesoderm)
Epithelial to Mesenchymal Transition
Epithelial cells (organised cellular layer) which loose their organisation and migrate/proliferate as a mesenchymal cells (disorganised cellular layers) are said to have undergone an Epithelial Mesenchymal Transition (EMT). Mesenchymal cells have an embryonic connective tissue-like cellular arrangement, that have undergone this process may at a later time and under specific signaling conditions undergo the opposite process, mesenchyme to epithelia. In development, this process can be repeated several times during tissue differentiation.
This process occurs at the primitive streak where epiblast cells undergo an epithelial to mesenchymal transition in order to delaminate and migrate.
Some Recent Findings
|
Human Gastrulation
The site of gastrulation, the primitive streak is visible during week 3 on the epiblast dorsal surface of the stage 7 embryonic disc.
Gastrulation Concepts
Links: Chicken Development
Gastrulation Movies
Additional Images
References
- ↑ <pubmed>20950598</pubmed>
Reviews
Articles
<pubmed></pubmed>
Books
Search Pubmed
Search Pubmed Now: gastrulation
External Links
- UNSW Embryology Movie - Gastrulation | Epithelial Mesenchymal Transition
Glossary Links
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Cite this page: Hill, M.A. (2024, April 25) Embryology Gastrulation. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Gastrulation
- © Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G