Vision - Cornea Development: Difference between revisions
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:'''Links:''' [[Frog Development]] | :'''Links:''' [[Frog Development]] | ||
==Mouse Cornea== | |||
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| [[File:Mouse eye neural crest.jpg|alt=histology Mouse eye neural crest|400px]] | |||
Neural crest-derived cells contribute to mouse cornea development.<ref name = PMID16403239><pubmed>16403239</pubmed>| [http://jbiol.com/content/4/3/11 J Biol.]</ref> | |||
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* '''a''' Toluidine blue staining of an adult eye. The boxed areas correspond to b and c | |||
* '''b''' A detailed view of the corneal assembly, including outer epithelium, stroma, and inner endothelium | |||
* '''c''' The chamber angle at the irido-corneal transition which includes the trabecular meshwork (tm). | |||
* '''d-j''' In vivo fate mapping of NC-derived, β-galactosidase (βGal)-expressing cells (blue) | |||
* '''d''' The NC origin of corneal keratocytes (arrows) and of corneal endothelium (arrowhead). | |||
* '''e''' Structures of the chamber angle, including the trabecular meshwork are seen to be NC-derived. | |||
* '''f''' At E10, the optic cup is surrounded by NC-derived cells expressing βGal. | |||
* '''g-i''' The majority of the cells in the periocular mesenchyme (arrows), which forms the anterior eye segment, are of NC origin, as assessed from E11.5 to E13.5. | |||
* '''j''' The primary vitreous at E13.5 (arrowheads) shows a strong NC contribution. | |||
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==Cornea Epithelia== | ==Cornea Epithelia== | ||
{| | {| |
Revision as of 14:25, 30 August 2014
Embryology - 17 Jun 2024 Expand to Translate |
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Introduction
These notes introduce the development of the cornea of the eye. The adult cornea has three layers: an outer epithelium layer, a middle stromal layer of collagen-rich extracellular matrix between keratocytes and an inner layer of endothelial cells.
Some Recent Findings
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More recent papers |
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This table allows an automated computer search of the external PubMed database using the listed "Search term" text link.
More? References | Discussion Page | Journal Searches | 2019 References | 2020 References Search term: Cornea Development <pubmed limit=5>Cornea Development</pubmed> Search term: Cornea Embryology <pubmed limit=5>Cornea Embryology</pubmed> |
Frog Cornea
This developmental timeline is from a recent frog (Xenopus laevis) cornea study[2]
- stage 25 - cornea starts from a simple embryonic epidermis overlying the developing optic vesicle.
- stage 30 - detachment of the lens placode, cranial neural crest cells start to invade the space between the lens and the embryonic epidermis to construct the corneal endothelium.
- stage 41 - a second wave of migratory cells containing presumptive keratocytes invades the matrix leading to the formation of inner cornea and outer cornea. A unique cell mass (stroma attracting center) connects the two layers like the center pole of a tent.
- stage 48 - many secondary stromal keratocytes individually migrate to the center and form the stroma layer.
- stage 60 - the stroma space is filled by collagen lamellae and keratocytes, and the stroma attracting center disappears. At early metamorphosis, the embryonic epithelium gradually changes to the adult corneal epithelium, which is covered by microvilli.
- stage 62 - the embryonic epithelium thickens and cell death is observed in the epithelium, coinciding with eyelid opening.
- After metamorphosis - cornea has attained the adult structure of three cellular layers, epithelium, stroma, and endothelium, and between the cellular layers lie two acellular layers (Bowman's layer and Descemet's membrane)
- Links: Frog Development
Mouse Cornea
Neural crest-derived cells contribute to mouse cornea development.[3] |
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Cornea Epithelia
The cornea ocular surface is composed of three epithelia, conjunctival, limbal and corneal.
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Corneal epithelial cells cartoon[4] |
The Adult Human Limbal Palisades of Vogt
Bar represents 500 μm in A and B, 200 μm in C and E, and 50 μm in D
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Adult human limbal palisades of Vogt[5] |
Limbal Stem Cells
Cartoon showing the location of limbal stem cells at the limbal basal layer.[5]
- Links: Stem Cells
Carnegie Stages - Eye
The following data is from a study of human embryonic carnegie stages[6] and other sources.
- Stage 10 - optic primordia appear.
- Stage 11 - right and left optic primordia meet at the optic chiasma forming a U-shaped rim.
- Stage 12 - optic neural crest reaches its maximum extent and the optic vesicle becomes covered by a complete sheath,
- Stage 13 - By the end of the fourth week the optic vesicle lies close to the surface ectoderm. Optic evagination differentiation allows identification of optic part of retina, future pigmented layer of retina, and optic stalk. The surface ectoderm overlying the optic vesicle, in response to this contact, has thickened to form the lense placode.
- Stage 14 - (about 32 days) the lens placode is indented by the lens pit, cup-shaped and still communicates with the surface by a narrowing pore.
- Stage 15 - (about 33 days) the lens pit is closed. The lens vesicle and optic cup lie close to the surface ectoderm and appear to press against the surface.
- Stage 16 - (37 days) Growth of the lens body results in a D-shaped lens cavity. Perilental blood vessels (tunica vasculosa lentis) are visible. Prior to the development of the eyelids, one small sulcus or groove forms above the eye (eyelid groove) and another below it.
- Stages 17 - 19 - Retinal pigment is visible and the retinal fissure is largely closed. Eyelids grooves deepen, eyelid folds develop, first below, and then above, the eye.
- Stages 18 - Mesenchyme invades the region between the lens epithelium and the surface ectoderm.
- Stages 19 - 22 - the eyelid folds develop into the eyelids and cover more of the eye as the palpebral fissure takes shape. The upper and the lower eyelids meet at the outer canthus in Stage 19.
- Stage 20 - The lens cavity is lost and a lens suture begins to form. The inner canthus is established.
- Stage 23 - The retina comprises the pigmented layer, external limiting membrane, proliferative zone, external neuroblastic layer, transient fiber layer, internal neuroblastic layer, nerve fiber layer, and internal limiting membrane. Eyelids closure is complete (Note - shown as still open in the Kyoto embryo).
Molecular
Mouse Eye TGF-beta Model - Summary of the TGFβ-dependent development of anterior and posterior ocular structures. [3]
a Neural crest-derived cells (NC, blue) contribute to structures of the anterior eye segment and the primary vitreous (PV).
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b In the cornea, prospective stromal keratocytes and endothelial cells are of neural crest origin.
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Additional Images
Historic Images
References
Reviews
<pubmed></pubmed> <pubmed>23819758</pubmed> <pubmed>20599432</pubmed>| PMC3726544 <pubmed>19343693</pubmed>
The International Journal of Developmental Biology Vol. 48 Nos. 8/9 (2004) Eye Development
Articles
<pubmed></pubmed> <pubmed></pubmed> <pubmed>13429485</pubmed>| PMC1358888
Bookshelf cornea development
Search Pubmed
Search Pubmed: cornea development
Search Entrez: cornea development
Terms
- Limbal epithelial stem cells - cells located at the limbal basal layer.
- palisades of Vogt
External Links
External Links Notice - The dynamic nature of the internet may mean that some of these listed links may no longer function. If the link no longer works search the web with the link text or name. Links to any external commercial sites are provided for information purposes only and should never be considered an endorsement. UNSW Embryology is provided as an educational resource with no clinical information or commercial affiliation.
- UNSW SoMS research - Ocular Diseases Research Group
- UNSW Virtual Slides Eye Development Histology (requires login)
Glossary Links
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Cite this page: Hill, M.A. (2024, June 17) Embryology Vision - Cornea Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Vision_-_Cornea_Development
- © Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G