PUBLICATION
Morphology of the developing and adult eye lens in the zebrafish
- Authors
- Dahm, R., Schonthaler, H.B., Soehn, A.S., van Marle, J., and Vrensen, G.F.
- ID
- ZDB-PUB-070504-24
- Date
- 2007
- Source
- Experimental Eye Research 85(1): 74-89 (Journal)
- Registered Authors
- Dahm, Ralf
- Keywords
- eye, ocular lens, zebrafish (Danio rerio), embryonic development, adult morphology
- MeSH Terms
-
- Animals
- Apoptosis/physiology
- Cell Differentiation/physiology
- Cell Nucleus/ultrastructure
- Embryo, Nonmammalian/anatomy & histology
- Embryo, Nonmammalian/cytology
- Embryo, Nonmammalian/ultrastructure
- Embryonic Development/physiology
- Epithelial Cells/cytology
- Epithelial Cells/ultrastructure
- Gap Junctions/ultrastructure
- In Situ Nick-End Labeling/methods
- Iris/anatomy & histology
- Lens, Crystalline/cytology*
- Lens, Crystalline/embryology
- Lens, Crystalline/ultrastructure
- Microscopy, Electron/methods
- Microscopy, Electron, Scanning/methods
- Microscopy, Interference/methods
- Models, Animal
- Zebrafish/anatomy & histology*
- Zebrafish/embryology
- PubMed
- 17467692 Full text @ Exp. Eye. Res.
Citation
Dahm, R., Schonthaler, H.B., Soehn, A.S., van Marle, J., and Vrensen, G.F. (2007) Morphology of the developing and adult eye lens in the zebrafish. Experimental Eye Research. 85(1):74-89.
Abstract
The zebrafish has become an important vertebrate model organism to study the development of the visual system. Mutagenesis projects have resulted in the identification of hundreds of eye mutants. Analysis of the phenotypes of these mutants relies on in depth knowledge of the embryogenesis in wild-type animals. While the morphological events leading to the formation of the retina and its connections to the central nervous system have been described in great detail, the characterization of the development of the eye lens is still incomplete. In the present study, we provide a morphological description of embryonic and larval lens development as well as adult lens morphology in the zebrafish. Our analyses show that, in contrast to other vertebrate species, the zebrafish lens delaminates from the surface ectoderm as a solid cluster of cells. Detachment of the prospective lens from the surface ectoderm is facilitated by apoptosis. Primary fibre cell elongation occurs in a circular fashion resulting in an embryonic lens nucleus with concentric shells of fibres. After formation of a monolayer of lens epithelial cells, differentiation and elongation of secondary lens fibres result in a final lens morphology similar to that of other vertebrate species. As in other vertebrates, secondary fibre cell differentiation includes the programmed degradation of nuclei, the interconnection of adjacent fibres via protrusions at the fibre cells' edges and the establishment of gap junctions between lens fibre cells. The very close spacing of the nuclei of the differentiating secondary fibres in a narrow zone close to the equatorial epithelium, however, suggests that secondary fibre cell differentiation deviates from that described for mammalian or avian lenses. In summary, while there are similarities in the development and final morphology of the zebrafish lens with mammalian and avian lenses, there are also significant differences, suggesting caution when extrapolating findings on the zebrafish to, for example, human lens development or function.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping