PUBLICATION
Abundant corneal gelsolin in Zebrafish and the 'four-eyed' fish, Anableps anableps: possible analogy with multifunctional lens crystallins
- Authors
- Kanungo, J., Swamynathan, S.K., and Piatigorsky, J.
- ID
- ZDB-PUB-050113-1
- Date
- 2004
- Source
- Experimental Eye Research 79(6): 949-956 (Journal)
- Registered Authors
- Piatigorsky, Joram
- Keywords
- crystallin; cornea; gelsolin; zebrafish
- MeSH Terms
-
- Animals
- Cornea/anatomy & histology
- Cornea/metabolism*
- Crystallins/genetics
- Crystallins/metabolism*
- Fishes/anatomy & histology
- Fishes/metabolism*
- Gelsolin/metabolism*
- Gene Expression
- In Situ Hybridization
- Lens, Crystalline/metabolism
- RNA, Messenger/genetics
- Reverse Transcriptase Polymerase Chain Reaction/methods
- Zebrafish/anatomy & histology
- Zebrafish/metabolism
- PubMed
- 15642334 Full text @ Exp. Eye. Res.
Citation
Kanungo, J., Swamynathan, S.K., and Piatigorsky, J. (2004) Abundant corneal gelsolin in Zebrafish and the 'four-eyed' fish, Anableps anableps: possible analogy with multifunctional lens crystallins. Experimental Eye Research. 79(6):949-956.
Abstract
The cornea accumulates high proportions (can be up to 50%) of taxon-specific, water-soluble, cytoplasmic proteins (often enzymes) that have been considered analogous to the multifunctional lens crystallins. We have shown that gelsolin (an actin-severing protein) is the major water-soluble corneal protein of the zebrafish (Danio rerio) and the 'four-eyed' fish (Anableps anableps). Each Anableps eye contains one lens, an aquatic ventral cornea with an epithelium comprising 5-7 cell layers, and an air-exposed flatter dorsal cornea with an epithelium comprising >20 cell layers and appreciably enriched with glycogen. Gelsolin accounts for 38 and 21% of the dorsal and ventral cornea, respectively, suggesting that the abundance of gelsolin in the cornea is not incompatible with its function in air. The thicker, glycogen-enriched, air-exposed dorsal cornea may protect against UV irradiation and desiccation. Gelsolin comprises approximately 50% of the 5 cell-layer thick aquatic corneal epithelium of zebrafish. Reported zebrafish ESTs have indicated the presence of a second gelsolin gene in this species. We show by RT-PCR that the abundant corneal gelsolin (also expressed weakly in lens) (C/L-gelsolin) is also expressed in early development and differs from a ubiquitously expressed gelsolin (U-gelsolin) that is not specialized for cornea. Microinjection tests showed that overexpression of C/L-gelsolin dorsalizes the embryo and can lead to axis duplication, while interruption of C/L-gelsolin expression with a specific morpholino oligonucleotide ventralizes the embryo and interferes with brain and eye development. The evidence that C/L-gelsolin participates in the bone morphogenetic protein (BMP)/Smad dorsal-ventral signaling pathway is reviewed. Finally, we speculate that soluble C/L-gelsolin:actin complexes in the cornea may be analogous to soluble alphaA:alphaB-crystallin complexes in the lens. Together, our data are consistent with an analogy between the abundance of gelsolin in fish corneas and taxon-specific multifunctional crystallins in lenses.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping