PUBLICATION

Zebrafish Optical Development Requires Regulated Water Permeability by Aquaporin 0

Authors
Safrina, O., Vorontsova, I., Donaldson, P.J., Schilling, T.F.
ID
ZDB-PUB-240928-5
Date
2024
Source
Investigative ophthalmology & visual science   65: 4242 (Journal)
Registered Authors
Schilling, Tom
Keywords
none
MeSH Terms
  • Animals
  • Water*/metabolism
  • Animals, Genetically Modified
  • Calcium/metabolism
  • Lens, Crystalline*/metabolism
  • Gene Expression Regulation, Developmental
  • Eye Proteins*/genetics
  • Eye Proteins*/metabolism
  • Permeability
  • Aquaporins*/genetics
  • Aquaporins*/metabolism
  • Zebrafish*
  • Zebrafish Proteins/genetics
  • Zebrafish Proteins/metabolism
PubMed
39330988 Full text @ Invest. Ophthalmol. Vis. Sci.
Abstract
Optical development of the zebrafish eye relies on the movement of the highly refractive lens nucleus from an anterior to a central location in the optical axis during development. We have shown that this mechanism in turn depends on the function of Aquaporin 0a (Aqp0a), a multifunctional and extremely abundant protein in lens fiber cell membranes. Here, we probe the specific cellular functions necessary for rescuing lens nucleus centralization defects in aqp0a-/- null mutants by stable overexpression of an Aqp0 orthologue from a killifish, MIPfun.
We test in vivo requirements for lens transparency and nucleus centralization of MIPfun for auto-adhesion, water permeability (Pf), and Pf sensitivity to regulation by Ca2+ or pH by overexpression of MIPfun mutants previously shown to have defects in these functions in vitro or in silico.
Water permeability of MIPfun is essential for rescuing lens transparency and nucleus centralization defects, whereas auto-adhesion is not. Furthermore, water permeability regulation by Ca2+ and pH appear residue-dependent, because some Ca2+-insensitive mutants fail to rescue, and pH-insensitive mutants only partially rescue defects. MIPfun lacking Pf sensitivity to both, Ca2+ and pH, also fails to rescue lens nucleus centralization.
This study shows that regulation of water permeability by Aqp0 plays a key role in the centralization of the zebrafish lens nucleus, providing the first direct evidence for water transport in this aspect of optical development.
Genes / Markers
Figures
Show all Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping