title: A conserved role of αA-crystallin in the development of the zebrafish embryonic lens.
abstract: αA- and αB-crystallins are small heat shock proteins that bind thermodynamically destabilized proteins thereby inhibiting their aggregation. Highly expressed in the mammalian lens, the α-crystallins have been postulated to play a critical role in the maintenance of lens optical properties by sequestering age-damaged proteins prone to aggregation as well as through a multitude of roles in lens epithelial cells. Here, we have examined the role of α-crystallins in the development of the vertebrate zebrafish lens. For this purpose, we have carried out morpholino-mediated knockdown of αA-, αBa- and αBb-crystallin and characterized the gross morphology of the lens. We observed lens abnormalities, including increased reflectance intensity, as a consequence of the interference with expression of these proteins. These abnormalities were less frequent in transgenic zebrafish embryos expressing rat αA-crystallin suggesting a specific role of α-crystallins in embryonic lens development. To extend and confirm these findings, we generated an αA-crystallin knockout zebrafish line. A more consistent and severe lens phenotype was evident in maternal/zygotic αA-crystallin mutants compared to those observed by morpholino knockdown. The penetrance of the lens phenotype was reduced by transgenic expression of rat αA-crystallin and its severity was attenuated by maternal αA-crystallin expression. These findings demonstrate that the role of α-crystallins in lens development is conserved from mammals to zebrafish and set the stage for using the embryonic lens as a model system to test mechanistic aspects of α-crystallin chaperone activity and to develop strategies to fine-tune protein-protein interactions in aging and cataracts.
authors.affiliation: Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA.
authors.forename: Ping
authors.initials: P
authors.lastname: Zou
authors.affiliation: Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA.
authors.forename: Shu-Yu
authors.initials: SY
authors.lastname: Wu
authors.affiliation: Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA.
authors.forename: Hanane A
authors.initials: HA
authors.lastname: Koteiche
authors.affiliation: Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA.
authors.forename: Sanjay
authors.initials: S
authors.lastname: Mishra
authors.affiliation: Department of Medicine, Division of Genetic Medicine, Vanderbilt University Medical Center, Nashville, TN, 37232, USA.
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Levic
authors.affiliation: Department of Medicine, Division of Genetic Medicine, Vanderbilt University Medical Center, Nashville, TN, 37232, USA.
authors.forename: Ela
authors.initials: E
authors.lastname: Knapik
authors.affiliation: Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA.
authors.forename: Wenbiao
authors.initials: W
authors.lastname: Chen
authors.affiliation: Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA. Electronic address: hassane.mchaourab@Vanderbilt.Edu.
authors.forename: Hassane S
authors.initials: HS
authors.lastname: Mchaourab
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D015153:Blotting, Western; D004591:Electrophoresis, Polyacrylamide Gel; D004625:Embryo, Nonmammalian / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D055786:Gene Knockout Techniques; D007908:Lens, Crystalline / Q000196:embryology*; D060888:Real-Time Polymerase Chain Reaction; D015027:Zebrafish / Q000196:embryology*; D038202:alpha-Crystallin A Chain / Q000502:physiology*
chemical_list: D038202:alpha-Crystallin A Chain
keywords: Alpha-crystallin; Cataract; Chaperone; Lens development; Maternal transcript; Morpholino; Small heat shock protein; TALEN; Zebrafish