Loss of alpha Ba-crystallin, but not alpha A-crystallin, increases age-related cataract in the zebrafish lens

The vertebrate eye lens is an unusual organ in that most of its cells lack nuclei and the ability to replace aging protein. The small heat shock protein α-crystallins evolved to become key components of this lens, possibly because of their ability to prevent aggregation of aging protein that would otherwise lead to lens opacity. Most vertebrates express two α-crystallins, αA- and αB-crystallin, and mutations in each are linked to human cataract. In a mouse knockout model, only the loss of αA-crystallin led to early-stage lens cataract. We have used the zebrafish as a model system to investigate the role of α-crystallins during lens development. Interestingly, while zebrafish express one lens-specific αA-crystallin gene (cryaa), they express two αB-crystallin genes, with one evolving lens specificity (cryaba) and the other retaining the broad expression of its mammalian ortholog (cryabb). In this study, we used individual mutant zebrafish lines for all three α-crystallin genes to determi..., Lenses from adult wildtype fish and each of our three α-crystallin mutant lines were removed at 6, 12, 18, and 24 months to assess any abnormalities. Fish within one month of these ages were pooled together to represent that age. One fish from each tank was genotyped to confirm their identity and fish were not selected based on any apparent differences between individuals. We collected lenses from at least 10 fish of each age, except for 24 months, when at least 15 fish were used. The standard length of each fish was measured by ruler and any opacity of the lens or cornea from the intact eye was noted. Lenses were dissected from anesthetized individuals, placed in PBS, and imaged under a dissecting microscope at 40X total magnification over a stage micrometer. Lenses were imaged within 15 minutes of removal and placement in PBS as we often saw a visible optical separation between the lens nucleus and cortex after prolonged incubation in PBS. Images have not been processed in any way. Fo..., , # Loss of alpha Ba-crystallin, but not alpha A-crystallin, increases age-related cataract in the zebrafish lens

[https://doi.org/10.5061/dryad.f4qrfj730](https://doi.org/10.5061/dryad.f4qrfj730)

# Description of the data and file structure

This dataset contains images of excised zebrafish lenses from wild-type and mutant strains at 6, 12, 18, and 24 months of age. These images were used to analyze the effects of alpha crystallin loss on the development of eye lens cataract during aging.

The primary data folder contains four folders labeled with each zebrafish strain. Three are mutants with CRISPR-damaged alpha crystallin genes and the fourth is a wild-type ZDR strain.

• cryaa mutant

• cryaba mutant

• cryabb mutant

• wild type

Each of these folders contains subfolders with lens images from four different ages (6, 12, 18, and 24 months).

Within each of these age folders are individual folders that list the date images were taken, the zebrafish strain, and its age. Individu...