# Pannexin 1a regulates visual system development and ocular integrity in zebrafish

## TL;DR

This study shows that Pannexin 1a is crucial for eye development and function in zebrafish, as its absence leads to vision problems, eye structure issues, and retinal thinning.

## Contribution

The study identifies Pannexin 1a as a key regulator of ocular integrity and refractive development in zebrafish.

## Key findings

- Panx1a deficiency causes impaired visuomotor behavior and reduced contrast sensitivity in zebrafish larvae.
- Adult zebrafish lacking Panx1a show axial myopia and progressive lens disruption.
- Retinal thinning and ganglion cell loss are observed in Panx1a−/− zebrafish.

## Abstract

Pannexin 1a (Panx1a), a large-pore ATP release channel broadly expressed in the vertebrate eye, has an unclear role in ocular development. Using a zebrafish Panx1a knockout, we observed progressive ocular phenotypes, including impaired visuomotor behavior, axial myopia, cataract-like lens abnormalities, lens defects, and retinal thinning. Optokinetic response (OKR) assays revealed markedly reduced responsiveness in Panx1a−/− larvae, with response rates declining from 91.7% to 50% at 20% contrast and from 100% to 41.7% at 100% contrast, along with prolonged saccade intervals (2-fold at 20% and 4-fold at 100% contrast). High-resolution optical coherence tomography (OCT) in adults showed increased normalized axial length (7–8% across ages) and reduced lens-to-axial length ratios (0.58 vs. 0.63 at 8 months). Histology revealed age-dependent lens epithelial disruption and increased light scatter. Retinal analyses demonstrated thinning of the whole retina (10%) and ganglion cell layer (33%), with occasional vascular tortuosity. Together, these findings identify Panx1a as a key regulator of ocular integrity and refractive development in zebrafish.

•Optimized whole-eye and retinal OCT enables detailed analysis of adult zebrafish eye structure•Panx1a loss impairs larval visuomotor behavior and reduces contrast sensitivity•Whole-eye OCT reveals axial myopia and age-progressive lens disruption in Panx1a−/− adults•Panx1a deficiency causes retinal thinning, ganglion cell loss, and tortuous blood vessels

Optimized whole-eye and retinal OCT enables detailed analysis of adult zebrafish eye structure

Panx1a loss impairs larval visuomotor behavior and reduces contrast sensitivity

Whole-eye OCT reveals axial myopia and age-progressive lens disruption in Panx1a−/− adults

Panx1a deficiency causes retinal thinning, ganglion cell loss, and tortuous blood vessels

Molecular neuroscience; Developmental neuroscience; Sensory neuroscience