Unilateral corneal insult in Zebrafish results in a bilateral cell shape and identity modification, supporting wound closure

Most of terrestrial and aquatic vertebrates are equipped with camera-type eyes, offering a focused and clear sight. This apparatus is rendered inefficient if its most superficial and transparent element, the cornea, is opaque. This structure, prone to environmental aggressions, bears excellent wound healing capabilities to preserve vision. Up to date, most of the corneal wound healing studies are made on mammals. Here, for the first time, zebrafish is used as model to study wound closure of corneal epithelium after abrasion. Our study demonstrates a swift wound closure after corneal insult. Interestingly, a unilateral wound induces a bilateral response. While cell proliferation is increased during wound closure, this parameter is not crucial, and cell rearrangements seems to be the driving force. Furthermore, we discovered a profound change in epithelial cell transcriptomic signature after abrasion, reflecting a modulation of cell identity and increase of phenotypic plasticity. The latter seems to unlock terminally differentiated cell capacities for wound healing, which could be the key for a speed up organ regeneration. Our results prove that zebrafish cornea is a powerful model to investigate, not only corneal wound healing, but ectodermal organ pathophysiology.