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Biology subjects

Ikkala, K.

Publications and source records attributed to Ikkala, K..

3 recordsLinked to original sources

Zebrafish cornea formation and homeostasis reflect robustness in camera-type eye biology, regardless of its environment

The cornea is the transparent tissue covering the camera-type eyes. This position makes this tissue prone to environmental aggressions, and physical alteration can have a drastic negative impact on sight. The current knowledge on zebrafish corneal physiology is too scarce to get an understanding on its strategy to maintain a clear sight in aquatic environment. In this study, we focus on corneal formation and maturation in zebrafish. After describing the morphological changes taking place from 3 days post fertilization to adulthood, we analyzed cell proliferation. We show that label retaining cells appear just before 1 month of age. Our cell proliferation study, combined to the study of Pax6a and krtt1c19e expression, demonstrate a long maturation process. This process ends with a solid patterning of corneal innervation. Finally, corneal abrasion wound healing process recapitulates the maturation process, via a plasticity period. Altogether, our study decipher the maturation steps of an aquatic cornea. These findings will facilitate the use of zebrafish as model of corneal physiology studies.

developmental biology↗

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.

physiology↗

PIM-related kinases selectively regulate sensory functions in C. elegans

The mammalian PIM family of serine/threonine kinases regulate several cellular functions, such as cell survival and motility. Since we have observed PIM expression in the olfactory epithelium and other sensory organs of mice, this has raised the question of whether PIM kinases regulate also sensory cell functions. As our model organism to investigate this question, we used the Caenorhabditis elegans nematodes, which express two PIM-related kinases, PRK-1 and PRK-2. We demonstrated them to be true PIM orthologs with similar substrate specificity as well as sensitivity to PIM-inhibitory compounds. Furthermore, we obtained evidence to indicate that PRKs are selectively involved in regulation of olfactory sensations via AWB or AWCON neurons to volatile attractants or repellants, but do not affect gustatory sensations.

neuroscience↗