Presentation description

The cornea is the outermost part of the eye, the first tissue that light encounters as it is focused onto the retina. It is comprised of three tissue layers: endothelium, stroma, and epithelium. The innermost layer, the corneal endothelium, maintains the transparency of the cornea which is critical for normal vision. Despite the importance of the cornea for proper vision, the cellular and molecular basis for corneal tissue assembly during development is largely unknown. We focused on how the endothelium forms during normal embryonic development and how its formation can go awry in disease. Axenfeld-Rieger Syndrome (ARS) is a congenital disease that is caused by a mutation in the transcription factor pitx2. This mutation causes malformation of cornea and iris tissues and can result in visual impairment; therefore, we seek to determine the cellular and genetic basis for endothelium assembly in both the wild type condition and in a disease model. |In zebrafish, it is not currently known when the corneal endothelium becomes a differentiated tissue layer. To help establish when the molecular identity of the corneal endothelium is established, we examined a set of candidate markers identified from genomic and transcriptomic studies in other vertebrate species. Using immunostaining, we detected the protein N-cadherin in the corneal endothelium of both wildtype and pitx2 mutant zebrafish at 5 days post fertilization (dpf). N-cadherin is a transmembrane protein that mediates cell-cell adhesion. Preliminary results suggest that N-cadherin expression is detected more strongly in the corneal endothelium of the pitx2 mutant in comparison to the wildtype. This highlights a potential role for N-cadherin, and possibly other cell adhesion molecules, in the pitx2 mutant corneal phenotype.