| Summary: | XIV Congress of the Iberian Association of Comparative Endocrinology, Bilbao, 11-13 September 2023 Predatory fish heavily rely on their visual capabilities to accurately detect and track theis prey. As a result, some species have developed unique adaptations in their morphology and visual system to facilitate ambush or shelter behavior. Flatfish, undergo a remarkable morphological transformation during a complex metamorphic process. In flatfish, one eye migrates to opposite side of the body, enabling them to live as benthic juveniles. Alongside this adaptation to varying light conditions, the eyes undergo several morphological asymmetries to accommodate the migrating eye to its future ocular side. Previous studies have also observed asymmetry in the length of the optic nerve, with the nonmigrating eye having a shorter optic nerve. Although it has been observed that the migrating eye of flatfish has a smaller optic tectum during metamorphosis, it remains unclear whether this eye is less functional than the non-migrating eye. In our study, we conducted a transcriptome analysis of eyes and surrounding tissue at three crucial stages of turbot metamorphosis (pre-metamorphic, climax and postmetamorphic stages). We discovered an intriguing and unique expression pattern in the ependymin (epd) gene. Our data revelead a peak of epd expression during the climax of metamorphosis in the migrating eye, while there were no changes in the temporal expression pattern in the non-migrating eye. EPD is a glycoprotein found in brain of teleosts and is involved in long-term memory, neural plasticity and refinement of connections in regenerating optic nerve. To further investigate the potential role of epd in eye migration, we created an epd knockout mutant fish (epd K.O.).We examined the axonal regrowth and dendritic remodeling after optic nerve injury in epd K.O. fish, comparing studying the differences in regeneration between wildtype and mutant fish and exploring the possible correlation with optic nerve asymmetry in flatfish ...
|
|---|