2023 23 B1

Photoreceptor Vesicle Quantification And Nuclei Imaging in the Simplex Retina of the Little Skate

By: Amir Chirar, Marjorie Hernandez, Josue Cruz

Department: Biology

Faculty Advisor: Dr. Ivan A. Anastassov

Little skates, Leucoraja erinacea, are bottom feeding cartilaginous fish that have a characteristic simplex retinal system containing only rod photoreceptors. This is contrary to most other vertebrate organisms, which contain a duplex retinal system with both rod and cone photoreceptors. Rods are photoreceptor cells that are responsible for detecting dim light. The focus of our research is on the structure rod photoreceptors in the Little skate retina. Samples of skate retina tissue were imaged using serial block face scanning electron microscopy. These images were traced in Reconstruct software across multiple sections to generate 3D reconstructions of cellular components, specifically the nuclei and vesicles of photoreceptors. We hypothesize that if the structure of skate rods are similar to that of rod photoreceptors in other organisms with duplex retinas, then this would suggest are great conservation of the function in these cells. Therefore, the differences in function of skate rods may still be present in the rods of other species, but may be masked by the increased complexity of the system. While the skate retina is unique in having a simplex photoreceptor system, understanding the origin of these differences can give greater insight into the development of other organisms’ visual systems and uncover the minimal requirements needed to arrive at a functioning retinal circuitry and complements of cell types.