Melanopsin (opn4) immunolabelling in the zebrafish (Danio rerio) brain
| dc.contributor.author | Ma, Isabel G. | |
| dc.date.accessioned | 2026-05-11T15:13:11Z | |
| dc.date.available | 2026-05-11T15:13:11Z | |
| dc.date.issued | 2026 | |
| dc.description.abstract | Light is an important signal for vertebrates, not only for image-forming vision, but for non-visual roles including development and physiological responses. Vertebrates detect light using light-sensitive proteins called opsins that are paired with a chromophore. Non-visual opsins are found in a diversity of tissues in vertebrates for both mammals, with the fewest opsins, and ray-finned fishes, with the largest opsin repertoires. Many studies have characterized non-visual opsin mRNA in fish brains, especially in the model zebrafish (Danio rerio), and a few studies have delved into the roles of non-visual opsins. Of the non-visual opsins, melanopsin (opn4) is the most well-studied. It has been observed in intrinsically photosensitive retinal ganglion cells (ipRGCs), which have various roles, including in the circadian rhythm, pupillary light reflex, and mood. Melanopsin mRNA has been characterized in the zebrafish brain, and melanopsin proteins have been observed in sablefish (Anoplopoma fimbria) brains. However, until now, no studies have investigated the expression of melanopsin proteins in zebrafish brains. This study uses immunohistochemistry to show melanopsin proteins in the adult zebrafish brain. Melanopsin occurs in two layers of the optic tectum (the superficial white and grey zone and central zone), the torus longitudinalis, large cells in the paraventricular organ, the torus lateralis, the inferior lobe, and the hypothalamus. Presence of melanopsin proteins in the zebrafish brain is consistent with the hypothesis that the brain is intrinsically light sensitive, and localizing the proteins will help direct future studies designed to test the light-sensitivity hypothesis. Supervisor: Dr. John S. Taylor | |
| dc.description.reviewstatus | Unreviewed | |
| dc.description.scholarlevel | Undergraduate | |
| dc.identifier.uri | https://hdl.handle.net/1828/23878 | |
| dc.language.iso | en | |
| dc.publisher | University of Victoria | |
| dc.subject.department | Department of Biology | |
| dc.title | Melanopsin (opn4) immunolabelling in the zebrafish (Danio rerio) brain | |
| dc.type | Honours thesis |