Summary
This thesis characterizes melanopsin-mediated phototransduction in zebrafish ZEM-2S embryonic cells, showing that a 10-minute blue light pulse alters clock gene expression through the phosphoinositide pathway in peripheral circadian clocks. These findings advance understanding of how non-mammalian vertebrates synchronize peripheral biological rhythms to light-dark cycles, with implications for the evolutionary basis of circadian photoentrainment.
Key Findings
- A 10-minute blue light pulse significantly altered expression of clock genes per1b, per2, cry1a, and cry1b in ZEM-2S zebrafish embryonic cells.
- Clock gene changes occurred via the phosphoinositide pathway, with additional interaction from nitric oxide (NO) and MAPK signaling cascades.
- Immunocytochemistry detected both Opn4m-1 and Opn4m-2 melanopsin proteins in ZEM-2S cells, with significant differences in their intracellular distribution.
- Melanopsin was identified as the leading candidate photopigment for peripheral clock synchronization, outranking Va-opsin, Tmt-opsin, and photosensitive cryptochromes based on combined detection, spectral, and pathway evidence.
Categories
The Science of Light: Investigates melanopsin phototransduction pathways (phosphoinositide cascade) in peripheral clock cells of zebrafish, characterizing Opn4m-1 and Opn4m-2 protein distribution and blue-light-driven clock gene regulation.
Sleep & Circadian Health: Demonstrates that light pulses activate clock genes (per1b, per2, cry1a, cry1b) via melanopsin-mediated signaling, contributing to understanding of peripheral circadian entrainment mechanisms.
Author(s)
BCR Ramos
Publication Year
2014
Related Publications
The Science of Light
- Phototransduction by retinal ganglion cells that set the circadian clock
- Color appearance models
- The mammalian circadian timing system: organization and coordination of central and peripheral clocks
- Diminished pupillary light reflex at high irradiances in melanopsin-knockout mice
- Melanopsin is required for non-image-forming photic responses in blind mice
Sleep & Circadian Health
- Phototransduction by retinal ganglion cells that set the circadian clock
- The mammalian circadian timing system: organization and coordination of central and peripheral clocks
- The two‐process model of sleep regulation: a reappraisal
- Melanopsin is required for non-image-forming photic responses in blind mice
- Strange vision: ganglion cells as circadian photoreceptors