Summary
This review examines the four distinct photoreceptor types in amphioxus (a basal chordate) to shed light on the evolutionary origins of vertebrate visual and circadian photoreception systems. While largely theoretical and evolutionary in scope, the findings help contextualize how rhabdomeric and ciliary photoreceptors diversified into the complex vertebrate systems — including non-visual light detection — relevant to circadian lighting science.
Key Findings
- Amphioxus possesses four distinct photoreceptive organ types: dorsal ocelli, Joseph cells (rhabdomeric), and frontal eye and lamellar body (ciliary), providing a model for understanding vertebrate opsin diversification.
- The coexistence of rhabdomeric and ciliary photoreceptors in amphioxus supports evolutionary hypotheses about the dual origins of vertebrate image-forming and non-image-forming (circadian) photoreception.
- Review concludes that amphioxus data supports a pre-vertebrate origin of circadian photoreceptive mechanisms, informing understanding of melanopsin-based (ipRGC) signaling in vertebrates.
Categories
The Science of Light: Reviews amphioxus opsin biology and photoreceptor evolution, providing foundational context for understanding vertebrate photoreception including melanopsin and ipRGC ancestry.
Author(s)
J Pergner, Z Kozmik
Publication Year
2017
Number of Citations
26
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