This invited paper is part of the Symposium-in-Print: Photobiology in Asia.
A Median Third Eye: Pineal Gland Retraces Evolution of Vertebrate Photoreceptive Organs†
Article first published online: 26 FEB 2007
Photochemistry and Photobiology
Volume 83, Issue 1, pages 11–18, January/February 2007
How to Cite
Mano, H. and Fukada, Y. (2007), A Median Third Eye: Pineal Gland Retraces Evolution of Vertebrate Photoreceptive Organs. Photochemistry and Photobiology, 83: 11–18. doi: 10.1562/2006-02-24-IR-813
- Issue published online: 26 FEB 2007
- Article first published online: 26 FEB 2007
- Received 24 February 2006; accepted 10 June 2006; published online 13 June 2006
In many vertebrates, the pineal gland serves as a photoreceptive neuroendocrine organ. Morphological and functional similarities between the pineal and retinal photoreceptor cells indicate their close evolutionary relationship, and hence the comparative studies on the pineal gland and the retina are the keys to deciphering the evolutionary traces of the vertebrate photoreceptive organs. Several studies have suggested common genetic and molecular mechanisms responsible for their similarities, but largely unknown are those underlying pineal-specific development and physiological functions. Recent studies have identified several cis-acting DNA elements that participate in transcriptional control of the pineal-specific genes. Genetic approaches in the zebrafish have also contributed to elucidating the genetic network regulating the pineal development and neurogenesis. These efforts toward elucidating the molecular instrumentation intrinsic to the pineal gland, back to back with those to the retina, should lead to a comprehensive understanding of the evolutionary history of the vertebrate photoreceptive structures. This article summarizes the current status of research on these topics.