Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 17 March 2006:
Vol. 311. no. 5767, p. 1517
DOI: 10.1126/science.311.5767.1517k
Prev | Table of Contents | Next

This Week in Science

The parietal eye of lizards responds to light and dark but does not form images. Su et al. (p. 1617) show that blue light and green light, working through opsins unlike those in visual eyes, send antagonistic signals to a key cyclic guanosine monophosphate (cGMP) phosphodiesterase. Subsequent alterations in cGMP concentrations modulate channel openings to depolarize or hyperpolarize the parietal photoreceptor cells. Comparison of the opsins and signaling molecules involved suggests an evolutionary trajectory by which the parietal eye diverged from the visual eyes.




To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)