C. elegans can see! Though lives in the soil, has no eyes and has not been reported to exhibit phototaxis before, in a recent study published online by Nature Neuroscience, researchers discovered that one of biology's favorite model organisms, Caenorhabditis elegans, can detect and react to light as a stimulus. The nematodes are particularly susceptible to UV-A wavelengths and the researches believe that the worm's ability to detect light in that range helps them (and possibly other soil dwelling, eyeless organisms) stay out of the potentially lethal sunlight. Alex Ward, Jie Liu, Zhaoyang Feng and Shawn Xu, all of the Shawn Xu Lab at the University of Michigan went on to identify the photoreceptor neuron cells in the nematodes and the nervous system mechanism by which light reception signal was conducted. Two of the chemical components of the transduction system in C. elegans are also present in the vertebrate eye.
"We're suggesting that the photoreceptor cells we've discovered in C. elegans resemble Darwin's primitive eye---the prototype for all visual systems---and that this system has been preserved over the course of several hundred million years of evolution," Xu said.More at Nature Neuroscience (subscription required), or at the University of Michigan LSI news releases.