Opsins: Not Just for Eyes

摘要

When researchers got their first glimpse of the sea urchin genome in 2006, they were surprised to find genes for opsins, light-sensitive proteins without which vision as we know it today would be impossible. Living in the sub-tidal zones, sea urchins are not only eyeless, but also headless, and, ostensibly brainless. They seemed to lack the specialized photo-receptor cells that house opsins in the eyes of other animals. "Nobody knew what [the opsins] were for," recalls Maria Ina Arnone, a developmental biologist who has long studied sea urchins at the Stazione Zoolog-ica Anton Dohrn in Naples, Italy, one of the world's oldest marine labs.