title: Photoreceptor evolution: ancient siblings serve different tasks.
abstract: Photoreceptor cells of vertebrate eyes are fundamentally different from those of invertebrate eyes. New work on the brain of a ragworm now suggests that ancestral bilaterians possessed both types of photoreceptor cell.
authors.affiliation: Department of Cell and Organism Biology, Lund University, Zoology building, Helgonavägen 3, SE-22362 Lund, Sweden. dan-e.nilsson@cob.lu.se
authors.forename: D-E
authors.initials: DE
authors.lastname: Nilsson
mesh_terms: D000818:Animals; D005075:Biological Evolution; D022081:Cell Surface Extensions / Q000502:physiology; D005123:Eye; D007448:Invertebrates / Q000502:physiology*; D008954:Models, Biological; D010786:Photoreceptor Cells / Q000166:cytology / Q000502:physiology*; D012243:Rhodopsin / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology; D013045:Species Specificity
chemical_list: D012243:Rhodopsin