title: Evolution of vertebrate visual pigments.
abstract: The visual pigments of vertebrates evolved about 500 million years ago, before the major evolutionary step of the development of jaws. Four spectrally distinct classes of cone opsin evolved through gene duplication, followed by the rod opsin class that arose from the duplication of the middle-wave-sensitive cone opsin. All four cone classes are present in many extant teleost fish, reptiles and birds, but one or more classes have been lost in primitive fish, amphibians and mammals. Gene duplication within the cone classes, especially in teleosts, has resulted in multiple opsins being available, both temporally and spatially, during development.
authors.affiliation: Department of Visual Science, UCL Institute of Ophthalmology, University College London, Bath Street, London EC1V 9EL, UK. j.bowmaker@ucl.ac.uk
authors.forename: James K
authors.initials: JK
authors.lastname: Bowmaker
mesh_terms: D000818:Animals; D005075:Biological Evolution; D003118:Color Perception / Q000235:genetics; D055355:Opsins / Q000235:genetics; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology; D012168:Retinal Pigments / Q000235:genetics*; D017948:Retinal Rod Photoreceptor Cells / Q000502:physiology; D014714:Vertebrates / Q000235:genetics* / Q000502:physiology
chemical_list: D055355:Opsins; D012168:Retinal Pigments