title: Developmental biology. Worm's light-sensing proteins suggest eye's single origin.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Pennisi
mesh_terms: D000818:Animals; D005075:Biological Evolution; D001921:Brain / Q000166:cytology; D002940:Circadian Rhythm; D005123:Eye; D020440:Gene Duplication; D016678:Genome; D018398:Homeodomain Proteins / Q000032:analysis*; D006801:Humans; D008027:Light; D017956:Photoreceptor Cells, Invertebrate / Q000737:chemistry / Q000166:cytology*; D020419:Photoreceptor Cells, Vertebrate / Q000737:chemistry / Q000166:cytology; D011077:Polychaeta / Q000737:chemistry / Q000166:cytology* / Q000235:genetics*; D012165:Retinal Ganglion Cells / Q000166:cytology; D017299:Rod Opsins / Q000032:analysis / Q000737:chemistry* / Q000235:genetics*
chemical_list: D018398:Homeodomain Proteins; D017299:Rod Opsins