title: Ci-opsin1, a vertebrate-type opsin gene, expressed in the larval ocellus of the ascidian Ciona intestinalis.
abstract: A novel gene encoding visual pigment, Ci-opsin1, was identified in a primitive chordate, the ascidian, Ciona intestinalis. Molecular phylogenetic analysis and the exon-intron organization suggest that Ci-opsin1 is closely related to the retinal and pineal opsins of vertebrates. During embryogenesis, Ci-opsin1 transcripts were first detected in part of the brain of mid tailbud embryos; its expression was confined to photoreceptor cells of the ocellus (eye spot) in the larval brain as development proceeded. These results suggest a common descent of the ascidian ocellus and the vertebrate eyes. The ocellus of ascidian larvae may represent an ancestral state of the vertebrate eye.
authors.affiliation: Department of Life Science, Faculty of Science, Himeji Institue of Technology, Harima Garden Science City, Hyogo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kusakabe
authors.forename: R
authors.initials: R
authors.lastname: Kusakabe
authors.forename: I
authors.initials: I
authors.lastname: Kawakami
authors.forename: Y
authors.initials: Y
authors.lastname: Satou
authors.forename: N
authors.initials: N
authors.lastname: Satoh
authors.forename: M
authors.initials: M
authors.lastname: Tsuda
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002816:Chordata, Nonvertebrate; D003001:Cloning, Molecular; D017931:DNA Primers; D018076:DNA, Complementary; D005123:Eye / Q000196:embryology; D018507:Gene Expression Regulation, Developmental; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics*; D007814:Larva / Q000378:metabolism*; D008969:Molecular Sequence Data; D010802:Phylogeny; D017299:Rod Opsins / Q000737:chemistry / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D014561:Urochordata / Q000196:embryology / Q000235:genetics*
chemical_list: C437926:Ci-opsin1 protein, Ciona intestinalis; D017931:DNA Primers; D018076:DNA, Complementary; D019476:Insect Proteins; D017299:Rod Opsins