title: Opsins from the lateral eyes and ocelli of the horseshoe crab, Limulus polyphemus.
abstract: cDNA clones encoding opsins from the lateral eyes and median ocelli of the horseshoe crab, Limulus polyphemus, were isolated from cDNA libraries. The opsin cDNAs obtained from the lateral eye and ocellar libraries code for deduced proteins with 376 amino acids. The two cDNAs are 96% identical at the nucleic acid level, differing primarily at the 3' untranslated region, and are apparently the products of two separate genes. The deduced opsin proteins are 99% identical to each other, differing at only 5 amino acids. The opsins encoded by these cDNAs are most likely the protein moiety of the visible-wavelength rhodopsins in this animal. In the lateral eye, expression of the opsin gene is restricted to the photoreceptor cells of the ommatidia. Comparisons with opsins of other species show that the Limulus opsin proteins are most similar (53% identity) to the opsin from the R1-6 photoreceptors of flies.
authors.affiliation: Whitney Marine Laboratory, University of Florida, Gainesville 32086.
authors.forename: W C
authors.initials: WC
authors.lastname: Smith
authors.forename: D A
authors.initials: DA
authors.lastname: Price
authors.forename: R M
authors.initials: RM
authors.lastname: Greenberg
authors.forename: B A
authors.initials: BA
authors.lastname: Battelle
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017124:Conserved Sequence; D004247:DNA / Q000302:isolation & purification; D004331:Drosophila melanogaster; D006737:Horseshoe Crabs / Q000737:chemistry*; D008969:Molecular Sequence Data; D010786:Photoreceptor Cells / Q000737:chemistry*; D010802:Phylogeny; D017299:Rod Opsins / Q000032:analysis / Q000737:chemistry* / Q000235:genetics
chemical_list: D017299:Rod Opsins; D004247:DNA