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Wang Y, Zhou L, Wu L, Song C, Ma X, Xu S, Du T, Li X, Li J. Evolutionary ecology of the visual opsin gene sequence and its expression in turbot (Scophthalmus maximus). BMC Ecol Evol 2021; 21:114. [PMID: 34098879 PMCID: PMC8186084 DOI: 10.1186/s12862-021-01837-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 05/24/2021] [Indexed: 11/27/2022] Open
Abstract
Background As flatfish, turbot undergo metamorphosis as part of their life cycle. In the larval stage, turbot live at the ocean surface, but after metamorphosis they move to deeper water and turn to benthic life. Thus, the light environment differs greatly between life stages. The visual system plays a great role in organic evolution, but reports of the relationship between the visual system and benthic life are rare. In this study, we reported the molecular and evolutionary analysis of opsin genes in turbot, and the heterochronic shifts in opsin expression during development. Results Our gene synteny analysis showed that subtype RH2C was not on the same gene cluster as the other four green-sensitive opsin genes (RH2) in turbot. It was translocated to chromosome 8 from chromosome 6. Based on branch-site test and spectral tuning sites analyses, E122Q and M207L substitutions in RH2C, which were found to be under positive selection, are closely related to the blue shift of optimum light sensitivities. And real-time PCR results indicated the dominant opsin gene shifted from red-sensitive (LWS) to RH2B1 during turbot development, which may lead to spectral sensitivity shifts to shorter wavelengths. Conclusions This is the first report that RH2C may be an important subtype of green opsin gene that was retained by turbot and possibly other flatfish species during evolution. Moreover, E122Q and M207L substitutions in RH2C may contribute to the survival of turbot in the bluish colored ocean. And heterochronic shifts in opsin expression may be an important strategy for turbot to adapt to benthic life. Supplementary Information The online version contains supplementary material available at 10.1186/s12862-021-01837-2.
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Affiliation(s)
- Yunong Wang
- College of Fisheries, Ocean University of China, Qingdao, 266003, People's Republic of China.,CAS Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, People's Republic of China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, People's Republic of China.,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, PR China
| | - Li Zhou
- CAS Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, People's Republic of China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, People's Republic of China.,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, PR China
| | - Lele Wu
- CAS Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, People's Republic of China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, People's Republic of China.,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, PR China
| | - Changbin Song
- Institute of Semiconductors, Chinese Academy of Science, Beijing, 100083, People's Republic of China
| | - Xiaona Ma
- CAS Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, People's Republic of China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, People's Republic of China
| | - Shihong Xu
- CAS Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, People's Republic of China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, People's Republic of China
| | - Tengfei Du
- CAS Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, People's Republic of China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, People's Republic of China.,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, PR China
| | - Xian Li
- College of Fisheries, Ocean University of China, Qingdao, 266003, People's Republic of China. .,CAS Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, People's Republic of China. .,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, People's Republic of China.
| | - Jun Li
- CAS Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, People's Republic of China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, People's Republic of China.,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, PR China
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Abstract
One of the critical times for the survival of animals is twilight where the most abundant visible lights are between 400 and 550 nanometres (nm). Green-sensitive RH2 pigments help nonmammalian vertebrate species to better discriminate wavelengths in this blue-green region. Here, evaluation of the wavelengths of maximal absorption (λmax s) of genetically engineered RH2 pigments representing 13 critical stages of vertebrate evolution revealed that the RH2 pigment of the most recent common ancestor of vertebrates had a λmax of 503 nm, while the 12 ancestral pigments exhibited an expanded range in λmax s between 474 and 524 nm, and present-day RH2 pigments have further expanded the range to ~ 450-530 nm. During vertebrate evolution, eight out of the 16 significant λmax shifts (or |Δλmax | ≥ 10 nm) of RH2 pigments identified were fully explained by the repeated mutations E122Q (twice), Q122E (thrice) and M207L (twice), and A292S (once). Our data indicated that the highly variable λmax s of teleost RH2 pigments arose from gene duplications followed by accelerated amino acid substitution.
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Affiliation(s)
- Shozo Yokoyama
- Department of BiologyEmory UniversityAtlantaGAUSA
- Willamette ViewPortlandORUSA
| | - Huiyong Jia
- Department of BiologyEmory UniversityAtlantaGAUSA
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3
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Mark MD, Donner M, Eickelbeck D, Stepien J, Nowrousian M, Kück U, Paris F, Hellinger J, Herlitze S. Visual tuning in the flashlight fish Anomalops katoptron to detect blue, bioluminescent light. PLoS One 2018; 13:e0198765. [PMID: 29995896 PMCID: PMC6040694 DOI: 10.1371/journal.pone.0198765] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 05/24/2018] [Indexed: 01/23/2023] Open
Abstract
Bioluminescence is a fascinating phenomenon and can be found in many different organisms including fish. It has been suggested that bioluminescence is used for example for defense, prey attraction, and for intraspecific communication to attract for example sexual partners. The flashlight fish, Anomalops katoptron (A. katoptron), is a nocturnal fish that produces bioluminescence and lives in shallow waters, which makes it ideal for laboratory studies. In order to understand A. katoptron's ability to detect bioluminescent light (480 to 490 nm) at night, we characterized the visual system adaptation of A. katoptron using phylogenetic, electrophysiological and behavioral studies. We found that the retinae of A. katoptron contain rods and sparse cones. A. katoptron retinae express two main visual pigments, rhodopsin (RH1), and to a lesser extent, rhodopsin-like opsin (RH2). Interestingly, recombinant RH1 and RH2 are maximally sensitive to a wavelength of approximately 490 nm light (λmax), which correspond to the spectral peak of in vivo electroretinogram (ERG) measurements. In addition, behavioral assays revealed that A. katoptron is attracted by low intensity blue but not red light. Collectively, our results suggest that the A. katoptron visual system is optimized to detect blue light in the frequency range of its own bioluminescence and residual starlight.
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Affiliation(s)
- Melanie D. Mark
- Department of General Zoology and Neurobiology, Ruhr-University Bochum, Bochum, Germany
- * E-mail:
| | - Marcel Donner
- Department of General Zoology and Neurobiology, Ruhr-University Bochum, Bochum, Germany
| | - Dennis Eickelbeck
- Department of General Zoology and Neurobiology, Ruhr-University Bochum, Bochum, Germany
| | - Jennifer Stepien
- Department of General Zoology and Neurobiology, Ruhr-University Bochum, Bochum, Germany
| | - Minou Nowrousian
- Department of General and Molecular Botany, Ruhr-University Bochum, Bochum, Germany
| | - Ulrich Kück
- Department of General and Molecular Botany, Ruhr-University Bochum, Bochum, Germany
| | - Frank Paris
- Department of Animal Physiology, Ruhr-University Bochum, Bochum, Germany
| | - Jens Hellinger
- Department of General Zoology and Neurobiology, Ruhr-University Bochum, Bochum, Germany
| | - Stefan Herlitze
- Department of General Zoology and Neurobiology, Ruhr-University Bochum, Bochum, Germany
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4
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Zhang Y, Sun J, Chen C, Watanabe HK, Feng D, Zhang Y, Chiu JM, Qian PY, Qiu JW. Adaptation and evolution of deep-sea scale worms (Annelida: Polynoidae): insights from transcriptome comparison with a shallow-water species. Sci Rep 2017; 7:46205. [PMID: 28397791 PMCID: PMC5387418 DOI: 10.1038/srep46205] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 03/10/2017] [Indexed: 12/31/2022] Open
Abstract
Polynoid scale worms (Polynoidae, Annelida) invaded deep-sea chemosynthesis-based ecosystems approximately 60 million years ago, but little is known about their genetic adaptation to the extreme deep-sea environment. In this study, we reported the first two transcriptomes of deep-sea polynoids (Branchipolynoe pettiboneae, Lepidonotopodium sp.) and compared them with the transcriptome of a shallow-water polynoid (Harmothoe imbricata). We determined codon and amino acid usage, positive selected genes, highly expressed genes and putative duplicated genes. Transcriptome assembly produced 98,806 to 225,709 contigs in the three species. There were more positively charged amino acids (i.e., histidine and arginine) and less negatively charged amino acids (i.e., aspartic acid and glutamic acid) in the deep-sea species. There were 120 genes showing clear evidence of positive selection. Among the 10% most highly expressed genes, there were more hemoglobin genes with high expression levels in both deep-sea species. The duplicated genes related to DNA recombination and metabolism, and gene expression were only enriched in deep-sea species. Deep-sea scale worms adopted two strategies of adaptation to hypoxia in the chemosynthesis-based habitats (i.e., rapid evolution of tetra-domain hemoglobin in Branchipolynoe or high expression of single-domain hemoglobin in Lepidonotopodium sp.).
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Affiliation(s)
- Yanjie Zhang
- Department of Biology, Hong Kong Baptist University, Hong Kong, P. R. China
| | - Jin Sun
- Division of Life Sciences, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, P. R. China
| | - Chong Chen
- Department of Subsurface Geobiological Analysis and Research, Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima-cho, Yokosuka, Kanagawa, 237-0061, Japan
| | - Hiromi K. Watanabe
- Department of Marine Biodiversity Research, Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima-cho, Yokosuka, Kanagawa, 237-0061, Japan
| | - Dong Feng
- CAS Key Laboratory of Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, P. R. China
| | - Yu Zhang
- College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, P. R. China
| | - Jill M.Y. Chiu
- Department of Biology, Hong Kong Baptist University, Hong Kong, P. R. China
| | - Pei-Yuan Qian
- Division of Life Sciences, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, P. R. China
| | - Jian-Wen Qiu
- Department of Biology, Hong Kong Baptist University, Hong Kong, P. R. China
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Drabeck DH, Dean AM, Jansa SA. Why the honey badger don't care: Convergent evolution of venom-targeted nicotinic acetylcholine receptors in mammals that survive venomous snake bites. Toxicon 2015; 99:68-72. [DOI: 10.1016/j.toxicon.2015.03.007] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 02/03/2015] [Accepted: 03/17/2015] [Indexed: 11/20/2022]
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6
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Yokoyama S, Starmer WT, Liu Y, Tada T, Britt L. Extraordinarily low evolutionary rates of short wavelength-sensitive opsin pseudogenes. Gene 2013; 534:93-9. [PMID: 24125953 DOI: 10.1016/j.gene.2013.09.114] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2013] [Revised: 09/24/2013] [Accepted: 09/26/2013] [Indexed: 01/08/2023]
Abstract
Aquatic organisms such as cichlids, coelacanths, seals, and cetaceans are active in UV-blue color environments, but many of them mysteriously lost their abilities to detect these colors. The loss of these functions is a consequence of the pseudogenization of their short wavelength-sensitive (SWS1) opsin genes without gene duplication. We show that the SWS1 gene (BdenS1ψ) of the deep-sea fish, pearleye (Benthalbella dentata), became a pseudogene in a similar fashion about 130 million years ago (Mya) yet it is still transcribed. The rates of nucleotide substitution (~1.4 × 10(-9)/site/year) of the pseudogenes of these aquatic species as well as some prosimian and bat species are much smaller than the previous estimates for the globin and immunoglobulin pseudogenes.
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Affiliation(s)
- Shozo Yokoyama
- Department of Biology, Emory University, Atlanta, GA 30322, USA.
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7
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Pallavicini A, Canapa A, Barucca M, Alfőldi J, Biscotti MA, Buonocore F, De Moro G, Di Palma F, Fausto AM, Forconi M, Gerdol M, Makapedua DM, Turner-Meier J, Olmo E, Scapigliati G. Analysis of the transcriptome of the Indonesian coelacanth Latimeria menadoensis. BMC Genomics 2013; 14:538. [PMID: 23927401 PMCID: PMC3750513 DOI: 10.1186/1471-2164-14-538] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Accepted: 06/26/2013] [Indexed: 02/01/2023] Open
Abstract
Background Latimeria menadoensis is a coelacanth species first identified in 1997 in Indonesia, at 10,000 Km of distance from its African congener. To date, only six specimens have been caught and just a very limited molecular data is available. In the present work we describe the de novo transcriptome assembly obtained from liver and testis samples collected from the fifth specimen ever caught of this species. Results The deep RNA sequencing performed with Illumina technologies generated 145,435,156 paired-end reads, accounting for ~14 GB of sequence data, which were de novo assembled using a Trinity/CLC combined strategy. The assembly output was processed and filtered producing a set of 66,308 contigs, whose quality was thoroughly assessed. The comparison with the recently sequenced genome of the African congener Latimeria chalumnae and with the available genomic resources of other vertebrates revealed a good reconstruction of full length transcripts and a high coverage of the predicted full coelacanth transcriptome. The RNA-seq analysis revealed remarkable differences in the expression profiles between the two tissues, allowing the identification of liver- and testis-specific transcripts which may play a fundamental role in important biological processes carried out by these two organs. Conclusion Given the high genomic affinity between the two coelacanth species, the here described de novo transcriptome assembly can be considered a valuable support tool for the improvement of gene prediction within the genome of L. chalumnae and a valuable resource for investigation of many aspects of tetrapod evolution.
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8
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Abstract
Among the five groups of visual pigments in vertebrates, the rhodopsin type 2 (RH2) group shows the largest number of gene duplication events. We have isolated three intact and one nonfunctional RH2 opsin genes each from Northern lampfish (Stenobrachius leucopsarus) and scabbardfish (Lepidopus fitchi). Using the deduced amino acid sequences of these and other representative RH2 opsin genes in vertebrates, we have estimated the divergence times and evolutionary rates of amino acid substitution at various stages of RH2 opsin evolution. The results show that the duplications of the lampfish and scabbardfish RH2 opsins have occurred approximately 60 and approximately 30 million years ago (Ma), respectively. The evolutionary rates of RH2 opsins in the early vertebrate ancestors were approximately 0.25 x 10(-9)/site/year, which increased to approximately 1 x 10(-9) to 3 x 10(-9)/site/year in euteleost lineages and to approximately 0.3 x 10(-9) to 0.5 x 10(-9)/site/year in coelacanth and tetrapods.
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Affiliation(s)
- Shozo Yokoyama
- Department of Biology, Rollins Research Center, Emory University, USA.
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9
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Li Z, Gan X, He S. Distinct Evolutionary Patterns Between Two Duplicated Color Vision Genes Within Cyprinid Fishes. J Mol Evol 2009; 69:346-59. [DOI: 10.1007/s00239-009-9283-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2009] [Accepted: 09/15/2009] [Indexed: 11/25/2022]
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10
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Wang FY, Yan HY, Chen JSC, Wang TY, Wang D. Adaptation of visual spectra and opsin genes in seabreams. Vision Res 2009; 49:1860-8. [DOI: 10.1016/j.visres.2009.04.023] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2009] [Revised: 04/27/2009] [Accepted: 04/27/2009] [Indexed: 10/20/2022]
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Abstract
An emerging synthesis of evolutionary biology and experimental molecular biology is providing much stronger and deeper inferences about the dynamics and mechanisms of evolution than were possible in the past. The new approach combines statistical analyses of gene sequences with manipulative molecular experiments to reveal how ancient mutations altered biochemical processes and produced novel phenotypes. This functional synthesis has set the stage for major advances in our understanding of fundamental questions in evolutionary biology. Here we describe this emerging approach, highlight important new insights that it has made possible, and suggest future directions for the field.
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Affiliation(s)
- Antony M Dean
- University of Minnesota, St Paul, Minnesota 55108, USA.
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13
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Jokela-Määttä M, Pahlberg J, Lindström M, Zak PP, Porter M, Ostrovsky MA, Cronin TW, Donner K. Visual pigment absorbance and spectral sensitivity of the Mysis relicta species group (Crustacea, Mysida) in different light environments. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2005; 191:1087-97. [PMID: 16133501 DOI: 10.1007/s00359-005-0039-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2005] [Revised: 06/10/2005] [Accepted: 06/11/2005] [Indexed: 11/27/2022]
Abstract
Visual-pigment absorbance spectra and eye spectral sensitivities were examined in eight populations of opossum shrimp from different light environments. Four Finnish populations, two from the Baltic Sea and two from freshwater lakes, represent Mysis relicta, sensu stricto. The sibling species M. salemaai and M. diluviana are represented by, respectively, two Baltic Sea populations and two populations from freshwater lakes in Idaho, USA. In M. relicta, the visual pigments of the two lake populations were similar (lambda(max)=554.3+/-0.8 nm and 556.4+/-0.4 nm), but significantly red-shifted compared with the sea populations (at 529 and 535 nm) and with M. salemaai (at 521 and 525 nm). All these pigments had only A2 chromophore and the lake/sea difference indicates adaptive evolution of the opsin. In M. diluviana, lambda(max) varied in the range 505-529 nm and the shapes of spectra suggested varying A1/A2 chromophore proportions, with pure A1 in the 505 nm animals. Eye sensitivity spectra were flatter and peaked at longer wavelengths than the relevant visual-pigment templates, but declined with the same slope beyond ca. 700 nm. The deviations from visual-pigment spectra can be explained by ocular light filters based on three types of identified screening pigments.
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Affiliation(s)
- Mirka Jokela-Määttä
- Department of Biological and Environmental Sciences, University of Helsinki, Helsinki, P.O. Box 65, Viikinkaari 1, FI-00014, Finland.
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14
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Pointer MA, Cheng CHC, Bowmaker JK, Parry JWL, Soto N, Jeffery G, Cowing JA, Hunt DM. Adaptations to an extreme environment: retinal organisation and spectral properties of photoreceptors in Antarctic notothenioid fish. ACTA ACUST UNITED AC 2005; 208:2363-76. [PMID: 15939776 DOI: 10.1242/jeb.01647] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The Notothenioid suborder of teleosts comprises a number of species that live below the sea ice of the Antarctic. The presence of 'antifreeze' glycoproteins in these fish as an adaptation to freezing temperature has been well documented but little is known about the adaptations of the visual system of these fish to a light environment in which both the quantity and spectral composition of downwelling sunlight has been reduced by passage through ice and snow. In this study, we show that the red/long-wave sensitive (LWS) opsin gene is not present in these fish but a UV-sensitive short-wave sensitive (SWS1) pigment is expressed along with blue-sensitive (SWS2) and green/middle-wave sensitive (Rh2) pigments. The identity and spectral location of maximal absorbance of the SWS1 and Rh2 pigments was confirmed by in vitro expression of the recombinant opsins followed by regeneration with 11-cis retinal. Only the SWS2 pigment showed interspecific variations in peak absorbance. Expression of the Rh2 opsin is localised to double cone receptors in both the central and peripheral retina, whereas SWS2 opsin expression is present only in the peripheral retina. SWS1 cones could not be identified by either microspectrophotometry or in situ hybridisation, presumably reflecting their low number and/or uneven distribution across the retina. A study of photoreceptor organisation in the retina of two species, the shallower dwelling Trematomus hansoni and the deeper dwelling Dissostichus mawsoni, identified a square mosaic in the former, and a row mosaic in the latter species; the row mosaic in Dissostichus mawsoni with less tightly packed cone photoreceptors allows for a higher rod photoreceptor density.
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Affiliation(s)
- Marie A Pointer
- Institute of Ophthalmology, University College London, 11-43 Bath Street, London, EC1V 9EL, UK
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15
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Carleton KL, Spady TC, Cote RH. Rod and cone opsin families differ in spectral tuning domains but not signal transducing domains as judged by saturated evolutionary trace analysis. J Mol Evol 2005; 61:75-89. [PMID: 15988624 DOI: 10.1007/s00239-004-0289-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2004] [Accepted: 12/15/2004] [Indexed: 11/26/2022]
Abstract
The visual receptor of rods and cones is a covalent complex of the apoprotein, opsin, and the light-sensitive chromophore, 11-cis-retinal. This pigment must fulfill many functions including photoactivation, spectral tuning, signal transmission, inactivation, and chromophore regeneration. Rod and cone photoreceptors employ distinct families of opsins. Although it is well known that these opsin families provide unique ranges in spectral sensitivity, it is unclear whether the families have additional functional differences. In this study, we use evolutionary trace (ET) analysis of 188 vertebrate opsin sequences to identify functionally important sites in each opsin family. We demonstrate the following results. (1) The available vertebrate opsin sequences produce a definitive description of all five vertebrate opsin families. This is the first demonstration of sequence saturation prior to ET analysis, which we term saturated ET (SET). (2) The cone opsin classes have class-specific sites compared to the rod opsin class. These sites reside in the transmembrane region and tune the spectral sensitivity of each opsin class to its characteristic wavelength range. (3) The cytoplasmic loops, primarily responsible for signal transmission and inactivation, are essentially invariant in rod versus cone opsins. This indicates that the electrophysiological differences between rod and cone photoreceptors cannot be ascribed to differences in the protein interaction regions of the opsins. SET shows that chromophore binding and regeneration are the only aspects of opsin structure likely to have functionally significant differences between rods and cones, whereas excitatory and adaptational properties of the opsin families appear to be functionally invariant.
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Affiliation(s)
- Karen L Carleton
- Hubbard Center for Genome Studies, University of New Hampshire, Durham, NH 03824, USA.
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Dann SG, Allison WT, Levin DB, Taylor JS, Hawryshyn CW. Salmonid opsin sequences undergo positive selection and indicate an alternate evolutionary relationship in oncorhynchus. J Mol Evol 2004; 58:400-12. [PMID: 15114419 DOI: 10.1007/s00239-003-2562-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2003] [Accepted: 10/28/2003] [Indexed: 10/26/2022]
Abstract
Positive selection can be demonstrated by statistical analysis when non-synonymous nucleotide substitutions occur more frequently than synonymous substitutions (dN>dS). This pattern of sequence evolution has been observed in the rhodopsin gene of cichlids. Mutations in opsin genes resulting in amino acid (AA) replacement appear to be associated with the evolution of specific color patterns and the evolution of courtship behaviors. Within fish, AA replacements in opsin proteins have improved vision at great depths and have occurred in deep-sea species. Salmonids experience diverse photic environments during their life history. Furthermore, sexual selection has resulted in species-specific male and female coloration during spawning. To look for evidence of positive selection in salmonid opsins, we sequenced the RH1, RH2, LWS, SWS1, and SWS2 genes from six Pacific salmon species as well as the Atlantic salmon. These salmonids include landlocked and migratory species and species that vary in their coloration during spawning. In each opsin gene comparison from all species sampled, traditional dN:dS analysis did not indicate positive selection. However, the more sensitive Creevey-McInerney statistical analysis indicates that RH1 and RH2 experienced positive selection early in the evolution and speciation of salmonids.
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Affiliation(s)
- Stephen G Dann
- Department of Biology, University of Victoria, P.O. Box 3020 STN CSC, Victoria, British Columbia, Canada V8W 3N5
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Abstract
Using site-directed mutagenesis and multiple regression analysis, we have studied the molecular genetics and evolution of short wavelength-sensitive (SWS2) pigments in vertebrates. These analyses suggest that the SWS2 pigment in the vertebrate ancestor had the wavelength of maximum absorption (lambda(max)) of approximately 440 nm and that various lambda(max)'s of the contemporary SWS2 pigments in vertebrates are caused mainly by additive effects of amino acid replacements at ten sites.
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Affiliation(s)
- Shozo Yokoyama
- Department of Biology, Biological Research Laboratories, Syracuse University, 130 College Place, Syracuse, NY 13244, USA.
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18
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Abstract
Visual systems of vertebrates exhibit a striking level of diversity, reflecting their adaptive responses to various color environments. The photosensitive molecules, visual pigments, can be synthesized in vitro and their absorption spectra can be determined. Comparing the amino acid sequences and absorption spectra of various visual pigments, we can identify amino acid changes that have modified the absorption spectra of visual pigments. These hypotheses can then be tested using the in vitro assay. This approach has been a powerful tool in elucidating not only the molecular bases of color vision, but the processes of adaptive evolution at the molecular level.
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Affiliation(s)
- Shozo Yokoyama
- Department of Biology, Biological Research Laboratories, Syracuse University, 130 College Place, Syracuse, NY 13244, USA.
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