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Fernández-Caballero L, Blanco-Kelly F, Swafiri ST, Martín-Mérida MI, Quinodoz M, Ullah M, Carreño E, Martin-Gutierrez MP, García-Sandoval B, Minguez P, Rivolta C, Corton M, Ayuso C. Identification of new families and variants in autosomal dominant macular dystrophy associated with THRB. Sci Rep 2025; 15:14904. [PMID: 40295579 PMCID: PMC12037757 DOI: 10.1038/s41598-025-97768-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2024] [Accepted: 04/07/2025] [Indexed: 04/30/2025] Open
Abstract
THRB encodes thyroid hormone receptor β which produces two human isoforms (TRβ1 and TRβ2) by alternative splicing. The first THRB variant associated with autosomal dominant macular dystrophy (ADMD), NM_001354712.2:c.283 + 1G > A, was recently described. This study aims to refine the ophthalmologic phenotype, report a novel THRB variant, and investigate the impact of these splicing variants at the protein level. THRB variants were identified by re-analysis of next-generation sequencing data from the FJD database. Family segregation was performed using Sanger sequencing. Clinical data were collected from self-reported ophthalmic history questionnaires and ophthalmic exams. Functional splicing test was performed by in vitro minigene approach. We identified 12 patients with ADMD from 3 families carrying variants in THRB. Two families carried the variant NM_001354712.2:c.283 + 1G > A, and one the novel variant NM_001354712.2:c.283G > A. Patients exhibited common ophthalmologic findings with disruption of subfoveal ellipsoid layers, and variable onset of symptoms. Splicing assays showed complete exon 5 skipping or a 6 bp deletion in both variants. Our results support the association of THRB with ADMD. The high intra-familial variability could be influenced by phenotype modifiers. Aberrant TRβ1/TRβ2 proteins could lead to a gain-of-function mechanism. Including THRB in inherited retinal dystrophy genetic panels could enhance diagnoses and clinical patient management.
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Affiliation(s)
- Lidia Fernández-Caballero
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Avda. Reyes Católicos, 2, 28040, Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Fiona Blanco-Kelly
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Avda. Reyes Católicos, 2, 28040, Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Saoud Tahsin Swafiri
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Avda. Reyes Católicos, 2, 28040, Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - María Inmaculada Martín-Mérida
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Avda. Reyes Católicos, 2, 28040, Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Mathieu Quinodoz
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel, Switzerland
- Department of Ophthalmology, University of Basel, Basel, Switzerland
| | - Mukhtar Ullah
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel, Switzerland
- Department of Ophthalmology, University of Basel, Basel, Switzerland
| | - Ester Carreño
- Department of Ophthalmology, Fundación Jiménez Díaz University Hospital, Madrid, Spain
| | | | | | - Pablo Minguez
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Avda. Reyes Católicos, 2, 28040, Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
- Bioinformatics Unit, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
| | - Carlo Rivolta
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel, Switzerland
- Department of Ophthalmology, University of Basel, Basel, Switzerland
| | - Marta Corton
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Avda. Reyes Católicos, 2, 28040, Madrid, Spain.
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain.
| | - Carmen Ayuso
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Avda. Reyes Católicos, 2, 28040, Madrid, Spain.
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain.
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2
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Bertinetti C, Mosley C, Jones S, Torres‐Dowdall J. Robust Sensory Traits Across Light Habitats: Visual Signals but Not Receptors Vary in Centrarchids Inhabiting Distinct Photic Environments. Mol Ecol 2025; 34:e17721. [PMID: 40066691 PMCID: PMC11974496 DOI: 10.1111/mec.17721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2024] [Revised: 01/08/2025] [Accepted: 02/21/2025] [Indexed: 04/08/2025]
Abstract
Visual communication in fish is often shaped by their light environment, which influences both sensory (e.g., eye size, opsin gene expression) and signalling traits (e.g., body reflectance). This study explores the phenotypic variation in the visual communication traits of six species of centrarchids (Centrarchidae) inhabiting two contrasting light environments. We measured morphological, molecular and signalling traits to determine their variation across photic conditions. Our findings reveal significant interspecific variation in sensory traits but no consistent phenotypic variation between light environments. Centrarchids showed robust visual systems with green-sensitive rh2 and red-sensitive lws opsin genes representing the main chromatic channels, with their expression remaining largely unaffected between distinct light habitats. We also found significant molecular evolution in the visual opsin genes, although these changes were not associated with environmental conditions. However, body reflectance displayed species-specific responses to environmental conditions, suggesting that signalling traits may be more flexible than sensory traits. Overall, our results challenge the generality of the current paradigm in visual ecology, which portrays visual systems in fish as highly tunable owing to photic conditions. Our study highlights the potential evolutionary or developmental constraints on centrarchid visual systems and their implications for adaptability to various habitats and novel environmental threats.
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Affiliation(s)
- César Bertinetti
- Department of Biological SciencesUniversity of Notre DameNotre DameIndianaUSA
| | - Camille Mosley
- Department of Biological SciencesUniversity of Notre DameNotre DameIndianaUSA
| | - Stuart Jones
- Department of Biological SciencesUniversity of Notre DameNotre DameIndianaUSA
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3
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Cui ZJ. Deep-sea photodynamic vision at low light level - Which is more important, prosthetic retinal or apo-rhodopsin moiety? FASEB J 2025; 39:e70470. [PMID: 40100047 DOI: 10.1096/fj.202500213r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2025] [Revised: 02/21/2025] [Accepted: 03/10/2025] [Indexed: 03/20/2025]
Abstract
The special case of far-red vision of mesopelagic dragonfish Malacosteus niger facilitated by the presence in the rod outer segment of photosensitizer chlorin e6 from diet has drawn considerable attention both in vision research and in photodynamic action. Rhodopsin binding of Ce6 from either the extracellular or intracellular loops may exert different effects. Theoretical works predict that the extracellularly bound Ce6 upon absorption of red light produces a singlet oxygen, which could via an oxygen tunnel reach the Lys-tethered 11-cis-retinal, by way of peroxy-dioxetane intermediates, to enhance 11-cis- to all-trans-retinal isomerization, therefore triggering the ultrafast phototransduction process. Recent works on the permanent photodynamic activation of some A-class G protein-coupled receptors suggest that the singlet oxygen generated by Ce6 photodynamic action might also oxidize the scotopsin moiety of rhodopsin, leading to direct oxidative rhodopsin activation. More attention needs to be paid to the latter respects of the far-red vision process of the deep-sea dragonfish, with potential translational values.
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Affiliation(s)
- Zong Jie Cui
- Department of Biology, College of Life Sciences, Beijing Normal University, Beijing, 100875, China
- Ministry of Education Laboratory of Cell Proliferation and Regulation, College of Life Sciences, Beijing Normal University, Beijing, 100875, China
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4
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Foster TN, Williamson AG, Foster BR, Toomey MB. Light environment and seasonal variation in the visual system of the red shiner (Cyprinella lutrensis). J Exp Biol 2025; 228:jeb249878. [PMID: 39935365 DOI: 10.1242/jeb.249878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Accepted: 02/08/2025] [Indexed: 02/13/2025]
Abstract
The light environment underwater can vary dramatically over space and time, challenging the visual systems of aquatic organisms. To meet these challenges, many species shift their spectral sensitivities through changes in visual pigment chromophore composition and opsin expression. The red shiner (Cyprinella lutrensis) is a North American cyprinid minnow species that inhabits waters ranging widely in turbidity and temperature. We hypothesized that the visual system of the red shiner is plastic with chromophore composition and opsin expression varying in response to the environment. To test this hypothesis, we collected red shiners throughout the year from three Oklahoma creeks that vary in turbidity. We characterized the light environment by spectroradiometry, measured chromophore composition of the eyes with high performance liquid chromatography, characterized the mechanisms of chromophore metabolism, and examined ocular gene expression by RNA sequencing and de novo transcriptome assembly. We observed significantly higher proportions of the long wavelength-shifted A2 chromophore in the eyes of fish from the turbid site and in samples collected in winter, suggesting that there may be a temperature-dependent trade-off between chromophore-based spectral tuning and chromophore-related noise. Opsin expression varied between turbid and clear creeks, but did not align with light environment as expected, and the magnitude of these differences was limited compared with the differences in chromophore composition. We confirmed that red shiner CYP27C1 catalyzes the conversion of A1 to A2, but the ocular expression of CYP27C1 was not well correlated with A2 levels in the eye, suggesting conversion may be occurring outside the eye.
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Affiliation(s)
- Tarah N Foster
- Department of Biological Sciences, University of Tulsa, Oklahoma 74104, USA
| | | | - Bradley R Foster
- Department of Biological Sciences, University of Tulsa, Oklahoma 74104, USA
| | - Matthew B Toomey
- Department of Biological Sciences, University of Tulsa, Oklahoma 74104, USA
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5
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Kondrashev SL. Spectral absorbance changes in the photoreceptors of the juvenile masked greenling, Hexagrammos octogrammus (Pisces, Hexagrammidae). JOURNAL OF FISH BIOLOGY 2025; 106:706-716. [PMID: 39523688 DOI: 10.1111/jfb.15990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2024] [Revised: 09/16/2024] [Accepted: 10/23/2024] [Indexed: 11/16/2024]
Abstract
When changing habitat during migration or ontogenesis, fish encounter changes of the visual environment, among which the most important is the spectral composition of light and turbidity. This leads to changes in the behavior, morphology, and physiology of the visual system, in particular, spectral sensitivity, which is determined by the properties of visual pigments. The masked greenling Hexagrammos octogrammus has an additional factor that shapes effective spectral sensitivity-the presence of densely bright orange cornea which reversibly changes its density depending on the state of light/dark adaptation. However, it is unknown to what extent the properties of visual pigments are matched to spectral properties of the developing cornea at the final stage of metamorphosis during migration of juveniles from pelagic to coastal environments. The findings of this microspectrophotometric study show that the range of the spectral sensitivity of rods and cones in juveniles is much wider than in adults, with a shift in the sensitivity of a significant part of the cells to shorter wavelengths. The reason for this is the large variation in the ratio of chromophores A1:A2 in the pigment mixture in each cell and possible expression of new opsins. This also indicates the asynchrony of pigment transformations in different types of photoreceptors and the incompleteness of these transformations on the eve of the transition to bottom life in shallow water.
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Affiliation(s)
- Sergei L Kondrashev
- Zhirmunsky National Scientific Center of Marine Biology, Far Eastern Branch, Russian Academy of Sciences, Vladivostok, Russia
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6
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Krishnamoorthi A, Salom D, Wu A, Palczewski K, Rentzepis PM. Ultrafast transient absorption spectra and kinetics of human blue cone visual pigment at room temperature. Proc Natl Acad Sci U S A 2024; 121:e2414037121. [PMID: 39356673 PMCID: PMC11474067 DOI: 10.1073/pnas.2414037121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2024] [Accepted: 09/01/2024] [Indexed: 10/04/2024] Open
Abstract
The ultrafast photochemical reaction mechanism, transient spectra, and transition kinetics of the human blue cone visual pigment have been recorded at room temperature. Ultrafast time-resolved absorption spectroscopy revealed the progressive formation and decay of several metastable photo-intermediates, corresponding to the Batho to Meta-II photo-intermediates previously observed with bovine rhodopsin and human green cone opsin, on the picosecond to millisecond timescales following pulsed excitation. The experimental data reveal several interesting similarities and differences between the photobleaching sequences of bovine rhodopsin, human green cone opsin, and human blue cone opsin. While Meta-II formation kinetics are comparable between bovine rhodopsin and blue cone opsin, the transition kinetics of earlier photo-intermediates and qualitative characteristics of the Meta-I to Meta-II transition are more similar for blue cone opsin and green cone opsin. Additionally, the blue cone photo-intermediate spectra exhibit a high degree of overlap with uniquely small spectral shifts. The observed variation in Meta-II formation kinetics between rod and cone visual pigments is explained based on key structural differences.
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Affiliation(s)
- Arjun Krishnamoorthi
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX77843
| | - David Salom
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA92697
- Department of Ophthalmology, School of Medicine, University of California Irvine, Irvine, CA92697
| | - Arum Wu
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA92697
- Department of Ophthalmology, School of Medicine, University of California Irvine, Irvine, CA92697
| | - Krzysztof Palczewski
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA92697
- Department of Ophthalmology, School of Medicine, University of California Irvine, Irvine, CA92697
- Department of Chemistry, University of California Irvine, Irvine, CA92697
- Department of Physiology and Biophysics, University of California Irvine, Irvine, CA92697
- Department of Molecular Biology and Biochemistry, University of California Irvine, Irvine, CA92697
| | - Peter M. Rentzepis
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX77843
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7
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Rossetto IH, Ludington AJ, Simões BF, Van Cao N, Sanders KL. Dynamic Expansions and Retinal Expression of Spectrally Distinct Short-Wavelength Opsin Genes in Sea Snakes. Genome Biol Evol 2024; 16:evae150. [PMID: 38985750 PMCID: PMC11316226 DOI: 10.1093/gbe/evae150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 07/02/2024] [Accepted: 07/04/2024] [Indexed: 07/12/2024] Open
Abstract
The photopigment-encoding visual opsin genes that mediate color perception show great variation in copy number and adaptive function across vertebrates. An open question is how this variation has been shaped by the interaction of lineage-specific structural genomic architecture and ecological selection pressures. We contribute to this issue by investigating the expansion dynamics and expression of the duplicated Short-Wavelength-Sensitive-1 opsin (SWS1) in sea snakes (Elapidae). We generated one new genome, 45 resequencing datasets, 10 retinal transcriptomes, and 81 SWS1 exon sequences for sea snakes, and analyzed these alongside 16 existing genomes for sea snakes and their terrestrial relatives. Our analyses revealed multiple independent transitions in SWS1 copy number in the marine Hydrophis clade, with at least three lineages having multiple intact SWS1 genes: the previously studied Hydrophis cyanocinctus and at least two close relatives of this species; Hydrophis atriceps and Hydrophis fasciatus; and an individual Hydrophis curtus. In each lineage, gene copy divergence at a key spectral tuning site resulted in distinct UV and Violet/Blue-sensitive SWS1 subtypes. Both spectral variants were simultaneously expressed in the retinae of H. cyanocinctus and H. atriceps, providing the first evidence that these SWS1 expansions confer novel phenotypes. Finally, chromosome annotation for nine species revealed shared structural features in proximity to SWS1 regardless of copy number. If these features are associated with SWS1 duplication, expanded opsin complements could be more common in snakes than is currently recognized. Alternatively, selection pressures specific to aquatic environments could favor improved chromatic distinction in just some lineages.
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Affiliation(s)
- Isaac H Rossetto
- School of Biological Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Alastair J Ludington
- School of Biological Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Bruno F Simões
- School of Biological Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia
- School of Biological and Marine Sciences, University of Plymouth, Plymouth PL4 8AA, UK
| | - Nguyen Van Cao
- Department of Aquaculture Biotechnology, Vietnamese Academy of Science and Technology, Institute of Oceanography, Nha Trang, Khánh Hòa, Vietnam
| | - Kate L Sanders
- School of Biological Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia
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8
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Chau KD, Hauser FE, Van Nynatten A, Daane JM, Harris MP, Chang BSW, Lovejoy NR. Multiple Ecological Axes Drive Molecular Evolution of Cone Opsins in Beloniform Fishes. J Mol Evol 2024; 92:93-103. [PMID: 38416218 DOI: 10.1007/s00239-024-10156-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Accepted: 01/12/2024] [Indexed: 02/29/2024]
Abstract
Ecological and evolutionary transitions offer an excellent opportunity to examine the molecular basis of adaptation. Fishes of the order Beloniformes include needlefishes, flyingfishes, halfbeaks, and allies, and comprise over 200 species occupying a wide array of habitats-from the marine epipelagic zone to tropical rainforest rivers. These fishes also exhibit a diversity of diets, including piscivory, herbivory, and zooplanktivory. We investigated how diet and habitat affected the molecular evolution of cone opsins, which play a key role in bright light and colour vision and are tightly linked to ecology and life history. We analyzed a targeted-capture dataset to reconstruct the evolutionary history of beloniforms and assemble cone opsin sequences. We implemented codon-based clade models of evolution to examine how molecular evolution was affected by habitat and diet. We found high levels of positive selection in medium- and long-wavelength beloniform opsins, with piscivores showing increased positive selection in medium-wavelength opsins and zooplanktivores showing increased positive selection in long-wavelength opsins. In contrast, short-wavelength opsins showed purifying selection. While marine/freshwater habitat transitions have an effect on opsin molecular evolution, we found that diet plays a more important role. Our study suggests that evolutionary transitions along ecological axes produce complex adaptive interactions that affect patterns of selection on genes that underlie vision.
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Affiliation(s)
- Katherine D Chau
- Department of Physical & Environmental Sciences, University of Toronto Scarborough, Toronto, ON, Canada
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON, Canada
- Department of Biology, York University, Toronto, ON, Canada
| | - Frances E Hauser
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON, Canada
| | - Alexander Van Nynatten
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON, Canada
- Department of Biology, University of Victoria, Victoria, Canada
| | - Jacob M Daane
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA
| | | | - Belinda S W Chang
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Nathan R Lovejoy
- Department of Physical & Environmental Sciences, University of Toronto Scarborough, Toronto, ON, Canada.
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON, Canada.
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada.
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada.
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9
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Margetts BM, Stuart‐Fox D, Franklin AM. Red vision in animals is broadly associated with lighting environment but not types of visual task. Ecol Evol 2024; 14:e10899. [PMID: 38304263 PMCID: PMC10828735 DOI: 10.1002/ece3.10899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 12/19/2023] [Accepted: 01/03/2024] [Indexed: 02/03/2024] Open
Abstract
Red sensitivity is the exception rather than the norm in most animal groups. Among species with red sensitivity, there is substantial variation in the peak wavelength sensitivity (λmax) of the long wavelength sensitive (LWS) photoreceptor. It is unclear whether this variation can be explained by visual tuning to the light environment or to visual tasks such as signalling or foraging. Here, we examine long wavelength sensitivity across a broad range of taxa showing diversity in LWS photoreceptor λmax: insects, crustaceans, arachnids, amphibians, reptiles, fish, sharks and rays. We collated a list of 161 species with physiological evidence for a photoreceptor sensitive to red wavelengths (i.e. λmax ≥ 550 nm) and for each species documented abiotic and biotic factors that may be associated with peak sensitivity of the LWS photoreceptor. We found evidence supporting visual tuning to the light environment: terrestrial species had longer λmax than aquatic species, and of these, species from turbid shallow waters had longer λmax than those from clear or deep waters. Of the terrestrial species, diurnal species had longer λmax than nocturnal species, but we did not detect any differences across terrestrial habitats (closed, intermediate or open). We found no association with proxies for visual tasks such as having red morphological features or utilising flowers or coral reefs. These results support the emerging consensus that, in general, visual systems are broadly adapted to the lighting environment and diverse visual tasks. Links between visual systems and specific visual tasks are commonly reported, but these likely vary among species and do not lead to general patterns across species.
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Affiliation(s)
- Bryony M. Margetts
- School of BioSciencesThe University of MelbourneParkvilleVictoriaAustralia
| | - Devi Stuart‐Fox
- School of BioSciencesThe University of MelbourneParkvilleVictoriaAustralia
| | - Amanda M. Franklin
- School of BioSciencesThe University of MelbourneParkvilleVictoriaAustralia
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10
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Gerhards J, Volkov LI, Corbo JC, Malan D, Sasse P. Enzymatic vitamin A 2 production enables red-shifted optogenetics. Pflugers Arch 2023; 475:1409-1419. [PMID: 37987804 PMCID: PMC10730639 DOI: 10.1007/s00424-023-02880-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 10/20/2023] [Accepted: 11/03/2023] [Indexed: 11/22/2023]
Abstract
Optogenetics is a technology using light-sensitive proteins to control signaling pathways and physiological processes in cells and organs and has been applied in neuroscience, cardiovascular sciences, and many other research fields. Most commonly used optogenetic actuators are sensitive to blue and green light, but red-light activation would allow better tissue penetration and less phototoxicity. Cyp27c1 is a recently deorphanized cytochrome P450 enzyme that converts vitamin A1 to vitamin A2, thereby red-shifting the spectral sensitivity of visual pigments and enabling near-infrared vision in some aquatic species.Here, we investigated the ability of Cyp27c1-generated vitamin A2 to induce a shift in spectral sensitivity of the light-gated ion channel Channelrhodopsin-2 (ChR2) and its red-shifted homolog ReaChR. We used patch clamp to measure photocurrents at specific wavelengths in HEK 293 cells expressing ChR2 or ReaChR. Vitamin A2 incubation red-shifted the wavelength for half-maximal currents (λ50%) by 6.8 nm for ChR2 and 12.4 nm for ReaChR. Overexpression of Cyp27c1 in HEK 293 cells showed mitochondrial localization, and HPLC analysis showed conversion of vitamin A1 to vitamin A2. Notably, the λ50% of ChR2 photocurrents was red-shifted by 10.5 nm, and normalized photocurrents at 550 nm were about twofold larger with Cyp27c1 expression. Similarly, Cyp27c1 shifted the λ50% of ReaChR photocurrents by 14.3 nm and increased normalized photocurrents at 650 nm almost threefold.Since vitamin A2 incubation is not a realistic option for in vivo applications and expression of Cyp27c1 leads to a greater red-shift in spectral sensitivity, we propose co-expression of this enzyme as a novel strategy for red-shifted optogenetics.
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Affiliation(s)
- Johanna Gerhards
- Institute of Physiology I, Medical Faculty, University of Bonn, 53125, Bonn, Germany
| | - Leo I Volkov
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Joseph C Corbo
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Daniela Malan
- Institute of Physiology I, Medical Faculty, University of Bonn, 53125, Bonn, Germany.
| | - Philipp Sasse
- Institute of Physiology I, Medical Faculty, University of Bonn, 53125, Bonn, Germany.
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11
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Qiu L, Wei S, Wang Y, Zhang R, Ru S, Zhang X. Mechanism of thyroid hormone and its structurally similar contaminant bisphenol S exposure on retinoid metabolism in zebrafish larval eyes. ENVIRONMENT INTERNATIONAL 2023; 180:108217. [PMID: 37748373 DOI: 10.1016/j.envint.2023.108217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 08/25/2023] [Accepted: 09/18/2023] [Indexed: 09/27/2023]
Abstract
The photoreceptor necessitates the retinoids metabolism processes in visual cycle pathway to regenerate visual pigments and sustain vision. Bisphenol S (BPS), with similar structure of thyroid hormone (TH), was reported to impair the light-sensing function of zebrafish larvae via disturbing TH-thyroid hormone receptor β (TRβ) signaling pathway. However, it remains unknown whether TRβ could modulate the toxicity of BPS on retinoid metabolism in visual cycle. This study showed that BPS diminished the optokinetic response of zebrafish larvae and had a stimulative effect on all-trans-retinoic acid (atRA) metabolism, like exogenous T3 exposure. By modulating CYP26A1 and TRβ expression, it was found that CYP26A1 played a crucial role in catalyzing oxidative metabolism of atRA and retinoids regeneration in visual cycle, and TRβ mediated cyp26a1 expression in zebrafish eyes. Similar with 10 nM T3 treatment, cyp26a1 expression could be induced by BPS in the presence of TRβ. Further, in CYP26A1 and TRβ- deficient eyes, 100 μg/L BPS could no longer promote atRA metabolism, or decrease the all-trans-retinol and 11-cis retinal contents in visual cycle, demonstrating that BPS exposure disturbed CYP26A1-mediated visual retinoids metabolism via TRβ. Overall, this study highlights the role of TRβ in mediating the retinoids homeostasis disruption caused by BPS, and provides new clues for exploring molecular targets of visual toxicity under pollutants stress.
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Affiliation(s)
- Liguo Qiu
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Shuhui Wei
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Yunsheng Wang
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Rui Zhang
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Shaoguo Ru
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Xiaona Zhang
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
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12
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Honisch C, Rodella U, Gatto C, Ruzza P, Tóthová JD. Oxidative Stress and Antioxidant-Based Interventional Medicine in Ophthalmology. Pharmaceuticals (Basel) 2023; 16:1146. [PMID: 37631061 PMCID: PMC10458870 DOI: 10.3390/ph16081146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 08/07/2023] [Accepted: 08/10/2023] [Indexed: 08/27/2023] Open
Abstract
The different anatomical compartments of the eye are highly subjected to reactive oxygen species (ROS) generation due to internal factors, such as metabolic high oxygen consumption, as well as environmental factors, including UV light. An antioxidant defense system is endowed in the eye tissues to regulate ROS quantity and activity. When this homeostatic system is overwhelmed, oxidative stress occurs, causing cellular damage, chronic inflammation, and tissue degeneration. It also plays a significant role in the development and progression of various ocular diseases. Understanding the mechanisms underlying oxidative stress in ocular conditions is thus crucial for the development of effective prevention and treatment strategies. To track marketed products based on antioxidant substances as active ingredients, the databases of the European Medicines Agency and the U.S. Food and Drug Administration were consulted. Only a limited number of items were identified, which were either used as therapeutic treatment or during ocular surgery, including antioxidants, synthetical derivatives, or pro-drugs designed to enhance tissue permeation and activity. This review aims to provide an overview of the primary ocular pathologies associated with oxidative stress and of the available pharmacological interventions centered around antioxidant molecules. Such insights are essential for advancing the development of effective prevention and novel treatment approaches.
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Affiliation(s)
- Claudia Honisch
- Institute of Biomolecular Chemistry of CNR (ICB-CNR), Via F. Marzolo, 1, 35131 Padova, Italy;
| | - Umberto Rodella
- Research and Development, AL.CHI.MI.A. S.R.L., Viale Austria, 14, 35020 Ponte San Nicolờ, Italy; (U.R.); (C.G.)
- Fondazione Banca degli Occhi del Veneto (FBOV), Via Paccagnella, 11, 30174 Zelarino, Italy
| | - Claudio Gatto
- Research and Development, AL.CHI.MI.A. S.R.L., Viale Austria, 14, 35020 Ponte San Nicolờ, Italy; (U.R.); (C.G.)
| | - Paolo Ruzza
- Institute of Biomolecular Chemistry of CNR (ICB-CNR), Via F. Marzolo, 1, 35131 Padova, Italy;
| | - Jana D’Amato Tóthová
- Research and Development, AL.CHI.MI.A. S.R.L., Viale Austria, 14, 35020 Ponte San Nicolờ, Italy; (U.R.); (C.G.)
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13
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Krishnamoorthi A, Khosh Abady K, Dhankhar D, Rentzepis PM. Ultrafast Transient Absorption Spectra and Kinetics of Rod and Cone Visual Pigments. Molecules 2023; 28:5829. [PMID: 37570798 PMCID: PMC10421382 DOI: 10.3390/molecules28155829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 07/28/2023] [Accepted: 07/31/2023] [Indexed: 08/13/2023] Open
Abstract
Rods and cones are the photoreceptor cells containing the visual pigment proteins that initiate visual phototransduction following the absorption of a photon. Photon absorption induces the photochemical transformation of a visual pigment, which results in the sequential formation of distinct photo-intermediate species on the femtosecond to millisecond timescales, whereupon a visual electrical signal is generated and transmitted to the brain. Time-resolved spectroscopic studies of the rod and cone photo-intermediaries enable the detailed understanding of initial events in vision, namely the key differences that underlie the functionally distinct scotopic (rod) and photopic (cone) visual systems. In this paper, we review our recent ultrafast (picoseconds to milliseconds) transient absorption studies of rod and cone visual pigments with a detailed comparison of the transient molecular spectra and kinetics of their respective photo-intermediaries. Key results include the characterization of the porphyropsin (carp fish rhodopsin) and human green-cone opsin photobleaching sequences, which show significant spectral and kinetic differences when compared against that of bovine rhodopsin. These results altogether reveal a rather strong interplay between the visual pigment structure and its corresponding photobleaching sequence, and relevant outstanding questions that will be further investigated through a forthcoming study of the human blue-cone visual pigment are discussed.
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Affiliation(s)
- Arjun Krishnamoorthi
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Keyvan Khosh Abady
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Dinesh Dhankhar
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX 77843, USA
- Thermo Fisher Scientific, Hillsboro, OR 97124, USA
| | - Peter M. Rentzepis
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX 77843, USA
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14
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Sharkey CR, Blanco J, Lord NP, Wardill TJ. Jewel Beetle Opsin Duplication and Divergence Is the Mechanism for Diverse Spectral Sensitivities. Mol Biol Evol 2023; 40:7017620. [PMID: 36721951 PMCID: PMC9937044 DOI: 10.1093/molbev/msad023] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 11/10/2022] [Accepted: 01/20/2023] [Indexed: 02/02/2023] Open
Abstract
The evolutionary history of visual genes in Coleoptera differs from other well-studied insect orders, such as Lepidoptera and Diptera, as beetles have lost the widely conserved short-wavelength (SW) insect opsin gene that typically underpins sensitivity to blue light (∼440 nm). Duplications of the ancestral ultraviolet (UV) and long-wavelength (LW) opsins have occurred in many beetle lineages and have been proposed as an evolutionary route for expanded spectral sensitivity. The jewel beetles (Buprestidae) are a highly ecologically diverse and colorful family of beetles that use color cues for mate and host detection. In addition, there is evidence that buprestids have complex spectral sensitivity with up to five photoreceptor classes. Previous work suggested that opsin duplication and subfunctionalization of the two ancestral buprestid opsins, UV and LW, has expanded sensitivity to different regions of the light spectrum, but this has not yet been tested. We show that both duplications are likely unique to Buprestidae or the wider superfamily of Buprestoidea. To directly test photopigment sensitivity, we expressed buprestid opsins from two Chrysochroa species in Drosophila melanogaster and functionally characterized each photopigment type as UV- (356-357 nm), blue- (431-442 nm), green- (507-509 nm), and orange-sensitive (572-584 nm). As these novel opsin duplicates result in significantly shifted spectral sensitivities from the ancestral copies, we explored spectral tuning at four candidate sites using site-directed mutagenesis. This is the first study to directly test opsin spectral tuning mechanisms in the diverse and specious beetles.
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Affiliation(s)
| | - Jorge Blanco
- Department of Ecology, Evolution and Behavior, University of Minnesota, Saint Paul, MN
| | - Nathan P Lord
- Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, LA
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15
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Ultrafast spectra and kinetics of human green-cone visual pigment at room temperature. Proc Natl Acad Sci U S A 2023; 120:e2214276120. [PMID: 36577071 PMCID: PMC9910472 DOI: 10.1073/pnas.2214276120] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Rhodopsin is the pigment that enables night vision, whereas cone opsins are the pigments responsible for color vision in bright-light conditions. Despite their importance for vision, cone opsins are poorly characterized at the molecular level compared to rhodopsin. Spectra and kinetics of the intermediate states of human green-cone visual pigment (mid-wavelength sensitive, or MWS opsin) were measured and compared with the intermediates and kinetics of bovine rhodopsin. All the major intermediates of the MWS opsin were recorded in the picosecond to millisecond time range. Several intermediates in MWS opsin appear to have characteristics similar to the intermediates of bovine rhodopsin; however, there are some marked differences. One of the most striking differences is in their kinetics, where the kinetics of the MWS opsin intermediates are slower compared to those of the bovine rhodopsin intermediates.
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16
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Corredor VH, Hauzman E, Gonçalves ADS, Ventura DF. Genetic characterization of the visual pigments of the red-eared turtle (Trachemys scripta elegans) and computational predictions of the spectral sensitivity. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY 2022. [DOI: 10.1016/j.jpap.2022.100141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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17
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Kondrashev SL. Photoreceptors, visual pigments and intraretinal variability in spectral sensitivity in two species of smelts (Pisces, Osmeridae). JOURNAL OF FISH BIOLOGY 2022; 101:584-596. [PMID: 35655413 DOI: 10.1111/jfb.15128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 05/30/2022] [Indexed: 06/15/2023]
Abstract
The main goal of this study was to clarify whether the spectral properties of retinal photoreceptors reflect the features of behaviour of closely related fish species cohabiting shallow marine and fresh waters. The spectral sensitivity of photoreceptors was compared between two smelt species, Hypomesus japonicus and Japanese smelt Hypomesus nipponensis. The spectral absorption of the visual pigments was measured using microspectrophotometry. In H. japonicus, a mostly marine species, all photoreceptors contained visual pigments based on retinal and were distributed differently in specific retinal areas. The absorbance maxima (λmax ) of rods and long-wave-sensitive members of double cones throughout the retina amounted to 507 and 573 nm, respectively, but the λmax value of the short-wave-sensitive members of double cones and single cones in the temporal hemiretina showed a significant blue shift compared to the nasal hemiretina: 485 vs. 516 nm and 375 vs. 412 nm, respectively, thus enhancing the short-wave sensitivity of the temporal hemiretina. In H. nipponensis, an euryhaline species, the estimated λmax value of both rods and cones significantly varied between the groups caught in different localities (sea, river or estuary) because of the presence of rhodopsin/porphyropsin mixtures. The long-wavelength shift in rod and cone photoreceptors was observed because of changes in the chromophore complement in closely related but ecologically different species dwelling in freshened bodies of water. Considering the data available in the literature, several putative common opsin genes have been suggested for species under study.
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Affiliation(s)
- Sergei L Kondrashev
- Zhirmunsky National Scientific Center of Marine Biology, Far Eastern Branch, Russian Academy of Sciences, Vladivostok, Russia
- Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, Russia
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18
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Schott RK, Bell RC, Loew ER, Thomas KN, Gower DJ, Streicher JW, Fujita MK. Transcriptomic evidence for visual adaptation during the aquatic to terrestrial metamorphosis in leopard frogs. BMC Biol 2022; 20:138. [PMID: 35761245 PMCID: PMC9238225 DOI: 10.1186/s12915-022-01341-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 05/30/2022] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Differences in morphology, ecology, and behavior through ontogeny can result in opposing selective pressures at different life stages. Most animals, however, transition through two or more distinct phenotypic phases, which is hypothesized to allow each life stage to adapt more freely to its ecological niche. How this applies to sensory systems, and in particular how sensory systems adapt across life stages at the molecular level, is not well understood. Here, we used whole-eye transcriptomes to investigate differences in gene expression between tadpole and juvenile southern leopard frogs (Lithobates sphenocephalus), which rely on vision in aquatic and terrestrial light environments, respectively. Because visual physiology changes with light levels, we also tested the effect of light and dark exposure. RESULTS We found 42% of genes were differentially expressed in the eyes of tadpoles versus juveniles and 5% for light/dark exposure. Analyses targeting a curated subset of visual genes revealed significant differential expression of genes that control aspects of visual function and development, including spectral sensitivity and lens composition. Finally, microspectrophotometry of photoreceptors confirmed shifts in spectral sensitivity predicted by the expression results, consistent with adaptation to distinct light environments. CONCLUSIONS Overall, we identified extensive expression-level differences in the eyes of tadpoles and juveniles related to observed morphological and physiological changes through metamorphosis and corresponding adaptive shifts to improve vision in the distinct aquatic and terrestrial light environments these frogs inhabit during their life cycle. More broadly, these results suggest that decoupling of gene expression can mediate the opposing selection pressures experienced by organisms with complex life cycles that inhabit different environmental conditions throughout ontogeny.
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Affiliation(s)
- Ryan K Schott
- Department of Biology, York University, Toronto, Ontario, Canada.
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington DC, USA.
| | - Rayna C Bell
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington DC, USA
- Department of Herpetology, California Academy of Sciences, San Francisco, CA, USA
| | - Ellis R Loew
- Department of Biomedical Sciences, Cornell University College of Veterinary Medicine, Ithaca, NY, USA
| | - Kate N Thomas
- Department of Life Sciences, The Natural History Museum, London, UK
| | - David J Gower
- Department of Life Sciences, The Natural History Museum, London, UK
| | | | - Matthew K Fujita
- Department of Biology, Amphibian and Reptile Diversity Research Center, The University of Texas at Arlington, Arlington, TX, USA
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19
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Shin KC, Seo MJ, Kim YS, Yeom SJ. Molecular Properties of β-Carotene Oxygenases and Their Potential in Industrial Production of Vitamin A and Its Derivatives. Antioxidants (Basel) 2022; 11:1180. [PMID: 35740077 PMCID: PMC9227343 DOI: 10.3390/antiox11061180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 06/11/2022] [Accepted: 06/13/2022] [Indexed: 11/16/2022] Open
Abstract
β-Carotene 15,15'-oxygenase (BCO1) and β-carotene 9',10'-oxygenase (BCO2) are potential producers of vitamin A derivatives, since they can catalyze the oxidative cleavage of dietary provitamin A carotenoids to retinoids and derivative such as apocarotenal. Retinoids are a class of chemical compounds that are vitamers of vitamin A or are chemically related to it, and are essential nutrients for humans and highly valuable in the food and cosmetics industries. β-carotene oxygenases (BCOs) from various organisms have been overexpressed in heterogeneous bacteria, such as Escherichia coli, and their biochemical properties have been studied. For the industrial production of retinal, there is a need for increased production of a retinal producer and biosynthesis of retinal using biocatalyst systems improved by enzyme engineering. The current review aims to discuss BCOs from animal, plants, and bacteria, and to elaborate on the recent progress in our understanding of their functions, biochemical properties, substrate specificity, and enzyme activities with respect to the production of retinoids in whole-cell conditions. Moreover, we specifically propose ways to integrate BCOs into retinal biosynthetic bacterial systems to improve the performance of retinal production.
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Affiliation(s)
- Kyung-Chul Shin
- Department of Integrative Bioscience and Biotechnology, Konkuk University, Seoul 05029, Korea;
| | - Min-Ju Seo
- School of Biological Sciences and Technology, Chonnam National University, Gwangju 61186, Korea
| | - Yeong-Su Kim
- Wild Plants Industrialization Research Division, Baekdudaegan National Arboretum, Bonghwa 36209, Korea
| | - Soo-Jin Yeom
- School of Biological Sciences and Technology, Chonnam National University, Gwangju 61186, Korea
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20
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Nagloo N, Mountford JK, Gundry BJ, Hart NS, Davies WIL, Collin SP, Hemmi JM. Enhanced short-wavelength sensitivity in the blue-tongued skink, Tiliqua rugosa. J Exp Biol 2022; 225:275680. [PMID: 35582824 PMCID: PMC9234500 DOI: 10.1242/jeb.244317] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 05/11/2022] [Indexed: 11/20/2022]
Abstract
Despite lizards using a wide range of color signals, the limited variation in photoreceptor spectral sensitivities across lizards suggests only weak selection for species-specific, spectral tuning of photoreceptors. Some species, however, have enhanced short wavelength sensitivity, which likely helps with the detection of signals rich in ultraviolet and short wavelengths. In this study, we examined the visual system of Tiliqua rugosa, which has a UV/blue tongue, to gain insight into this species' visual ecology. We used electroretinograms, opsin sequencing and immunohistochemical labelling to characterize whole eye spectral sensitivity and the elements that shape it. Our findings reveal that T. rugosa expresses all five opsins typically found in lizards (SWS1, SWS2, RH1, RH2 and LWS) but possesses greatly enhanced short wavelength sensitivity compared to other diurnal lizards. This enhanced short wavelength sensitivity is characterized by a broadening of the spectral sensitivity curve of the eye towards shorter wavelengths while the peak sensitivity of the eye at longer wavelengths (560 nm) remains similar to other diurnal lizards. While an increased abundance of SWS1 photoreceptors is thought to mediate elevated ultraviolet sensitivity in a couple of other lizard species, SWS1 photoreceptor abundance remains low in our species. Instead, our findings suggest that short-wavelength sensitivity is driven by multiple factors which include a potentially red-shifted SWS1 photoreceptor and the absence of short-wavelength absorbing oil droplets. Examining the coincidence of enhanced short-wavelength sensitivity with blue tongues among lizards of this genus will provide further insight into the co-evolution of conspecific signals and whole-eye spectral sensitivity.
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Affiliation(s)
- Nicolas Nagloo
- School of Biological Sciences, The University of Western Australia, 6009 WA, Australia.,Department of Biology, Lund University, Lund, S-212263, Sweden.,The UWA Oceans Institute, The University of Western Australia, 6009 WA, Australia
| | - Jessica K Mountford
- School of Biological Sciences, The University of Western Australia, 6009 WA, Australia.,The UWA Oceans Institute, The University of Western Australia, 6009 WA, Australia.,Oceans Graduate School, The University of Western Australia, 6009 WA, Australia.,Clinical Genetics and Epidemiology, and Centre for Ophthalmology and Visual Science incorporating the Lions Eye Institute, The University of Western Australia, 6009 WA, Australia
| | - Ben J Gundry
- School of Biological Sciences, The University of Western Australia, 6009 WA, Australia
| | - Nathan S Hart
- School of Biological Sciences, The University of Western Australia, 6009 WA, Australia.,School of Natural Sciences, Macquarie University, 2109 NSW, Australia
| | - Wayne I L Davies
- School of Biological Sciences, The University of Western Australia, 6009 WA, Australia.,The UWA Oceans Institute, The University of Western Australia, 6009 WA, Australia.,Oceans Graduate School, The University of Western Australia, 6009 WA, Australia.,Clinical Genetics and Epidemiology, and Centre for Ophthalmology and Visual Science incorporating the Lions Eye Institute, The University of Western Australia, 6009 WA, Australia.,Umeå Centre for Molecular Medicine (UCMM), Umeå University, Umeå, S-90187, Sweden.,School of Agriculture, Biomedicine and Environment, La Trobe University Bundoora, Victoria 3086, Australia
| | - Shaun P Collin
- School of Biological Sciences, The University of Western Australia, 6009 WA, Australia.,The UWA Oceans Institute, The University of Western Australia, 6009 WA, Australia.,Oceans Graduate School, The University of Western Australia, 6009 WA, Australia.,Clinical Genetics and Epidemiology, and Centre for Ophthalmology and Visual Science incorporating the Lions Eye Institute, The University of Western Australia, 6009 WA, Australia.,School of Agriculture, Biomedicine and Environment, La Trobe University Bundoora, Victoria 3086, Australia
| | - Jan M Hemmi
- School of Biological Sciences, The University of Western Australia, 6009 WA, Australia.,The UWA Oceans Institute, The University of Western Australia, 6009 WA, Australia
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21
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Karagic N, Härer A, Meyer A, Torres-Dowdall J. Thyroid hormone tinkering elicits integrated phenotypic changes potentially explaining rapid adaptation of color vision in cichlid fish. Evolution 2022; 76:837-845. [PMID: 35247267 DOI: 10.1111/evo.14455] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 01/05/2022] [Indexed: 01/21/2023]
Abstract
Vision is critical for most vertebrates, including fish. One challenge that aquatic habitats pose is the high variability in spectral properties depending on depth and the inherent optical properties of the water. By altering opsin gene expression and chromophore usage, cichlid fish modulate visual sensitivities to maximize sensory input from the available light in their respective habitat. Thyroid hormone (TH) has been proposed to play a role in governing adaptive diversification in visual sensitivity in Nicaraguan Midas cichlids, which evolved in less than 4000 generations. As suggested by indirect measurements of TH levels (i.e., expression of deiodinases), populations adapted to short wavelength light in clear lakes have lower TH levels than ones inhabiting turbid lakes enriched in long-wavelength light. We experimentally manipulated TH levels by exposing 2-week-old Midas cichlids to exogenous TH or a TH inhibitor and measured opsin gene expression and chromophore usage (via cyp27c1 expression). Although exogenous TH induces long-wavelength sensitivity by changing opsin gene expression and chromophore usage in a concerted manner, TH-inhibited fish exhibit a visual phenotype with sensitivities shifted to shorter wavelengths. Tinkering with TH levels in eyes results in concerted phenotypic changes that can provide a rapid mechanism of adaptation to novel light environments.
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Affiliation(s)
- Nidal Karagic
- Department of Biology, University of Konstanz, Konstanz, 78464, Germany
| | - Andreas Härer
- Department of Biology, University of Konstanz, Konstanz, 78464, Germany.,Division of Biological Sciences, Section of Ecology, Behavior and Evolution, University of California San Diego, La Jolla, California, 92093
| | - Axel Meyer
- Department of Biology, University of Konstanz, Konstanz, 78464, Germany
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22
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Dhankhar D, Nagpal A, Tachibanaki S, Li R, Cesario TC, Rentzepis PM. Comparison of Bovine and Carp Fish Visual Pigment Photo-Intermediates at Room Temperature. Photochem Photobiol 2022; 98:1303-1311. [PMID: 35313014 DOI: 10.1111/php.13621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 03/17/2022] [Indexed: 11/29/2022]
Abstract
This paper presents room temperature nanoseconds to milliseconds time-resolved spectra and kinetics of the intermediate states and species of bovine and carp fish rhodopsin visual pigments, which also contained ~5% cone pigments. The nanoseconds to milliseconds range cover all the major intermediates in the visual phototransduction process except the formation of bathorhodopsin intermediate which occurs at the femtosecond time scale. The dynamics of these visual pigment intermediates are initiated by excitation with a 532 nm nanosecond laser pulse. The recorded differences between bovine and carp rhodopsin time-resolved spectra of the formation and decay kinetics of their intermediates are presented and discussed. The data show that the carp samples batho intermediate decays faster, nearly by a factor of three, compared to the bovine samples. The formation and decay spectra and kinetics of rhodopsin outer segments and extracted rhodopsin inserted in buffer solution were found to be identical, with very small differences between them in the decay lifetimes of bathorhodopsin and formation of lumirhodopsin.
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Affiliation(s)
- Dinesh Dhankhar
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX, USA
| | - Anushka Nagpal
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX, USA
| | - Shuji Tachibanaki
- Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, Japan
| | - Runze Li
- School of Physical Science and Technology, Shanghai Tech University, Shanghai, China
| | | | - Peter M Rentzepis
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX, USA
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23
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Fouilloux CA, Yovanovich CAM, Rojas B. Tadpole Responses to Environments With Limited Visibility: What We (Don’t) Know and Perspectives for a Sharper Future. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2021.766725] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Amphibian larvae typically inhabit relatively shallow freshwater environments, and within these boundaries there is considerable diversity in the structure of the habitats exploited by different species. This diversity in habitat structure is usually taken into account in relation to aspects such as locomotion and feeding, and plays a fundamental role in the classification of tadpoles into ecomorphological guilds. However, its impact in shaping the sensory worlds of different species is rarely addressed, including the optical qualities of each of these types of water bodies and the challenges and limitations that they impose on the repertoire of visual abilities available for a typical vertebrate eye. In this Perspective article, we identify gaps in knowledge on (1) the role of turbidity and light-limited environments in shaping the larval visual system; and (2) the possible behavioral and phenotypic responses of larvae to such environments. We also identify relevant unaddressed study systems paying special attention to phytotelmata, whose small size allows for extensive quantification and manipulation providing a rich and relatively unexplored research model. Furthermore, we generate hypotheses ranging from proximate shifts (i.e., red-shifted spectral sensitivity peaks driven by deviations in chromophore ratios) to ultimate changes in tadpole behavior and phenotype, such as reduced foraging efficiency and the loss of antipredator signaling. Overall, amphibians provide an exciting opportunity to understand adaptations to visually limited environments, and this framework will provide novel experimental considerations and interpretations to kickstart future research based on understanding the evolution and diversity of strategies used to cope with limited visibility.
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24
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Molina-Ortiz D, Torres-Zárate C, Santes-Palacios R. Human Orphan Cytochromes P450: An Update. Curr Drug Metab 2022; 23:942-963. [PMID: 36503398 DOI: 10.2174/1389200224666221209153032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 10/25/2022] [Accepted: 11/11/2022] [Indexed: 12/14/2022]
Abstract
Orphan cytochromes P450 (CYP) are enzymes whose biological functions and substrates are unknown. However, the use of new experimental strategies has allowed obtaining more information about their relevance in the metabolism of endogenous and exogenous compounds. Likewise, the modulation of their expression and activity has been associated with pathogenesis and prognosis in different diseases. In this work, we review the regulatory pathways and the possible role of orphan CYP to provide evidence that allow us to stop considering some of them as orphan enzymes and to propose them as possible therapeutic targets in the design of new strategies for the treatment of diseases associated with CYP-mediated metabolism.
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Affiliation(s)
- Dora Molina-Ortiz
- Laboratorio de Toxicología Genética, Instituto Nacional de Pediatría, Coyoacán 04530, Mexico City, México
| | - Carmen Torres-Zárate
- Laboratorio de Toxicología Genética, Instituto Nacional de Pediatría, Coyoacán 04530, Mexico City, México
| | - Rebeca Santes-Palacios
- Laboratorio de Toxicología Genética, Instituto Nacional de Pediatría, Coyoacán 04530, Mexico City, México
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25
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Genovese F, Reisert J, Kefalov VJ. Sensory Transduction in Photoreceptors and Olfactory Sensory Neurons: Common Features and Distinct Characteristics. Front Cell Neurosci 2021; 15:761416. [PMID: 34690705 PMCID: PMC8531253 DOI: 10.3389/fncel.2021.761416] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 09/20/2021] [Indexed: 12/24/2022] Open
Abstract
The past decades have seen tremendous progress in our understanding of the function of photoreceptors and olfactory sensory neurons, uncovering the mechanisms that determine their properties and, ultimately, our ability to see and smell. This progress has been driven to a large degree by the powerful combination of physiological experimental tools and genetic manipulations, which has enabled us to identify the main molecular players in the transduction cascades of these sensory neurons, how their properties affect the detection and discrimination of stimuli, and how diseases affect our senses of vision and smell. This review summarizes some of the common and unique features of photoreceptors and olfactory sensory neurons that make these cells so exciting to study.
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Affiliation(s)
| | | | - Vladimir J Kefalov
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA, United States.,Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA, United States
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Ogawa Y, Corbo JC. Partitioning of gene expression among zebrafish photoreceptor subtypes. Sci Rep 2021; 11:17340. [PMID: 34462505 PMCID: PMC8405809 DOI: 10.1038/s41598-021-96837-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 08/17/2021] [Indexed: 02/07/2023] Open
Abstract
Vertebrate photoreceptors are categorized into two broad classes, rods and cones, responsible for dim- and bright-light vision, respectively. While many molecular features that distinguish rods and cones are known, gene expression differences among cone subtypes remain poorly understood. Teleost fishes are renowned for the diversity of their photoreceptor systems. Here, we used single-cell RNA-seq to profile adult photoreceptors in zebrafish, a teleost. We found that in addition to the four canonical zebrafish cone types, there exist subpopulations of green and red cones (previously shown to be located in the ventral retina) that express red-shifted opsin paralogs (opn1mw4 or opn1lw1) as well as a unique combination of cone phototransduction genes. Furthermore, the expression of many paralogous phototransduction genes is partitioned among cone subtypes, analogous to the partitioning of the phototransduction paralogs between rods and cones seen across vertebrates. The partitioned cone-gene pairs arose via the teleost-specific whole-genome duplication or later clade-specific gene duplications. We also discovered that cone subtypes express distinct transcriptional regulators, including many factors not previously implicated in photoreceptor development or differentiation. Overall, our work suggests that partitioning of paralogous gene expression via the action of differentially expressed transcriptional regulators enables diversification of cone subtypes in teleosts.
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Affiliation(s)
- Yohey Ogawa
- Department of Pathology and Immunology, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO, 63110-1093, USA
| | - Joseph C Corbo
- Department of Pathology and Immunology, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO, 63110-1093, USA.
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