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Sharkova M, Aparicio G, Mouzaaber C, Zolessi FR, Hocking JC. Photoreceptor calyceal processes accompany the developing outer segment, adopting a stable length despite a dynamic core. J Cell Sci 2024; 137:jcs261721. [PMID: 38477343 PMCID: PMC11058337 DOI: 10.1242/jcs.261721] [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: 10/16/2023] [Accepted: 03/04/2024] [Indexed: 03/14/2024] Open
Abstract
Vertebrate photoreceptors detect light through a large cilium-based outer segment, which is filled with photopigment-laden membranous discs. Surrounding the base of the outer segment are microvilli-like calyceal processes (CPs). Although CP disruption has been associated with altered outer segment morphology and photoreceptor degeneration, the role of the CPs remains elusive. Here, we used zebrafish as a model to characterize CPs. We quantified CP parameters and report a strong disparity in outer segment coverage between photoreceptor subtypes. CP length is stable across light and dark conditions, yet heat-shock inducible expression of tagged actin revealed rapid turnover of the CP actin core. Detailed imaging of the embryonic retina uncovered substantial remodeling of the developing photoreceptor apical surface, including a transition from dynamic tangential processes to vertically oriented CPs immediately prior to outer segment formation. Remarkably, we also found a direct connection between apical extensions of the Müller glia and retinal pigment epithelium, arranged as bundles around the ultraviolet sensitive cones. In summary, our data characterize the structure, development and surrounding environment of photoreceptor microvilli in the zebrafish retina.
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Affiliation(s)
- Maria Sharkova
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Gonzalo Aparicio
- Sección Biología Celular, Facultad de Ciencias, Universidad de la República, 11400, Uruguay
- Institut Pasteur Montevideo, Uruguay
| | - Constantin Mouzaaber
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Flavio R. Zolessi
- Sección Biología Celular, Facultad de Ciencias, Universidad de la República, 11400, Uruguay
- Institut Pasteur Montevideo, Uruguay
| | - Jennifer C. Hocking
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
- Division of Anatomy, Department of Surgery, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
- Women and Children's Health Research Institute, University of Alberta, Edmonton, Alberta, Canada
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2
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Porcino C, Mhalhel K, Briglia M, Cometa M, Guerrera MC, Germanà PG, Montalbano G, Levanti M, Laurà R, Abbate F, Germanà A, Aragona M. Neurotrophins and Trk Neurotrophin Receptors in the Retina of Adult Killifish ( Nothobranchius guentheri). Int J Mol Sci 2024; 25:2732. [PMID: 38473977 DOI: 10.3390/ijms25052732] [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: 01/15/2024] [Revised: 02/19/2024] [Accepted: 02/23/2024] [Indexed: 03/14/2024] Open
Abstract
Specific subpopulations of neurons in nerve and sensory systems must be developed and maintained, and this is accomplished in significant part by neurotrophins (NTs) and the signaling receptors on which they act, called tyrosine protein kinase receptors (Trks). The neurotrophins-tyrosine protein kinase receptors (NTs/Trks) system is involved in sensory organ regulation, including the visual system. An NTs/Trks system alteration is associated with neurodegeneration related to aging and diseases, including retinal pathologies. An emergent model in the field of translational medicine, for instance, in aging study, is the annual killifish belonging to the Nothobranchius genus, thanks to its short lifespan. Members of this genus, such as Nothobranchius guentheri, and humans share a similar retinal stratigraphy. Nevertheless, according to the authors' knowledge, the occurrence and distribution of the NTs/Trks system in the retina of N. guentheri has never been investigated before. Therefore, the present study aimed to localize neurotrophin BDNF, NGF, and NT-3 and TrkA, TrkB, and TrkC receptors in the N. guentheri retina using the immunofluorescence method. The present investigation demonstrates, for the first time, the occurrence of the NTs/Trks system in N. guentheri retina and, consequently, the potential key role of these proteins in the biology and survival of the retinal cells.
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Affiliation(s)
- Caterina Porcino
- Zebrafish Neuromorphology Lab, Department of Veterinary Sciences, University of Messina, 98168 Messina, Italy
| | - Kamel Mhalhel
- Zebrafish Neuromorphology Lab, Department of Veterinary Sciences, University of Messina, 98168 Messina, Italy
| | - Marilena Briglia
- Zebrafish Neuromorphology Lab, Department of Veterinary Sciences, University of Messina, 98168 Messina, Italy
| | - Marzio Cometa
- Zebrafish Neuromorphology Lab, Department of Veterinary Sciences, University of Messina, 98168 Messina, Italy
| | - Maria Cristina Guerrera
- Zebrafish Neuromorphology Lab, Department of Veterinary Sciences, University of Messina, 98168 Messina, Italy
| | - Patrizia Germana Germanà
- Zebrafish Neuromorphology Lab, Department of Veterinary Sciences, University of Messina, 98168 Messina, Italy
| | - Giuseppe Montalbano
- Zebrafish Neuromorphology Lab, Department of Veterinary Sciences, University of Messina, 98168 Messina, Italy
| | - Maria Levanti
- Zebrafish Neuromorphology Lab, Department of Veterinary Sciences, University of Messina, 98168 Messina, Italy
| | - Rosaria Laurà
- Zebrafish Neuromorphology Lab, Department of Veterinary Sciences, University of Messina, 98168 Messina, Italy
| | - Francesco Abbate
- Zebrafish Neuromorphology Lab, Department of Veterinary Sciences, University of Messina, 98168 Messina, Italy
| | - Antonino Germanà
- Zebrafish Neuromorphology Lab, Department of Veterinary Sciences, University of Messina, 98168 Messina, Italy
| | - Marialuisa Aragona
- Zebrafish Neuromorphology Lab, Department of Veterinary Sciences, University of Messina, 98168 Messina, Italy
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3
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Aragona M, Briglia M, Porcino C, Mhalhel K, Cometa M, Germanà PG, Montalbano G, Levanti M, Laurà R, Abbate F, Germanà A, Guerrera MC. Localization of Calretinin, Parvalbumin, and S100 Protein in Nothobranchius guentheri Retina: A Suitable Model for the Retina Aging. Life (Basel) 2023; 13:2050. [PMID: 37895432 PMCID: PMC10608213 DOI: 10.3390/life13102050] [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: 06/28/2023] [Revised: 08/05/2023] [Accepted: 09/28/2023] [Indexed: 10/29/2023] Open
Abstract
Calcium-binding proteins (CaBPs) are members of a heterogeneous family of proteins able to buffer intracellular Ca2+ ion concentration. CaBPs are expressed in the central and peripheral nervous system, including a subpopulation of retinal neurons. Since neurons expressing different CaBPs show different susceptibility to degeneration, it could be hypothesized that they are not just markers of different neuronal subpopulations, but that they might be crucial in survival. CaBPs' ability to buffer Ca2+ cytoplasmatic concentration makes them able to defend against a toxic increase in intracellular calcium that can lead to neurodegenerative processes, including those related to aging. An emergent model for aging studies is the annual killifish belonging to the Nothobranchius genus, thanks to its short lifespan. Members of this genus, such as Nothobranchius guentheri, show a retinal stratigraphy similar to that of other actinopterygian fishes and humans. However, according to our knowledge, CaBPs' occurrence and distribution in the retina of N. guentheri have never been investigated before. Therefore, the present study aimed to localize Calretinin N-18, Parvalbumin, and S100 protein (S100p) in the N. guentheri retina with immunohistochemistry methods. The results of the present investigation demonstrate for the first time the occurrence of Calretinin N-18, Parvalbumin, and S100p in N. guentheri retina and, consequently, the potential key role of these CaBPs in the biology of the retinal cells. Hence, the suitability of N. guentheri as a model to study the changes in CaBPs' expression patterns during neurodegenerative processes affecting the retina related both to disease and aging can be assumed.
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Affiliation(s)
| | | | - Caterina Porcino
- Zebrafish Neuromorphology Lab, Department of Veterinary Sciences, University of Messina, 98168 Messina, Italy; (M.A.); (M.B.); (K.M.); (M.C.); (P.G.G.); (G.M.); (M.L.); (R.L.); (F.A.); (A.G.); (M.C.G.)
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4
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Herrera ML, Silva S, Berrosteguieta I, Casanova G, Rosillo JC, Fernández AS. Rod precursors in the adult retina of the Austrolebias charrua annual fish. Tissue Cell 2023; 83:102150. [PMID: 37423033 DOI: 10.1016/j.tice.2023.102150] [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: 04/28/2023] [Revised: 06/23/2023] [Accepted: 06/25/2023] [Indexed: 07/11/2023]
Abstract
Rod photoreceptors in the adult teleost retina are produced by rod precursors located in the outer nuclear layer (ONL). Annual fishes of the genus Austrolebias exhibit extensive adult retinal cell proliferation and neurogenesis, as well as surprising adaptive strategies to their extreme and changing environment, including adult retinal plasticity. Thus, here we identify and characterize rod precursors in the ONL of the Austrolebias charrua retina. For this aim we used classical histological techniques, transmission electron microscopy, detection of cell proliferation, and immunohistochemistry. Through these complementary approaches, we describe a cell population clearly distinguishable from photoreceptors in the ONL of the adult retina of A. charrua, which we propose corresponds to the rod precursor population. These cells exhibited particular morphological and ultrastructural characteristics, uptake of cell proliferation markers (BrdU+) and expression of stem cell markers (Sox2+). Determining the existence of the population of rod precursors is crucial to understand the sequence of events related to retinal plasticity and regeneration.
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Affiliation(s)
- M L Herrera
- Departamento Neurociencias Integrativas y Computacionales, Lab. Neurobiología Comparada, Instituto de Investigaciones Biológicas Clemente Estable (IIBCE), Avenida. Italia 3318, 11600 Montevideo, Uruguay; Sección Fisiología y Nutrición, Facultad de Ciencias, Universidad de la República, Iguá 4225, 11400 Montevideo, Uruguay
| | - S Silva
- Departamento Neurociencias Integrativas y Computacionales, Lab. Neurobiología Comparada, Instituto de Investigaciones Biológicas Clemente Estable (IIBCE), Avenida. Italia 3318, 11600 Montevideo, Uruguay
| | - I Berrosteguieta
- Departamento Neurociencias Integrativas y Computacionales, Lab. Neurobiología Comparada, Instituto de Investigaciones Biológicas Clemente Estable (IIBCE), Avenida. Italia 3318, 11600 Montevideo, Uruguay
| | - G Casanova
- Unidad de Microscopía Electrónica, Facultad de Ciencias, Universidad de la República, Iguá 4225, 11400 Montevideo, Uruguay
| | - J C Rosillo
- Departamento Neurociencias Integrativas y Computacionales, Lab. Neurobiología Comparada, Instituto de Investigaciones Biológicas Clemente Estable (IIBCE), Avenida. Italia 3318, 11600 Montevideo, Uruguay; Departamento de Histología y Embriología, Facultad de Medicina, Universidad de la República, Avda. General Flores 2125, 11800 Montevideo, Uruguay.
| | - A S Fernández
- Departamento Neurociencias Integrativas y Computacionales, Lab. Neurobiología Comparada, Instituto de Investigaciones Biológicas Clemente Estable (IIBCE), Avenida. Italia 3318, 11600 Montevideo, Uruguay; Laboratorio de Neurociencias, Facultad de Ciencias, Universidad de la República, Iguá 4225, 11400 Montevideo, Uruguay.
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Park JS, Wei X. Size variations in synaptic terminals among different types of photoreceptors and across the zebrafish retina. Exp Eye Res 2023; 227:109377. [PMID: 36587757 PMCID: PMC9918681 DOI: 10.1016/j.exer.2022.109377] [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: 11/02/2022] [Revised: 12/06/2022] [Accepted: 12/27/2022] [Indexed: 12/31/2022]
Abstract
Photoreceptor synaptic terminals are responsible for transmitting visual information to downstream neurons. In vertebrate retinas, photoreceptor synaptic terminals are of different sizes and structures. The molecular mechanisms that underlie photoreceptor synaptic development are not clearly understood. Here, we have systematically examined the size variations in the synaptic terminals of cone and rod photoreceptors in the adult zebrafish retina. We reveal that the average cone pedicle sizes expand in the order of UV, blue, green, and red cones, echoing the increasing maximally sensitive wavelengths of the opsins expressed in the corresponding cone types. In addition, rod spherules are smaller than all cone pedicles. The terminals of each photoreceptor type also display distinct regional variations across the retina and between males and females. These findings establish the basis for using the zebrafish retina to study the molecular mechanisms that regulate the sizes and structures of photoreceptor terminals for proper visual functions.
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Affiliation(s)
- Jong-Su Park
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, 15213, Pennsylvania, USA
| | - Xiangyun Wei
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, 15213, Pennsylvania, USA; Department of Molecular Genetics and Microbiology, University of Pittsburgh School of Medicine, Pittsburgh, 15213, Pennsylvania, USA; Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, 15213, Pennsylvania, USA.
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6
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Barrett LM, Mitchell DM, Meighan PC, Varnum MD, Stenkamp DL. Dynamic functional and structural remodeling during retinal regeneration in zebrafish. Front Mol Neurosci 2022; 15:1070509. [PMID: 36533135 PMCID: PMC9748287 DOI: 10.3389/fnmol.2022.1070509] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 11/14/2022] [Indexed: 12/03/2022] Open
Abstract
Introduction Zebrafish regenerate their retinas following damage, resulting in restoration of visual function. Here we evaluate recovery of retinal function through qualitative and quantitative analysis of the electroretinogram (ERG) over time following retinal damage, in correlation to histological features of regenerated retinal tissue. Methods Retinas of adult zebrafish were lesioned by intravitreal injection of 10 μM (extensive lesion; destroys all neurons) or 2 μM (selective lesion; spares photoreceptors) ouabain. Unlesioned contralateral retinas served as controls. Function of retinal circuitry was analyzed at selected timepoints using ERG recordings from live zebrafish, and whole eyes were processed for histological analyses immediately thereafter. Results Qualitative and quantitative assessment of waveforms during retinal regeneration revealed dynamic changes that were heterogeneous on an individual level within each sampling time, but still followed common waveform recovery patterns on a per-fish and population-level basis. Early in the regeneration period (13-30 days post injury; DPI), for both lesion types, b-waves were essentially not detected, and unmasked increased apparent amplitudes, implicit times, and half-widths of a-waves (vs. controls). In control recordings, d-waves were not obviously detected, but apparent d-waves (OFF-bipolar responses) from regenerating retinas of several fish became prominent by 30DPI and dominated the post-photoreceptor response (PPR). Beyond 45DPI, b-waves became detectable, and the ratio of apparent d- to b-wave contributions progressively shifted with most, but not all, fish displaying a b-wave dominated PPR. At the latest timepoints (extensive, 90DPI; selective, 80DPI), recordings with measurable b-waves approached a normal waveform (implicit times and half-widths), but amplitudes were not restored to control levels. Histological analyses of the retinas from which ERGs were recorded showed that as regeneration progressed, PKCa + ON-bipolar terminals and parvalbumin + amacrine cell processes became more stereotypically positioned within the deep sublaminae of the INL over recovery time after each lesion type, consistent with the shift in PPR seen in the ERG recordings. Discussion Taken together, these data suggest that photoreceptor-OFF-bipolar component/connectivity may functionally recover and mature earlier during regeneration compared to the photoreceptor-ON-bipolar component, though the timeframe in which such recovery happens is heterogeneous on a per-fish basis. Collectively our studies suggest gradual restoration of ON-bipolar functional circuitry during retinal regeneration.
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Affiliation(s)
- Lindsey M. Barrett
- Department of Biological Sciences, University of Idaho, Moscow, ID, United States
| | - Diana M. Mitchell
- Department of Biological Sciences, University of Idaho, Moscow, ID, United States
| | - Peter C. Meighan
- Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA, United States
| | - Michael D. Varnum
- Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA, United States
| | - Deborah L. Stenkamp
- Department of Biological Sciences, University of Idaho, Moscow, ID, United States,*Correspondence: Deborah L. Stenkamp,
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7
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Burgoyne T, Toms M, Way C, Tracey-White D, Futter CE, Moosajee M. Changes in Mitochondrial Size and Morphology in the RPE and Photoreceptors of the Developing and Ageing Zebrafish. Cells 2022; 11:cells11223542. [PMID: 36428971 PMCID: PMC9688747 DOI: 10.3390/cells11223542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 10/05/2022] [Accepted: 11/04/2022] [Indexed: 11/12/2022] Open
Abstract
Mitochondria are essential adenosine triphosphate (ATP)-generating cellular organelles. In the retina, they are highly numerous in the photoreceptors and retinal pigment epithelium (RPE) due to their high energetic requirements. Fission and fusion of the mitochondria within these cells allow them to adapt to changing demands over the lifespan of the organism. Using transmission electron microscopy, we examined the mitochondrial ultrastructure of zebrafish photoreceptors and RPE from 5 days post fertilisation (dpf) through to late adulthood (3 years). Notably, mitochondria in the youngest animals were large and irregular shaped with a loose cristae architecture, but by 8 dpf they had reduced in size and expanded in number with more defined cristae. Investigation of temporal gene expression of several mitochondrial-related markers indicated fission as the dominant mechanism contributing to the changes observed over time. This is likely to be due to continued mitochondrial stress resulting from the oxidative environment of the retina and prolonged light exposure. We have characterised retinal mitochondrial ageing in a key vertebrate model organism, that provides a basis for future studies of retinal diseases that are linked to mitochondrial dysfunction.
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Affiliation(s)
- Thomas Burgoyne
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
- Royal Brompton Hospital, Guy’s and St Thomas’ NHS Foundation Trust, London SW3 6NP, UK
| | - Maria Toms
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
- The Francis Crick Institute, London NW1 1AT, UK
| | - Chris Way
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Dhani Tracey-White
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Clare E. Futter
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Mariya Moosajee
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
- The Francis Crick Institute, London NW1 1AT, UK
- Department of Ophthalmology, Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, UK
- Department of Genetics, Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK
- Correspondence:
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8
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Masek M, Zang J, Mateos JM, Garbelli M, Ziegler U, Neuhauss SCF, Bachmann-Gagescu R. Studying the morphology, composition and function of the photoreceptor primary cilium in zebrafish. Methods Cell Biol 2022; 175:97-128. [PMID: 36967148 DOI: 10.1016/bs.mcb.2022.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Vision is one of our dominant senses and its loss has a profound impact on the life quality of affected individuals. Highly specialized neurons in the retina called photoreceptors convert photons into neuronal responses. This conversion of photons is mediated by light sensitive opsin proteins, which are found in the outer segments of the photoreceptors. These outer segments are highly specialized primary cilia, explaining why retinal dystrophy is a key feature of ciliopathies, a group of diseases resulting from abnormal and dysfunctional cilia. Therefore, research on ciliopathies often includes the analysis of the retina with special focus on the photoreceptor and its outer segment. In the last decade, the zebrafish has emerged as an excellent model organism to study human diseases, in particular with respect to the retina. The cone-rich retina of zebrafish resembles the fovea of the human macula and thus represents an excellent model to study human retinal diseases. Here we give detailed guidance on how to analyze the morphological and ultra-structural integrity of photoreceptors in the zebrafish using various histological and imaging techniques. We further describe how to conduct functional analysis of the retina by electroretinography and how to prepare isolated outer segment fractions for different -omic approaches. These different methods allow a comprehensive analysis of photoreceptors, helping to enhance our understanding of the molecular and structural basis of ciliary function in health and of the consequences of its dysfunction in disease.
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Affiliation(s)
- Markus Masek
- Institute of Medical Genetics, University of Zurich, Zurich, Switzerland; Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
| | - Jingjing Zang
- Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
| | - José M Mateos
- Center for Microscopy and Image Analysis, University of Zurich, Zurich, Switzerland
| | - Marco Garbelli
- Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
| | - Urs Ziegler
- Center for Microscopy and Image Analysis, University of Zurich, Zurich, Switzerland
| | - Stephan C F Neuhauss
- Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
| | - Ruxandra Bachmann-Gagescu
- Institute of Medical Genetics, University of Zurich, Zurich, Switzerland; Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland.
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Miles A, Blair C, Emili A, Tropepe V. Usher syndrome type 1-associated gene, pcdh15b, is required for photoreceptor structural integrity in zebrafish. Dis Model Mech 2021; 14:272551. [PMID: 34668518 PMCID: PMC8669488 DOI: 10.1242/dmm.048965] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Accepted: 10/13/2021] [Indexed: 12/23/2022] Open
Abstract
Blindness associated with Usher syndrome type 1 (USH1) is typically characterized as rod photoreceptor degeneration, followed by secondary loss of cones. The mechanisms leading to blindness are unknown because most genetic mouse models only recapitulate auditory defects. We generated zebrafish mutants for one of the USH1 genes, protocadherin-15b (pcdh15b), a putative cell adhesion molecule. Zebrafish Pcdh15 is expressed exclusively in photoreceptors within calyceal processes (CPs), at the base of the outer segment (OS) and within the synapse. In our mutants, rod and cone photoreceptor integrity is compromised, with early and progressively worsening abnormal OS disc growth and detachment, in part due to weakening CP contacts. These effects were attenuated or exacerbated by growth in dark and bright-light conditions, respectively. We also describe novel evidence for structural defects in synapses of pcdh15b mutant photoreceptors. Cell death does not accompany these defects at early stages, suggesting that photoreceptor structural defects, rather than overt cell loss, may underlie vision deficits. Thus, we present the first genetic animal model of a PCDH15-associated retinopathy that can be used to understand the aetiology of blindness in USH1. This article has an associated First Person interview with the first author of the paper. Summary: We present one of the first genetic animal mutants for PCDH15 that displays a severe, early retinopathy and suggests that zebrafish could be a useful model for PCDH15-associated retinal phenotypes.
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Affiliation(s)
- Amanda Miles
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Clarke Blair
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
| | - Andrew Emili
- Center for Network Systems Biology, Boston University, Boston, MA 02118, USA
| | - Vincent Tropepe
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada
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Nikiforov-Nikishin DL, Irkha VA, Kochetkov NI, Kalita TL, Nikiforov-Nikishin AL, Blokhin EE, Antipov SS, Makarenkov DA, Zhavnerov AN, Glebova IA, Smorodinskaya SV, Chebotarev SN. Some Aspects of Development and Histological Structure of the Visual System of Nothobranchius Guentheri. Animals (Basel) 2021; 11:2755. [PMID: 34573720 PMCID: PMC8470241 DOI: 10.3390/ani11092755] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 09/17/2021] [Accepted: 09/19/2021] [Indexed: 12/04/2022] Open
Abstract
In this, work some aspects of the development of the visual system of Nothobranchius guentheri at the main stages of ontogenesis were described for the first time. It was possible to establish that the formation of the visual system occurs similarly to other representatives of the order Cyprinodontiformes, but significantly differs in terms of the individual stages of embryogenesis due to the presence of diapause. In the postembryonic period, there is a further increase in the size of the fish's eyes and head, to the proportions characteristic of adult fish. The histological structure of the eye in adult N. guentheri practically does not differ from most teleost fish living in the same environmental conditions. The study of the structure of the retina showed the heterogeneity of the thickness of the temporal and nasal areas, which indicates the predominant role of peripheral vision. Morphoanatomical measurements of the body and eyes of N. guentheri showed that their correlation was conservative. This indicates an important role of the visual system for the survival of fish in natural conditions, both for the young and adults. In individuals of the older age group, a decrease in the amount of sodium (Na) and an increase in magnesium (Mg) and calcium (Ca) were found in the eye lens. Such changes in the elemental composition of the lens can be a sign of the initial stage of cataractogenesis and disturbances in the metabolism of lens fibers as a result of aging. This allows us to propose N. guentheri as a model for studying the structure, formation, and aging of the visual and nervous systems.
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Affiliation(s)
- Dmitry L. Nikiforov-Nikishin
- Institute of Biotechnology and Fisheries, Moscow State University of Technologies and Management (FCU), 73, Zemlyanoy Val Str., 109004 Moscow, Russia; (D.L.N.-N.); (T.L.K.); (A.L.N.-N.); (A.N.Z.); (I.A.G.); (S.V.S.)
| | - Vladimir A. Irkha
- Scientific Department, Moscow State University of Technologies and Management (FCU), 73, Zemlyanoy Val Str., 109004 Moscow, Russia; (V.A.I.); (S.S.A.)
| | - Nikita I. Kochetkov
- Institute of Biotechnology and Fisheries, Moscow State University of Technologies and Management (FCU), 73, Zemlyanoy Val Str., 109004 Moscow, Russia; (D.L.N.-N.); (T.L.K.); (A.L.N.-N.); (A.N.Z.); (I.A.G.); (S.V.S.)
| | - Tatyana L. Kalita
- Institute of Biotechnology and Fisheries, Moscow State University of Technologies and Management (FCU), 73, Zemlyanoy Val Str., 109004 Moscow, Russia; (D.L.N.-N.); (T.L.K.); (A.L.N.-N.); (A.N.Z.); (I.A.G.); (S.V.S.)
| | - Alexei L. Nikiforov-Nikishin
- Institute of Biotechnology and Fisheries, Moscow State University of Technologies and Management (FCU), 73, Zemlyanoy Val Str., 109004 Moscow, Russia; (D.L.N.-N.); (T.L.K.); (A.L.N.-N.); (A.N.Z.); (I.A.G.); (S.V.S.)
| | - Eduard E. Blokhin
- Federal Research Centre the Southern Scientific Centre of the Russian Academy of Science, Chekhova Ave., 41, 344006 Rostov-on-Don, Russia;
| | - Sergei S. Antipov
- Scientific Department, Moscow State University of Technologies and Management (FCU), 73, Zemlyanoy Val Str., 109004 Moscow, Russia; (V.A.I.); (S.S.A.)
- Department of Biophysics and Biotechnology, Voronezh State University, 1, University Square, 394063 Voronezh, Russia
| | - Dmitry A. Makarenkov
- Institute of Chemical Reagents and High Purity Chemical Substances of the National Research Centre “Kurchatov Institute”, Str. Bogorodsky Val, 3, 107076 Moscow, Russia;
| | - Alexey N. Zhavnerov
- Institute of Biotechnology and Fisheries, Moscow State University of Technologies and Management (FCU), 73, Zemlyanoy Val Str., 109004 Moscow, Russia; (D.L.N.-N.); (T.L.K.); (A.L.N.-N.); (A.N.Z.); (I.A.G.); (S.V.S.)
| | - Irina A. Glebova
- Institute of Biotechnology and Fisheries, Moscow State University of Technologies and Management (FCU), 73, Zemlyanoy Val Str., 109004 Moscow, Russia; (D.L.N.-N.); (T.L.K.); (A.L.N.-N.); (A.N.Z.); (I.A.G.); (S.V.S.)
| | - Svetlana V. Smorodinskaya
- Institute of Biotechnology and Fisheries, Moscow State University of Technologies and Management (FCU), 73, Zemlyanoy Val Str., 109004 Moscow, Russia; (D.L.N.-N.); (T.L.K.); (A.L.N.-N.); (A.N.Z.); (I.A.G.); (S.V.S.)
| | - Sergei N. Chebotarev
- Management Department, Moscow State University of Technologies and Management (FCU), 73, Zemlyanoy Val Str., 109004 Moscow, Russia;
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11
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Jaroszynska N, Harding P, Moosajee M. Metabolism in the Zebrafish Retina. J Dev Biol 2021; 9:10. [PMID: 33804189 PMCID: PMC8006245 DOI: 10.3390/jdb9010010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 03/08/2021] [Accepted: 03/11/2021] [Indexed: 12/12/2022] Open
Abstract
Retinal photoreceptors are amongst the most metabolically active cells in the body, consuming more glucose as a metabolic substrate than even the brain. This ensures that there is sufficient energy to establish and maintain photoreceptor functions during and after their differentiation. Such high dependence on glucose metabolism is conserved across vertebrates, including zebrafish from early larval through to adult retinal stages. As the zebrafish retina develops rapidly, reaching an adult-like structure by 72 hours post fertilisation, zebrafish larvae can be used to study metabolism not only during retinogenesis, but also in functionally mature retinae. The interplay between rod and cone photoreceptors and the neighbouring retinal pigment epithelium (RPE) cells establishes a metabolic ecosystem that provides essential control of their individual functions, overall maintaining healthy vision. The RPE facilitates efficient supply of glucose from the choroidal vasculature to the photoreceptors, which produce metabolic products that in turn fuel RPE metabolism. Many inherited retinal diseases (IRDs) result in photoreceptor degeneration, either directly arising from photoreceptor-specific mutations or secondary to RPE loss, leading to sight loss. Evidence from a number of vertebrate studies suggests that the imbalance of the metabolic ecosystem in the outer retina contributes to metabolic failure and disease pathogenesis. The use of larval zebrafish mutants with disease-specific mutations that mirror those seen in human patients allows us to uncover mechanisms of such dysregulation and disease pathology with progression from embryonic to adult stages, as well as providing a means of testing novel therapeutic approaches.
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Affiliation(s)
| | - Philippa Harding
- Institute of Ophthalmology, University College London, London EC1V 9EL, UK;
| | - Mariya Moosajee
- Institute of Ophthalmology, University College London, London EC1V 9EL, UK;
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK
- Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, UK
- The Francis Crick Institute, London NW1 1AT, UK
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12
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Jin X, Zhang Z, Nie Z, Wang C, Meng F, Yi Q, Chen M, Sun J, Zou J, Jiang P, Guan MX. An animal model for mitochondrial tyrosyl-tRNA synthetase deficiency reveals links between oxidative phosphorylation and retinal function. J Biol Chem 2021; 296:100437. [PMID: 33610547 PMCID: PMC8010715 DOI: 10.1016/j.jbc.2021.100437] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 02/09/2021] [Accepted: 02/16/2021] [Indexed: 12/13/2022] Open
Abstract
Mitochondria maintain a distinct pool of ribosomal machinery, including tRNAs and tRNAs activating enzymes, such as mitochondrial tyrosyl-tRNA synthetase (YARS2). Mutations in YARS2, which typically lead to the impairment of mitochondrial protein synthesis, have been linked to an array of human diseases including optic neuropathy. However, the lack of YARS2 mutation animal model makes us difficult to elucidate the pathophysiology underlying YARS2 deficiency. To explore this system, we generated YARS2 knockout (KO) HeLa cells and zebrafish using CRISPR/Cas9 technology. We observed the aberrant tRNATyr aminoacylation overall and reductions in the levels in mitochondrion- and nucleus-encoding subunits of oxidative phosphorylation system (OXPHOS), which were especially pronounced effects in the subunits of complex I and complex IV. These deficiencies manifested the decreased levels of intact supercomplexes overall. Immunoprecipitation assays showed that YARS2 bound to specific subunits of complex I and complex IV, suggesting the posttranslational stabilization of OXPHOS. Furthermore, YARS2 ablation caused defects in the stability and activities of OXPHOS complexes. These biochemical defects could be rescued by the overexpression of YARS2 cDNA in the YARS2KO cells. In zebrafish, the yars2KO larva conferred deficient COX activities in the retina, abnormal mitochondrial morphology, and numbers in the photoreceptor and retinal ganglion cells. The zebrafish further exhibited the retinal defects affecting both rods and cones. Vision defects in yars2KO zebrafish recapitulated the clinical phenotypes in the optic neuropathy patients carrying the YARS2 mutations. Our findings highlighted the critical role of YARS2 in the stability and activity of OXPHOS and its pathological consequence in vision impairments.
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Affiliation(s)
- Xiaofen Jin
- Key Laboratory of Reproductive Genetics, Ministry of Education of PRC, The Woman's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China; Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, and National Clinic Research Center for Child Health, Hangzhou, Zhejiang, China; Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Zengming Zhang
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Zhipeng Nie
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Chenghui Wang
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Feilong Meng
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, and National Clinic Research Center for Child Health, Hangzhou, Zhejiang, China; Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Qiuzi Yi
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Mengquan Chen
- Department of Lab Medicine, Wenzhou Hospital of Traditional Chinese Medicine, Wenzhou, Zhejiang, China
| | - Jiji Sun
- Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Jian Zou
- Insitute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Pingping Jiang
- Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, and National Clinic Research Center for Child Health, Hangzhou, Zhejiang, China; Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China; Zhejiang Provincial Key Laboratory of Genetic & Developmental Disorders, Zhejiang Univesity, Hangzhou, Zhejiang, China.
| | - Min-Xin Guan
- Key Laboratory of Reproductive Genetics, Ministry of Education of PRC, The Woman's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China; Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine, and National Clinic Research Center for Child Health, Hangzhou, Zhejiang, China; Institute of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China; Zhejiang Provincial Key Laboratory of Genetic & Developmental Disorders, Zhejiang Univesity, Hangzhou, Zhejiang, China; Division of Mitochondrial Biomedicine, Joint Institute of Genetics and Genome Medicine between Zhejiang University and University of Toronto, Hangzhou, Zhejiang, China.
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13
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Oel AP, Neil GJ, Dong EM, Balay SD, Collett K, Allison WT. Nrl Is Dispensable for Specification of Rod Photoreceptors in Adult Zebrafish Despite Its Deeply Conserved Requirement Earlier in Ontogeny. iScience 2020; 23:101805. [PMID: 33299975 PMCID: PMC7702016 DOI: 10.1016/j.isci.2020.101805] [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: 07/02/2020] [Revised: 10/06/2020] [Accepted: 11/10/2020] [Indexed: 12/11/2022] Open
Abstract
The transcription factor NRL (neural retina leucine zipper) has been canonized as the master regulator of photoreceptor cell fate in the retina. NRL is necessary and sufficient to specify rod cell fate and to preclude cone cell fate in mice. By engineering zebrafish, we tested if NRL function has conserved roles beyond mammals or beyond nocturnal species, i.e., in a vertebrate possessing a greater and more typical diversity of cone sub-types. Transgenic expression of Nrl from zebrafish or mouse was sufficient to induce rod photoreceptor cells. Zebrafish nrl−/− mutants lacked rods (and had excess UV-sensitive cones) as young larvae; thus, the conservation of Nrl function between mice and zebrafish appears sound. Strikingly, however, rods were abundant in adult nrl−/− null mutant zebrafish. Rods developed in adults despite Nrl protein being undetectable. Therefore, a yet-to-be-revealed non-canonical pathway independent of Nrl is able to specify the fate of some rod photoreceptors. Nrl is conserved and sufficient to specify rod photoreceptors in the zebrafish retina Nrl is necessary for rod photoreceptors in early ontogeny of zebrafish larvae Zebrafish Nrl is functionally conserved with mouse and human NRL Remarkably, Nrl is dispensable for rod specification in adult zebrafish
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Affiliation(s)
- A Phillip Oel
- Department of Biological Sciences, University of Alberta, Edmonton AB, T7Y 1C4, Canada
| | - Gavin J Neil
- Department of Biological Sciences, University of Alberta, Edmonton AB, T7Y 1C4, Canada
| | - Emily M Dong
- Department of Biological Sciences, University of Alberta, Edmonton AB, T7Y 1C4, Canada
| | - Spencer D Balay
- Department of Biological Sciences, University of Alberta, Edmonton AB, T7Y 1C4, Canada
| | - Keon Collett
- Department of Biological Sciences, University of Alberta, Edmonton AB, T7Y 1C4, Canada
| | - W Ted Allison
- Department of Biological Sciences, University of Alberta, Edmonton AB, T7Y 1C4, Canada.,Department of Medical Genetics, University of Alberta, Edmonton AB, T6G 2R3, Canada
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14
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Furukawa T, Ueno A, Omori Y. Molecular mechanisms underlying selective synapse formation of vertebrate retinal photoreceptor cells. Cell Mol Life Sci 2020; 77:1251-1266. [PMID: 31586239 PMCID: PMC11105113 DOI: 10.1007/s00018-019-03324-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 09/21/2019] [Accepted: 09/25/2019] [Indexed: 11/29/2022]
Abstract
In vertebrate central nervous systems (CNSs), highly diverse neurons are selectively connected via synapses, which are essential for building an intricate neural network. The vertebrate retina is part of the CNS and is comprised of a distinct laminar organization, which serves as a good model system to study developmental synapse formation mechanisms. In the retina outer plexiform layer, rods and cones, two types of photoreceptor cells, elaborate selective synaptic contacts with ON- and/or OFF-bipolar cell terminals as well as with horizontal cell terminals. In the mouse retina, three photoreceptor subtypes and at least 15 bipolar subtypes exist. Previous and recent studies have significantly progressed our understanding of how selective synapse formation, between specific subtypes of photoreceptor and bipolar cells, is designed at the molecular level. In the ON pathway, photoreceptor-derived secreted and transmembrane proteins directly interact in trans with the GRM6 (mGluR6) complex, which is localized to ON-bipolar cell dendritic terminals, leading to selective synapse formation. Here, we review our current understanding of the key factors and mechanisms underlying selective synapse formation of photoreceptor cells with bipolar and horizontal cells in the retina. In addition, we describe how defects/mutations of the molecules involved in photoreceptor synapse formation are associated with human retinal diseases and visual disorders.
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Affiliation(s)
- Takahisa Furukawa
- Laboratory for Molecular and Developmental Biology, Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Akiko Ueno
- Laboratory for Molecular and Developmental Biology, Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Yoshihiro Omori
- Laboratory for Molecular and Developmental Biology, Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
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15
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Hutto RA, Bisbach CM, Abbas F, Brock DC, Cleghorn WM, Parker ED, Bauer BH, Ge W, Vinberg F, Hurley JB, Brockerhoff SE. Increasing Ca 2+ in photoreceptor mitochondria alters metabolites, accelerates photoresponse recovery, and reveals adaptations to mitochondrial stress. Cell Death Differ 2019; 27:1067-1085. [PMID: 31371786 PMCID: PMC7206026 DOI: 10.1038/s41418-019-0398-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 06/19/2019] [Accepted: 07/11/2019] [Indexed: 11/09/2022] Open
Abstract
Photoreceptors are specialized neurons that rely on Ca2+ to regulate phototransduction and neurotransmission. Photoreceptor dysfunction and degeneration occur when intracellular Ca2+ homeostasis is disrupted. Ca2+ homeostasis is maintained partly by mitochondrial Ca2+ uptake through the mitochondrial Ca2+ uniporter (MCU), which can influence cytosolic Ca2+ signals, stimulate energy production, and trigger apoptosis. Here we discovered that zebrafish cone photoreceptors express unusually low levels of MCU. We expected that this would be important to prevent mitochondrial Ca2+ overload and consequent cone degeneration. To test this hypothesis, we generated a cone-specific model of MCU overexpression. Surprisingly, we found that cones tolerate MCU overexpression, surviving elevated mitochondrial Ca2+ and disruptions to mitochondrial ultrastructure until late adulthood. We exploited the survival of MCU overexpressing cones to additionally demonstrate that mitochondrial Ca2+ uptake alters the distributions of citric acid cycle intermediates and accelerates recovery kinetics of the cone response to light. Cones adapt to mitochondrial Ca2+ stress by decreasing MICU3, an enhancer of MCU-mediated Ca2+ uptake, and selectively transporting damaged mitochondria away from the ellipsoid toward the synapse. Our findings demonstrate how mitochondrial Ca2+ can influence physiological and metabolic processes in cones and highlight the remarkable ability of cone photoreceptors to adapt to mitochondrial stress.
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Affiliation(s)
- Rachel A Hutto
- Biochemistry Department, University of Washington, Seattle, WA, 98109, USA
| | - Celia M Bisbach
- Biochemistry Department, University of Washington, Seattle, WA, 98109, USA
| | - Fatima Abbas
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, 84132, USA
| | - Daniel C Brock
- Biochemistry Department, University of Washington, Seattle, WA, 98109, USA
| | - Whitney M Cleghorn
- Biochemistry Department, University of Washington, Seattle, WA, 98109, USA
| | - Edward D Parker
- Opthalmology Department, University of Washington, Seattle, WA, 98109, USA
| | - Benjamin H Bauer
- Biochemistry Department, University of Washington, Seattle, WA, 98109, USA
| | - William Ge
- Biochemistry Department, University of Washington, Seattle, WA, 98109, USA
| | - Frans Vinberg
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, 84132, USA
| | - James B Hurley
- Biochemistry Department, University of Washington, Seattle, WA, 98109, USA.,Opthalmology Department, University of Washington, Seattle, WA, 98109, USA
| | - Susan E Brockerhoff
- Biochemistry Department, University of Washington, Seattle, WA, 98109, USA. .,Opthalmology Department, University of Washington, Seattle, WA, 98109, USA.
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16
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Li L. Circadian Vision in Zebrafish: From Molecule to Cell and from Neural Network to Behavior. J Biol Rhythms 2019; 34:451-462. [DOI: 10.1177/0748730419863917] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Most visual system functions, such as opsin gene expression, retinal neural transmission, light perception, and visual sensitivity, display robust day-night rhythms. The rhythms persist in constant lighting conditions, suggesting the involvement of endogenous circadian clocks. While the circadian pacemakers that control the rhythms of animal behaviors are mostly found in the forebrain and midbrain, self-sustained circadian oscillators are also present in the neural retina, where they play important roles in the regulation of circadian vision. This review highlights some of the correlative studies of the circadian control of visual system functions in zebrafish. Because zebrafish maintain a high evolutionary proximity to mammals, the findings from zebrafish research may provide insights for a better understanding of the mechanisms of circadian vision in other vertebrate species including humans.
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Affiliation(s)
- Lei Li
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana
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17
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Abstract
There are four cone morphologies in zebrafish, corresponding to UV (U), blue (B), green (G), and red (R)-sensing types; yet genetically, eight cone opsins are expressed. How eight opsins are physiologically siloed in four cone types is not well understood, and in larvae, cone physiological spectral peaks are unstudied. We use a spectral model to infer cone wavelength peaks, semisaturation irradiances, and saturation amplitudes from electroretinogram (ERG) datasets composed of multi-wavelength, multi-irradiance, aspartate-isolated, cone-PIII signals, as compiled from many 5- to 12-day larvae and 8- to 18-month-old adult eyes isolated from wild-type (WT) or roy orbison (roy) strains. Analysis suggests (in nm) a seven-cone, U-360/B1-427/B2-440/G1-460/G3-476/R1-575/R2-556, spectral physiology in WT larvae but a six-cone, U-349/B1-414/G3-483/G4-495/R1-572/R2-556, structure in WT adults. In roy larvae, there is a five-cone structure: U-373/B2-440/G1-460/R1-575/R2-556; in roy adults, there is a four-cone structure, B1-410/G3-482/R1-571/R2-556. Existence of multiple B, G, and R types is inferred from shifts in peaks with red or blue backgrounds. Cones were either high or low semisaturation types. The more sensitive, low semisaturation types included U, B1, and G1 cones [3.0–3.6 log(quanta·μm−2·s−1)]. The less sensitive, high semisaturation types were B2, G3, G4, R1, and R2 types [4.3-4.7 log(quanta·μm−2·s−1)]. In both WT and roy, U- and B- cone saturation amplitudes were greater in larvae than in adults, while G-cone saturation levels were greater in adults. R-cone saturation amplitudes were the largest (50–60% of maximal dataset amplitudes) and constant throughout development. WT and roy larvae differed in cone signal levels, with lesser UV- and greater G-cone amplitudes occurring in roy, indicating strain variation in physiological development of cone signals. These physiological measures of cone types suggest chromatic processing in zebrafish involves at least four to seven spectral signal processing pools.
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18
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Nagashima M, Hadidjojo J, Barthel LK, Lubensky DK, Raymond PA. Anisotropic Müller glial scaffolding supports a multiplex lattice mosaic of photoreceptors in zebrafish retina. Neural Dev 2017; 12:20. [PMID: 29141686 PMCID: PMC5688757 DOI: 10.1186/s13064-017-0096-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 10/19/2017] [Indexed: 11/21/2022] Open
Abstract
Background The multiplex, lattice mosaic of cone photoreceptors in the adult fish retina is a compelling example of a highly ordered epithelial cell pattern, with single cell width rows and columns of cones and precisely defined neighbor relationships among different cone types. Cellular mechanisms patterning this multiplex mosaic are not understood. Physical models can provide new insights into fundamental mechanisms of biological patterning. In earlier work, we developed a mathematical model of photoreceptor cell packing in the zebrafish retina, which predicted that anisotropic mechanical tension in the retinal epithelium orients planar polarized adhesive interfaces to align the columns as cone photoreceptors are generated at the retinal margin during post-embryonic growth. Methods With cell-specific fluorescent reporters and in vivo imaging of the growing retinal margin in transparent juvenile zebrafish we provide the first view of how cell packing, spatial arrangement, and cell identity are coordinated to build the lattice mosaic. With targeted laser ablation we probed the tissue mechanics of the retinal epithelium. Results Within the lattice mosaic, planar polarized Crumbs adhesion proteins pack cones into a single cell width column; between columns, N-cadherin-mediated adherens junctions stabilize Müller glial apical processes. The concentration of activated pMyosin II at these punctate adherens junctions suggests that these glial bands are under tension, forming a physical barrier between cone columns and contributing to mechanical stress anisotropies in the epithelial sheet. Unexpectedly, we discovered that the appearance of such parallel bands of Müller glial apical processes precedes the packing of cones into single cell width columns, hinting at a possible role for glia in the initial organization of the lattice mosaic. Targeted laser ablation of Müller glia directly demonstrates that these glial processes support anisotropic mechanical tension in the planar dimension of the retinal epithelium. Conclusions These findings uncovered a novel structural feature of Müller glia associated with alignment of photoreceptors into a lattice mosaic in the zebrafish retina. This is the first demonstration, to our knowledge, of planar, anisotropic mechanical forces mediated by glial cells. Electronic supplementary material The online version of this article (10.1186/s13064-017-0096-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Mikiko Nagashima
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 830 North University Avenue, Ann Arbor, MI, 48109-1048, USA
| | - Jeremy Hadidjojo
- Department of Physics, University of Michigan, 450 Church Street, Ann Arbor, MI, 48109-1040, USA
| | - Linda K Barthel
- Microscopy and Image Analysis Laboratory, University of Michigan, Ann Arbor, MI, USA
| | - David K Lubensky
- Department of Physics, University of Michigan, 450 Church Street, Ann Arbor, MI, 48109-1040, USA.
| | - Pamela A Raymond
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 830 North University Avenue, Ann Arbor, MI, 48109-1048, USA.
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19
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Abstract
Zebrafish (Danio rerio) provide many advantages as a model organism for studying ocular disease and development, and there is great interest in the ability to non-invasively assess their photoreceptor mosaic. Despite recent applications of scanning light ophthalmoscopy, fundus photography, and gonioscopy to in vivo imaging of the adult zebrafish eye, current techniques either lack accurate scaling information (limiting quantitative analyses) or require euthanizing the fish (precluding longitudinal analyses). Here we describe improved methods for imaging the adult zebrafish retina using spectral domain optical coherence tomography (OCT). Transgenic fli1:eGFP zebrafish were imaged using the Bioptigen Envisu R2200 broadband source OCT with a 12-mm telecentric probe to measure axial length and a mouse retina probe to acquire retinal volume scans subtending 1.2 × 1.2 mm nominally. En face summed volume projections were generated from the volume scans using custom software that allows the user to create contours tailored to specific retinal layer(s) of interest. Following imaging, the eyes were dissected for ex vivo fluorescence microscopy, and measurements of blood vessel branch points were compared to those made from the en face OCT images to determine the OCT lateral scale as a function of axial length. Using this scaling model, we imaged the photoreceptor layer of five wild-type zebrafish and quantified the density and packing geometry of the UV cone submosaic. Our in vivo cone density measurements agreed with measurements from previously published histology values. The method presented here allows accurate, quantitative assessment of cone structure in vivo and will be useful for longitudinal studies of the zebrafish cone mosaics.
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20
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Ablation of EYS in zebrafish causes mislocalisation of outer segment proteins, F-actin disruption and cone-rod dystrophy. Sci Rep 2017; 7:46098. [PMID: 28378834 PMCID: PMC5380955 DOI: 10.1038/srep46098] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 03/10/2017] [Indexed: 01/08/2023] Open
Abstract
Mutations in EYS are associated with autosomal recessive retinitis pigmentosa (arRP) and autosomal recessive cone-rod dystrophy (arCRD) however, the function of EYS and the molecular mechanisms of how these mutations cause retinal degeneration are still unclear. Because EYS is absent in mouse and rat, and the structure of the retina differs substantially between humans and Drosophila, we utilised zebrafish as a model organism to study the function of EYS in the retina. We constructed an EYS-knockout zebrafish-line by TALEN technology which showed visual impairment at an early age, while the histological and immunofluorescence assays indicated the presence of progressive retinal degeneration with a cone predominately affected pattern. These phenotypes recapitulate the clinical manifestations of arCRD patients. Furthermore, the EYS-/- zebrafish also showed mislocalisation of certain outer segment proteins (rhodopsin, opn1lw, opn1sw1, GNB3 and PRPH2), and disruption of actin filaments in photoreceptors. Protein mislocalisation may, therefore, disrupt the function of cones and rods in these zebrafish and cause photoreceptor death. Collectively, these results point to a novel role for EYS in maintaining the morphological structure of F-actin and in protein transport, loss of this function might be the trigger for the resultant cellular events that ultimately lead to photoreceptor death.
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21
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Mitochondria Maintain Distinct Ca 2+ Pools in Cone Photoreceptors. J Neurosci 2017; 37:2061-2072. [PMID: 28115482 DOI: 10.1523/jneurosci.2689-16.2017] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 01/10/2017] [Accepted: 01/12/2017] [Indexed: 01/01/2023] Open
Abstract
Ca2+ ions have distinct roles in the outer segment, cell body, and synaptic terminal of photoreceptors. We tested the hypothesis that distinct Ca2+ domains are maintained by Ca2+ uptake into mitochondria. Serial block face scanning electron microscopy of zebrafish cones revealed that nearly 100 mitochondria cluster at the apical side of the inner segment, directly below the outer segment. The endoplasmic reticulum surrounds the basal and lateral surfaces of this cluster, but does not reach the apical surface or penetrate into the cluster. Using genetically encoded Ca2+ sensors, we found that mitochondria take up Ca2+ when it accumulates either in the cone cell body or outer segment. Blocking mitochondrial Ca2+ uniporter activity compromises the ability of mitochondria to maintain distinct Ca2+ domains. Together, our findings indicate that mitochondria can modulate subcellular functional specialization in photoreceptors.SIGNIFICANCE STATEMENT Ca2+ homeostasis is essential for the survival and function of retinal photoreceptors. Separate pools of Ca2+ regulate phototransduction in the outer segment, metabolism in the cell body, and neurotransmitter release at the synaptic terminal. We investigated the role of mitochondria in compartmentalization of Ca2+ We found that mitochondria form a dense cluster that acts as a diffusion barrier between the outer segment and cell body. The cluster is surprisingly only partially surrounded by the endoplasmic reticulum, a key mediator of mitochondrial Ca2+ uptake. Blocking the uptake of Ca2+ by mitochondria causes redistribution of Ca2+ throughout the cell. Our results show that mitochondrial Ca2+ uptake in photoreceptors is complex and plays an essential role in normal function.
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22
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Du J, Rountree A, Cleghorn WM, Contreras L, Lindsay KJ, Sadilek M, Gu H, Djukovic D, Raftery D, Satrústegui J, Kanow M, Chan L, Tsang SH, Sweet IR, Hurley JB. Phototransduction Influences Metabolic Flux and Nucleotide Metabolism in Mouse Retina. J Biol Chem 2015; 291:4698-710. [PMID: 26677218 DOI: 10.1074/jbc.m115.698985] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Indexed: 01/20/2023] Open
Abstract
Production of energy in a cell must keep pace with demand. Photoreceptors use ATP to maintain ion gradients in darkness, whereas in light they use it to support phototransduction. Matching production with consumption can be accomplished by coupling production directly to consumption. Alternatively, production can be set by a signal that anticipates demand. In this report we investigate the hypothesis that signaling through phototransduction controls production of energy in mouse retinas. We found that respiration in mouse retinas is not coupled tightly to ATP consumption. By analyzing metabolic flux in mouse retinas, we also found that phototransduction slows metabolic flux through glycolysis and through intermediates of the citric acid cycle. We also evaluated the relative contributions of regulation of the activities of α-ketoglutarate dehydrogenase and the aspartate-glutamate carrier 1. In addition, a comprehensive analysis of the retinal metabolome showed that phototransduction also influences steady-state concentrations of 5'-GMP, ribose-5-phosphate, ketone bodies, and purines.
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Affiliation(s)
- Jianhai Du
- From the Department of Biochemistry, Department of Ophthalmology, University of Washington, Seattle, Washington 98109
| | | | | | - Laura Contreras
- Department of Molecular Biology, Centre for Molecular Biology Severo Ochoa, Universidad Autonoma de Madrid-Consejo Superior de Investigaciones Científicas, CIBER of Rare Diseases (CIBERER), and Health Research Institute Jimenez Diaz Foundation, Autonomous University of Madrid, 28049 Madrid, Spain
| | | | | | - Haiwei Gu
- Northwest Metabolomics Research Center, Department of Anesthesiology and Pain Medicine
| | - Danijel Djukovic
- Northwest Metabolomics Research Center, Department of Anesthesiology and Pain Medicine
| | - Dan Raftery
- Northwest Metabolomics Research Center, Department of Anesthesiology and Pain Medicine
| | - Jorgina Satrústegui
- Department of Molecular Biology, Centre for Molecular Biology Severo Ochoa, Universidad Autonoma de Madrid-Consejo Superior de Investigaciones Científicas, CIBER of Rare Diseases (CIBERER), and Health Research Institute Jimenez Diaz Foundation, Autonomous University of Madrid, 28049 Madrid, Spain
| | | | - Lawrence Chan
- Bernard and Shirlee Brown Glaucoma Laboratory and Barbara and Donald Jonas Stem Cell Laboratory, Department of Ophthalmology, Columbia University, New York, New York, and
| | - Stephen H Tsang
- Bernard and Shirlee Brown Glaucoma Laboratory and Barbara and Donald Jonas Stem Cell Laboratory, Department of Ophthalmology, Columbia University, New York, New York, and Department of Pathology and Cell Biology and Institute of Human Nutrition, Columbia University, New York, New York 10032
| | | | - James B Hurley
- From the Department of Biochemistry, Department of Ophthalmology, University of Washington, Seattle, Washington 98109,
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The pros and cons of vertebrate animal models for functional and therapeutic research on inherited retinal dystrophies. Prog Retin Eye Res 2015; 48:137-59. [DOI: 10.1016/j.preteyeres.2015.04.004] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 04/12/2015] [Accepted: 04/16/2015] [Indexed: 01/19/2023]
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Hurley JB, Lindsay KJ, Du J. Glucose, lactate, and shuttling of metabolites in vertebrate retinas. J Neurosci Res 2015; 93:1079-92. [PMID: 25801286 PMCID: PMC4720126 DOI: 10.1002/jnr.23583] [Citation(s) in RCA: 159] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Revised: 02/11/2015] [Accepted: 02/12/2015] [Indexed: 02/06/2023]
Abstract
The vertebrate retina has specific functions and structures that give it a unique set of constraints on the way in which it can produce and use metabolic energy. The retina's response to illumination influences its energy requirements, and the retina's laminated structure influences the extent to which neurons and glia can access metabolic fuels. There are fundamental differences between energy metabolism in retina and that in brain. The retina relies on aerobic glycolysis much more than the brain does, and morphological differences between retina and brain limit the types of metabolic relationships that are possible between neurons and glia. This Mini-Review summarizes the unique metabolic features of the retina with a focus on the role of lactate shuttling.
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Affiliation(s)
- James B. Hurley
- Departments of Biochemistry and Ophthalmology, University of Washington, Seattle, Washington
| | - Kenneth J. Lindsay
- Departments of Biochemistry and Ophthalmology, University of Washington, Seattle, Washington
| | - Jianhai Du
- Departments of Biochemistry and Ophthalmology, University of Washington, Seattle, Washington
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25
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Knabe W, Washausen S. Early development of the nervous system of the eutherian <i>Tupaia belangeri</i>. Primate Biol 2015. [DOI: 10.5194/pb-2-25-2015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Abstract. The longstanding debate on the taxonomic status of Tupaia belangeri (Tupaiidae, Scandentia, Mammalia) has persisted in times of molecular biology and genetics. But way beyond that Tupaia belangeri has turned out to be a valuable and widely accepted animal model for studies in neurobiology, stress research, and virology, among other topics. It is thus a privilege to have the opportunity to provide an overview on selected aspects of neural development and neuroanatomy in Tupaia belangeri on the occasion of this special issue dedicated to Hans-Jürg Kuhn. Firstly, emphasis will be given to the optic system. We report rather "unconventional" findings on the morphogenesis of photoreceptor cells, and on the presence of capillary-contacting neurons in the tree shrew retina. Thereafter, network formation among directionally selective retinal neurons and optic chiasm development are discussed. We then address the main and accessory olfactory systems, the terminal nerve, the pituitary gland, and the cerebellum of Tupaia belangeri. Finally, we demonstrate how innovative 3-D reconstruction techniques helped to decipher and interpret so-far-undescribed, strictly spatiotemporally regulated waves of apoptosis and proliferation which pass through the early developing forebrain and eyes, midbrain and hindbrain, and through the panplacodal primordium which gives rise to all ectodermal placodes. Based on examples, this paper additionally wants to show how findings gained from the reported projects have influenced current neuroembryological and, at least partly, medical research.
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26
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Histological Characterization of the Dicer1 Mutant Zebrafish Retina. J Ophthalmol 2015; 2015:309510. [PMID: 26124959 PMCID: PMC4466466 DOI: 10.1155/2015/309510] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 10/29/2014] [Indexed: 02/02/2023] Open
Abstract
DICER1, a multidomain RNase III endoribonuclease, plays a critical role in microRNA (miRNA) and RNA-interference (RNAi) functional pathways. Loss of Dicer1 affects different developmental processes. Dicer1 is essential for retinal development and maintenance. DICER1 was recently shown to have another function of silencing the toxicity of Alu RNAs in retinal pigment epithelium (RPE) cells, which are involved in the pathogenesis of age related macular degeneration. In this study, we characterized a Dicer1 mutant fish line, which carries a nonsense mutation (W1457Ter) induced by N-ethyl-N-nitrosourea mutagenesis. Zebrafish DICER1 protein is highly conserved in the evolution. Zebrafish Dicer1 is expressed at the earliest stages of zebrafish development and persists into late developmental stages; it is widely expressed in adult tissues. Homozygous Dicer1 mutant fish (DICER1(W1457Ter/W1457Ter)) have an arrest in early growth with significantly smaller eyes and are dead at 14-18 dpf. Heterozygous Dicer1 mutant fish have similar retinal structure to that of control fish; the retinal pigment epithelium (RPE) cells are normal with no sign of degeneration at the age of 20 months.
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27
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Abstract
Ultrastructural examination of photoreceptor inner segment ellipsoids in larval (4, 8, and 15 days postfertilization; dpf) and adult zebrafish identified morphologically different types of mitochondria. All photoreceptors had mitochondria of different sizes (large and small). At 4 dpf, rods had small, moderately stained electron-dense mitochondria (E-DM), and two cone types could be distinguished: (1) those with electron-lucent mitochondria (E-LM) and (2) those with mitochondria of moderate electron density. These distinctions were also apparent at later ages (8 and 15 dpf). Rods from adult fish had fewer mitochondria than their corresponding cones. The ellipsoids of some fully differentiated single and double cones contained large E-DM with few cristae; these were surrounded by small E-LM with typical internal morphology. The mitochondria within the ellipsoids of other single cones showed similar electron density. Microspectrophotometry of cone ellipsoids from adult fish indicated that the large E-DM had a small absorbance peak (∼0.03 OD units) and did not contain cytochrome-c, but crocetin, a carotenoid found in old world monkeys. Crocetin functions to prevent oxidative damage to photoreceptors, suggesting that the ellipsoid mitochondria in adult zebrafish cones protect against apoptosis and function metabolically, rather than as a light filter.
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28
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Hoon M, Okawa H, Della Santina L, Wong ROL. Functional architecture of the retina: development and disease. Prog Retin Eye Res 2014; 42:44-84. [PMID: 24984227 DOI: 10.1016/j.preteyeres.2014.06.003] [Citation(s) in RCA: 327] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 06/08/2014] [Accepted: 06/22/2014] [Indexed: 12/22/2022]
Abstract
Structure and function are highly correlated in the vertebrate retina, a sensory tissue that is organized into cell layers with microcircuits working in parallel and together to encode visual information. All vertebrate retinas share a fundamental plan, comprising five major neuronal cell classes with cell body distributions and connectivity arranged in stereotypic patterns. Conserved features in retinal design have enabled detailed analysis and comparisons of structure, connectivity and function across species. Each species, however, can adopt structural and/or functional retinal specializations, implementing variations to the basic design in order to satisfy unique requirements in visual function. Recent advances in molecular tools, imaging and electrophysiological approaches have greatly facilitated identification of the cellular and molecular mechanisms that establish the fundamental organization of the retina and the specializations of its microcircuits during development. Here, we review advances in our understanding of how these mechanisms act to shape structure and function at the single cell level, to coordinate the assembly of cell populations, and to define their specific circuitry. We also highlight how structure is rearranged and function is disrupted in disease, and discuss current approaches to re-establish the intricate functional architecture of the retina.
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Affiliation(s)
- Mrinalini Hoon
- Department of Biological Structure, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195, USA
| | - Haruhisa Okawa
- Department of Biological Structure, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195, USA
| | - Luca Della Santina
- Department of Biological Structure, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195, USA
| | - Rachel O L Wong
- Department of Biological Structure, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195, USA.
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29
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de Busserolles F, Marshall NJ, Collin SP. The eyes of lanternfishes (Myctophidae, Teleostei): Novel ocular specializations for vision in dim light. J Comp Neurol 2014; 522:1618-40. [DOI: 10.1002/cne.23495] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2013] [Revised: 10/14/2013] [Accepted: 10/15/2013] [Indexed: 11/11/2022]
Affiliation(s)
- Fanny de Busserolles
- Neuroecology Group; School of Animal Biology and the Oceans Institute; The University of Western Australia; Crawley Western Australia 6012 Australia
| | - N. Justin Marshall
- Sensory Neurobiology Group; Queensland Brain Institute; University of Queensland; St. Lucia Queensland 4072 Australia
| | - Shaun P. Collin
- Neuroecology Group; School of Animal Biology and the Oceans Institute; The University of Western Australia; Crawley Western Australia 6012 Australia
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