1
|
Schott RK, Fujita MK, Streicher JW, Gower DJ, Thomas KN, Loew ER, Bamba Kaya AG, Bittencourt-Silva GB, Guillherme Becker C, Cisneros-Heredia D, Clulow S, Davila M, Firneno TJ, Haddad CFB, Janssenswillen S, Labisko J, Maddock ST, Mahony M, Martins RA, Michaels CJ, Mitchell NJ, Portik DM, Prates I, Roelants K, Roelke C, Tobi E, Woolfolk M, Bell RC. Diversity and Evolution of Frog Visual Opsins: Spectral Tuning and Adaptation to Distinct Light Environments. Mol Biol Evol 2024; 41:msae049. [PMID: 38573520 PMCID: PMC10994157 DOI: 10.1093/molbev/msae049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 02/07/2024] [Accepted: 02/26/2024] [Indexed: 04/05/2024] Open
Abstract
Visual systems adapt to different light environments through several avenues including optical changes to the eye and neurological changes in how light signals are processed and interpreted. Spectral sensitivity can evolve via changes to visual pigments housed in the retinal photoreceptors through gene duplication and loss, differential and coexpression, and sequence evolution. Frogs provide an excellent, yet understudied, system for visual evolution research due to their diversity of ecologies (including biphasic aquatic-terrestrial life cycles) that we hypothesize imposed different selective pressures leading to adaptive evolution of the visual system, notably the opsins that encode the protein component of the visual pigments responsible for the first step in visual perception. Here, we analyze the diversity and evolution of visual opsin genes from 93 new eye transcriptomes plus published data for a combined dataset spanning 122 frog species and 34 families. We find that most species express the four visual opsins previously identified in frogs but show evidence for gene loss in two lineages. Further, we present evidence of positive selection in three opsins and shifts in selective pressures associated with differences in habitat and life history, but not activity pattern. We identify substantial novel variation in the visual opsins and, using microspectrophotometry, find highly variable spectral sensitivities, expanding known ranges for all frog visual pigments. Mutations at spectral-tuning sites only partially account for this variation, suggesting that frogs have used tuning pathways that are unique among vertebrates. These results support the hypothesis of adaptive evolution in photoreceptor physiology across the frog tree of life in response to varying environmental and ecological factors and further our growing understanding of vertebrate visual evolution.
Collapse
Affiliation(s)
- Ryan K Schott
- Department of Biology and Centre for Vision Research, York University, Toronto, Ontario, Canada
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
| | - Matthew K Fujita
- Department of Biology, Amphibian and Reptile Diversity Research Center, The University of Texas at Arlington, Arlington, TX, USA
| | | | | | - Kate N Thomas
- Department of Biology, Amphibian and Reptile Diversity Research Center, The University of Texas at Arlington, Arlington, TX, USA
- Natural History Museum, London, UK
| | - Ellis R Loew
- Department of Biomedical Sciences, Cornell University College of Veterinary Medicine, Ithaca, NY, USA
| | | | | | - C Guillherme Becker
- Department of Biology and One Health Microbiome Center, Center for Infectious Disease Dynamics, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, USA
| | - Diego Cisneros-Heredia
- Laboratorio de Zoología Terrestre, Instituto de Biodiversidad Tropical IBIOTROP, Colegio de Ciencias Biológicas y Ambientales, Universidad San Francisco de Quito USFQ, Quito, Ecuador
| | - Simon Clulow
- Centre for Conservation Ecology and Genomics, Institute for Applied Ecology, University of Canberra, Bruce, ACT, Australia
| | - Mateo Davila
- Laboratorio de Zoología Terrestre, Instituto de Biodiversidad Tropical IBIOTROP, Colegio de Ciencias Biológicas y Ambientales, Universidad San Francisco de Quito USFQ, Quito, Ecuador
| | - Thomas J Firneno
- Department of Biological Sciences, University of Denver, Denver, USA
| | - Célio F B Haddad
- Department of Biodiversity and Center of Aquaculture—CAUNESP, I.B., São Paulo State University, Rio Claro, São Paulo, Brazil
| | - Sunita Janssenswillen
- Amphibian Evolution Lab, Biology Department, Vrije Universiteit Brussel, Brussels, Belgium
| | - Jim Labisko
- Natural History Museum, London, UK
- Centre for Biodiversity and Environment Research, Department of Genetics, Evolution and Environment, University College London, London, UK
- Island Biodiversity and Conservation Centre, University of Seychelles, Mahé, Seychelles
| | - Simon T Maddock
- Natural History Museum, London, UK
- Island Biodiversity and Conservation Centre, University of Seychelles, Mahé, Seychelles
- School of Natural and Environmental Sciences, Newcastle University, Newcastle Upon Tyne, UK
| | - Michael Mahony
- Department of Biological Sciences, The University of Newcastle, Newcastle 2308, Australia
| | - Renato A Martins
- Programa de Pós-graduação em Conservação da Fauna, Universidade Federal de São Carlos, São Carlos, Brazil
| | | | - Nicola J Mitchell
- School of Biological Sciences, The University of Western Australia, Crawley, WA 6009, Australia
| | - Daniel M Portik
- Department of Herpetology, California Academy of Sciences, San Francisco, CA, USA
| | - Ivan Prates
- Department of Biology, Lund University, Lund, Sweden
| | - Kim Roelants
- Amphibian Evolution Lab, Biology Department, Vrije Universiteit Brussel, Brussels, Belgium
| | - Corey Roelke
- Department of Biology, Amphibian and Reptile Diversity Research Center, The University of Texas at Arlington, Arlington, TX, USA
| | - Elie Tobi
- Gabon Biodiversity Program, Center for Conservation and Sustainability, Smithsonian National Zoo and Conservation Biology Institute, Gamba, Gabon
| | - Maya Woolfolk
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
- Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, Harvard University, Cambridge, MA, 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
| |
Collapse
|
2
|
Abbas F, Becker S, Jones BW, Mure LS, Panda S, Hanneken A, Vinberg F. Revival of light signalling in the postmortem mouse and human retina. Nature 2022; 606:351-357. [PMID: 35545677 PMCID: PMC10000337 DOI: 10.1038/s41586-022-04709-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 03/31/2022] [Indexed: 12/21/2022]
Abstract
Death is defined as the irreversible cessation of circulatory, respiratory or brain activity. Many peripheral human organs can be transplanted from deceased donors using protocols to optimize viability. However, tissues from the central nervous system rapidly lose viability after circulation ceases1,2, impeding their potential for transplantation. The time course and mechanisms causing neuronal death and the potential for revival remain poorly defined. Here, using the retina as a model of the central nervous system, we systemically examine the kinetics of death and neuronal revival. We demonstrate the swift decline of neuronal signalling and identify conditions for reviving synchronous in vivo-like trans-synaptic transmission in postmortem mouse and human retina. We measure light-evoked responses in human macular photoreceptors in eyes removed up to 5 h after death and identify modifiable factors that drive reversible and irreversible loss of light signalling after death. Finally, we quantify the rate-limiting deactivation reaction of phototransduction, a model G protein signalling cascade, in peripheral and macular human and macaque retina. Our approach will have broad applications and impact by enabling transformative studies in the human central nervous system, raising questions about the irreversibility of neuronal cell death, and providing new avenues for visual rehabilitation.
Collapse
Affiliation(s)
- Fatima Abbas
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
| | - Silke Becker
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
| | - Bryan W Jones
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
| | - Ludovic S Mure
- Salk Institute for Biological Studies, La Jolla, CA, USA.,Institute of Physiology, University of Bern, Bern, Switzerland.,Department of Neurology, Zentrum für Experimentelle Neurologie, Inselspital University Hospital Bern, Bern, Switzerland
| | | | - Anne Hanneken
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA. .,Retina Consultants San Diego, La Jolla, CA, USA.
| | - Frans Vinberg
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA.
| |
Collapse
|
3
|
Pang JJ, Gao F, Wu SM. Dual-Cell Patch-Clamp Recording Revealed a Mechanism for a Ribbon Synapse to Process Both Digital and Analog Inputs and Outputs. Front Cell Neurosci 2021; 15:722533. [PMID: 34720878 PMCID: PMC8552968 DOI: 10.3389/fncel.2021.722533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 09/13/2021] [Indexed: 12/02/2022] Open
Abstract
A chemical synapse is either an action potential (AP) synapse or a graded potential (GP) synapse but not both. This study investigated how signals passed the glutamatergic synapse between the rod photoreceptor and its postsynaptic hyperpolarizing bipolar cells (HBCs) and light responses of retinal neurons with dual-cell and single-cell patch-clamp recording techniques. The results showed that scotopic lights evoked GPs in rods, whose depolarizing Phase 3 associated with the light offset also evoked APs of a duration of 241.8 ms and a slope of 4.5 mV/ms. The depolarization speed of Phase 3 (Speed) was 0.0001–0.0111 mV/ms and 0.103–0.469 mV/ms for rods and cones, respectively. On pairs of recorded rods and HBCs, only the depolarizing limbs of square waves applied to rods evoked clear currents in HBCs which reversed at −6.1 mV, indicating cation currents. We further used stimuli that simulated the rod light response to stimulate rods and recorded the rod-evoked excitatory current (rdEPSC) in HBCs. The normalized amplitude (R/Rmax), delay, and rising slope of rdEPSCs were differentially exponentially correlated with the Speed (all p < 0.001). For the Speed < 0.1 mV/ms, R/Rmax grew while the delay and duration reduced slowly; for the Speed between 0.1 and 0.4 mV/ms, R/Rmax grew fast while the delay and duration dramatically decreased; for the Speed > 0.4 mV/ms, R/Rmax reached the plateau, while the delay and duration approached the minimum, resembling digital signals. The rdEPSC peak was left-shifted and much faster than currents in rods. The scotopic-light-offset-associated major and minor cation currents in retinal ganglion cells (RGCs), the gigantic excitatory transient currents (GTECs) in HBCs, and APs and Phase 3 in rods showed comparable light-intensity-related locations. The data demonstrate that the rod-HBC synapse is a perfect synapse that can differentially decode and code analog and digital signals to process enormously varied rod and coupled-cone inputs.
Collapse
Affiliation(s)
- Ji-Jie Pang
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, United States
| | - Fan Gao
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, United States
| | - Samuel M Wu
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, United States
| |
Collapse
|
5
|
Rod Photoreceptors Signal Fast Changes in Daylight Levels Using a Cx36-Independent Retinal Pathway in Mouse. J Neurosci 2019; 40:796-810. [PMID: 31776212 DOI: 10.1523/jneurosci.0455-19.2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 11/11/2019] [Accepted: 11/17/2019] [Indexed: 11/21/2022] Open
Abstract
Temporal contrast detected by rod photoreceptors is channeled into multiple retinal rod pathways that ultimately connect to cone photoreceptor pathways via Cx36 gap junctions or via chemical synapses. However, we do not yet understand how the different rod pathways contribute to the perception of temporal contrast (changes in luminance with time) at mesopic light levels, where both rods and cones actively respond to light. Here, we use a forced-choice, operant behavior assay to investigate rod-driven, temporal contrast sensitivity (TCS) in mice of either sex. Transgenic mice with desensitized cones (GNAT2 cpfl3 line) were used to identify rod contributions to TCS in mesopic lights. We found that at low mesopic lights (400 photons/s/μm2 at the retina), control and GNAT2 cpfl3 mice had similar TCS. Surprisingly, at upper mesopic lights (8000 photons/s/μm2), GNAT2 cpfl3 mice exhibited a relative reduction in TCS to low (<12 Hz) while maintaining normal TCS to high (12-36 Hz) temporal frequencies. The rod-driven responses to high temporal frequencies developed gradually over time (>30 min). Furthermore, the TCS of GNAT2 cpfl3 and GNAT2 cpfl3 ::Cx36-/- mice matched closely, indicating that transmission of high-frequency signals (1) does not require the rod-cone Cx36 gap junctions as has been proposed in the past; and (2) a Cx36-independent rod pathway(s) (e.g., direct rod to OFF cone bipolar cell synapses and/or glycinergic synapses from AII amacrine cells to OFF ganglion cells) is sufficient for fast, mesopic rod-driven vision. These findings extend our understanding of the link between visual circuits and perception in mouse.SIGNIFICANCE STATEMENT The contributions of specific retinal pathways to visual perception are not well understood. We found that the temporal processing properties of rod-driven vision in mice change significantly with light level. In dim lights, rods relay relatively slow temporal variations. However, in daylight conditions, rod pathways exhibit high sensitivity to fast but not to slow temporal variations, whereas cone-driven responses supplement the loss in rod-driven sensitivity to slow temporal variations. Our findings highlight the dynamic interplay of rod- and cone-driven vision as light levels rise from night to daytime levels. Furthermore, the fast, rod-driven signals do not require the rod-to-cone Cx36 gap junctions as proposed in the past, but rather, can be relayed by alternative Cx36-independent rod pathways.
Collapse
|
6
|
Rod Photoresponse Kinetics Limit Temporal Contrast Sensitivity in Mesopic Vision. J Neurosci 2019; 39:3041-3056. [PMID: 30737308 DOI: 10.1523/jneurosci.1404-18.2019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Revised: 01/29/2019] [Accepted: 01/30/2019] [Indexed: 11/21/2022] Open
Abstract
The mammalian visual system operates over an extended range of ambient light levels by switching between rod and cone photoreceptors. Rod-driven vision is sluggish, highly sensitive, and operates in dim or scotopic lights, whereas cone-driven vision is brisk, less sensitive, and operates in bright or photopic lights. At intermediate or mesopic lights, vision transitions seamlessly from rod-driven to cone-driven, despite the profound differences in rod and cone response dynamics. The neural mechanisms underlying such a smooth handoff are not understood. Using an operant behavior assay, electrophysiological recordings, and mathematical modeling we examined the neural underpinnings of the mesopic visual transition in mice of either sex. We found that rods, but not cones, drive visual sensitivity to temporal light variations over much of the mesopic range. Surprisingly, speeding up rod photoresponse recovery kinetics in transgenic mice improved visual sensitivity to slow temporal variations, in the range where perceptual sensitivity is governed by Weber's law of sensation. In contrast, physiological processes acting downstream from phototransduction limit sensitivity to high frequencies and temporal resolution. We traced the paradoxical control of visual temporal sensitivity to rod photoresponses themselves. A scenario emerges where perceptual sensitivity is limited by: (1) the kinetics of neural processes acting downstream from phototransduction in scotopic lights, (2) rod response kinetics in mesopic lights, and (3) cone response kinetics as light levels rise into the photopic range.SIGNIFICANCE STATEMENT Our ability to detect flickering lights is constrained by the dynamics of the slowest step in the visual pathway. Cone photoresponse kinetics limit visual temporal sensitivity in bright (photopic) lights, whereas mechanisms in the inner retina limit sensitivity in dim (scotopic) lights. The neural mechanisms underlying the transition between scotopic and photopic vision in mesopic lights, when both rods are cones are active, are unknown. This study provides a missing link in this mechanism by establishing that rod photoresponse kinetics limit temporal sensitivity during the mesopic transition. Surprisingly, this range is where Weber's Law of Sensation governs temporal contrast sensitivity in mouse. Our results will help guide future studies of complex and dynamic interactions between rod-cone signals in the mesopic retina.
Collapse
|
7
|
Peinado Allina G, Fortenbach C, Naarendorp F, Gross OP, Pugh EN, Burns ME. Bright flash response recovery of mammalian rods in vivo is rate limited by RGS9. J Gen Physiol 2017; 149:443-454. [PMID: 28302678 PMCID: PMC5379920 DOI: 10.1085/jgp.201611692] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 02/08/2017] [Indexed: 11/20/2022] Open
Abstract
Peinado Allina et al. measure rod responses in living mice across a wide range of flash strengths and find that responses are much faster in vivo than ex vivo, though the biochemical mechanisms underlying the kinetics appear to be the same in both cases. Although RGS9 overexpression sped recovery from bright flashes, faster rod recovery did not improve the temporal resolution of scotopic vision. The temporal resolution of scotopic vision is thought to be constrained by the signaling kinetics of retinal rods, which use a highly amplified G-protein cascade to transduce absorbed photons into changes in membrane potential. Much is known about the biochemical mechanisms that determine the kinetics of rod responses ex vivo, but the rate-limiting mechanisms in vivo are unknown. Using paired flash electroretinograms with improved signal-to-noise, we have recorded the amplitude and kinetics of rod responses to a wide range of flash strengths from living mice. Bright rod responses in vivo recovered nearly twice as fast as all previous recordings, although the kinetic consequences of genetic perturbations previously studied ex vivo were qualitatively similar. In vivo, the dominant time constant of recovery from bright flashes was dramatically reduced by overexpression of the RGS9 complex, revealing G-protein deactivation to be rate limiting for recovery. However, unlike previous ex vivo recordings, dim flash responses in vivo were relatively unaffected by RGS9 overexpression, suggesting that other mechanisms, such as calcium feedback dynamics that are strongly regulated by the restricted subretinal microenvironment, act to determine rod dim flash kinetics. To assess the consequences for scotopic vision, we used a nocturnal wheel-running assay to measure the ability of wild-type and RGS9-overexpressing mice to detect dim flickering stimuli and found no improvement when rod recovery was speeded by RGS9 overexpression. These results are important for understanding retinal circuitry, in particular as modeled in the large literature that addresses the relationship between the kinetics and sensitivity of retinal responses and visual perception.
Collapse
Affiliation(s)
| | | | | | - Owen P Gross
- Center for Neuroscience, University of California, Davis, Davis, CA 95618
| | - Edward N Pugh
- Center for Neuroscience, University of California, Davis, Davis, CA 95618.,Department of Ophthalmology and Vision Science, University of California, Davis, Davis, CA 95618.,Department of Cell Biology and Human Anatomy, University of California, Davis, Davis, CA 95618
| | - Marie E Burns
- Center for Neuroscience, University of California, Davis, Davis, CA 95618 .,Department of Ophthalmology and Vision Science, University of California, Davis, Davis, CA 95618.,Department of Cell Biology and Human Anatomy, University of California, Davis, Davis, CA 95618
| |
Collapse
|