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
|
Thüs P, Lunau K, Wester P. Associative colour learning and discrimination in the South African Cape rock sengi Elephantulus edwardii (Macroscelidea, Afrotheria, Mammalia). MAMMALIA 2022. [DOI: 10.1515/mammalia-2022-0034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Abstract
Beside insects, sengis also consume plant material such as leaves, fruits, seeds and floral nectar. It is known that they use olfaction for foraging, but little is known about their vision and visual learning capabilities. Colour vision has been tested in two species, showing that they are likely dichromats (green- and blue-sensitive retinal cone-photoreceptors, meaning red-green colour blind). Our aim was to examine the learning and colour discrimination abilities of another species, Elephantulus edwardii. Using training procedures and choice experiments, we tested the hypotheses that the animals can associate a reward with trained colours and that they can discriminate between different colour hues. The sengis preferred the trained colours over the others, indicating associative learning. They could discriminate between all tested colours (blue, red, green, yellow). The sengis’ colour choice behaviour indicates that the animals can use also colour features to find food plant material. Additionally, learning abilities most likely are essential for the sengis’ foraging activities, for instance by associating floral or fruit shape, colour or scent with nectar or ripe fruit, to increase the efficiency to locate food sources.
Collapse
Affiliation(s)
- Patricia Thüs
- Institute of Sensory Ecology , Heinrich-Heine-University , Düsseldorf , Germany
| | - Klaus Lunau
- Institute of Sensory Ecology , Heinrich-Heine-University , Düsseldorf , Germany
| | - Petra Wester
- Institute of Sensory Ecology , Heinrich-Heine-University , Düsseldorf , Germany
- School of Life Sciences , University of KwaZulu-Natal , PB X01 , Pietermaritzburg 3209 , South Africa
| |
Collapse
|
3
|
Schott RK, Perez L, Kwiatkowski MA, Imhoff V, Gumm JM. Evolutionary analyses of visual opsin genes in frogs and toads: Diversity, duplication, and positive selection. Ecol Evol 2022; 12:e8595. [PMID: 35154658 PMCID: PMC8820127 DOI: 10.1002/ece3.8595] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 01/07/2022] [Accepted: 01/08/2022] [Indexed: 01/12/2023] Open
Abstract
Among major vertebrate groups, anurans (frogs and toads) are understudied with regard to their visual systems, and little is known about variation among species that differ in ecology. We sampled North American anurans representing diverse evolutionary and life histories that likely possess visual systems adapted to meet different ecological needs. Using standard molecular techniques, visual opsin genes, which encode the protein component of visual pigments, were obtained from anuran retinas. Additionally, we extracted the visual opsins from publicly available genome and transcriptome assemblies, further increasing the phylogenetic and ecological diversity of our dataset to 33 species in total. We found that anurans consistently express four visual opsin genes (RH1, LWS, SWS1, and SWS2, but not RH2) even though reported photoreceptor complements vary widely among species. The proteins encoded by these genes showed considerable sequence variation among species, including at sites known to shift the spectral sensitivity of visual pigments in other vertebrates and had conserved substitutions that may be related to dim-light adaptation. Using molecular evolutionary analyses of selection (dN/dS) we found significant evidence for positive selection at a subset of sites in the dim-light rod opsin gene RH1 and the long wavelength sensitive cone opsin LWS. The function of sites inferred to be under positive selection are largely unknown, but a few are likely to affect spectral sensitivity and other visual pigment functions based on proximity to previously identified sites in other vertebrates. We also found the first evidence of visual opsin duplication in an amphibian with the duplication of the LWS gene in the African bullfrog, which had distinct LWS copies on the sex chromosomes suggesting the possibility of sex-specific visual adaptation. Taken together, our results indicate that ecological factors, such as habitat and life history, as well as behavior, may be driving changes to anuran visual systems.
Collapse
Affiliation(s)
- Ryan K. Schott
- Department of BiologyYork UniversityTorontoOntarioCanada
- Department of Vertebrate ZoologyNational Museum of Natural HistorySmithsonian InstitutionWashingtonDistrict of ColumbiaUSA
| | - Leah Perez
- Department of BiologyStephen F. Austin State UniversityNacogdochesTexasUSA
| | | | - Vance Imhoff
- Southern Nevada Fish and Wildlife OfficeUS Fish and Wildlife ServiceLas VegasNevadaUSA
| | - Jennifer M. Gumm
- Department of BiologyStephen F. Austin State UniversityNacogdochesTexasUSA
- Ash Meadows Fish Conservation FacilityUS Fish and Wildlife ServiceAmargosa ValleyNevadaUSA
| |
Collapse
|
4
|
McConkey KR, Aldy F, Ong L, Sutisna DJ, Campos‐Arceiz A. Lost mutualisms: Seed dispersal by Sumatran rhinos, the world’s most threatened megafauna. Biotropica 2022. [DOI: 10.1111/btp.13056] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Kim R. McConkey
- School of Environmental and Geographical Sciences University of Nottingham Malaysia Kajang Selangor Malaysia
| | - Firmann Aldy
- Konservasi Rimba Indonesia Kota Depok West Java Indonesia
| | - Lisa Ong
- School of Environmental and Geographical Sciences University of Nottingham Malaysia Kajang Selangor Malaysia
- Southeast Asia Biodiversity Research Institute Chinese Academy of Sciences & Center for Integrative Conservation Xishuangbanna Tropical Botanical Garden Chinese Academy of Sciences Mengla Yunnan China
| | | | - Ahimsa Campos‐Arceiz
- School of Environmental and Geographical Sciences University of Nottingham Malaysia Kajang Selangor Malaysia
- Southeast Asia Biodiversity Research Institute Chinese Academy of Sciences & Center for Integrative Conservation Xishuangbanna Tropical Botanical Garden Chinese Academy of Sciences Mengla Yunnan China
| |
Collapse
|
5
|
Hauzman E, Pierotti MER, Bhattacharyya N, Tashiro JH, Yovanovich CAM, Campos PF, Ventura DF, Chang BSW. Simultaneous expression of UV and violet SWS1 opsins expands the visual palette in a group of freshwater snakes. Mol Biol Evol 2021; 38:5225-5240. [PMID: 34562092 PMCID: PMC8662652 DOI: 10.1093/molbev/msab285] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Snakes are known to express a rod visual opsin and two cone opsins, only (SWS1, LWS), a reduced palette resulting from their supposedly fossorial origins. Dipsadid snakes in the genus Helicops are highly visual predators that successfully invaded freshwater habitats from ancestral terrestrial-only habitats. Here, we report the first case of multiple SWS1 visual pigments in a vertebrate, simultaneously expressed in different photoreceptors and conferring both UV and violet sensitivity to Helicops snakes. Molecular analysis and in vitro expression confirmed the presence of two functional SWS1 opsins, likely the result of recent gene duplication. Evolutionary analyses indicate that each sws1 variant has undergone different evolutionary paths with strong purifying selection acting on the UV-sensitive copy and dN/dS ∼1 on the violet-sensitive copy. Site-directed mutagenesis points to the functional role of a single amino acid substitution, Phe86Val, in the large spectral shift between UV and violet opsins. In addition, higher densities of photoreceptors and SWS1 cones in the ventral retina suggest improved acuity in the upper visual field possibly correlated with visually guided behaviors. The expanded visual opsin repertoire and specialized retinal architecture are likely to improve photon uptake in underwater and terrestrial environments, and provide the neural substrate for a gain in chromatic discrimination, potentially conferring unique color vision in the UV–violet range. Our findings highlight the innovative solutions undertaken by a highly specialized lineage to tackle the challenges imposed by the invasion of novel photic environments and the extraordinary diversity of evolutionary trajectories taken by visual opsin-based perception in vertebrates.
Collapse
Affiliation(s)
- Einat Hauzman
- Department of Experimental Psychology, Psychology Institute, University of São Paulo, São Paulo, Brazil.,Hospital Israelita Albert Einstein, São Paulo, Brazil
| | - Michele E R Pierotti
- Department of Zoology, Institute of Biosciences, University of São Paulo, São Paulo, Brazil
| | - Nihar Bhattacharyya
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Juliana H Tashiro
- Department of Experimental Psychology, Psychology Institute, University of São Paulo, São Paulo, Brazil
| | - Carola A M Yovanovich
- Department of Zoology, Institute of Biosciences, University of São Paulo, São Paulo, Brazil
| | - Pollyanna F Campos
- Laboratório de Toxinologia Aplicada, Center of Toxins, Immune-Response and Cell Signaling (CeTICS), Instituto Butantan, São Paulo, Brazil
| | - Dora F Ventura
- Department of Experimental Psychology, Psychology Institute, University of São Paulo, São Paulo, Brazil.,Hospital Israelita Albert Einstein, São Paulo, Brazil
| | - Belinda S W Chang
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON, Canada.,Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, ON, Canada
| |
Collapse
|
6
|
Moore AM, Hartstone-Rose A, Gonzalez-Socoloske D. Review of sensory modalities of sirenians and the other extant Paenungulata clade. Anat Rec (Hoboken) 2021; 305:715-735. [PMID: 34424615 DOI: 10.1002/ar.24741] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 06/15/2021] [Accepted: 07/18/2021] [Indexed: 11/12/2022]
Abstract
Extant members of Paenungulata (sirenians, proboscideans, and hyracoideans) form a monophyletic clade which originated in Africa. While paenungulates are all herbivorous, they differ greatly in size, life history, and habitat. Therefore, we would expect both phylogenetically related similarities and ecologically driven differences in their use and specializations of sensory systems, especially in adaptations in sirenians related to their fully aquatic habitat. Here we review what is known about the sensory modalities of this clade in an attempt to better elucidate their sensory adaptations. Manatees have a higher frequency range for hearing than elephants, who have the best low-frequency hearing range known to mammals, while the hearing range of hyraxes is unknown. All paenungulates have vibrissae assisting in tactile abilities such as feeding and navigating the environment and share relatively small eyes and dichromatic vision. Taste buds are present in varying quantities in all three orders. While the olfactory abilities of manatees and hyraxes are unknown, elephants have an excellent sense of smell which is reflected by having the relatively largest cranial nerve related to olfaction among the three lineages. Manatees have the relatively largest trigeminal nerve-the nerve responsible for, among other things, mystacial vibrissae-while hyraxes have the relatively largest optic nerve (and therefore, presumably, the best vision) among the Paenungulata. All three orders have diverged significantly; however, they still retain some anatomical and physiological adaptations in common with regard to sensory abilities.
Collapse
Affiliation(s)
- Amanda Marie Moore
- Department of Biology, Andrews University, Berrien Springs, Michigan, USA
| | - Adam Hartstone-Rose
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, USA
| | | |
Collapse
|
7
|
Eagleman DM, Vaughn DA. The Defensive Activation Theory: REM Sleep as a Mechanism to Prevent Takeover of the Visual Cortex. Front Neurosci 2021; 15:632853. [PMID: 34093109 PMCID: PMC8176926 DOI: 10.3389/fnins.2021.632853] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 04/27/2021] [Indexed: 11/13/2022] Open
Abstract
Regions of the brain maintain their territory with continuous activity: if activity slows or stops (e.g., because of blindness), the territory tends to be taken over by its neighbors. A surprise in recent years has been the speed of takeover, which is measurable within an hour. These findings lead us to a new hypothesis on the origin of REM sleep. We hypothesize that the circuitry underlying REM sleep serves to amplify the visual system's activity periodically throughout the night, allowing it to defend its territory against takeover from other senses. We find that measures of plasticity across 25 species of primates correlate positively with the proportion of rapid eye movement (REM) sleep. We further find that plasticity and REM sleep increase in lockstep with evolutionary recency to humans. Finally, our hypothesis is consistent with the decrease in REM sleep and parallel decrease in neuroplasticity with aging.
Collapse
Affiliation(s)
- David M. Eagleman
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, United States
| | - Don A. Vaughn
- Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, United States
| |
Collapse
|
8
|
Tan WH, Hii A, Solana‐Mena A, Wong EP, Loke VPW, Tan ASL, Kromann‐Clausen A, Hii N, bin Pura P, bin Tunil MT, A/L Din S, Chin CF, Campos‐Arceiz A. Long‐term monitoring of seed dispersal by Asian elephants in a Sundaland rainforest. Biotropica 2021. [DOI: 10.1111/btp.12889] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Wei Harn Tan
- School of Environmental and Geographical Sciences The University of Nottingham Malaysia Kajang Malaysia
| | - Adeline Hii
- School of Environmental and Geographical Sciences The University of Nottingham Malaysia Kajang Malaysia
| | - Alicia Solana‐Mena
- School of Environmental and Geographical Sciences The University of Nottingham Malaysia Kajang Malaysia
| | - Ee Phin Wong
- School of Environmental and Geographical Sciences The University of Nottingham Malaysia Kajang Malaysia
- Management & Ecology of Malaysian Elephants University of Nottingham Malaysia Semenyih Malaysia
| | - Vivienne P. W. Loke
- School of Environmental and Geographical Sciences The University of Nottingham Malaysia Kajang Malaysia
| | - Ange S. L. Tan
- School of Environmental and Geographical Sciences The University of Nottingham Malaysia Kajang Malaysia
| | - Anders Kromann‐Clausen
- School of Environmental and Geographical Sciences The University of Nottingham Malaysia Kajang Malaysia
| | - Ning Hii
- School of Environmental and Geographical Sciences The University of Nottingham Malaysia Kajang Malaysia
| | - Param bin Pura
- School of Environmental and Geographical Sciences The University of Nottingham Malaysia Kajang Malaysia
| | - Muhamad Tauhid bin Tunil
- School of Environmental and Geographical Sciences The University of Nottingham Malaysia Kajang Malaysia
| | - Sudin A/L Din
- School of Environmental and Geographical Sciences The University of Nottingham Malaysia Kajang Malaysia
| | - Chiew Foan Chin
- School of Biosciences The University of Nottingham Malaysia Kajang Malaysia
| | - Ahimsa Campos‐Arceiz
- School of Environmental and Geographical Sciences The University of Nottingham Malaysia Kajang Malaysia
- Southeast Asia Biodiversity Research Institute Chinese Academy of Sciences Nay Pyi Taw Myanmar
- Center for Integrative Conservation Xishuangbanna Tropical Botanical GardenChinese Academy of Sciences Mengla China
| |
Collapse
|
9
|
Simões BF, Gower DJ, Rasmussen AR, Sarker MAR, Fry GC, Casewell NR, Harrison RA, Hart NS, Partridge JC, Hunt DM, Chang BS, Pisani D, Sanders KL. Spectral Diversification and Trans-Species Allelic Polymorphism during the Land-to-Sea Transition in Snakes. Curr Biol 2020; 30:2608-2615.e4. [PMID: 32470360 DOI: 10.1016/j.cub.2020.04.061] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Revised: 03/05/2020] [Accepted: 04/23/2020] [Indexed: 11/16/2022]
Abstract
Snakes are descended from highly visual lizards [1] but have limited (probably dichromatic) color vision attributed to a dim-light lifestyle of early snakes [2-4]. The living species of front-fanged elapids, however, are ecologically very diverse, with ∼300 terrestrial species (cobras, taipans, etc.) and ∼60 fully marine sea snakes, plus eight independently marine, amphibious sea kraits [1]. Here, we investigate the evolution of spectral sensitivity in elapids by analyzing their opsin genes (which are responsible for sensitivity to UV and visible light), retinal photoreceptors, and ocular lenses. We found that sea snakes underwent rapid adaptive diversification of their visual pigments when compared with their terrestrial and amphibious relatives. The three opsins present in snakes (SWS1, LWS, and RH1) have evolved under positive selection in elapids, and in sea snakes they have undergone multiple shifts in spectral sensitivity toward the longer wavelengths that dominate below the sea surface. Several relatively distantly related Hydrophis sea snakes are polymorphic for shortwave sensitive visual pigment encoded by alleles of SWS1. This spectral site polymorphism is expected to confer expanded "UV-blue" spectral sensitivity and is estimated to have persisted twice as long as the predicted survival time for selectively neutral nuclear alleles. We suggest that this polymorphism is adaptively maintained across Hydrophis species via balancing selection, similarly to the LWS polymorphism that confers allelic trichromacy in some primates. Diving sea snakes thus appear to share parallel mechanisms of color vision diversification with fruit-eating primates.
Collapse
Affiliation(s)
- Bruno F Simões
- University of Plymouth, School of Biological and Marine Sciences, Drake Circus, Plymouth PL4 8AA, United Kingdom; University of Bristol, School of Biological Sciences and School of Earth Sciences, Tyndall Avenue, Bristol BS8 1TG, United Kingdom; The University of Adelaide, School of Biological Sciences, North Terrace, Adelaide, South Australia 5005, Australia.
| | - David J Gower
- Department of Life Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD, United Kingdom
| | - Arne R Rasmussen
- The Royal Danish Academy of Fine Arts, School of Architecture, Design and Conservation, Philip de Langes Allé, 1435 Copenhagen K, Denmark
| | - Mohammad A R Sarker
- University of Dhaka, Department of Zoology, Curzon Hall Campus, Dhaka 1000, Bangladesh
| | - Gary C Fry
- CSIRO Oceans and Atmosphere, Queensland Biosciences Precinct, St Lucia, Queensland 4072, Australia
| | - Nicholas R Casewell
- Liverpool School of Tropical Medicine, Centre for Snakebite Research & Interventions, Pembroke Place, Liverpool L3 5QA, United Kingdom
| | - Robert A Harrison
- Liverpool School of Tropical Medicine, Centre for Snakebite Research & Interventions, Pembroke Place, Liverpool L3 5QA, United Kingdom
| | - Nathan S Hart
- Macquarie University, Department of Biological Sciences, North Ryde, Sydney, New South Wales 2109, Australia
| | - Julian C Partridge
- The University of Western Australia, Oceans Institute, Crawley, Perth, Western Australia 6009, Australia
| | - David M Hunt
- The University of Western Australia, School of Biological Sciences, Crawley, Perth, Western Australia 6009, Australia; The Lions Eye Institute, Centre for Ophthalmology and Visual Science, Nedlands, Perth, Western Australia 6009, Australia
| | - Belinda S Chang
- University of Toronto, Departments of Ecology & Evolutionary, Cell & Systems Biology, Willcocks Street, Toronto M5S 3G5, Canada
| | - Davide Pisani
- University of Bristol, School of Biological Sciences and School of Earth Sciences, Tyndall Avenue, Bristol BS8 1TG, United Kingdom
| | - Kate L Sanders
- The University of Adelaide, School of Biological Sciences, North Terrace, Adelaide, South Australia 5005, Australia; Department of Life Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD, United Kingdom
| |
Collapse
|
10
|
Escobar-Camacho D, Carleton KL, Narain DW, Pierotti MER. Visual pigment evolution in Characiformes: The dynamic interplay of teleost whole-genome duplication, surviving opsins and spectral tuning. Mol Ecol 2020; 29:2234-2253. [PMID: 32421918 DOI: 10.1111/mec.15474] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 05/09/2020] [Accepted: 05/11/2020] [Indexed: 01/06/2023]
Abstract
Vision represents an excellent model for studying adaptation, given the genotype-to-phenotype map that has been characterized in a number of taxa. Fish possess a diverse range of visual sensitivities and adaptations to underwater light, making them an excellent group to study visual system evolution. In particular, some speciose but understudied lineages can provide a unique opportunity to better understand aspects of visual system evolution such as opsin gene duplication and neofunctionalization. In this study, we showcase the visual system evolution of neotropical Characiformes and the spectral tuning mechanisms they exhibit to modulate their visual sensitivities. Such mechanisms include gene duplications and losses, gene conversion, opsin amino acid sequence and expression variation, and A1 /A2 -chromophore shifts. The Characiforms we studied utilize three cone opsin classes (SWS2, RH2, LWS) and a rod opsin (RH1). However, the characiform's entire opsin gene repertoire is a product of dynamic evolution by opsin gene loss (SWS1, RH2) and duplication (LWS, RH1). The LWS- and RH1-duplicates originated from a teleost specific whole-genome duplication as well as characiform-specific duplication events. Both LWS-opsins exhibit gene conversion and, through substitutions in key tuning sites, one of the LWS-paralogues has acquired spectral sensitivity to green light. These sequence changes suggest reversion and parallel evolution of key tuning sites. Furthermore, characiforms' colour vision is based on the expression of both LWS-paralogues and SWS2. Finally, we found interspecific and intraspecific variation in A1 /A2 -chromophores proportions, correlating with the light environment. These multiple mechanisms may be a result of the diverse visual environments where Characiformes have evolved.
Collapse
Affiliation(s)
| | - Karen L Carleton
- Department of Biology, University of Maryland, College Park, MD, USA
| | - Devika W Narain
- Environmental Sciences, Anton de Kom University of Suriname, Paramaribo, Suriname
| | - Michele E R Pierotti
- Naos Marine Laboratories, Smithsonian Tropical Research Institute, Panama, Republic of Panama
| |
Collapse
|
11
|
Musilova Z, Cortesi F, Matschiner M, Davies WIL, Patel JS, Stieb SM, de Busserolles F, Malmstrøm M, Tørresen OK, Brown CJ, Mountford JK, Hanel R, Stenkamp DL, Jakobsen KS, Carleton KL, Jentoft S, Marshall J, Salzburger W. Vision using multiple distinct rod opsins in deep-sea fishes. Science 2019; 364:588-592. [PMID: 31073066 DOI: 10.1126/science.aav4632] [Citation(s) in RCA: 98] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2018] [Accepted: 04/16/2019] [Indexed: 02/01/2023]
Abstract
Vertebrate vision is accomplished through light-sensitive photopigments consisting of an opsin protein bound to a chromophore. In dim light, vertebrates generally rely on a single rod opsin [rhodopsin 1 (RH1)] for obtaining visual information. By inspecting 101 fish genomes, we found that three deep-sea teleost lineages have independently expanded their RH1 gene repertoires. Among these, the silver spinyfin (Diretmus argenteus) stands out as having the highest number of visual opsins in vertebrates (two cone opsins and 38 rod opsins). Spinyfins express up to 14 RH1s (including the most blueshifted rod photopigments known), which cover the range of the residual daylight as well as the bioluminescence spectrum present in the deep sea. Our findings present molecular and functional evidence for the recurrent evolution of multiple rod opsin-based vision in vertebrates.
Collapse
Affiliation(s)
- Zuzana Musilova
- Zoological Institute, Department of Environmental Sciences, University of Basel, Basel, Switzerland. .,Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Fabio Cortesi
- Zoological Institute, Department of Environmental Sciences, University of Basel, Basel, Switzerland. .,Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Michael Matschiner
- Zoological Institute, Department of Environmental Sciences, University of Basel, Basel, Switzerland.,Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, Oslo, Norway.,Department of Palaeontology and Museum, University of Zurich, Zurich, Switzerland
| | - Wayne I L Davies
- UWA Oceans Institute, The University of Western Australia, Perth, WA, Australia.,School of Biological Sciences, The University of Western Australia, Perth, WA, Australia.,Lions Eye Institute, The University of Western Australia, Perth, WA, Australia.,Oceans Graduate School, The University of Western Australia, Perth, WA, Australia
| | - Jagdish Suresh Patel
- Center for Modeling Complex Interactions, University of Idaho, Moscow, ID, USA.,Department of Biological Sciences, University of Idaho, Moscow, ID, USA
| | - Sara M Stieb
- Zoological Institute, Department of Environmental Sciences, University of Basel, Basel, Switzerland.,Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia.,Center for Ecology, Evolution and Biogeochemistry, Department of Fish Ecology and Evolution, Swiss Federal Institute of Aquatic Science and Technology (EAWAG), Kastanienbaum, Switzerland
| | - Fanny de Busserolles
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia.,Red Sea Research Center (RSRC), Biological and Environmental Sciences and Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Martin Malmstrøm
- Zoological Institute, Department of Environmental Sciences, University of Basel, Basel, Switzerland.,Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, Oslo, Norway
| | - Ole K Tørresen
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, Oslo, Norway
| | - Celeste J Brown
- Department of Biological Sciences, University of Idaho, Moscow, ID, USA
| | - Jessica K Mountford
- UWA Oceans Institute, The University of Western Australia, Perth, WA, Australia.,School of Biological Sciences, The University of Western Australia, Perth, WA, Australia.,Lions Eye Institute, The University of Western Australia, Perth, WA, Australia
| | - Reinhold Hanel
- Thünen Institute of Fisheries Ecology, Bremerhaven, Germany
| | | | - Kjetill S Jakobsen
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, Oslo, Norway
| | - Karen L Carleton
- Department of Biology, University of Maryland, College Park, MD, USA
| | - Sissel Jentoft
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, Oslo, Norway
| | - Justin Marshall
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Walter Salzburger
- Zoological Institute, Department of Environmental Sciences, University of Basel, Basel, Switzerland. .,Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, Oslo, Norway
| |
Collapse
|
12
|
Hart NS, Mountford JK, Davies WIL, Collin SP, Hunt DM. Visual pigments in a palaeognath bird, the emu Dromaius novaehollandiae: implications for spectral sensitivity and the origin of ultraviolet vision. Proc Biol Sci 2017; 283:rspb.2016.1063. [PMID: 27383819 DOI: 10.1098/rspb.2016.1063] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Accepted: 06/14/2016] [Indexed: 11/12/2022] Open
Abstract
A comprehensive description of the spectral characteristics of retinal photoreceptors in palaeognaths is lacking. Moreover, controversy exists with respect to the spectral sensitivity of the short-wavelength-sensitive-1 (SWS1) opsin-based visual pigment expressed in one type of single cone: previous microspectrophotometric (MSP) measurements in the ostrich (Struthio camelus) suggested a violet-sensitive (VS) SWS1 pigment, but all palaeognath SWS1 opsin sequences obtained to date (including the ostrich) imply that the visual pigment is ultraviolet-sensitive (UVS). In this study, MSP was used to measure the spectral properties of visual pigments and oil droplets in the retinal photoreceptors of the emu (Dromaius novaehollandiae). Results show that the emu resembles most other bird species in possessing four spectrally distinct single cones, as well as double cones and rods. Four cone and a single rod opsin are expressed, each an orthologue of a previously identified pigment. The SWS1 pigment is clearly UVS (wavelength of maximum absorbance [λmax] = 376 nm), with key tuning sites (Phe86 and Cys90) consistent with other vertebrate UVS SWS1 pigments. Palaeognaths would appear, therefore, to have UVS SWS1 pigments. As they are considered to be basal in avian evolution, this suggests that UVS is the most likely ancestral state for birds. The functional significance of a dedicated UVS cone type in the emu is discussed.
Collapse
Affiliation(s)
- Nathan S Hart
- Department of Biological Sciences, Macquarie University, North Ryde, New South Wales 2109, Australia School of Animal Biology, University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Jessica K Mountford
- School of Animal Biology, University of Western Australia, Crawley, Western Australia 6009, Australia Oceans Institute, University of Western Australia, Crawley, Western Australia 6009, Australia Lions Eye Institute, University of Western Australia, Nedlands, Western Australia 6009, Australia
| | - Wayne I L Davies
- School of Animal Biology, University of Western Australia, Crawley, Western Australia 6009, Australia Oceans Institute, University of Western Australia, Crawley, Western Australia 6009, Australia Lions Eye Institute, University of Western Australia, Nedlands, Western Australia 6009, Australia
| | - Shaun P Collin
- School of Animal Biology, University of Western Australia, Crawley, Western Australia 6009, Australia Oceans Institute, University of Western Australia, Crawley, Western Australia 6009, Australia Lions Eye Institute, University of Western Australia, Nedlands, Western Australia 6009, Australia
| | - David M Hunt
- School of Animal Biology, University of Western Australia, Crawley, Western Australia 6009, Australia Lions Eye Institute, University of Western Australia, Nedlands, Western Australia 6009, Australia
| |
Collapse
|
13
|
Carvalho LS, Pessoa DMA, Mountford JK, Davies WIL, Hunt DM. The Genetic and Evolutionary Drives behind Primate Color Vision. Front Ecol Evol 2017. [DOI: 10.3389/fevo.2017.00034] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
14
|
Kuhrt H, Bringmann A, Härtig W, Wibbelt G, Peichl L, Reichenbach A. The Retina of Asian and African Elephants: Comparison of Newborn and Adult. BRAIN, BEHAVIOR AND EVOLUTION 2017; 89:84-103. [PMID: 28437785 DOI: 10.1159/000464097] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 02/14/2017] [Indexed: 11/19/2022]
Abstract
Elephants are precocial mammals that are relatively mature as newborns and mobile shortly after birth. To determine whether the retina of newborn elephants is capable of supporting the mobility of elephant calves, we compared the retinal structures of 2 newborn elephants (1 African and 1 Asian) and 2 adult animals of both species by immunohistochemical and morphometric methods. For the first time, we present here a comprehensive qualitative and quantitative characterization of the cellular composition of the newborn and the adult retinas of 2 elephant species. We found that the retina of elephants is relatively mature at birth. All retinal layers were well discernible, and various retinal cell types were detected in the newborns, including Müller glial cells (expressing glutamine synthetase and cellular retinal binding protein; CRALBP), cone photoreceptors (expressing S-opsin or M/L-opsin), protein kinase Cα-expressing bipolar cells, tyrosine hydroxylase-, choline acetyltransferase (ChAT)-, calbindin-, and calretinin-expressing amacrine cells, and calbindin-expressing horizontal cells. The retina of newborn elephants contains discrete horizontal cells which coexpress ChAT, calbindin, and calretinin. While the overall structure of the retina is very similar between newborn and adult elephants, various parameters change after birth. The postnatal thickening of the retinal ganglion cell axons and the increase in ganglion cell soma size are explained by the increase in body size after birth, and the decreases in the densities of neuronal and glial cells are explained by the postnatal expansion of the retinal surface area. The expression of glutamine synthetase and CRALBP in the Müller cells of newborn elephants suggests that the cells are already capable of supporting the activities of photoreceptors and neurons. As a peculiarity, the elephant retina contains both normally located and displaced giant ganglion cells, with single cells reaching a diameter of more than 50 µm in adults and therefore being almost in the range of giant retinal ganglion cells found in aquatic mammals. Some of these ganglion cells are displaced into the inner nuclear layer, a unique feature of terrestrial mammals. For the first time, we describe here the occurrence of many bistratified rod bipolar cells in the elephant retina. These bistratified bipolar cells may improve nocturnal contrast perception in elephants given their arrhythmic lifestyle.
Collapse
Affiliation(s)
- Heidrun Kuhrt
- Paul Flechsig Institute of Brain Research, University of Leipzig Medical Faculty, Leipzig, Germany
| | | | | | | | | | | |
Collapse
|
15
|
Simões BF, Sampaio FL, Douglas RH, Kodandaramaiah U, Casewell NR, Harrison RA, Hart NS, Partridge JC, Hunt DM, Gower DJ. Visual Pigments, Ocular Filters and the Evolution of Snake Vision. Mol Biol Evol 2016; 33:2483-95. [DOI: 10.1093/molbev/msw148] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
|
16
|
Yokoyama S, Tada T, Liu Y, Faggionato D, Altun A. A simple method for studying the molecular mechanisms of ultraviolet and violet reception in vertebrates. BMC Evol Biol 2016; 16:64. [PMID: 27001075 PMCID: PMC4802639 DOI: 10.1186/s12862-016-0637-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Accepted: 03/16/2016] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND Many vertebrate species use ultraviolet (UV) reception for such basic behaviors as foraging and mating, but many others switched to violet reception and improved their visual resolution. The respective phenotypes are regulated by the short wavelength-sensitive (SWS1) pigments that absorb light maximally (λmax) at ~360 and 395-440 nm. Because of strong epistatic interactions, the biological significance of the extensive mutagenesis results on the molecular basis of spectral tuning in SWS1 pigments and the mechanisms of their phenotypic adaptations remains uncertain. RESULTS The magnitudes of the λmax-shifts caused by mutations in a present-day SWS1 pigment and by the corresponding forward mutations in its ancestral pigment are often dramatically different. To resolve these mutagenesis results, the A/B ratio, in which A and B are the areas formed by amino acids at sites 90, 113 and 118 and by those at sites 86, 90 and 118 and 295, respectively, becomes indispensable. Then, all critical mutations that generated the λmax of a SWS1 pigment can be identified by establishing that 1) the difference between the λmax of the ancestral pigment with these mutations and that of the present-day pigment is small (3 ~ 5 nm, depending on the entire λmax-shift) and 2) the difference between the corresponding A/B ratios is < 0.002. CONCLUSION Molecular adaptation has been studied mostly by using comparative sequence analyses. These statistical results provide biological hypotheses and need to be tested using experimental means. This is an opportune time to explore the currently available and new genetic systems and test these statistical hypotheses. Evaluating the λmaxs and A/B ratios of mutagenized present-day and their ancestral pigments, we now have a method to identify all critical mutations that are responsible for phenotypic adaptation of SWS1 pigments. The result also explains spectral tuning of the same pigments, a central unanswered question in phototransduction.
Collapse
Affiliation(s)
- Shozo Yokoyama
- Department of Biology, Emory University, Atlanta, GA, 30322, USA.
| | - Takashi Tada
- Department of Biology, Emory University, Atlanta, GA, 30322, USA
| | - Yang Liu
- Department of Biology, Emory University, Atlanta, GA, 30322, USA
| | | | - Ahmet Altun
- Department of Physics, Fatih University, Istanbul, 34500, Turkey.,Department of Genetics and Bioengineering, Fatih University, Istanbul, 34500, Turkey
| |
Collapse
|
17
|
Emerling CA, Huynh HT, Nguyen MA, Meredith RW, Springer MS. Spectral shifts of mammalian ultraviolet-sensitive pigments (short wavelength-sensitive opsin 1) are associated with eye length and photic niche evolution. Proc Biol Sci 2015; 282:20151817. [PMID: 26582021 PMCID: PMC4685808 DOI: 10.1098/rspb.2015.1817] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Accepted: 10/09/2015] [Indexed: 11/12/2022] Open
Abstract
Retinal opsin photopigments initiate mammalian vision when stimulated by light. Most mammals possess a short wavelength-sensitive opsin 1 (SWS1) pigment that is primarily sensitive to either ultraviolet or violet light, leading to variation in colour perception across species. Despite knowledge of both ultraviolet- and violet-sensitive SWS1 classes in mammals for 25 years, the adaptive significance of this variation has not been subjected to hypothesis testing, resulting in minimal understanding of the basis for mammalian SWS1 spectral tuning evolution. Here, we gathered data on SWS1 for 403 mammal species, including novel SWS1 sequences for 97 species. Ancestral sequence reconstructions suggest that the most recent common ancestor of Theria possessed an ultraviolet SWS1 pigment, and that violet-sensitive pigments evolved at least 12 times in mammalian history. We also observed that ultraviolet pigments, previously considered to be a rarity, are common in mammals. We then used phylogenetic comparative methods to test the hypotheses that the evolution of violet-sensitive SWS1 is associated with increased light exposure, extended longevity and longer eye length. We discovered that diurnal mammals and species with longer eyes are more likely to have violet-sensitive pigments and less likely to possess UV-sensitive pigments. We hypothesize that (i) as mammals evolved larger body sizes, they evolved longer eyes, which limited transmittance of ultraviolet light to the retina due to an increase in Rayleigh scattering, and (ii) as mammals began to invade diurnal temporal niches, they evolved lenses with low UV transmittance to reduce chromatic aberration and/or photo-oxidative damage.
Collapse
Affiliation(s)
- Christopher A Emerling
- Department of Biology, University of California Riverside, Riverside, CA, USA Museum of Vertebrate Zoology, University of California Berkeley, Berkeley, CA, USA
| | - Hieu T Huynh
- Department of Biology, University of California Riverside, Riverside, CA, USA School of Pharmacy, Loma Linda University, Loma Linda, CA, USA
| | - Minh A Nguyen
- Department of Biology, University of California Riverside, Riverside, CA, USA School of Pharmacy, Loma Linda University, Loma Linda, CA, USA
| | - Robert W Meredith
- Department of Biology, University of California Riverside, Riverside, CA, USA Department of Biology and Molecular Biology, Montclair State University, Montclair, NJ, USA
| | - Mark S Springer
- Department of Biology, University of California Riverside, Riverside, CA, USA
| |
Collapse
|
18
|
Yokoyama S, Altun A, Jia H, Yang H, Koyama T, Faggionato D, Liu Y, Starmer WT. Adaptive evolutionary paths from UV reception to sensing violet light by epistatic interactions. SCIENCE ADVANCES 2015; 1:e1500162. [PMID: 26601250 PMCID: PMC4643761 DOI: 10.1126/sciadv.1500162] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 08/02/2015] [Indexed: 06/05/2023]
Abstract
Ultraviolet (UV) reception is useful for such basic behaviors as mate choice, foraging, predator avoidance, communication, and navigation, whereas violet reception improves visual resolution and subtle contrast detection. UV and violet reception are mediated by the short wavelength-sensitive (SWS1) pigments that absorb light maximally (λmax) at ~360 nm and ~395 to 440 nm, respectively. Because of strong nonadditive (epistatic) interactions among amino acid changes in the pigments, the adaptive evolutionary mechanisms of these phenotypes are not well understood. Evolution of the violet pigment of the African clawed frog (Xenopus laevis, λmax = 423 nm) from the UV pigment in the amphibian ancestor (λmax = 359 nm) can be fully explained by eight mutations in transmembrane (TM) I-III segments. We show that epistatic interactions involving the remaining TM IV-VII segments provided evolutionary potential for the frog pigment to gradually achieve its violet-light reception by tuning its color sensitivity in small steps. Mutants in these segments also impair pigments that would cause drastic spectral shifts and thus eliminate them from viable evolutionary pathways. The overall effects of epistatic interactions involving TM IV-VII segments have disappeared at the last evolutionary step and thus are not detectable by studying present-day pigments. Therefore, characterizing the genotype-phenotype relationship during each evolutionary step is the key to uncover the true nature of epistasis.
Collapse
Affiliation(s)
- Shozo Yokoyama
- Department of Biology, Emory University, Atlanta, GA 30322, USA
| | - Ahmet Altun
- Department of Physics and Department of Genetics and Bioengineering, Fatih University, Istanbul 34500, Turkey
| | - Huiyong Jia
- Department of Biology, Emory University, Atlanta, GA 30322, USA
| | - Hui Yang
- Department of Biology, Emory University, Atlanta, GA 30322, USA
| | - Takashi Koyama
- Department of Biology, Emory University, Atlanta, GA 30322, USA
| | | | - Yang Liu
- Department of Biology, Emory University, Atlanta, GA 30322, USA
| | | |
Collapse
|
19
|
English M, Kaplan G, Rogers LJ. Is painting by elephants in zoos as enriching as we are led to believe? PeerJ 2014; 2:e471. [PMID: 25071994 PMCID: PMC4103097 DOI: 10.7717/peerj.471] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 06/16/2014] [Indexed: 11/25/2022] Open
Abstract
The relationship between the activity of painting and performance of stereotyped and other stress-related behaviour was investigated in four captive Asian elephants at Melbourne Zoo, Australia. The activity involved the elephant being instructed to paint on a canvas by its keeper in front of an audience. Painting by elephants in zoos is commonly believed to be a form of enrichment, but this assumption had not been based on any systematic research. If an activity is enriching we would expect stress-related behaviour to be reduced but we found no evidence of the elephants anticipating the painting activity and no effect on the performance of stereotyped or other stress-related behaviour either before or after the painting session. This indicates that the activity does not fulfil one of the main aims of enrichment. However, if an elephant was not selected to paint on a given day this was associated with higher levels of non-interactive behaviour, a possible indicator of stress. Behavioural observations associated with ear, eye and trunk positions during the painting session showed that the elephant’s attentiveness to the painting activity or to the keeper giving instruction varied between individuals. Apart from positive reinforcement from the keeper, the results indicated that elephants gain little enrichment from the activity of painting. Hence, the benefits of this activity appear to be limited to the aesthetic appeal of these paintings to the people viewing them.
Collapse
Affiliation(s)
- Megan English
- Centre for Neuroscience and Animal Behaviour, School of Science and Technology, University of New England , Armidale, NSW , Australia ; Centre for Biodiversity and Restoration Ecology, School of Biological Sciences, Victoria University of Wellington , New Zealand
| | - Gisela Kaplan
- Centre for Neuroscience and Animal Behaviour, School of Science and Technology, University of New England , Armidale, NSW , Australia
| | - Lesley J Rogers
- Centre for Neuroscience and Animal Behaviour, School of Science and Technology, University of New England , Armidale, NSW , Australia
| |
Collapse
|
20
|
Hauser FE, van Hazel I, Chang BSW. Spectral tuning in vertebrate short wavelength-sensitive 1 (SWS1) visual pigments: Can wavelength sensitivity be inferred from sequence data? JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2014; 322:529-39. [DOI: 10.1002/jez.b.22576] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 03/05/2014] [Accepted: 05/06/2014] [Indexed: 01/12/2023]
Affiliation(s)
- Frances E. Hauser
- Department of Ecology & Evolutionary Biology; University of Toronto; Toronto Ontario Canada
| | - Ilke van Hazel
- Department of Ecology & Evolutionary Biology; University of Toronto; Toronto Ontario Canada
| | - Belinda S. W. Chang
- Department of Ecology & Evolutionary Biology; University of Toronto; Toronto Ontario Canada
- Department of Cell & Systems Biology; University of Toronto; Toronto Ontario Canada
- Centre for the Analysis of Genome Evolution & Function; University of Toronto; Toronto Ontario Canada
| |
Collapse
|
21
|
van Hazel I, Sabouhanian A, Day L, Endler JA, Chang BSW. Functional characterization of spectral tuning mechanisms in the great bowerbird short-wavelength sensitive visual pigment (SWS1), and the origins of UV/violet vision in passerines and parrots. BMC Evol Biol 2013; 13:250. [PMID: 24499383 PMCID: PMC4029201 DOI: 10.1186/1471-2148-13-250] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Accepted: 11/01/2013] [Indexed: 12/18/2022] Open
Abstract
Background One of the most striking features of avian vision is the variation in spectral sensitivity of the short wavelength sensitive (SWS1) opsins, which can be divided into two sub-types: violet- and UV- sensitive (VS & UVS). In birds, UVS has been found in both passerines and parrots, groups that were recently shown to be sister orders. While all parrots are thought to be UVS, recent evidence suggests some passerine lineages may also be VS. The great bowerbird (Chlamydera nuchalis) is a passerine notable for its courtship behaviours in which males build and decorate elaborate bower structures. Results The great bowerbird SWS1 sequence possesses an unusual residue combination at known spectral tuning sites that has not been previously investigated in mutagenesis experiments. In this study, the SWS1 opsin of C. nuchalis was expressed along with a series of spectral tuning mutants and ancestral passerine SWS1 pigments, allowing us to investigate spectral tuning mechanisms and explore the evolution of UV/violet sensitivity in early passerines and parrots. The expressed C. nuchalis SWS1 opsin was found to be a VS pigment, with a λmax of 403 nm. Bowerbird SWS1 mutants C86F, S90C, and C86S/S90C all shifted λmax into the UV, whereas C86S had no effect. Experimentally recreated ancestral passerine and parrot/passerine SWS1 pigments were both found to be VS, indicating that UV sensitivity evolved independently in passerines and parrots from a VS ancestor. Conclusions Our mutagenesis studies indicate that spectral tuning in C. nuchalis is mediated by mechanisms similar to those of other birds. Interestingly, our ancestral sequence reconstructions of SWS1 in landbird evolution suggest multiple transitions from VS to UVS, but no instances of the reverse. Our results not only provide a more precise prediction of where these spectral sensitivity shifts occurred, but also confirm the hypothesis that birds are an unusual exception among vertebrates where some descendants re-evolved UVS from a violet type ancestor. The re-evolution of UVS from a VS type pigment has not previously been predicted elsewhere in the vertebrate phylogeny.
Collapse
Affiliation(s)
| | | | | | | | - Belinda S W Chang
- Department of Ecology & Evolutionary, Biology University of Toronto, Toronto, Canada.
| |
Collapse
|
22
|
Smet A, Byrne R. African Elephants Can Use Human Pointing Cues to Find Hidden Food. Curr Biol 2013; 23:2033-7. [DOI: 10.1016/j.cub.2013.08.037] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 07/30/2013] [Accepted: 08/12/2013] [Indexed: 11/24/2022]
|
23
|
Abstract
AbstractS cones expressing the short wavelength-sensitive type 1 (SWS1) class of visual pigment generally form only a minority type of cone photoreceptor within the vertebrate duplex retina. Hence, their primary role is in color vision, not in high acuity vision. In mammals, S cones may be present as a constant fraction of the cones across the retina, may be restricted to certain regions of the retina or may form a gradient across the retina, and in some species, there is coexpression of SWS1 and the long wavelength-sensitive (LWS) class of pigment in many cones. During retinal development, SWS1 opsin expression generally precedes that of LWS opsin, and evidence from genetic studies indicates that the S cone pathway may be the default pathway for cone development. With the notable exception of the cartilaginous fishes, where S cones appear to be absent, they are present in representative species from all other vertebrate classes. S cone loss is not, however, uncommon; they are absent from most aquatic mammals and from some but not all nocturnal terrestrial species. The peak spectral sensitivity of S cones depends on the spectral characteristics of the pigment present. Evidence from the study of agnathans and teleost fishes indicates that the ancestral vertebrate SWS1 pigment was ultraviolet (UV) sensitive with a peak around 360 nm, but this has shifted into the violet region of the spectrum (>380 nm) on many separate occasions during vertebrate evolution. In all cases, the shift was generated by just one or a few replacements in tuning-relevant residues. Only in the avian lineage has tuning moved in the opposite direction, with the reinvention of UV-sensitive pigments.
Collapse
|
24
|
Davies WIL, Wilkie SE, Cowing JA, Hankins MW, Hunt DM. Anion sensitivity and spectral tuning of middle- and long-wavelength-sensitive (MWS/LWS) visual pigments. Cell Mol Life Sci 2012; 69:2455-64. [PMID: 22349213 PMCID: PMC11115090 DOI: 10.1007/s00018-012-0934-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Revised: 01/10/2012] [Accepted: 01/26/2012] [Indexed: 10/14/2022]
Abstract
The long-wavelength-sensitive (LWS) opsins form one of four classes of vertebrate cone visual pigment and exhibit peak spectral sensitivities (λ(max)) that generally range from 525 to 560 nm for rhodopsin/vitamin-A(1) photopigments. Unique amongst the opsin classes, many LWS pigments show anion sensitivity through the interaction of chloride ions with a histidine residue at site 197 (H197) to give a long-wavelength spectral shift in peak sensitivity. Although it has been shown that amino acid substitutions at five sites (180, 197, 277, 285 and 308) are useful in predicting the λ(max) values of the LWS pigment class, some species, such as the elephant shark and most marine mammals, express LWS opsins that possess λ(max) values that are not consistent with this 'five-site' rule, indicating that other interactions may be involved. This study has taken advantage of the natural mutation at the chloride-binding site in the mouse LWS pigment. Through the use of a number of mutant pigments generated by site-directed mutagenesis, a new model has been formulated that takes into account the role of charge and steric properties of the side chains of residues at sites 197 and 308 in the function of the chloride-binding site in determining the peak sensitivity of LWS photopigments.
Collapse
Affiliation(s)
- Wayne I. L. Davies
- UCL Institute of Ophthalmology, 11–43 Bath Street, London, EC1V 9EL UK
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neuroscience, University of Oxford, John Radcliffe Hospital, Headley Way, Oxford, OX3 9DU UK
- School of Animal Biology and UWA Oceans Institute, University of Western Australia, 35 Stirling Highway, Perth, WA 6009 Australia
| | - Susan E. Wilkie
- UCL Institute of Ophthalmology, 11–43 Bath Street, London, EC1V 9EL UK
| | - Jill A. Cowing
- UCL Institute of Ophthalmology, 11–43 Bath Street, London, EC1V 9EL UK
| | - Mark W. Hankins
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neuroscience, University of Oxford, John Radcliffe Hospital, Headley Way, Oxford, OX3 9DU UK
| | - David M. Hunt
- UCL Institute of Ophthalmology, 11–43 Bath Street, London, EC1V 9EL UK
- School of Animal Biology and UWA Oceans Institute, University of Western Australia, 35 Stirling Highway, Perth, WA 6009 Australia
- Lions Eye Institute, 2 Verdun Street, Perth, WA 6009 Australia
| |
Collapse
|
25
|
DAVIES WAYNEIL, COLLIN SHAUNP, HUNT DAVIDM. Molecular ecology and adaptation of visual photopigments in craniates. Mol Ecol 2012; 21:3121-58. [DOI: 10.1111/j.1365-294x.2012.05617.x] [Citation(s) in RCA: 156] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
26
|
Carvalho LS, Davies WL, Robinson PR, Hunt DM. Spectral tuning and evolution of primate short-wavelength-sensitive visual pigments. Proc Biol Sci 2012; 279:387-93. [PMID: 21697177 PMCID: PMC3223675 DOI: 10.1098/rspb.2011.0782] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Accepted: 06/02/2011] [Indexed: 11/12/2022] Open
Abstract
The peak sensitivities (λ(max)) of the short-wavelength-sensitive-1 (SWS1) pigments in mammals range from the ultraviolet (UV) (360-400 nm) to the violet (400-450 nm) regions of the spectrum. In most cases, a UV or violet peak is determined by the residue present at site 86, with Phe conferring UV sensitivity (UVS) and either Ser, Tyr or Val causing a shift to violet wavelengths. In primates, however, the tuning mechanism of violet-sensitive (VS) pigments would appear to differ. In this study, we examine the tuning mechanisms of prosimian SWS1 pigments. One species, the aye-aye, possesses a pigment with Phe86 but in vitro spectral analysis reveals a VS rather than a UVS pigment. Other residues (Cys, Ser and Val) at site 86 in prosimians also gave VS pigments. Substitution at site 86 is not, therefore, the primary mechanism for the tuning of VS pigments in primates, and phylogenetic analysis indicates that substitutions at site 86 have occurred at least five times in primate evolution. The sole potential tuning site that is conserved in all primate VS pigments is Pro93, which when substituted by Thr (as found in mammalian UVS pigments) in the aye-aye pigment shifted the peak absorbance into the UV region with a λ(max) value at 371 nm. We, therefore, conclude that the tuning of VS pigments in primates depends on Pro93, not Tyr86 as in other mammals. However, it remains uncertain whether the initial event that gave rise to the VS pigment in the ancestral primate was achieved by a Thr93Pro or a Phe86Tyr substitution.
Collapse
Affiliation(s)
| | - Wayne L. Davies
- UCL Institute of Ophthalmology, London EC1V 9EL, UK
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | | | - David M. Hunt
- UCL Institute of Ophthalmology, London EC1V 9EL, UK
- School of Animal Biology and Oceans Institute, University of Western Australia, Perth, WA 6009, Australia
| |
Collapse
|
27
|
Campos-Arceiz A, Blake S. Megagardeners of the forest – the role of elephants in seed dispersal. ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY 2011. [DOI: 10.1016/j.actao.2011.01.014] [Citation(s) in RCA: 190] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
28
|
Altun A, Morokuma K, Yokoyama S. H-bond network around retinal regulates the evolution of ultraviolet and violet vision. ACS Chem Biol 2011; 6:775-80. [PMID: 21650174 DOI: 10.1021/cb200100f] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Ancestors of vertebrates used ultraviolet vision. Some descendants preserved ultraviolet vision, whereas some others replaced it with violet vision, and then, some of avian lineages reinvented ultraviolet vision. Ultraviolet (absorption at ∼360 nm) and violet (410-440 nm) sensitivities of visual pigments are known to be affected by around 20 amino acid substitutions. The present quantum mechanical/molecular mechanical calculations show that these substitutions modify a H-bond network formed by two waters and sites 86, 90, 113, 114, 118, and 295, which determines the protonation state of Schiff base linked 11-cis-retinal. A pigment is ultraviolet-sensitive when it is more stable with an unprotonated retinal (SBR) form than with its protonated analogue (PSBR) and is violet-sensitive when the PSBR form is more stable. These results establish for the first time the chemical basis of ultraviolet and violet vision in vertebrates.
Collapse
Affiliation(s)
- Ahmet Altun
- Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
- Department of Biology, Rollins Research Center, Emory University, 1510 Clifton Road, Atlanta, Georgia 30322, United States
- Department of Physics, Fatih University, 34900 B. Cekmece, Istanbul, Turkey
| | - Keiji Morokuma
- Cherry L. Emerson Center for Scientific Computation and Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
- Fukui Institute for Fundamental Chemistry, Kyoto University, 34−4 Takano Nishihiraki-cho, Sakyo, Kyoto 606−8103, Japan
| | - Shozo Yokoyama
- Department of Biology, Rollins Research Center, Emory University, 1510 Clifton Road, Atlanta, Georgia 30322, United States
| |
Collapse
|
29
|
Hunt DM, Carvalho LS, Cowing JA, Davies WL. Evolution and spectral tuning of visual pigments in birds and mammals. Philos Trans R Soc Lond B Biol Sci 2009; 364:2941-55. [PMID: 19720655 DOI: 10.1098/rstb.2009.0044] [Citation(s) in RCA: 129] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Variation in the types and spectral characteristics of visual pigments is a common mechanism for the adaptation of the vertebrate visual system to prevailing light conditions. The extent of this diversity in mammals and birds is discussed in detail in this review, alongside an in-depth consideration of the molecular changes involved. In mammals, a nocturnal stage in early evolution is thought to underlie the reduction in the number of classes of cone visual pigment genes from four to only two, with the secondary loss of one of these genes in many monochromatic nocturnal and marine species. The trichromacy seen in many primates arises from either a polymorphism or duplication of one of these genes. In contrast, birds have retained the four ancestral cone visual pigment genes, with a generally conserved expression in either single or double cone classes. The loss of sensitivity to ultraviolet (UV) irradiation is a feature of both mammalian and avian visual evolution, with UV sensitivity retained among mammals by only a subset of rodents and marsupials. Where it is found in birds, it is not ancestral but newly acquired.
Collapse
Affiliation(s)
- David M Hunt
- UCL Institute of Ophthalmology, London EC1V 9EL, UK.
| | | | | | | |
Collapse
|
30
|
Zhao H, Ru B, Teeling EC, Faulkes CG, Zhang S, Rossiter SJ. Rhodopsin molecular evolution in mammals inhabiting low light environments. PLoS One 2009; 4:e8326. [PMID: 20016835 PMCID: PMC2790605 DOI: 10.1371/journal.pone.0008326] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2009] [Accepted: 11/25/2009] [Indexed: 11/21/2022] Open
Abstract
The ecological radiation of mammals to inhabit a variety of light environments is largely attributed to adaptive changes in their visual systems. Visual capabilities are conferred by anatomical features of the eyes as well as the combination and properties of their constituent light sensitive pigments. To test whether evolutionary switches to different niches characterized by dim-light conditions coincided with molecular adaptation of the rod pigment rhodopsin, we sequenced the rhodopsin gene in twenty-two mammals including several bats and subterranean mole-rats. We compared these to thirty-seven published mammal rhodopsin sequences, from species with divergent visual ecologies, including nocturnal, diurnal and aquatic groups. All taxa possessed an intact functional rhodopsin; however, phylogenetic tree reconstruction recovered a gene tree in which rodents were not monophyletic, and also in which echolocating bats formed a monophyletic group. These conflicts with the species tree appear to stem from accelerated evolution in these groups, both of which inhabit low light environments. Selection tests confirmed divergent selection pressures in the clades of subterranean rodents and bats, as well as in marine mammals that live in turbid conditions. We also found evidence of divergent selection pressures among groups of bats with different sensory modalities based on vision and echolocation. Sliding window analyses suggest most changes occur in transmembrane domains, particularly obvious within the pinnipeds; however, we found no obvious pattern between photopic niche and predicted spectral sensitivity based on known critical amino acids. This study indicates that the independent evolution of rhodopsin vision in ecologically specialised groups of mammals has involved molecular evolution at the sequence level, though such changes might not mediate spectral sensitivity directly.
Collapse
Affiliation(s)
- Huabin Zhao
- School of Life Sciences, East China Normal University, Shanghai, China
| | - Binghua Ru
- School of Life Sciences, East China Normal University, Shanghai, China
| | - Emma C. Teeling
- UCD School of Biology and Environmental Science and UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin, Ireland
| | - Christopher G. Faulkes
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom
| | - Shuyi Zhang
- School of Life Sciences, East China Normal University, Shanghai, China
| | - Stephen J. Rossiter
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom
| |
Collapse
|
31
|
Sugawara T, Imai H, Nikaido M, Imamoto Y, Okada N. Vertebrate rhodopsin adaptation to dim light via rapid meta-II intermediate formation. Mol Biol Evol 2009; 27:506-19. [PMID: 19858068 DOI: 10.1093/molbev/msp252] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Rhodopsin is a photoreceptive protein present in vertebrate rod photoreceptor cells, which are responsible for scotopic vision. Recent molecular studies have shown that several aquatic vertebrate species have independently acquired rhodopsin containing Asp83Asn, Glu122Gln, and Ala292Ser substitutions, causing a blue shift in the rhodopsin absorption spectra for adaptation to the blue-green photic environment in deep water. Here, we provide new evidence for the evolutionary and functional relevance of the Asp83Asn substitution. Spectroscopic and kinetic analyses of rhodopsins in six cichlid fishes from the East African Great Lakes using charge-coupled device spectrophotometer revealed that the Asp83Asn substitution accelerated the formation of meta-II, a rhodopsin intermediate crucial for activation of the G-protein transducin. Because rapid formation of meta-II likely results in effective transduction of photic signals, it is reasonable to assume that deep-water cichlid species have acquired rhodopsin containing Asn83 to adapt to dim lighting. Remarkably, rhodopsin containing Asn83 has been identified in terrestrial vertebrates such as bats, and these rhodopsin variants also exhibit accelerated meta-II formation. Our results indicated that the Asp83Asn substitution observed in a variety of animal species was acquired independently in many different lineages during vertebrate evolution for adaptation to dimly lit environments.
Collapse
Affiliation(s)
- Tohru Sugawara
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, Japan
| | | | | | | | | |
Collapse
|
32
|
Abstract
Colour vision allows animals to reliably distinguish differences in the distributions of spectral energies reaching the eye. Although not universal, a capacity for colour vision is sufficiently widespread across the animal kingdom to provide prima facie evidence of its importance as a tool for analysing and interpreting the visual environment. The basic biological mechanisms on which vertebrate colour vision ultimately rests, the cone opsin genes and the photopigments they specify, are highly conserved. Within that constraint, however, the utilization of these basic elements varies in striking ways in that they appear, disappear and emerge in altered form during the course of evolution. These changes, along with other alterations in the visual system, have led to profound variations in the nature and salience of colour vision among the vertebrates. This article concerns the evolution of colour vision among the mammals, viewing that process in the context of relevant biological mechanisms, of variations in mammalian colour vision, and of the utility of colour vision.
Collapse
Affiliation(s)
- Gerald H Jacobs
- Neuroscience Research Institute and Department of Psychology, University of California, Santa Barbara, CA 93106, USA.
| |
Collapse
|
33
|
Abstract
The vertebrate ancestor possessed ultraviolet (UV) vision and many species have retained it during evolution. Many other species switched to violet vision and, then again, some avian species switched back to UV vision. These UV and violet vision are mediated by short wavelength-sensitive (SWS1) pigments that absorb light maximally (lambda(max)) at approximately 360 and 390-440 nm, respectively. It is not well understood why and how these functional changes have occurred. Here, we cloned the pigment of scabbardfish (Lepidopus fitchi) with a lambda(max) of 423 nm, an example of violet-sensitive SWS1 pigment in fish. Mutagenesis experiments and quantum mechanical/molecular mechanical (QM/MM) computations show that the violet-sensitivity was achieved by the deletion of Phe-86 that converted the unprotonated Schiff base-linked 11-cis-retinal to a protonated form. The finding of a violet-sensitive SWS1 pigment in scabbardfish suggests that many other fish also have orthologous violet pigments. The isolation and comparison of such violet and UV pigments in fish living in different ecological habitats will open an unprecedented opportunity to elucidate not only the molecular basis of phenotypic adaptations, but also the genetics of UV and violet vision.
Collapse
|
34
|
Shyan-Norwalt MR, Peterson J, Milankow King B, Staggs TE, Dale RHI. Initial findings on visual acuity thresholds in an African elephant (Loxodonta africana). Zoo Biol 2009; 29:30-5. [PMID: 19598240 DOI: 10.1002/zoo.20259] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
There are only a few published examinations of elephant visual acuity. All involved Asian elephants (Elephas maximus) and found visual acuity to be between 8' and 11' of arc for a stimulus near the tip of the trunk, equivalent to a 0.50 cm gap, at a distance of about 2 m from the eyes. We predicted that African elephants (Loxodonta africana) would have similarly high visual acuity, necessary to facilitate eye-trunk coordination for feeding, drinking and social interactions. When tested on a discrimination task using Landolt-C stimuli, one African elephant cow demonstrated a visual acuity of 48' of arc. This represents the ability to discriminate a gap as small as 2.75 cm in a stimulus 196 cm from the eye. This single-subject study provides a preliminary estimate of the visual acuity of African elephants.
Collapse
|
35
|
Elucidation of phenotypic adaptations: Molecular analyses of dim-light vision proteins in vertebrates. Proc Natl Acad Sci U S A 2008; 105:13480-5. [PMID: 18768804 DOI: 10.1073/pnas.0802426105] [Citation(s) in RCA: 196] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Vertebrate ancestors appeared in a uniform, shallow water environment, but modern species flourish in highly variable niches. A striking array of phenotypes exhibited by contemporary animals is assumed to have evolved by accumulating a series of selectively advantageous mutations. However, the experimental test of such adaptive events at the molecular level is remarkably difficult. One testable phenotype, dim-light vision, is mediated by rhodopsins. Here, we engineered 11 ancestral rhodopsins and show that those in early ancestors absorbed light maximally (lambda(max)) at 500 nm, from which contemporary rhodopsins with variable lambda(max)s of 480-525 nm evolved on at least 18 separate occasions. These highly environment-specific adaptations seem to have occurred largely by amino acid replacements at 12 sites, and most of those at the remaining 191 ( approximately 94%) sites have undergone neutral evolution. The comparison between these results and those inferred by commonly-used parsimony and Bayesian methods demonstrates that statistical tests of positive selection can be misleading without experimental support and that the molecular basis of spectral tuning in rhodopsins should be elucidated by mutagenesis analyses using ancestral pigments.
Collapse
|
36
|
Bowmaker JK. Evolution of vertebrate visual pigments. Vision Res 2008; 48:2022-41. [PMID: 18590925 DOI: 10.1016/j.visres.2008.03.025] [Citation(s) in RCA: 223] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2008] [Revised: 03/14/2008] [Accepted: 03/18/2008] [Indexed: 10/21/2022]
|
37
|
Affiliation(s)
- Shozo Yokoyama
- Department of Biology, Emory University, Atlanta, Georgia 30322;
| |
Collapse
|
38
|
Molecular basis of spectral tuning in the red- and green-sensitive (M/LWS) pigments in vertebrates. Genetics 2008; 179:2037-43. [PMID: 18660543 DOI: 10.1534/genetics.108.090449] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Vertebrate vision is mediated by five groups of visual pigments, each absorbing a specific wavelength of light between ultraviolet and red. Despite extensive mutagenesis analyses, the mechanisms by which contemporary pigments absorb variable wavelengths of light are poorly understood. We show that the molecular basis of the spectral tuning of contemporary visual pigments can be illuminated only by mutagenesis analyses using ancestral pigments. Following this new principle, we derive the "five-sites" rule that explains the absorption spectra of red and green (M/LWS) pigments that range from 510 to 560 nm. Our findings demonstrate that the evolutionary method should be used in elucidating the mechanisms of spectral tuning of four other pigment groups and, for that matter, functional differentiations of any other proteins.
Collapse
|
39
|
Yokoyama S, Tada T, Yamato T. Modulation of the absorption maximum of rhodopsin by amino acids in the C-terminus. Photochem Photobiol 2007; 83:236-41. [PMID: 16922606 PMCID: PMC2572076 DOI: 10.1562/2006-06-19-ra-939] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Vision begins when light is absorbed by visual pigments. It is commonly believed that the absorption spectra of visual pigments are modulated by interactions between the retinal and amino acids within or near 4.5 angstroms of the retinal in the transmembrane (TM) segments. However, this dogma has not been rigorously tested. In this study, we show that the retinal-opsin interactions extend well beyond the retinal binding pocket. We found that, although it is positioned outside of TM segments, the C-terminus of the rhodopsin in the rockfish longspine thornyhead (Sebastolobus altivelis) modulates its lambda(max) by interacting mainly with the last TM segment. Our results illustrate how amino acids in the C-terminus are likely to interact with the retinal. We anticipate our analyses to be a starting point for viewing the spectral tuning of visual pigments as interactions between the retinal and key amino acids that are distributed throughout the entire pigment.
Collapse
Affiliation(s)
- Shozo Yokoyama
- Department of Biology, Emory University, Atlanta, GA, USA.
| | | | | |
Collapse
|
40
|
Elephants classify human ethnic groups by odor and garment color. Curr Biol 2007; 17:1938-42. [PMID: 17949977 DOI: 10.1016/j.cub.2007.09.060] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2007] [Revised: 09/25/2007] [Accepted: 09/26/2007] [Indexed: 11/20/2022]
Abstract
Animals can benefit from classifying predators or other dangers into categories, tailoring their escape strategies to the type and nature of the risk. Studies of alarm vocalizations have revealed various levels of sophistication in classification. In many taxa, reactions to danger are inflexible, but some species can learn the level of threat presented by the local population of a predator or by specific, recognizable individuals. Some species distinguish several species of predator, giving differentiated warning calls and escape reactions; here, we explore an animal's classification of subgroups within a species. We show that elephants distinguish at least two Kenyan ethnic groups and can identify them by olfactory and color cues independently. In the Amboseli ecosystem, Kenya, young Maasai men demonstrate virility by spearing elephants (Loxodonta africana), but Kamba agriculturalists pose little threat. Elephants showed greater fear when they detected the scent of garments previously worn by Maasai than by Kamba men, and they reacted aggressively to the color associated with Maasai. Elephants are therefore able to classify members of a single species into subgroups that pose different degrees of danger.
Collapse
|
41
|
Carvalho LS, Cowing JA, Wilkie SE, Bowmaker JK, Hunt DM. The Molecular Evolution of Avian Ultraviolet- and Violet-Sensitive Visual Pigments. Mol Biol Evol 2007; 24:1843-52. [PMID: 17556758 DOI: 10.1093/molbev/msm109] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The shortwave-sensitive SWS1 class of vertebrate visual pigments range in lambda(max) from the violet (385-445 nm) to the ultraviolet (UV) (365-355 nm), with UV-sensitivity almost certainly ancestral. In birds, however, the UV-sensitive pigments present in a number of species have evolved secondarily from an avian violet-sensitive (VS) pigment. All avian VS pigments expressed in vitro to date encode Ser86 whereas Phe86 is present in all non-avian ultraviolet sensitive (UVS) pigments. In this paper, we show by site directed mutagenesis of avian VS pigments that Ser86 is required in an avian VS pigment to maintain violet-sensitivity and therefore underlies the evolution of avian VS pigments. The major mechanism for the evolution of avian UVS pigments from an ancestral avian VS pigment is undoubtedly a Ser90Cys substitution. However, Phe86, as found in the Blue-crowned trogon, will also short-wave shift the pigeon VS pigment into the UV whereas Ala86 and Cys86 which are also found in natural avian pigments do not generate short-wave shifts when substituted into the pigeon pigment. From available data on avian SWS1 pigments, it would appear that UVS pigments have evolved on at least 5 separate occasions and utilize 2 different mechanisms for the short-wave shift.
Collapse
|
42
|
Takenaka N, Yokoyama S. Mechanisms of spectral tuning in the RH2 pigments of Tokay gecko and American chameleon. Gene 2007; 399:26-32. [PMID: 17590287 PMCID: PMC2693072 DOI: 10.1016/j.gene.2007.04.036] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2007] [Revised: 04/21/2007] [Accepted: 04/23/2007] [Indexed: 11/19/2022]
Abstract
At present, molecular bases of spectral tuning in rhodopsin-like (RH2) pigments are not well understood. Here, we have constructed the RH2 pigments of nocturnal Tokay gecko (Gekko gekko) and diurnal American chameleon (Anolis carolinensis) as well as chimeras between them. The RH2 pigments of the gecko and chameleon reconstituted with 11-cis-retinal had the wavelengths of maximal absorption (lambda(max)'s) of 467 and 496 nm, respectively. Chimeric pigment analyses indicated that 76-86%, 14-24%, and 10% of the spectral difference between them could be explained by amino acid differences in transmembrane (TM) helices I-IV, V-VII, and amino acid interactions between the two segments, respectively. Evolutionary and mutagenesis analyses revealed that the lambda(max)'s of the gecko and chameleon pigments diverged from each other not only by S49A (serine to alanine replacement at residue 49), S49F (serine to phenylalanine), L52M (leucine to methionine), D83N (aspartic acid to asparagine), M86T (methionine to threonine), and T97A (threonine to alanine) but also by other amino acid replacements that cause minor lambda(max)-shifts individually.
Collapse
Affiliation(s)
| | - Shozo Yokoyama
- Corresponding author: Department of Biology, Rollins Research Center, Emory University, 1510 Clifton Road, Atlanta, GA 30322, E-mail address:
| |
Collapse
|
43
|
Yokoyama S, Takenaka N, Blow N. A novel spectral tuning in the short wavelength-sensitive (SWS1 and SWS2) pigments of bluefin killifish (Lucania goodei). Gene 2007; 396:196-202. [PMID: 17498892 PMCID: PMC1963460 DOI: 10.1016/j.gene.2007.03.019] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2007] [Revised: 03/22/2007] [Accepted: 03/25/2007] [Indexed: 10/23/2022]
Abstract
The molecular bases of spectral tuning in the UV-, violet-, and blue-sensitive pigments are not well understood. Using the in vitro assay, here we show that the SWS1, SWS2-A, and SWS2-B pigments of bluefin killifish (Lucania goodei) have the wavelengths of maximal absorption (lambda(max)'s) of 354, 448, and 397 nm, respectively. The spectral difference between the SWS2-A and SWS2-B pigments is largest among those of all currently known pairs of SWS2 pigments within a species. The SWS1 pigment contains no amino acid replacement at the currently known 25 critical sites and seems to have inherited its UV-sensitivity directly from the vertebrate ancestor. Mutagenesis analyses show that the amino acid differences at sites 44, 46, 94, 97, 109, 116, 118, 265, and 292 of the SWS2-A and SWS2-B pigments explain 80% of their spectral difference. Moreover, the larger the individual effects of amino acid changes on the lambda(max)-shift are, the larger the synergistic effects tend to be generated, revealing a novel mechanism of spectral tuning of visual pigments.
Collapse
Affiliation(s)
- Shozo Yokoyama
- Department of Biology, Rollins Research Center, Emory University, 1510 Clifton Road, Atlanta, GA 30322, USA.
| | | | | |
Collapse
|
44
|
Hunt DM, Carvalho LS, Cowing JA, Parry JWL, Wilkie SE, Davies WL, Bowmaker JK. Spectral Tuning of Shortwave-sensitive Visual Pigments in Vertebrates†. Photochem Photobiol 2007; 83:303-10. [PMID: 17576346 DOI: 10.1562/2006-06-27-ir-952] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Of the four classes of vertebrate cone visual pigments, the shortwave-sensitive SWS1 class shows some of the largest shifts in lambda(max), with values ranging in different species from 390-435 nm in the violet region of the spectrum to < 360 nm in the ultraviolet. Phylogenetic evidence indicates that the ancestral pigment most probably had a lambda(max) in the UV and that shifts between violet and UV have occurred many times during evolution. In violet-sensitive (VS) pigments, the Schiff base is protonated whereas in UV-sensitive (UVS) pigments, it is almost certainly unprotonated. The generation of VS pigments in amphibia, birds and mammals from ancestral UVS pigments must involve therefore the stabilization of protonation. Similarly, stabilization must be lost in the evolution of avian UVS pigments from a VS ancestral pigment. The key residues in the opsin protein for these shifts are at sites 86 and 90, both adjacent to the Schiff base and the counterion at Glu113. In this review, the various molecular mechanisms for the UV and violet shifts in the different vertebrate groups are presented and the changes in the opsin protein that are responsible for the spectral shifts are discussed in the context of the structural model of bovine rhodopsin.
Collapse
Affiliation(s)
- David M Hunt
- UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK.
| | | | | | | | | | | | | |
Collapse
|
45
|
Yokoyama S, Starmer WT, Takahashi Y, Tada T. Tertiary structure and spectral tuning of UV and violet pigments in vertebrates. Gene 2005; 365:95-103. [PMID: 16343816 PMCID: PMC2810422 DOI: 10.1016/j.gene.2005.09.028] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2005] [Revised: 07/04/2005] [Accepted: 09/07/2005] [Indexed: 11/16/2022]
Abstract
Many vertebrate species use ultraviolet (UV) vision for such behaviors as mating, foraging, and communication. UV vision is mediated by UV-sensitive visual pigments, which have the wavelengths of maximal absorption (lambda max) at approximately 360 nm, whereas violet (or blue) vision is mediated by orthologous pigments with lambda max values of 390-440 nm. It is widely believed that amino acids in transmembrane (TM) I-III are solely responsible for the spectral tuning of these SWS1 pigments. Recent molecular analyses of SWS1 pigments, however, show that amino acids in TM IV-VII are also involved in the spectral tuning of these pigments through synergistic interactions with those in TM I-III. Comparisons of the tertiary structures of UV and violet pigments reveal that the distance between the counterion E113 in TM III and amino acid sites 87-93 in TM II is narrower for UV pigments than for violet pigments, which may restrict the access of water molecules to the Schiff base pocket and deprotonate the Schiff base nitrogen. Both mutagenesis analyses of E113Q and quantum chemical calculations strongly suggest that unprotonated Schiff base-linked chromophore is responsible for detecting UV light.
Collapse
Affiliation(s)
- Shozo Yokoyama
- Department of Biology, Rollins Research Center, Emory University, 1510 Clifton Road, Atlanta, GA 30322, USA.
| | | | | | | |
Collapse
|
46
|
Takahashi Y, Yokoyama S. Genetic basis of spectral tuning in the violet-sensitive visual pigment of African clawed frog, Xenopus laevis. Genetics 2005; 171:1153-60. [PMID: 16079229 PMCID: PMC1456818 DOI: 10.1534/genetics.105.045849] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Ultraviolet (UV) and violet vision in vertebrates is mediated by UV and violet visual pigments that absorb light maximally (lambdamax) at approximately 360 and 390-440 nm, respectively. So far, a total of 11 amino acid sites only in transmembrane (TM) helices I-III are known to be involved in the functional differentiation of these short wavelength-sensitive type 1 (SWS1) pigments. Here, we have constructed chimeric pigments between the violet pigment of African clawed frog (Xenopus laevis) and its ancestral UV pigment. The results show that not only are the absorption spectra of these pigments modulated strongly by amino acids in TM I-VII, but also, for unknown reasons, the overall effect of amino acid changes in TM IV-VII on the lambdamax-shift is abolished. The spectral tuning of the contemporary frog pigment is explained by amino acid replacements F86M, V91I, T93P, V109A, E113D, L116V, and S118T, in which V91I and V109A are previously unknown, increasing the total number of critical amino acid sites that are involved in the spectral tuning of SWS1 pigments in vertebrates to 13.
Collapse
Affiliation(s)
- Yusuke Takahashi
- Department of Biology, Emory University, Atlanta, Georgia 30322, USA
| | | |
Collapse
|