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Zhang T, Jing H, Wang J, Zhao L, Liu Y, Rossiter SJ, Lu H, Li G. Evolution of olfactory receptor superfamily in bats based on high throughput molecular modelling. Mol Ecol Resour 2024; 24:e13958. [PMID: 38567648 DOI: 10.1111/1755-0998.13958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 03/05/2024] [Accepted: 03/25/2024] [Indexed: 04/04/2024]
Abstract
The origin of flight and laryngeal echolocation in bats is likely to have been accompanied by evolutionary changes in other aspects of their sensory biology. Of all sensory modalities in bats, olfaction is perhaps the least well understood. Olfactory receptors (ORs) function in recognizing odour molecules, with crucial roles in evaluating food, as well as in processing social information. Here we compare OR repertoire sizes across taxa and apply a new pipeline that integrates comparative genome data with protein structure modelling and then we employ molecular docking techniques with small molecules to analyse OR functionality based on binding energies. Our results suggest a sharp contraction in odorant recognition of the functional OR repertoire during the origin of bats, consistent with a reduced dependence on olfaction. We also compared bat lineages with contrasting different ecological characteristics and found evidence of differences in OR gene expansion and contraction, and in the composition of ORs with different tuning breadths. The strongest binding energies of ORs in non-echolocating fruit-eating bats were seen to correspond to ester odorants, although we did not detect a quantitative advantage of functional OR repertoires in these bats compared with echolocating insectivorous species. Overall, our findings based on molecular modelling and computational docking suggest that bats have undergone olfactory evolution linked to dietary adaptation. Our results from extant and ancestral bats help to lay the groundwork for targeted experimental functional tests in the future.
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Affiliation(s)
- Tianmin Zhang
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, China
| | - Haohao Jing
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Jinhong Wang
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Le Zhao
- School of Biological Science and Engineering, Shaanxi University of Technology, Hanzhong, China
| | - Yang Liu
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
| | - Stephen J Rossiter
- School of Biological and Behavioural Sciences, Queen Mary, University of London, London, UK
| | - Huimeng Lu
- School of Life Sciences, Northwestern Polytechnical University, Xi'an, China
| | - Gang Li
- College of Life Sciences, Shaanxi Normal University, Xi'an, China
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2
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Zhou D, Deng Y, Wei X, Li T, Li Z, Wang S, Jiang Y, Liu W, Luo B, Feng J. Behavioral responses of cave-roosting bats to artificial light of different spectra and intensities: Implications for lighting management strategy. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 916:170339. [PMID: 38278253 DOI: 10.1016/j.scitotenv.2024.170339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Revised: 12/26/2023] [Accepted: 01/19/2024] [Indexed: 01/28/2024]
Abstract
Artificial light at night has become an emerging environmental pollutant, posing a serious threat to biodiversity. Cave-roosting animals are vulnerable to light pollution due to long-term adaptation to nocturnal niches, and the problem is especially severe in the context of cave tourism and limestone mining. Mitigating the adverse impacts of artificial light on cave-dwelling animals presents a challenge. This study aimed to assess the relative contributions of spectral parameters and light intensity to the emergence behavior of nine cave-roosting bat species: Rhinolophus macrotis, Rhinolophus pearsonii, Rhinolophus rex, Rhinolophus pusillus, Rhinolophus siamensis, Rhinolophus sinicus, Hipposideros armiger, Myotis davidii, and Miniopterus fuliginosus. We manipulated light spectra and intensities through light-emitting diode (LED) lighting and gel filters at the entrance of bat roost. We monitored nightly passes per species to quantify bat emergence under the dark control and ten lighting conditions (blue, green, yellow, red, and white light at high and low intensities) using ultrasonic recording. Our analyses showed that the number of bat passes tended to be reduced in the presence of white, green, and yellow light, independent of light intensity. In contrast, the number of bat passes showed no pronounced differences under the dark control, blue light, and red light. The number of bat passes was primarily affected by LED light's blue component, red component, peak wavelength, and half-width instead of light intensity. These results demonstrate that spectral parameters of LED light can significantly affect emergence behavior of cave-dwelling bats. Our findings highlight the importance of manipulating light colors to reduce the negative impacts of light pollution on cave-roosting bats as a function of their spectral sensitivity. We recommend the use of gel filters to manage existing artificial lighting systems at the entrance of bat-inhabited caves.
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Affiliation(s)
- Daying Zhou
- Key Laboratory of Southwest China Wildlife Resources Conservation of Ministry of Education, China West Normal University, 1# Shida Road, Nanchong 637009, China; Liziping Giant Panda's Ecology and Conservation Observation and Research Station of Sichuan Province, Nanchong 637000, China
| | - Yingchun Deng
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun 130117, China
| | - Xinyi Wei
- Key Laboratory of Southwest China Wildlife Resources Conservation of Ministry of Education, China West Normal University, 1# Shida Road, Nanchong 637009, China
| | - Taohong Li
- Key Laboratory of Southwest China Wildlife Resources Conservation of Ministry of Education, China West Normal University, 1# Shida Road, Nanchong 637009, China
| | - Ziyi Li
- Key Laboratory of Southwest China Wildlife Resources Conservation of Ministry of Education, China West Normal University, 1# Shida Road, Nanchong 637009, China
| | - Sirui Wang
- Key Laboratory of Southwest China Wildlife Resources Conservation of Ministry of Education, China West Normal University, 1# Shida Road, Nanchong 637009, China
| | - Yunke Jiang
- Key Laboratory of Southwest China Wildlife Resources Conservation of Ministry of Education, China West Normal University, 1# Shida Road, Nanchong 637009, China
| | - Wenqin Liu
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun 130117, China
| | - Bo Luo
- Key Laboratory of Southwest China Wildlife Resources Conservation of Ministry of Education, China West Normal University, 1# Shida Road, Nanchong 637009, China; Liziping Giant Panda's Ecology and Conservation Observation and Research Station of Sichuan Province, Nanchong 637000, China.
| | - Jiang Feng
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun 130117, China; College of Life Science, Jilin Agricultural University, 2888 Xincheng street, Changchun 130118, China.
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3
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Mutumi GL, Hall RP, Hedrick BP, Yohe LR, Sadier A, Davies KTJ, Rossiter SJ, Sears KE, Dávalos LM, Dumont ER. Disentangling Mechanical and Sensory Modules in the Radiation of Noctilionoid Bats. Am Nat 2023; 202:216-230. [PMID: 37531274 DOI: 10.1086/725368] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/04/2023]
Abstract
AbstractWith diverse mechanical and sensory functions, the vertebrate cranium is a complex anatomical structure whose shifts between modularity and integration, especially in mechanical function, have been implicated in adaptive diversification. Yet how mechanical and sensory systems and their functions coevolve, as well as how their interrelationship contributes to phenotypic disparity, remain largely unexplored. To examine the modularity, integration, and evolutionary rates of sensory and mechanical structures within the head, we analyzed hard and soft tissue scans from ecologically diverse bats in the superfamily Noctilionoidea, a clade that ranges from insectivores and carnivores to frugivores and nectarivores. We identified eight regions that evolved in a coordinated fashion, thus recognizable as evolutionary modules: five associated with bite force and three linked to olfactory, visual, and auditory systems. Interrelationships among these modules differ between Neotropical leaf-nosed bats (family Phyllostomidae) and other noctilionoids. Consistent with the hypothesis that dietary transitions begin with changes in the capacity to detect novel food items followed by adaptations to process them, peak rates of sensory module evolution predate those of some mechanical modules. We propose that the coevolution of structures influencing bite force, olfaction, vision, and hearing constituted a structural opportunity that allowed the phyllostomid ancestor to take advantage of existing ecological opportunities and contributed to the clade's remarkable radiation.
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4
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Darras KFA, Yusti E, Huang JC, Zemp D, Kartono AP, Wanger TC. Bat point counts: A novel sampling method shines light on flying bat communities. Ecol Evol 2021; 11:17179-17190. [PMID: 34938501 PMCID: PMC8668732 DOI: 10.1002/ece3.8356] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 09/14/2021] [Accepted: 10/18/2021] [Indexed: 11/14/2022] Open
Abstract
Emerging technologies based on the detection of electro-magnetic energy offer promising opportunities for sampling biodiversity. We exploit their potential by showing here how they can be used in bat point counts-a novel method to sample flying bats-to overcome shortcomings of traditional sampling methods, and to maximize sampling coverage and taxonomic resolution of this elusive taxon with minimal sampling bias. We conducted bat point counts with a sampling rig combining a thermal scope to detect bats, an ultrasound recorder to obtain echolocation calls, and a near-infrared camera to capture bat morphology. We identified bats with a dedicated identification key combining acoustic and morphological features, and compared bat point counts with the standard bat sampling methods of mist-netting and automated ultrasound recording in three oil palm plantation sites in Indonesia, over nine survey nights. Based on rarefaction and extrapolation sampling curves, bat point counts were similarly effective but more time-efficient than the established methods for sampling the oil palm species pool in our study. Point counts sampled species that tend to avoid nets and those that are not echolocating, and thus cannot be detected acoustically. We identified some bat sonotypes with near-infrared imagery, and bat point counts revealed strong sampling biases in previous studies using capture-based methods, suggesting similar biases in other regions might exist. Our method should be tested in a wider range of habitats and regions to assess its performance. However, while capture-based methods allow to identify bats with absolute and internal morphometry, and unattended ultrasound recorders can effectively sample echolocating bats, bat point counts are a promising, non-invasive, and potentially competitive new tool for sampling all flying bats without bias and observing their behavior in the wild.
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Affiliation(s)
- Kevin Felix Arno Darras
- AgroecologyDepartment of Crop SciencesUniversity of GöttingenGöttingenGermany
- Sustainable Agriculture & Technology LabSchool of EngineeringWestlake UniversityHangzhouChina
| | | | | | - Delphine‐Clara Zemp
- Biodiversity, Macroecology and BiogeographyUniversity of GöttingenGöttingenGermany
- Laboratory of Conservation BiologyInstitute of BiologyUniversity of NeuchâtelNeuchâtelSwitzerland
| | - Agus Priyono Kartono
- Department of Forest Resources Conservation and EcotourismFaculty of ForestryIPB UniversityBogorIndonesia
| | - Thomas Cherico Wanger
- Sustainable Agriculture & Technology LabSchool of EngineeringWestlake UniversityHangzhouChina
- Key Laboratory of Coastal Environment and Resources of Zhejiang ProvinceWestlake UniversityHangzhouChina
- GlobalAgroforestryNetwork.orgChina
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5
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Hall RP, Mutumi GL, Hedrick BP, Yohe LR, Sadier A, Davies KTJ, Rossiter SJ, Sears K, Dávalos LM, Dumont ER. Find the food first: An omnivorous sensory morphotype predates biomechanical specialization for plant based diets in phyllostomid bats. Evolution 2021; 75:2791-2801. [PMID: 34021589 DOI: 10.1111/evo.14270] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 03/03/2021] [Accepted: 04/05/2021] [Indexed: 11/30/2022]
Abstract
The role of mechanical morphologies in the exploitation of novel niche space is well characterized; however, the role of sensory structures in unlocking new niches is less clear. Here, we investigate the relationship between the evolution of sensory structures and diet during the radiation of noctilionoid bats. With a broad range of foraging ecologies and a well-supported phylogeny, noctilionoids constitute an ideal group for studying this relationship. We used diffusible iodine-based contrast enhanced computed tomography scans of 44 noctilionoid species to analyze relationships between the relative volumes of three sensory structures (olfactory bulbs, orbits, and cochleae) and diet. We found a positive relationship between frugivory and both olfactory and orbit size. However, we also found a negative relationship between nectarivory and cochlea size. Ancestral state estimates suggest that larger orbits and olfactory bulbs were present in the common ancestor of family Phyllostomidae, but not in other noctilionoid. This constellation of traits indicates a shift toward omnivory at the base of Phyllostomidae, predating their radiation into an exceptionally broad range of dietary niches. This is consistent with a scenario in which changes in sensory systems associated with foraging and feeding set the stage for subsequent morphological modification and diversification.
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Affiliation(s)
- Ronald P Hall
- Life and Environmental Sciences, University of California-Merced, Merced, California
| | - Gregory L Mutumi
- Life and Environmental Sciences, University of California-Merced, Merced, California
| | - Brandon P Hedrick
- Department of Cell Biology and Anatomy, Louisiana State University Health Sciences Center, New Orleans, Louisiana
| | - Laurel R Yohe
- Department of Geology and Geophysics, Yale University, New Haven, Connecticut
| | - Alexa Sadier
- Department of Ecology and Evolutionary Biology, University of California-Los Angeles, Los Angeles, California
| | - Kalina T J Davies
- School of Biological and Chemical Sciences, Queen Mary University of London, London, UK
| | - Stephen J Rossiter
- School of Biological and Chemical Sciences, Queen Mary University of London, London, UK
| | - Karen Sears
- Department of Ecology and Evolutionary Biology, University of California-Los Angeles, Los Angeles, California
| | - Liliana M Dávalos
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, New York.,Consortium for Inter-Disciplinary Environmental Research, School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, New York
| | - Elizabeth R Dumont
- Life and Environmental Sciences, University of California-Merced, Merced, California
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6
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Turner RC, Alexander AB, Wellehan JFX, Heard D, Abbott JR, Crevasse SE, Plummer CE. Retrospective analysis of ocular disease in a population of captive pteropodid bats, 2003-2020. Vet Ophthalmol 2021; 24:240-251. [PMID: 33682341 DOI: 10.1111/vop.12879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 02/05/2021] [Accepted: 02/15/2021] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To perform retrospective analysis of captive pteropodid bats presented to the University of Florida for ocular or adnexal disease from 2003-2020. ANIMALS STUDIED Twenty-four individuals from seven species were included. PROCEDURES Records were analyzed for disease process, methods of treatment, and surgical techniques and complications. RESULTS The most frequently reported abnormality was corneal disease (79%), followed by cataracts (54%), and uveitis (42%). Corneal disease was primarily attributed to either trauma or exposure keratitis secondary to buphthalmia. The majority of uveitis appeared to be lens-induced. Five cases (21%) of glaucoma were reported, all of which accompanied lens luxation. Of the seven enucleations performed, six had post-operative complications (85.7%), including swelling at the surgical site, seroma formation, and bacterial infection. There was no significant relationship between age and trauma, age and cataract formation, sex and trauma, or species and cataract formation. CONCLUSIONS The most common underlying cause of ocular pathology in these cases was trauma. While the bats tolerated topical and systemic treatment well, individual temperament must be taken into account when developing treatment plans, and prevention of injury is the most effective management strategy.
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Affiliation(s)
- Rachel C Turner
- Department of Comparative, Diagnostic, and Population Medicine, University of Florida College of Veterinary Medicine, Gainesville, FL, USA
| | - Amy B Alexander
- Department of Comparative, Diagnostic, and Population Medicine, University of Florida College of Veterinary Medicine, Gainesville, FL, USA
| | - James F X Wellehan
- Department of Comparative, Diagnostic, and Population Medicine, University of Florida College of Veterinary Medicine, Gainesville, FL, USA
| | - Darryl Heard
- Department of Comparative, Diagnostic, and Population Medicine, University of Florida College of Veterinary Medicine, Gainesville, FL, USA
| | - Jeffrey R Abbott
- Department of Veterinary Microbiology and Pathology, Washington State University College of Veterinary Medicine, Pullman, WA, USA
| | - Sarah E Crevasse
- Department of Comparative, Diagnostic, and Population Medicine, University of Florida College of Veterinary Medicine, Gainesville, FL, USA
| | - Caryn E Plummer
- Department of Small Animal Clinical Sciences, University of Florida College of Veterinary Medicine, Gainesville, FL, USA
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7
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Sadier A, Urban DJ, Anthwal N, Howenstine AO, Sinha I, Sears KE. Making a bat: The developmental basis of bat evolution. Genet Mol Biol 2021; 43:e20190146. [PMID: 33576369 PMCID: PMC7879332 DOI: 10.1590/1678-4685-gmb-2019-0146] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 12/11/2020] [Indexed: 11/28/2022] Open
Abstract
Bats are incredibly diverse, both morphologically and taxonomically. Bats are the only mammalian group to have achieved powered flight, an adaptation that is hypothesized to have allowed them to colonize various and diverse ecological niches. However, the lack of fossils capturing the transition from terrestrial mammal to volant chiropteran has obscured much of our understanding of bat evolution. Over the last 20 years, the emergence of evo-devo in non-model species has started to fill this gap by uncovering some developmental mechanisms at the origin of bat diversification. In this review, we highlight key aspects of studies that have used bats as a model for morphological adaptations, diversification during adaptive radiations, and morphological novelty. To do so, we review current and ongoing studies on bat evolution. We first investigate morphological specialization by reviewing current knowledge about wing and face evolution. Then, we explore the mechanisms behind adaptive diversification in various ecological contexts using vision and dentition. Finally, we highlight the emerging work into morphological novelties using bat wing membranes.
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Affiliation(s)
- Alexa Sadier
- University of California at Los Angeles, Department of Ecology and Evolutionary Biology, Los Angeles, USA
| | - Daniel J Urban
- University of California at Los Angeles, Department of Ecology and Evolutionary Biology, Los Angeles, USA.,American Museum of Natural History, Department of Mammalogy, New York, USA
| | - Neal Anthwal
- University of California at Los Angeles, Department of Ecology and Evolutionary Biology, Los Angeles, USA
| | - Aidan O Howenstine
- University of California at Los Angeles, Department of Ecology and Evolutionary Biology, Los Angeles, USA
| | - Ishani Sinha
- University of California at Los Angeles, Department of Ecology and Evolutionary Biology, Los Angeles, USA
| | - Karen E Sears
- University of California at Los Angeles, Department of Ecology and Evolutionary Biology, Los Angeles, USA
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8
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Aboelnour A, Noreldin AE, Massoud D, Abumandour MMA. Retinal characterization in the eyes of two bats endemic in the Egyptian fauna, the Egyptian fruit bat (Rousettus aegyptiacus) and insectivorous bat (Pipistrellus kuhlii), using the light microscope and transmission electron microscope. Microsc Res Tech 2020; 83:1391-1400. [PMID: 33405350 DOI: 10.1002/jemt.23530] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 05/02/2020] [Accepted: 05/26/2020] [Indexed: 11/06/2022]
Abstract
Bats are the only mammals that can fly in the dark without eye usage. This study was conducted to describe the structural and functional adaptations of the retina of two bats very common in the Egyptian fauna having a different lifestyle: the Egyptian fruit bat (Rousettus aegyptiacus) and insectivorous bat (Pipistrellus kuhlii). Seven eyes were collected from adult individuals of each species. Examination of the retina using a light microscope and a transmission electron microscope was carried out. The retina of P. kuhlii was thicker than that of R. aegyptiacus, which had many projections extended from the choroid layer into retina forming papillae. Despite rods being dominant in retinae of both species, cone photoreceptors were encountered in both retinae. The outer plexiform layer of R. aegyptiacus was arranged into islets between the outer nuclear layer produced differences in its thickness. However, the retina of P. kuhlii showed a normal arrangement of retinal structure. The retinal pigment epithelium of both bat species consists of a single layer of the cuboidal cells with a round to oval vesicular nuclei, which showed a lack of pigmentation in R. aegyptiacus and poor pigmentation in the P. kuhlii. In conclusion, our investigation detected many structural and ultrastructural differences between the two bat species. The presence of many projections protruded from the choroid layer of R. aegyptiacus retina is considered the most characteristic difference between the retinae of R. aegyptiacus and P. kuhlii.
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Affiliation(s)
- Asmaa Aboelnour
- Department of Histology and Cytology, Faculty of Veterinary Medicine, Damanhour University, Damanhour, Egypt.,Institute of Ophthalmology, University College London, London, United Kingdom
| | - Ahmed E Noreldin
- Department of Histology and Cytology, Faculty of Veterinary Medicine, Damanhour University, Damanhour, Egypt
| | - Diaa Massoud
- Department of Biology, College of Science, Jouf University, Sakaka, Saudi Arabia.,Department of Zoology, Faculty of Science, Fayoum University, Fayoum, Egypt
| | - Mohamed M A Abumandour
- Department of Anatomy and Embryology, Faculty of Veterinary Medicine, Alexandria University, Alexandria, Egypt
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9
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El-Mansi AA, Al-Kahtani MA, Al-Sayyad KM, Ahmed EA, Gad AR. Visual adaptability and retinal characterization of the Egyptian fruit bat (Rousettus aegyptiacus, Pteropodidae): New insights into photoreceptors spatial distribution and melanosomal activity. Micron 2020; 137:102897. [PMID: 32563026 DOI: 10.1016/j.micron.2020.102897] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 05/27/2020] [Accepted: 05/27/2020] [Indexed: 12/14/2022]
Abstract
Our study was conducted to characterize the retinal structure of the Egyptian fruit bat, Rousettus aegyptiacus to determine the distribution of photoreceptors and melanosomal populations in various retinal zones. Also, we paid attention to the specific structural and functional adaptations related to their nocturnal habits. We analyzed the retinae of 12 adult male Egyptian fruit bats using morphometrical, histological, ultrastructural, and immunoblotting standard techniques. Histological findings revealed that the retinal cells have variations in geometrical architecture and different retinal thickness together with their corresponding layers bearing specific choroidal papillae projecting towards the inner retina. Immunoblotting and ultrastructure results showed that the microstructure of the retina conforms to that pattern found in mammalian species. The retinal photoreceptors are rod-dominant; alternatively, possess two spectral types of cones: SWS and LW/MWS cones as evidence for the basis for dichromatic vision. In addition, the outer retina showed densely-distributed melanin granules with a significant increase in the number of pigment epithelium cells in the eccentric retina. Furthermore, the asymmetric distribution among the retinal quadrants for the visual pigments of both rods and cones coinciding with neuronal cells such as bipolar and ganglion cells confers instructive information about their visual perception and orientation. In conclusion, our findings indicate that R. aegyptiacus efficiently discriminates colors with complex visual adaptations to mediate increased visual acuity coopted for the nocturnal niches.
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Affiliation(s)
- Ahmed A El-Mansi
- Biology Dept., Faculty of Science, King Khalid University, Abha, Saudi Arabia; Zoology Dept., Faculty of Science, Mansoura University, Mansoura, Egypt.
| | - M A Al-Kahtani
- Biology Dept., Faculty of Science, King Khalid University, Abha, Saudi Arabia
| | - K M Al-Sayyad
- Biology Dept., Faculty of Science, King Khalid University, Abha, Saudi Arabia
| | - E A Ahmed
- Biology Dept., Faculty of Science, King Khalid University, Abha, Saudi Arabia; Department of Theriogenology, Faculty of Veterinary Medicine, South Valley University, Qena, Egypt
| | - A R Gad
- Biology Dept., Faculty of Science, King Saud University, Riyadh, Saudi Arabia
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10
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Gutierrez EDA, Schott RK, Preston MW, Loureiro LO, Lim BK, Chang BSW. The role of ecological factors in shaping bat cone opsin evolution. Proc Biol Sci 2019; 285:rspb.2017.2835. [PMID: 29618549 DOI: 10.1098/rspb.2017.2835] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 03/15/2018] [Indexed: 12/16/2022] Open
Abstract
Bats represent one of the largest and most striking nocturnal mammalian radiations, exhibiting many visual system specializations for performance in light-limited environments. Despite representing the greatest ecological diversity and species richness in Chiroptera, Neotropical lineages have been undersampled in molecular studies, limiting the potential for identifying signatures of selection on visual genes associated with differences in bat ecology. Here, we investigated how diverse ecological pressures mediate long-term shifts in selection upon long-wavelength (Lws) and short-wavelength (Sws1) opsins, photosensitive cone pigments that form the basis of colour vision in most mammals, including bats. We used codon-based likelihood clade models to test whether ecological variables associated with reliance on visual information (e.g. echolocation ability and diet) or exposure to varying light environments (e.g. roosting behaviour and foraging habitat) mediated shifts in evolutionary rates in bat cone opsin genes. Using additional cone opsin sequences from newly sequenced eye transcriptomes of six Neotropical bat species, we found significant evidence for different ecological pressures influencing the evolution of the cone opsins. While Lws is evolving under significantly lower constraint in highly specialized high-duty cycle echolocating lineages, which have enhanced sonar ability to detect and track targets, variation in Sws1 constraint was significantly associated with foraging habitat, exhibiting elevated rates of evolution in species that forage among vegetation. This suggests that increased reliance on echolocation as well as the spectral environment experienced by foraging bats may differentially influence the evolution of different cone opsins. Our study demonstrates that different ecological variables may underlie contrasting evolutionary patterns in bat visual opsins, and highlights the suitability of clade models for testing ecological hypotheses of visual evolution.
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Affiliation(s)
- Eduardo de A Gutierrez
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada M5S 3B2
| | - Ryan K Schott
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada M5S 3B2
| | - Matthew W Preston
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada M5S 3B2
| | - Lívia O Loureiro
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada M5S 3B2
| | - Burton K Lim
- Department of Natural History, Royal Ontario Museum, Toronto, Ontario, Canada M5S 2C6
| | - Belinda S W Chang
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada M5S 3B2 .,Centre for the Analysis of Genome Evolution and Function, University of Toronto, Toronto, Ontario, Canada M5S 3B2.,Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada M5S 3G5
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11
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Danilovich S, Yovel Y. Integrating vision and echolocation for navigation and perception in bats. SCIENCE ADVANCES 2019; 5:eaaw6503. [PMID: 31249874 PMCID: PMC6594759 DOI: 10.1126/sciadv.aaw6503] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Accepted: 05/16/2019] [Indexed: 05/26/2023]
Abstract
How animals integrate information from various senses to navigate and generate perceptions is a fundamental question. Bats are ideal animal models to study multisensory integration due to their reliance on vision and echolocation, two modalities that allow distal sensing with high spatial resolution. Using three behavioral paradigms, we studied different aspects of multisensory integration in Egyptian fruit bats. We show that bats learn the three-dimensional shape of an object using vision only, even when using both vision and echolocation. Nevertheless, we demonstrate that they can classify objects using echolocation and even translate echoic information into a visual representation. Last, we show that in navigation, bats dynamically switch between the modalities: Vision was given more weight when deciding where to fly, while echolocation was more dominant when approaching an obstacle. We conclude that sensory integration is task dependent and that bimodal information is weighed in a more complex manner than previously suggested.
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Affiliation(s)
- S. Danilovich
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
- Department of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Y. Yovel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
- Department of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
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12
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Simões BF, Foley NM, Hughes GM, Zhao H, Zhang S, Rossiter SJ, Teeling EC. As Blind as a Bat? Opsin Phylogenetics Illuminates the Evolution of Color Vision in Bats. Mol Biol Evol 2019; 36:54-68. [PMID: 30476197 PMCID: PMC6340466 DOI: 10.1093/molbev/msy192] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Through their unique use of sophisticated laryngeal echolocation bats are considered sensory specialists amongst mammals and represent an excellent model in which to explore sensory perception. Although several studies have shown that the evolution of vision is linked to ecological niche adaptation in other mammalian lineages, this has not yet been fully explored in bats. Recent molecular analysis of the opsin genes, which encode the photosensitive pigments underpinning color vision, have implicated high-duty cycle (HDC) echolocation and the adoption of cave roosting habits in the degeneration of color vision in bats. However, insufficient sampling of relevant taxa has hindered definitive testing of these hypotheses. To address this, novel sequence data was generated for the SWS1 and MWS/LWS opsin genes and combined with existing data to comprehensively sample species representing diverse echolocation types and niches (SWS1 n = 115; MWS/LWS n = 45). A combination of phylogenetic analysis, ancestral state reconstruction, and selective pressure analyses were used to reconstruct the evolution of these visual pigments in bats and revealed that although both genes are evolving under purifying selection in bats, MWS/LWS is highly conserved but SWS1 is highly variable. Spectral tuning analyses revealed that MWS/LWS opsin is tuned to a long wavelength, 555-560 nm in the bat ancestor and the majority of extant taxa. The presence of UV vision in bats is supported by our spectral tuning analysis, but phylogenetic analyses demonstrated that the SWS1 opsin gene has undergone pseudogenization in several lineages. We do not find support for a link between the evolution of HDC echolocation and the pseudogenization of the SWS1 gene in bats, instead we show the SWS1 opsin is functional in the HDC echolocator, Pteronotus parnellii. Pseudogenization of the SWS1 is correlated with cave roosting habits in the majority of pteropodid species. Together these results demonstrate that the loss of UV vision in bats is more widespread than was previously considered and further elucidate the role of ecological niche specialization in the evolution of vision in bats.
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Affiliation(s)
- Bruno F Simões
- UCD School of Biology and Environmental Science, University College Dublin, Dublin 4, Ireland
- School of Earth Science, University of Bristol, Bristol, United Kingdom
- School of Biological Science, The University of Adelaide, South Australia, Australia
| | - Nicole M Foley
- UCD School of Biology and Environmental Science, University College Dublin, Dublin 4, Ireland
| | - Graham M Hughes
- UCD School of Biology and Environmental Science, University College Dublin, Dublin 4, Ireland
| | - Huabin Zhao
- Department of Ecology and Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Shuyi Zhang
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China
| | - Stephen J Rossiter
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom
| | - Emma C Teeling
- UCD School of Biology and Environmental Science, University College Dublin, Dublin 4, Ireland
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Sadier A, Davies KT, Yohe LR, Yun K, Donat P, Hedrick BP, Dumont ER, Dávalos LM, Rossiter SJ, Sears KE. Multifactorial processes underlie parallel opsin loss in neotropical bats. eLife 2018; 7:37412. [PMID: 30560780 PMCID: PMC6333445 DOI: 10.7554/elife.37412] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 12/04/2018] [Indexed: 12/27/2022] Open
Abstract
The loss of previously adaptive traits is typically linked to relaxation in selection, yet the molecular steps leading to such repeated losses are rarely known. Molecular studies of loss have tended to focus on gene sequences alone, but overlooking other aspects of protein expression might underestimate phenotypic diversity. Insights based almost solely on opsin gene evolution, for instance, have made mammalian color vision a textbook example of phenotypic loss. We address this gap by investigating retention and loss of opsin genes, transcripts, and proteins across ecologically diverse noctilionoid bats. We find multiple, independent losses of short-wave-sensitive opsins. Mismatches between putatively functional DNA sequences, mRNA transcripts, and proteins implicate transcriptional and post-transcriptional processes in the ongoing loss of S-opsins in some noctilionoid bats. Our results provide a snapshot of evolution in progress during phenotypic trait loss, and suggest vertebrate visual phenotypes cannot always be predicted from genotypes alone. Bats are famous for using their hearing to explore their environments, yet fewer people are aware that these flying mammals have both good night and daylight vision. Some bats can even see in color thanks to two light-sensitive proteins at the back of their eyes: S-opsin which detects blue and ultraviolet light and L-opsin which detects green and red light. Many species of bat, however, are missing one of these proteins and cannot distinguish any colors; in other words, they are completely color-blind. Some bat species found in Central and South America have independently lost their ability to see blue-ultraviolet light and have thus also lost their color vision. These bats have diverse diets – ranging from insects to fruits and even blood – and being able to distinguish color may offer an advantage in many of their activities, including hunting or foraging. The vision genes in these bats, therefore, give scientists an opportunity to explore how a seemingly important trait can be lost at the molecular level. Sadier, Davies et al. now report that S-opsin has been lost more than a dozen times during the evolutionary history of these Central and South American bats. The analysis used samples from 55 species, including animals caught from the wild and specimens from museums. As with other proteins, the instructions encoded in the gene sequence for S opsin need to be copied into a molecule of RNA before they can be translated into protein. As expected, S-opsin was lost several times because of changes in the gene sequence that disrupted the formation of the protein. However, at several points in these bats’ evolutionary history, additional changes have taken place that affected the production of the RNA or the protein, without an obvious change to the gene itself. This finding suggests that other studies that rely purely on DNA to understand evolution may underestimate how often traits may be lost. By capturing ‘evolution in action’, these results also provide a more complete picture of the molecular targets of evolution in a diverse set of bats.
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Affiliation(s)
- Alexa Sadier
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, United States
| | - Kalina Tj Davies
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom
| | - Laurel R Yohe
- Department of Ecology and Evolution, Stony Brook University, New York, United States.,Geology & Geophysics, Yale University, New Haven, United States
| | - Kun Yun
- Department of Animal Biology, University of Illinois, Urbana, United States
| | - Paul Donat
- Department of Ecology and Evolution, Stony Brook University, New York, United States
| | - Brandon P Hedrick
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, United States
| | - Elizabeth R Dumont
- School of Natural Sciences, University of California, Merced, United States
| | - Liliana M Dávalos
- Department of Ecology and Evolution, Stony Brook University, New York, United States.,Consortium for Inter-Disciplinary Environmental Research, School of Marine and Atmospheric Sciences, Stony Brook University, New York, United States
| | - Stephen J Rossiter
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom
| | - Karen E Sears
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, United States
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Kries K, Barros MAS, Duytschaever G, Orkin JD, Janiak MC, Pessoa DMA, Melin AD. Colour vision variation in leaf-nosed bats (Phyllostomidae): Links to cave roosting and dietary specialization. Mol Ecol 2018; 27:3627-3640. [PMID: 30059176 DOI: 10.1111/mec.14818] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 06/15/2018] [Accepted: 06/21/2018] [Indexed: 11/30/2022]
Abstract
Bats are a diverse radiation of mammals of enduring interest for understanding the evolution of sensory specialization. Colour vision variation among species has previously been linked to roosting preferences and echolocation form in the suborder Yinpterochiroptera, yet questions remain about the roles of diet and habitat in shaping bat visual ecology. We sequenced OPN1SW and OPN1LW opsin genes for 20 species of leaf-nosed bats (family Phyllostomidae; suborder Yangochiroptera) with diverse roosting and dietary ecologies, along with one vespertilionid species (Myotis lavali). OPN1LW genes appear intact for all species, and predicted spectral tuning of long-wavelength opsins varied among lineages. OPN1SW genes appear intact and under purifying selection for Myotis lavali and most phyllostomid bats, with two exceptions: (a) We found evidence of ancient OPN1SW pseudogenization in the vampire bat lineage, and loss-of-function mutations in all three species of extant vampire bats; (b) we additionally found a recent, independently derived OPN1SW pseudogene in Lonchophylla mordax, a cave-roosting species. These mutations in leaf-nosed bats are independent of the OPN1SW pseudogenization events previously reported in Yinpterochiropterans. Therefore, the evolution of monochromacy (complete colour blindness) has occurred in both suborders of bats and under various evolutionary drivers; we find independent support for the hypothesis that obligate cave roosting drives colour vision loss. We additionally suggest that haematophagous dietary specialization and corresponding selection on nonvisual senses led to loss of colour vision through evolutionary sensory trade-off. Our results underscore the evolutionary plasticity of opsins among nocturnal mammals.
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Affiliation(s)
- Kelly Kries
- Department of Anthropology, Washington University in St. Louis, St. Louis, Missouri
| | - Marília A S Barros
- Department of Physiology, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Gwen Duytschaever
- Department of Anthropology and Archaeology, University of Calgary, Calgary, Alberta, Canada
| | - Joseph D Orkin
- Department of Anthropology and Archaeology, University of Calgary, Calgary, Alberta, Canada
| | - Mareike C Janiak
- Department of Anthropology, Rutgers University, New Brunswick, New Jersey
| | - Daniel M A Pessoa
- Department of Physiology, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Amanda D Melin
- Department of Anthropology and Archaeology, University of Calgary, Calgary, Alberta, Canada.,Department of Medical Genetics, Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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15
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Retention and losses of ultraviolet-sensitive visual pigments in bats. Sci Rep 2018; 8:11933. [PMID: 30093712 PMCID: PMC6085362 DOI: 10.1038/s41598-018-29646-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 07/16/2018] [Indexed: 12/01/2022] Open
Abstract
Ultraviolet (UV)-sensitive visual pigment and its corresponding ability for UV vision was retained in early mammals from their common ancestry with sauropsids. Subsequently, UV-sensitive pigments, encoded by the short wavelength-sensitive 1 (SWS1) opsin gene, were converted to violet sensitivity or have lost function in multiple lineages during the diversification of mammals. However, many mammalian species, including most bats, are suggested to retain a UV-sensitive pigment. Notably, some cave-dwelling fruit bats and high duty cycle echolocating bats have lost their SWS1 genes, which are proposed to be due to their roosting ecology and as a sensory trade-off between vision and echolocation, respectively. Here, we sequenced SWS1 genes from ecologically diverse bats and found that this gene is also non-functional in both common vampire bat (Desmodus rotundus) and white-winged vampire bat (Diaemus youngi). Apart from species with pesudogenes, our evolutionary and functional studies demonstrate that the SWS1 pigment of bats are UV-sensitive and well-conserved since their common ancestor, suggesting an important role across major ecological types. Given the constrained function of SWS1 pigments in these bats, why some other species, such as vampire bats, have lost this gene is even more interesting and needs further investigation.
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16
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Arms race of temporal partitioning between carnivorous and herbivorous mammals. Sci Rep 2018; 8:1713. [PMID: 29379083 PMCID: PMC5789060 DOI: 10.1038/s41598-018-20098-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 01/12/2018] [Indexed: 01/31/2023] Open
Abstract
Reciprocal coevolutionary changes in predation and anti-predator behaviours have long been hypothesized, but evolutionary-scale evidence is rare. Here, we reconstructed the evolutionary-scale changes in the diel activity patterns of a predator-prey system (carnivorous and herbivorous mammals) based on a molecular phyloecological approach, providing evidence of long-term antagonistic coevolutionary changes in their diel activities. Our molecular reconstruction of diel activity patterns, which is supported by morphological evidence, consistently showed that carnivorous mammals were subjected to a shift from diurnality to nocturnality, while herbivorous mammals experienced a shift from nocturnality to diurnality during their evolutionary histories. A shift in the diel activity of the herbivores as a result of carnivore avoidance is hypothesized based on molecular, morphological and behavioural evidence, and our results suggest an evolutionary-scale arms race of diel activity shifts between carnivorous and herbivorous mammals.
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Thiagavel J, Cechetto C, Santana SE, Jakobsen L, Warrant EJ, Ratcliffe JM. Auditory opportunity and visual constraint enabled the evolution of echolocation in bats. Nat Commun 2018; 9:98. [PMID: 29311648 PMCID: PMC5758785 DOI: 10.1038/s41467-017-02532-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 12/07/2017] [Indexed: 11/09/2022] Open
Abstract
Substantial evidence now supports the hypothesis that the common ancestor of bats was nocturnal and capable of both powered flight and laryngeal echolocation. This scenario entails a parallel sensory and biomechanical transition from a nonvolant, vision-reliant mammal to one capable of sonar and flight. Here we consider anatomical constraints and opportunities that led to a sonar rather than vision-based solution. We show that bats' common ancestor had eyes too small to allow for successful aerial hawking of flying insects at night, but an auditory brain design sufficient to afford echolocation. Further, we find that among extant predatory bats (all of which use laryngeal echolocation), those with putatively less sophisticated biosonar have relatively larger eyes than do more sophisticated echolocators. We contend that signs of ancient trade-offs between vision and echolocation persist today, and that non-echolocating, phytophagous pteropodid bats may retain some of the necessary foundations for biosonar.
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Affiliation(s)
- Jeneni Thiagavel
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, ON, M5S 3B2, Canada
| | - Clément Cechetto
- Department of Biology, University of Southern Denmark, Campusvej 55, 5230, Odense C, Denmark
| | - Sharlene E Santana
- Department of Biology and Burke Museum of Natural History and Culture, University of Washington, Seattle, WA, 98195, USA
| | - Lasse Jakobsen
- Department of Biology, University of Southern Denmark, Campusvej 55, 5230, Odense C, Denmark
| | - Eric J Warrant
- Department of Biology, Lund University, Sölvegatan 35, 22362, Lund, Sweden
| | - John M Ratcliffe
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, ON, M5S 3B2, Canada. .,Department of Biology, University of Southern Denmark, Campusvej 55, 5230, Odense C, Denmark. .,Department of Biology, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, ON, L5L 1C6, Canada. .,Department of Natural History, Royal Ontario Museum, 100 Queens Park, Toronto, ON, M5S 2C6, Canada.
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18
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The organization of melanopsin-immunoreactive cells in microbat retina. PLoS One 2018; 13:e0190435. [PMID: 29304147 PMCID: PMC5755760 DOI: 10.1371/journal.pone.0190435] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2017] [Accepted: 12/14/2017] [Indexed: 01/05/2023] Open
Abstract
Intrinsically photosensitive retinal ganglion cells (ipRGCs) respond to light and play roles in non-image forming vision, such as circadian rhythms, pupil responses, and sleep regulation, or image forming vision, such as processing visual information and directing eye movements in response to visual clues. The purpose of the present study was to identify the distribution, types, and proportion of melanopsin-immunoreactive (IR) cells in the retina of a nocturnal animal, i.e., the microbat (Rhinolophus ferrumequinum). Three types of melanopsin-IR cells were observed in the present study. The M1 type had dendritic arbors that extended into the OFF sublayer of the inner plexiform layer (IPL). M1 soma locations were identified either in the ganglion cell layer (GCL, M1c; 21.00%) or in the inner nuclear layer (INL, M1d; 5.15%). The M2 type had monostratified dendrites in the ON sublayer of the IPL and their cell bodies lay in the GCL (M2; 5.79%). The M3 type was bistratified cells with dendrites in both the ON and OFF sublayers of the IPL. M3 soma locations were either in the GCL (M3c; 26.66%) or INL (M3d; 4.69%). Additionally, some M3c cells had curved dendrites leading up towards the OFF sublayer of the IPL and down to the ON sublayer of the IPL (M3c-crv; 7.67%). Melanopsin-IR cells displayed a medium soma size and medium dendritic field diameters. There were 2-5 primary dendrites and sparsely branched dendrites with varicosities. The total number of the neurons in the GCL was 12,254.17 ± 660.39 and that of the optic nerve axons was 5,179.04 ± 208.00 in the R. ferrumequinum retina. The total number of melanopsin-IR cells was 819.74 ± 52.03. The ipRGCs constituted approximately 15.83% of the total RGC population. This study demonstrated that the nocturnal microbat, R. ferrumequinum, has a much higher density of melanopsin-IR cells than documented in diurnal animals.
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Jacobs GH. Photopigments and the dimensionality of animal color vision. Neurosci Biobehav Rev 2017; 86:108-130. [PMID: 29224775 DOI: 10.1016/j.neubiorev.2017.12.006] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 12/04/2017] [Accepted: 12/05/2017] [Indexed: 12/31/2022]
Abstract
Early color-matching studies established that normal human color vision is trichromatic. Subsequent research revealed a causal link between trichromacy and the presence in the retina of three classes of cone photopigments. Over the years, measurements of the photopigment complements of other species have expanded greatly and these are frequently used to predict the dimensionality of an animal's color vision. This review provides an account of how the linkage between the number of active photopigments and the dimensions of human color vision developed, summarizes the various mechanisms that can impact photopigment spectra and number, and provides an across-species survey to examine cases where the photopigment link to the dimensionality of color vision has been claimed. The literature reveals numerous instances where the human model fails to account for the ways in which the visual systems of other animals exploit information obtained from the presence of multiple photopigments in support of their behavior.
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Affiliation(s)
- Gerald H Jacobs
- Department of Psychological and Brain Science, University of California, Santa Barbara, CA 93106, USA.
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20
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Moritz GL, Ong PS, Perry GH, Dominy NJ. Functional preservation and variation in the cone opsin genes of nocturnal tarsiers. Philos Trans R Soc Lond B Biol Sci 2017; 372:rstb.2016.0075. [PMID: 28193820 DOI: 10.1098/rstb.2016.0075] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/14/2016] [Indexed: 11/12/2022] Open
Abstract
The short-wavelength sensitive (S-) opsin gene OPN1SW is pseudogenized in some nocturnal primates and retained in others, enabling dichromatic colour vision. Debate on the functional significance of this variation has focused on dark conditions, yet many nocturnal species initiate activity under dim (mesopic) light levels that can support colour vision. Tarsiers are nocturnal, twilight-active primates and exemplary visual predators; they also express different colour vision phenotypes, raising the possibility of discrete adaptations to mesopic conditions. To explore this premise, we conducted a field study in two stages. First, to estimate the level of functional constraint on colour vision, we sequenced OPN1SW in 12 wild-caught Philippine tarsiers (Tarsius syrichta). Second, to explore whether the dichromatic visual systems of Philippine and Bornean (Tarsius bancanus) tarsiers-which express alternate versions of the medium/long-wavelength sensitive (M/L-) opsin gene OPN1MW/OPN1LW-confer differential advantages specific to their respective habitats, we used twilight and moonlight conditions to model the visual contrasts of invertebrate prey. We detected a signature of purifying selection for OPN1SW, indicating that colour vision confers an adaptive advantage to tarsiers. However, this advantage extends to a relatively small proportion of prey-background contrasts, and mostly brown arthropod prey amid leaf litter. We also found that the colour vision of T. bancanus is advantageous for discriminating prey under twilight that is enriched in shorter (bluer) wavelengths, a plausible idiosyncrasy of understorey habitats in Borneo.This article is part of the themed issue 'Vision in dim light'.
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Affiliation(s)
- Gillian L Moritz
- Department of Evolutionary Anthropology, Duke University, 104 Biological Sciences Building, Campus Box 90383, Durham, NC 27708, USA
| | - Perry S Ong
- Institute of Biology, University of the Philippines Diliman, Quezon City, Philippines
| | - George H Perry
- Departments of Anthropology and Biology, Pennsylvania State University, 513 Carpenter Building, University Park, PA 16802, USA
| | - Nathaniel J Dominy
- Department of Anthropology, Dartmouth College, 6047 Silsby Hall, Hanover, NH 03755, USA .,Department of Biological Sciences, Dartmouth College, Class of 1978 Life Sciences Center, 78 College Street, Hanover, NH 03755, USA
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Coimbra JP, Pettigrew JD, Kaswera-Kyamakya C, Gilissen E, Collin SP, Manger PR. Retinal ganglion cell topography and spatial resolving power in African megachiropterans: Influence of roosting microhabitat and foraging. J Comp Neurol 2016; 525:186-203. [DOI: 10.1002/cne.24055] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Revised: 06/07/2016] [Accepted: 06/07/2016] [Indexed: 11/10/2022]
Affiliation(s)
- João Paulo Coimbra
- School of Anatomical Sciences; University of the Witwatersrand; Parktown 2193 Johannesburg South Africa
- The Oceans Institute; The University of Western Australia; Crawley Western Australia 6009 Australia
- School of Animal Biology; The University of Western Australia; Crawley Western Australia 6009 Australia
| | - John D. Pettigrew
- Queensland Brain Institute; The University of Queensland; Santa Lucia Queensland 4072 Australia
| | | | - Emmanuel Gilissen
- Department of Anthropology; University of Arkansas; Fayetteville Arkansas 72701
- Faculty of Sciences; University of Kisangani; B.P. 1232 Kisangani Democratic Republic of the Congo
- Department of African Zoology; Royal Museum for Central Africa; B-3080 Tervuren Belgium
- Laboratory of Histology and Neuropathology; Free University of Brussells; B-1070 Brussels Belgium
| | - Shaun P. Collin
- The Oceans Institute; The University of Western Australia; Crawley Western Australia 6009 Australia
- School of Animal Biology; The University of Western Australia; Crawley Western Australia 6009 Australia
| | - Paul R. Manger
- School of Anatomical Sciences; University of the Witwatersrand; Parktown 2193 Johannesburg South Africa
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Dichromatic vision in a fruit bat with diurnal proclivities: the Samoan flying fox (Pteropus samoensis). J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2014; 200:1015-22. [DOI: 10.1007/s00359-014-0951-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 09/26/2014] [Accepted: 10/01/2014] [Indexed: 11/25/2022]
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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.
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Joffe B, Peichl L, Hendrickson A, Leonhardt H, Solovei I. Diurnality and Nocturnality in Primates: An Analysis from the Rod Photoreceptor Nuclei Perspective. Evol Biol 2013. [DOI: 10.1007/s11692-013-9240-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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25
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Moritz GL, Lim NTL, Neitz M, Peichl L, Dominy NJ. Expression and Evolution of Short Wavelength Sensitive Opsins in Colugos: A Nocturnal Lineage That Informs Debate on Primate Origins. Evol Biol 2013; 40:542-553. [PMID: 24293738 PMCID: PMC3832777 DOI: 10.1007/s11692-013-9230-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Accepted: 03/29/2013] [Indexed: 11/25/2022]
Abstract
A nocturnal activity pattern is central to almost all hypotheses on the adaptive origins of primates. This enduring view has been challenged in recent years on the basis of variation in the opsin genes of nocturnal primates. A correspondence between the opsin genes and activity patterns of species in Euarchonta-the superordinal group that includes the orders Primates, Dermoptera (colugos), and Scandentia (treeshrews)-could prove instructive, yet the basic biology of the dermopteran visual system is practically unknown. Here we show that the eye of the Sunda colugo (Galeopterus variegatus) lacks a tapetum lucidum and has an avascular retina, and we report on the expression and spectral sensitivity of cone photopigments. We found that Sunda colugos have intact short wavelength sensitive (S-) and long wavelength sensitive (L-) opsin genes, and that both opsins are expressed in cone photoreceptors of the retina. The inferred peak spectral sensitivities are 451 and 562 nm, respectively. In line with adaptation to nocturnal vision, cone densities are low. Surprisingly, a majority of S-cones coexpress some L-opsin. We also show that the ratio of rates of nonsynonymous to synonymous substitutions of exon 1 of the S-opsin gene is indicative of purifying selection. Taken together, our results suggest that natural selection has favored a functional S-opsin in a nocturnal lineage for at least 45 million years. Accordingly, a nocturnal activity pattern remains the most likely ancestral character state of euprimates.
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Affiliation(s)
- Gillian L. Moritz
- Department of Biological Sciences, Dartmouth College, The Class of 1978 Life Sciences Center, 78 College Street, Hanover, NH 03755 USA
| | - Norman T.-L. Lim
- Department of Wildlife, Fish and Conservation Biology, University of California, One Shields Avenue, Davis, CA 95616 USA
| | - Maureen Neitz
- Department of Ophthalmology, University of Washington, Box 356485, 1959 NE Pacific Street, Seattle, WA 98195 USA
| | - Leo Peichl
- Max Planck Institute for Brain Research, Deutschordenstrasse 46, 60528 Frankfurt am Main, Germany
| | - Nathaniel J. Dominy
- Department of Biological Sciences, Dartmouth College, The Class of 1978 Life Sciences Center, 78 College Street, Hanover, NH 03755 USA
- Department of Anthropology, Dartmouth College, 6047 Silsby Hall, Hanover, NH 03755 USA
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Meredith RW, Gatesy J, Emerling CA, York VM, Springer MS. Rod monochromacy and the coevolution of cetacean retinal opsins. PLoS Genet 2013; 9:e1003432. [PMID: 23637615 PMCID: PMC3630094 DOI: 10.1371/journal.pgen.1003432] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Accepted: 02/15/2013] [Indexed: 01/02/2023] Open
Abstract
Cetaceans have a long history of commitment to a fully aquatic lifestyle that extends back to the Eocene. Extant species have evolved a spectacular array of adaptations in conjunction with their deployment into a diverse array of aquatic habitats. Sensory systems are among those that have experienced radical transformations in the evolutionary history of this clade. In the case of vision, previous studies have demonstrated important changes in the genes encoding rod opsin (RH1), short-wavelength sensitive opsin 1 (SWS1), and long-wavelength sensitive opsin (LWS) in selected cetaceans, but have not examined the full complement of opsin genes across the complete range of cetacean families. Here, we report protein-coding sequences for RH1 and both color opsin genes (SWS1, LWS) from representatives of all extant cetacean families. We examine competing hypotheses pertaining to the timing of blue shifts in RH1 relative to SWS1 inactivation in the early history of Cetacea, and we test the hypothesis that some cetaceans are rod monochomats. Molecular evolutionary analyses contradict the "coastal" hypothesis, wherein SWS1 was pseudogenized in the common ancestor of Cetacea, and instead suggest that RH1 was blue-shifted in the common ancestor of Cetacea before SWS1 was independently knocked out in baleen whales (Mysticeti) and in toothed whales (Odontoceti). Further, molecular evidence implies that LWS was inactivated convergently on at least five occasions in Cetacea: (1) Balaenidae (bowhead and right whales), (2) Balaenopteroidea (rorquals plus gray whale), (3) Mesoplodon bidens (Sowerby's beaked whale), (4) Physeter macrocephalus (giant sperm whale), and (5) Kogia breviceps (pygmy sperm whale). All of these cetaceans are known to dive to depths of at least 100 m where the underwater light field is dim and dominated by blue light. The knockout of both SWS1 and LWS in multiple cetacean lineages renders these taxa rod monochromats, a condition previously unknown among mammalian species.
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Affiliation(s)
- Robert W. Meredith
- Department of Biology, University of California Riverside, Riverside, California, United States of America
- Department of Biology and Molecular Biology, Montclair State University, Montclair, New Jersey, United States of America
| | - John Gatesy
- Department of Biology, University of California Riverside, Riverside, California, United States of America
| | - Christopher A. Emerling
- Department of Biology, University of California Riverside, Riverside, California, United States of America
| | - Vincent M. York
- Department of Biology, University of California Riverside, Riverside, California, United States of America
- Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Mark S. Springer
- Department of Biology, University of California Riverside, Riverside, California, United States of America
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Losses of functional opsin genes, short-wavelength cone photopigments, and color vision--a significant trend in the evolution of mammalian vision. Vis Neurosci 2013; 30:39-53. [PMID: 23286388 DOI: 10.1017/s0952523812000429] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
All mammalian cone photopigments are derived from the operation of representatives from two opsin gene families (SWS1 and LWS in marsupial and eutherian mammals; SWS2 and LWS in monotremes), a process that produces cone pigments with respective peak sensitivities in the short and middle-to-long wavelengths. With the exception of a number of primate taxa, the modal pattern for mammals is to have two types of cone photopigment, one drawn from each of the gene families. In recent years, it has been discovered that the SWS1 opsin genes of a widely divergent collection of eutherian mammals have accumulated mutational changes that render them nonfunctional. This alteration reduces the retinal complements of these species to a single cone type, thus rendering ordinary color vision impossible. At present, several dozen species from five mammalian orders have been identified as falling into this category, but the total number of mammalian species that have lost short-wavelength cones in this way is certain to be much larger, perhaps reaching as high as 10% of all species. A number of circumstances that might be used to explain this widespread cone loss can be identified. Among these, the single consistent fact is that the species so affected are nocturnal or, if they are not technically nocturnal, they at least feature retinal organizations that are typically associated with that lifestyle. At the same time, however, there are many nocturnal mammals that retain functional short-wavelength cones. Nocturnality thus appears to set the stage for loss of functional SWS1 opsin genes in mammals, but it cannot be the sole circumstance.
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Vocalizations in the Malagasy Cave-Dwelling Fruit Bat, Eidolon dupreanum: Possible Evidence of Incipient Echolocation? ACTA CHIROPTEROLOGICA 2012. [DOI: 10.3161/150811012x661729] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Andrianaivoarivelo RA, Jenkins RKB, Petit EJ, Ramilijaona O, Razafindrakoto N, Racey PA. Rousettus madagascariensis (Chiroptera: Pteropodidae) shows a preference for native and commercially unimportant fruits. ENDANGER SPECIES RES 2012. [DOI: 10.3354/esr00441] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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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]
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31
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Immunohistochemical evidence of cone-based ultraviolet vision in divergent bat species and implications for its evolution. Comp Biochem Physiol B Biochem Mol Biol 2012; 161:398-403. [DOI: 10.1016/j.cbpb.2012.01.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2011] [Revised: 01/10/2012] [Accepted: 01/10/2012] [Indexed: 11/22/2022]
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MELIN AMANDAD, MORITZ GILLIANL, FOSBURY ROBERTAE, KAWAMURA SHOJI, DOMINY NATHANIELJ. Why Aye-Ayes See Blue. Am J Primatol 2012; 74:185-92. [DOI: 10.1002/ajp.21996] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- AMANDA D. MELIN
- Department of Anthropology; Dartmouth College; Hanover; New Hampshire
| | - GILLIAN L. MORITZ
- Department of Biological Sciences; Dartmouth College; Hanover; New Hampshire
| | | | - SHOJI KAWAMURA
- Department of Integrated Bioscience; University of Tokyo; Kashiwa; Chiba; Japan
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Hárosi FI, Novales Flamarique I. Functional significance of the taper of vertebrate cone photoreceptors. ACTA ACUST UNITED AC 2012; 139:159-87. [PMID: 22250013 PMCID: PMC3269789 DOI: 10.1085/jgp.201110692] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Vertebrate photoreceptors are commonly distinguished based on the shape of their outer segments: those of cones taper, whereas the ones from rods do not. The functional advantages of cone taper, a common occurrence in vertebrate retinas, remain elusive. In this study, we investigate this topic using theoretical analyses aimed at revealing structure–function relationships in photoreceptors. Geometrical optics combined with spectrophotometric and morphological data are used to support the analyses and to test predictions. Three functions are considered for correlations between taper and functionality. The first function proposes that outer segment taper serves to compensate for self-screening of the visual pigment contained within. The second function links outer segment taper to compensation for a signal-to-noise ratio decline along the longitudinal dimension. Both functions are supported by the data: real cones taper more than required for these compensatory roles. The third function relates outer segment taper to the optical properties of the inner compartment whereby the primary determinant is the inner segment’s ability to concentrate light via its ellipsoid. In support of this idea, the rod/cone ratios of primarily diurnal animals are predicted based on a principle of equal light flux gathering between photoreceptors. In addition, ellipsoid concentration factor, a measure of ellipsoid ability to concentrate light onto the outer segment, correlates positively with outer segment taper expressed as a ratio of characteristic lengths, where critical taper is the yardstick. Depending on a light-funneling property and the presence of focusing organelles such as oil droplets, cone outer segments can be reduced in size to various degrees. We conclude that outer segment taper is but one component of a miniaturization process that reduces metabolic costs while improving signal detection. Compromise solutions in the various retinas and retinal regions occur between ellipsoid size and acuity, on the one hand, and faster response time and reduced light sensitivity, on the other.
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Affiliation(s)
- Ferenc I Hárosi
- Laboratory of Sensory Physiology, Marine Biological Laboratory, Woods Hole, MA 02543, USA
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The Effect of Tourist Visits on the Behavior of Rousettus madagascariensis (Chiroptera: Pteropodidae) in the Caves of Ankarana, Northern Madagascar. ACTA CHIROPTEROLOGICA 2012. [DOI: 10.3161/150811012x661783] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Ebeling W, Natoli RC, Hemmi JM. Diversity of color vision: not all Australian marsupials are trichromatic. PLoS One 2010; 5:e14231. [PMID: 21151905 PMCID: PMC2997786 DOI: 10.1371/journal.pone.0014231] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Accepted: 11/01/2010] [Indexed: 11/25/2022] Open
Abstract
Color vision in marsupials has recently emerged as a particularly interesting case among mammals. It appears that there are both dichromats and trichromats among closely related species. In contrast to primates, marsupials seem to have evolved a different type of trichromacy that is not linked to the X-chromosome. Based on microspectrophotometry and retinal whole-mount immunohistochemistry, four trichromatic marsupial species have been described: quokka, quenda, honey possum, and fat-tailed dunnart. It has, however, been impossible to identify the photopigment of the third cone type, and genetically, all evidence so far suggests that all marsupials are dichromatic. The tammar wallaby is the only Australian marsupial to date for which there is no evidence of a third cone type. To clarify whether the wallaby is indeed a dichromat or trichromatic like other Australian marsupials, we analyzed the number of cone types in the “dichromatic” wallaby and the “trichromatic” dunnart. Employing identical immunohistochemical protocols, we confirmed that the wallaby has only two cone types, whereas 20–25% of cones remained unlabeled by S- and LM-opsin antibodies in the dunnart retina. In addition, we found no evidence to support the hypothesis that the rod photopigment (rod opsin) is expressed in cones which would have explained the absence of a third cone opsin gene. Our study is the first comprehensive and quantitative account of color vision in Australian marsupials where we now know that an unexpected diversity of different color vision systems appears to have evolved.
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Affiliation(s)
- Wiebke Ebeling
- ARC Centre of Excellence in Vision Science, Research School of Biology, ANU College of Medicine, Biology and Environment, The Australian National University, Canberra, Australia.
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36
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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: 130] [Impact Index Per Article: 8.7] [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.
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Affiliation(s)
- David M Hunt
- UCL Institute of Ophthalmology, London EC1V 9EL, UK.
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37
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Feller KD, Lagerholm S, Clubwala R, Silver MT, Haughey D, Ryan JM, Loew ER, Deutschlander ME, Kenyon KL. Characterization of photoreceptor cell types in the little brown bat Myotis lucifugus (Vespertilionidae). Comp Biochem Physiol B Biochem Mol Biol 2009; 154:412-8. [PMID: 19720154 DOI: 10.1016/j.cbpb.2009.08.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2009] [Revised: 08/21/2009] [Accepted: 08/21/2009] [Indexed: 11/26/2022]
Abstract
We report the expression of three visual opsins in the retina of the little brown bat (Myotis lucifugus, Vespertilionidae). Gene sequences for a rod-specific opsin and two cone-specific opsins were cloned from cDNA derived from bat eyes. Comparative sequence analyses indicate that the two cone opsins correspond to an ultraviolet short-wavelength opsin (SWS1) and a long-wavelength opsin (LWS). Immunocytochemistry using antisera to visual opsins revealed that the little brown bat retina contains two types of cone photoreceptors within a rod-dominated background. However, unlike other mammalian photoreceptors, M. lucifugus cones and rods are morphologically indistinguishable by light microscopy. Both photoreceptor types have a thin, elongated outer segment. Using microspectrophotometry we classified the absorption spectrum for the ubiquitous rods. Similar to other mammals, bat rhodopsin has an absorption peak near 500 nm. Although we were unable to confirm a spectral range, cellular and molecular analyses indicate that M. lucifugus expresses two types of cone visual pigments located within the photoreceptor layer. This study provides important insights into the visual capacity of a nocturnal microchiropteran species.
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Affiliation(s)
- K D Feller
- Department of Biology, Hobart and William Smith Colleges, Geneva, New York, 14456, USA
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38
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Müller B, Glösmann M, Peichl L, Knop GC, Hagemann C, Ammermüller J. Bat eyes have ultraviolet-sensitive cone photoreceptors. PLoS One 2009; 4:e6390. [PMID: 19636375 PMCID: PMC2712075 DOI: 10.1371/journal.pone.0006390] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2009] [Accepted: 06/26/2009] [Indexed: 11/18/2022] Open
Abstract
Mammalian retinae have rod photoreceptors for night vision and cone photoreceptors for daylight and colour vision. For colour discrimination, most mammals possess two cone populations with two visual pigments (opsins) that have absorption maxima at short wavelengths (blue or ultraviolet light) and long wavelengths (green or red light). Microchiropteran bats, which use echolocation to navigate and forage in complete darkness, have long been considered to have pure rod retinae. Here we use opsin immunohistochemistry to show that two phyllostomid microbats, Glossophaga soricina and Carollia perspicillata, possess a significant population of cones and express two cone opsins, a shortwave-sensitive (S) opsin and a longwave-sensitive (L) opsin. A substantial population of cones expresses S opsin exclusively, whereas the other cones mostly coexpress L and S opsin. S opsin gene analysis suggests ultraviolet (UV, wavelengths <400 nm) sensitivity, and corneal electroretinogram recordings reveal an elevated sensitivity to UV light which is mediated by an S cone visual pigment. Therefore bats have retained the ancestral UV tuning of the S cone pigment. We conclude that bats have the prerequisite for daylight vision, dichromatic colour vision, and UV vision. For bats, the UV-sensitive cones may be advantageous for visual orientation at twilight, predator avoidance, and detection of UV-reflecting flowers for those that feed on nectar.
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Affiliation(s)
- Brigitte Müller
- Max Planck Institute for Brain Research, Frankfurt/Main, Germany.
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Zhao H, Xu D, Zhou Y, Flanders J, Zhang S. Evolution of opsin genes reveals a functional role of vision in the echolocating little brown bat (Myotis lucifugus). BIOCHEM SYST ECOL 2009. [DOI: 10.1016/j.bse.2009.03.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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40
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Zhao H, Rossiter SJ, Teeling EC, Li C, Cotton JA, Zhang S. The evolution of color vision in nocturnal mammals. Proc Natl Acad Sci U S A 2009; 106:8980-5. [PMID: 19470491 PMCID: PMC2690009 DOI: 10.1073/pnas.0813201106] [Citation(s) in RCA: 138] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2008] [Indexed: 11/18/2022] Open
Abstract
Nonfunctional visual genes are usually associated with species that inhabit poor light environments (aquatic/subterranean/nocturnal), and these genes are believed to have lost function through relaxed selection acting on the visual system. Indeed, the visual system is so adaptive that the reconstruction of intact ancestral opsin genes has been used to reject nocturnality in ancestral primates. To test these assertions, we examined the functionality of the short and medium- to long-wavelength opsin genes in a group of mammals that are supremely adapted to a nocturnal niche: the bats. We sequenced the visual cone opsin genes in 33 species of bat with diverse sensory ecologies and reconstructed their evolutionary history spanning 65 million years. We found that, whereas the long-wave opsin gene was conserved in all species, the short-wave opsin gene has undergone dramatic divergence among lineages. The occurrence of gene defects in the short-wave opsin gene leading to loss of function was found to directly coincide with the origin of high-duty-cycle echolocation and changes in roosting ecology in some lineages. Our findings indicate that both opsin genes have been under purifying selection in the majority bats despite a long history of nocturnality. However, when spectacular losses do occur, these result from an evolutionary sensory modality tradeoff, most likely driven by subtle shifts in ecological specialization rather than a nocturnal lifestyle. Our results suggest that UV color vision plays a considerably more important role in nocturnal mammalian sensory ecology than previously appreciated and highlight the caveat of inferring light environments from visual opsins and vice versa.
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Affiliation(s)
- Huabin Zhao
- Institute of Zoology and Graduate University, Chinese Academy of Sciences, Beijing 100080, China
- School of Life Sciences, East China Normal University, Shanghai 200062, China
| | - Stephen J. Rossiter
- School of Biological and Chemical Sciences, Queen Mary, University of London, London E1 4NS, United Kingdom; and
| | - Emma C. Teeling
- UCD School of Biology and Environmental Science and UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland
| | - Chanjuan Li
- School of Life Sciences, East China Normal University, Shanghai 200062, China
| | - James A. Cotton
- School of Biological and Chemical Sciences, Queen Mary, University of London, London E1 4NS, United Kingdom; and
| | - Shuyi Zhang
- School of Life Sciences, East China Normal University, Shanghai 200062, China
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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]
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Heffner RS, Koay G, Heffner HE. Sound localization acuity and its relation to vision in large and small fruit-eating bats: II. Non-echolocating species, Eidolon helvum and Cynopterus brachyotis. Hear Res 2008; 241:80-6. [PMID: 18571883 PMCID: PMC2531287 DOI: 10.1016/j.heares.2008.05.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2008] [Revised: 05/05/2008] [Accepted: 05/06/2008] [Indexed: 11/19/2022]
Abstract
Passive sound-localization acuity for 100-msec noise bursts was determined behaviorally for two species of non-echolocating bats: the Straw-colored fruit bat, Eidolon helvum, a large frugivore, and the Dog-faced fruit bat, Cynopterus brachyotis, a small frugivore. The mean minimum audible angle for two E. helvum was 11.7 degrees, and for two C. brachyotis was 10.5 degrees. This places their passive sound-localization acuity near the middle of the range for echolocating bats as well as the middle of the range for other mammals. Sound-localization acuity varies widely among mammals, and the best predictor of this auditory function remains the width of the field of best vision (r=.89, p<.0001). Among echolocating and non-echolocating bats, as well as among other mammals, the use of hearing to direct the eyes to the source of a sound still appears to serve as an important selective factor for sound localization. Absolute visual acuity and the magnitude of the binaural locus cues available to a species remain unreliable predictors of sound-localization acuity.
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Affiliation(s)
- R S Heffner
- Department of Psychology, University of Toledo, Toledo, OH 43606, United States.
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