1
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Tetrault E, Aaronson B, Gilbert MC, Albertson RC. Foraging-induced craniofacial plasticity is associated with an early, robust and dynamic transcriptional response. Proc Biol Sci 2024; 291:20240215. [PMID: 38654651 PMCID: PMC11040245 DOI: 10.1098/rspb.2024.0215] [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: 02/12/2024] [Accepted: 03/19/2024] [Indexed: 04/26/2024] Open
Abstract
Phenotypic plasticity is the ability of a single genotype to vary its phenotype in response to the environment. Plasticity of the skeletal system in response to mechanical input is widely studied, but the timing of its transcriptional regulation is not well understood. Here, we used the cichlid feeding apparatus to examine the transcriptional dynamics of skeletal plasticity over time. Using three closely related species that vary in their ability to remodel bone and a panel of 11 genes, including well-studied skeletal differentiation markers and newly characterized environmentally sensitive genes, we examined plasticity at one, two, four and eight weeks following the onset of alternate foraging challenges. We found that the plastic species exhibited environment-specific bursts in gene expression beginning at one week, followed by a sharp decline in levels, while the species with more limited plasticity exhibited consistently low levels of gene expression. This trend held across nearly all genes, suggesting that it is a hallmark of the larger plasticity regulatory network. We conclude that plasticity of the cichlid feeding apparatus is not the result of slowly accumulating gene expression difference over time, but rather is stimulated by early bursts of environment-specific gene expression followed by a return to homeostatic levels.
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Affiliation(s)
- Emily Tetrault
- Molecular and Cell Biology Graduate Program, University of Massachusetts, Amherst, MA 01003, USA
| | - Ben Aaronson
- Department of Biology, University of Massachusetts, Amherst, MA 01003, USA
| | - Michelle C. Gilbert
- Department of Biology, Pennsylvania State University, State College, PA 16802, USA
| | - R. Craig Albertson
- Department of Biology, University of Massachusetts, Amherst, MA 01003, USA
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2
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Hagen JFD, Roberts NS, Johnston RJ. The evolutionary history and spectral tuning of vertebrate visual opsins. Dev Biol 2023; 493:40-66. [PMID: 36370769 PMCID: PMC9729497 DOI: 10.1016/j.ydbio.2022.10.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 10/27/2022] [Accepted: 10/31/2022] [Indexed: 11/11/2022]
Abstract
Many animals depend on the sense of vision for survival. In eumetazoans, vision requires specialized, light-sensitive cells called photoreceptors. Light reaches the photoreceptors and triggers the excitation of light-detecting proteins called opsins. Here, we describe the story of visual opsin evolution from the ancestral bilaterian to the extant vertebrate lineages. We explain the mechanisms determining color vision of extant vertebrates, focusing on opsin gene losses, duplications, and the expression regulation of vertebrate opsins. We describe the sequence variation both within and between species that has tweaked the sensitivities of opsin proteins towards different wavelengths of light. We provide an extensive resource of wavelength sensitivities and mutations that have diverged light sensitivity in many vertebrate species and predict how these mutations were accumulated in each lineage based on parsimony. We suggest possible natural and sexual selection mechanisms underlying these spectral differences. Understanding how molecular changes allow for functional adaptation of animals to different environments is a major goal in the field, and therefore identifying mutations affecting vision and their relationship to photic selection pressures is imperative. The goal of this review is to provide a comprehensive overview of our current understanding of opsin evolution in vertebrates.
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Affiliation(s)
- Joanna F D Hagen
- Department of Biology, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD, 21218, USA
| | - Natalie S Roberts
- Department of Biology, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD, 21218, USA
| | - Robert J Johnston
- Department of Biology, Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD, 21218, USA.
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3
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Wilwert E, Etienne RS, van de Zande L, Maan ME. Contribution of opsins and chromophores to cone pigment variation across populations of Lake Victoria cichlids. JOURNAL OF FISH BIOLOGY 2022; 101:365-377. [PMID: 34860424 PMCID: PMC9543281 DOI: 10.1111/jfb.14969] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 09/24/2021] [Accepted: 11/25/2021] [Indexed: 06/13/2023]
Abstract
Adaptation to heterogeneous sensory environments has been implicated as a key parameter in speciation. Cichlid fish are a textbook example of divergent visual adaptation, mediated by variation in the sequences and expression levels of cone opsin genes (encoding the protein component of visual pigments). In some vertebrates including fish, visual sensitivity is also tuned by the ratio of vitamin A1 /A2 -derived chromophores (i.e., the light-sensitive component of the visual pigment bound to the opsin protein), where higher proportions of A2 cause a more red-shifted wavelength absorbance. This study explores the variation in chromophore ratios across multiple cichlid populations in Lake Victoria, using as a proxy the expression of the gene Cyp27c1, which has been shown to regulate the conversion of vitamin A1 into vitamin A2 in several vertebrates. This study focuses on sympatric Pundamilia cichlids, where species with blue or red male coloration co-occur at multiple islands but occupy different depths and consequently different visual habitats. In the red species, we found higher cyp27c1 expression in populations from turbid waters than from clear waters, but there was no such pattern in the blue species. Across populations, differences between the sympatric species in cyp27c1 expression had a consistent relationship with species differences in opsin expression patterns, but the red/blue identity reversed between clear and turbid waters. To assess the contribution of heritable vs. environmental causes of variation, we tested whether light manipulations induce a change in cyp27c1 expression in the laboratory. We found that cyp27c1 expression was not influenced by experimental light conditions, suggesting that the observed variation in the wild is due to genetic differences. Nonetheless, compared to other cichlid species, cyp27c1 is expressed at very low levels in Pundamilia, suggesting that it may not be relevant for visual adaptation in this species. Conclusively, establishing the biological importance of this variation requires testing of actual A1 /A2 ratios in the eye, as well as its consequences for visual performance.
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Affiliation(s)
- Elodie Wilwert
- Groningen Institute for Evolutionary Life Sciences (GELIFES)GroningenThe Netherlands
| | - Rampal S. Etienne
- Groningen Institute for Evolutionary Life Sciences (GELIFES)GroningenThe Netherlands
| | - Louis van de Zande
- Groningen Institute for Evolutionary Life Sciences (GELIFES)GroningenThe Netherlands
| | - Martine E. Maan
- Groningen Institute for Evolutionary Life Sciences (GELIFES)GroningenThe Netherlands
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4
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Fish Behavior for the Exotic Pet Practitioner. Vet Clin North Am Exot Anim Pract 2021; 24:211-227. [PMID: 33189252 DOI: 10.1016/j.cvex.2020.09.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Interpreting fish behavior is an important component of providing veterinary care. There are over 28,000 species of fish and while only a handful are commonly encountered by exotic pet and public display veterinarians, there are still hundreds of species to consider. Three models-natural history (species typical modal action patterns), medical (disease state), and learning experience (classical and operant conditioning)-are useful for taking an actionable, holistic approach to interpreting behavior. Models help clinicians formulate appropriate differentials, ensuring they do not exclusively consider disease, particularly in unfamiliar species.
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5
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Mehta TK, Koch C, Nash W, Knaack SA, Sudhakar P, Olbei M, Bastkowski S, Penso-Dolfin L, Korcsmaros T, Haerty W, Roy S, Di-Palma F. Evolution of regulatory networks associated with traits under selection in cichlids. Genome Biol 2021; 22:25. [PMID: 33419455 PMCID: PMC7791837 DOI: 10.1186/s13059-020-02208-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 11/18/2020] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Seminal studies of vertebrate protein evolution speculated that gene regulatory changes can drive anatomical innovations. However, very little is known about gene regulatory network (GRN) evolution associated with phenotypic effect across ecologically diverse species. Here we use a novel approach for comparative GRN analysis in vertebrate species to study GRN evolution in representative species of the most striking examples of adaptive radiations, the East African cichlids. We previously demonstrated how the explosive phenotypic diversification of East African cichlids can be attributed to diverse molecular mechanisms, including accelerated regulatory sequence evolution and gene expression divergence. RESULTS To investigate these mechanisms across species at a genome-wide scale, we develop a novel computational pipeline that predicts regulators for co-extant and ancestral co-expression modules along a phylogeny, and candidate regulatory regions associated with traits under selection in cichlids. As a case study, we apply our approach to a well-studied adaptive trait-the visual system-for which we report striking cases of network rewiring for visual opsin genes, identify discrete regulatory variants, and investigate their association with cichlid visual system evolution. In regulatory regions of visual opsin genes, in vitro assays confirm that transcription factor binding site mutations disrupt regulatory edges across species and segregate according to lake species phylogeny and ecology, suggesting GRN rewiring in radiating cichlids. CONCLUSIONS Our approach reveals numerous novel potential candidate regulators and regulatory regions across cichlid genomes, including some novel and some previously reported associations to known adaptive evolutionary traits.
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Affiliation(s)
| | - Christopher Koch
- Department of Biostatistics and Medical Informatics, UW Madison, Madison, USA
| | | | - Sara A Knaack
- Wisconsin Institute for Discovery (WID), Madison, USA
| | | | - Marton Olbei
- Earlham Institute (EI), Norwich, UK
- Quadram Institute, Norwich, UK
| | - Sarah Bastkowski
- Earlham Institute (EI), Norwich, UK
- Quadram Institute, Norwich, UK
| | | | - Tamas Korcsmaros
- Earlham Institute (EI), Norwich, UK
- Quadram Institute, Norwich, UK
| | | | - Sushmita Roy
- Department of Biostatistics and Medical Informatics, UW Madison, Madison, USA.
- Wisconsin Institute for Discovery (WID), Madison, USA.
- Department of Computer Sciences, UW Madison, Madison, USA.
| | - Federica Di-Palma
- Earlham Institute (EI), Norwich, UK.
- Norwich Medical School, University of East Anglia, Norwich, UK.
- School of Biological Sciences, University of East Anglia, Norwich, UK.
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6
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Musilova Z, Indermaur A, Bitja‐Nyom AR, Omelchenko D, Kłodawska M, Albergati L, Remišová K, Salzburger W. Evolution of the visual sensory system in cichlid fishes from crater lake Barombi Mbo in Cameroon. Mol Ecol 2019; 28:5010-5031. [DOI: 10.1111/mec.15217] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 08/09/2019] [Accepted: 08/13/2019] [Indexed: 01/09/2023]
Affiliation(s)
- Zuzana Musilova
- Department of Zoology Charles University in Prague Prague Czech Republic
- Zoological Institute University of Basel Basel Switzerland
| | | | - Arnold Roger Bitja‐Nyom
- Department of Biological Sciences University of Ngaoundéré Ngaoundéré Cameroon
- Department of Management of Fisheries and Aquatic Ecosystems University of Douala Douala Cameroon
| | - Dmytro Omelchenko
- Department of Zoology Charles University in Prague Prague Czech Republic
| | - Monika Kłodawska
- Department of Zoology Charles University in Prague Prague Czech Republic
| | - Lia Albergati
- Zoological Institute University of Basel Basel Switzerland
| | - Kateřina Remišová
- Department of Physiology Charles University in Prague Prague Czech Republic
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7
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Escobar-Camacho D, Taylor MA, Cheney KL, Green NF, Marshall NJ, Carleton KL. Color discrimination thresholds in a cichlid fish: Metriaclima benetos. J Exp Biol 2019; 222:jeb201160. [PMID: 31399486 PMCID: PMC6765173 DOI: 10.1242/jeb.201160] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Accepted: 08/05/2019] [Indexed: 01/31/2023]
Abstract
Color vision is essential for animals as it allows them to detect, recognize and discriminate between colored objects. Studies analyzing color vision require an integrative approach, combining behavioral experiments, physiological models and quantitative analyses of photoreceptor stimulation. Here, we demonstrate, for the first time, the limits of chromatic discrimination in Metriaclima benetos, a rock-dwelling cichlid from Lake Malawi, using behavioral experiments and visual modeling. Fish were trained to discriminate between colored stimuli. Color discrimination thresholds were quantified by testing fish chromatic discrimination between the rewarded stimulus and distracter stimuli that varied in chromatic distance (ΔS). This was done under fluorescent lights alone and with additional violet lights. Our results provide two main outcomes. First, cichlid color discrimination thresholds correspond with predictions from the receptor noise limited (RNL) model but only if we assume a Weber fraction higher than the typical value of 5%. Second, cichlids may exhibit limited color constancy under certain lighting conditions as most individuals failed to discriminate colors when violet light was added. We further used the color discrimination thresholds obtained from these experiments to model color discrimination of actual fish colors and backgrounds under natural lighting for Lake Malawi. We found that, for M. benetos, blue is most chromatically contrasting against yellows and space-light, which might be important for discriminating male nuptial colorations and detecting males against the background. This study highlights the importance of lab-based behavioral experiments in understanding color vision and in parameterizing the assumptions of the RNL vision model for different species.
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Affiliation(s)
| | - Michaela A Taylor
- Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - Karen L Cheney
- School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
- Queensland Brain Institute, University of Queensland, Brisbane, QLD 4072, Australia
| | - Naomi F Green
- School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - N Justin Marshall
- Queensland Brain Institute, University of Queensland, Brisbane, QLD 4072, Australia
| | - Karen L Carleton
- Department of Biology, University of Maryland, College Park, MD 20742, USA
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8
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The relative importance of body size and UV coloration in influencing male-male competition in a lacertid lizard. Behav Ecol Sociobiol 2019. [DOI: 10.1007/s00265-019-2710-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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9
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Fuss T, John L, Schluessel V. Same or different? Abstract relational concept use in juvenile bamboo sharks and Malawi cichlids. Curr Zool 2018; 67:279-292. [PMID: 34616920 PMCID: PMC8489000 DOI: 10.1093/cz/zoy059] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 07/06/2018] [Indexed: 11/17/2022] Open
Abstract
Sorting objects and events into categories and concepts is an important cognitive prerequisite that spares an individual the learning of every object or situation encountered in its daily life. Accordingly, specific items are classified in general groups that allow fast responses to novel situations. The present study assessed whether bamboo sharks Chiloscyllium griseum and Malawi cichlids Pseudotropheus zebra can distinguish sets of stimuli (each stimulus consisting of two abstract, geometric objects) that meet two conceptual preconditions, i.e., (1) “sameness” versus “difference” and (2) a certain spatial arrangement of both objects. In two alternative forced choice experiments, individuals were first trained to choose two different, vertically arranged objects from two different but horizontally arranged ones. Pair discriminations were followed by extensive transfer test experiments. Transfer tests using stimuli consisting of (a) black and gray circles and (b) squares with novel geometric patterns provided conflicting information with respect to the learnt rule “choose two different, vertically arranged objects”, thereby investigating (1) the individuals’ ability to transfer previously gained knowledge to novel stimuli and (2) the abstract relational concept(s) or rule(s) applied to categorize these novel objects. Present results suggest that the level of processing and usage of both abstract concepts differed considerably between bamboo sharks and Malawi cichlids. Bamboo sharks seemed to combine both concepts—although not with equal but hierarchical prominence—pointing to advanced cognitive capabilities. Conversely, Malawi cichlids had difficulties in discriminating between symbols and failed to apply the acquired training knowledge on new sets of geometric and, in particular, gray-level transfer stimuli.
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Affiliation(s)
- Theodora Fuss
- Institute of Zoology, Rheinische Friedrich-Wilhelms-University Bonn, Meckenheimer Allee 169, Bonn, 53115, Germany
| | - Leonie John
- Institute of Zoology, Rheinische Friedrich-Wilhelms-University Bonn, Meckenheimer Allee 169, Bonn, 53115, Germany
| | - Vera Schluessel
- Institute of Zoology, Rheinische Friedrich-Wilhelms-University Bonn, Meckenheimer Allee 169, Bonn, 53115, Germany
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10
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Terai Y, Miyagi R, Aibara M, Mizoiri S, Imai H, Okitsu T, Wada A, Takahashi-Kariyazono S, Sato A, Tichy H, Mrosso HDJ, Mzighani SI, Okada N. Visual adaptation in Lake Victoria cichlid fishes: depth-related variation of color and scotopic opsins in species from sand/mud bottoms. BMC Evol Biol 2017; 17:200. [PMID: 28830359 PMCID: PMC5568302 DOI: 10.1186/s12862-017-1040-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 08/07/2017] [Indexed: 11/17/2022] Open
Abstract
Background For Lake Victoria cichlid species inhabiting rocky substrates with differing light regimes, it has been proposed that adaptation of the long-wavelength-sensitive (LWS) opsin gene triggered speciation by sensory drive through color signal divergence. The extensive and continuous sand/mud substrates are also species-rich, and a correlation between male nuptial coloration and the absorption of LWS pigments has been reported. However, the factors driving genetic and functional diversity of LWS pigments in sand/mud habitats are still unresolved. Results To address this issue, nucleotide sequences of eight opsin genes were compared in ten Lake Victoria cichlid species collected from sand/mud bottoms. Among eight opsins, the LWS and rod-opsin (RH1) alleles were diversified and one particular allele was dominant or fixed in each species. Natural selection has acted on and fixed LWS alleles in each species. The functions of LWS and RH1 alleles were measured by absorption of reconstituted A1- and A2-derived visual pigments. The absorption of pigments from RH1 alleles most common in deep water were largely shifted toward red, whereas those of LWS alleles were largely shifted toward blue in both A1 and A2 pigments. In both RH1 and LWS pigments, A2-derived pigments were closer to the dominant light in deep water, suggesting the possibility of the adaptation of A2-derived pigments to depth-dependent light regimes. Conclusions The RH1 and LWS sequences may be diversified for adaptation of A2-derived pigments to different light environments in sand/mud substrates. Diversification of the LWS alleles may have originally taken place in riverine environments, with a new mutation occurring subsequently in Lake Victoria. Electronic supplementary material The online version of this article (doi:10.1186/s12862-017-1040-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yohey Terai
- Department of Evolutionary Studies of Biosystems, SOKENDAI (The Graduate University for Advanced Studies), Shonan Village, Hayama, Kanagawa, 240-0193, Japan. .,Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, 226-8501, Japan.
| | - Ryutaro Miyagi
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, 226-8501, Japan
| | - Mitsuto Aibara
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, 226-8501, Japan
| | - Shinji Mizoiri
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, 226-8501, Japan
| | - Hiroo Imai
- Department of Cellular and Molecular Biology, Primate Research Institute, Kyoto University, Kyoto, Japan
| | - Takashi Okitsu
- Department of Organic Chemistry for Life Science, Kobe Pharmaceutical University, 4-19-1, Motoyamakita-machi, Higashinada-ku, Kobe, 658-8558, Japan
| | - Akimori Wada
- Department of Organic Chemistry for Life Science, Kobe Pharmaceutical University, 4-19-1, Motoyamakita-machi, Higashinada-ku, Kobe, 658-8558, Japan
| | - Shiho Takahashi-Kariyazono
- Department of Evolutionary Studies of Biosystems, SOKENDAI (The Graduate University for Advanced Studies), Shonan Village, Hayama, Kanagawa, 240-0193, Japan
| | - Akie Sato
- Department of Anatomy and Cytohistology, School of Dental Medicine, Tsurumi University, 2-1-3 Tsurumi, Tsurumi-ku, Yokohama, 230-8501, Japan
| | - Herbert Tichy
- Max-Planck-Institut für Biologie, Abteilung Immungenetik, Corrensstrasse 42, 72076, Tübingen, Germany
| | | | - Semvua I Mzighani
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, 226-8501, Japan.,Tanzania Fisheries Research Institute (TAFIRI), Mwanza, Tanzania
| | - Norihiro Okada
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, 226-8501, Japan. .,Present address: Department of Life Sciences, National Cheng Kung University, 701, Tainan, Taiwan. .,Present address: Foundation for Advancement of International Science (FAIS), Tsukuba, Japan.
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11
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Escobar-Camacho D, Marshall J, Carleton KL. Behavioral color vision in a cichlid fish: Metriaclima benetos. ACTA ACUST UNITED AC 2017; 220:2887-2899. [PMID: 28546509 DOI: 10.1242/jeb.160473] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 05/23/2017] [Indexed: 01/30/2023]
Abstract
Color vision is the capacity to discriminate color regardless of brightness. It is essential for many fish species as they rely on color discrimination for numerous ecological tasks. The study of color vision is important because it can unveil the mechanisms that shape coloration patterns, visual system sensitivities and, hence, visual signals. In order to better understand the mechanisms underlying color vision, an integrative approach is necessary. This usually requires combining behavioral, physiological and genetic experiments with quantitative modeling, resulting in a distinctive characterization of the visual system. Here, we provide new data on the color vision of a rock-dwelling cichlid from Lake Malawi: Metriaclima benetos. For this study we used a behavioral approach to demonstrate color vision through classical conditioning, complemented with modeling of color vision to estimate color contrast. For our experiments we took into account opsin coexpression and considered whether cichlids exhibit a dichromatic or a trichromatic visual system. Behavioral experiments confirmed color vision in M. benetos; most fish were significantly more likely to choose the trained over the distracter stimuli, irrespective of brightness. Our results are supported by visual modeling that suggests that cichlids are trichromats and achieve color vision through color opponency mechanisms, which are a result of three different photoreceptor channels. Our analyses also suggest that opsin coexpression can negatively affect perceived color contrast. This study is particularly relevant for research on the cichlid lineage because cichlid visual capabilities and coloration patterns are implicated in their adaptive radiation.
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Affiliation(s)
| | - Justin Marshall
- Queensland Brain Institute, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Karen L Carleton
- Department of Biology, University of Maryland, College Park, MD 20742, USA
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12
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Miyazaki T, Kondrashev SL, Kasagi S, Mizusawa K, Takahashi A. Sequence and localization of an ultraviolet (sws1) opsin in the retina of the Japanese sardine Sardinops melanostictus (Teleostei: Clupeiformes). JOURNAL OF FISH BIOLOGY 2017; 90:954-967. [PMID: 27861878 DOI: 10.1111/jfb.13210] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 10/13/2016] [Indexed: 06/06/2023]
Abstract
A full-length complementary (c)DNA encoding ultraviolet (UV)-sensitive opsin (sws1) was isolated from the retina of the Japanese sardine Sardinops melanostictus. The sws1 phylogenetic tree showed a sister group relationship with the Cypriniformes, following the ray-finned fish phylogeny. By expressing reconstituted opsin in vitro, it was determined that the maximum absorbance spectrum (λmax ) of sws1 is around 382 nm, being intermediate in position between two subtypes of sws1 pigment that are UV sensitive (λmax = 355-380 nm) and violet sensitive (λmax = 388-455 nm), which have been reported to date. The ocular media transmitted >20% transmittance of light in the range of 360-600 nm. In situ hybridization analyses revealed that sws1 messenger (m)RNA is localized in a central single cone surrounded by four double cones in a square mosaic. The square mosaic occupies the ventro-temporal quadrant of the retina and the in situ hybridization signals were dominant in this area suggesting that the fish may use UV vision when looking upward. Based on these results, considerable significances of potential UV sensitivity, in relation to characteristic habits of S. melanostictus, are discussed.
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Affiliation(s)
- T Miyazaki
- Department of Life Sciences, Graduate School of Bioresources, Mie University, Kurimamachiya 1577, Tsu, Mie, 514-8507, Japan
| | - S L Kondrashev
- A. V. Zhirmunsky Institute of Marine Biology, Far Eastern Branch, Russian Academy of Sciences, Vladivostok, 690041, Russia
| | - S Kasagi
- School of Marine Biosciences, Kitasato University, Kitasato 1-15-1, Minami-ku, Sagamihara, Kanagawa, 252-0373, Japan
| | - K Mizusawa
- School of Marine Biosciences, Kitasato University, Kitasato 1-15-1, Minami-ku, Sagamihara, Kanagawa, 252-0373, Japan
| | - A Takahashi
- School of Marine Biosciences, Kitasato University, Kitasato 1-15-1, Minami-ku, Sagamihara, Kanagawa, 252-0373, Japan
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13
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Balzarini V, Taborsky M, Villa F, Frommen JG. Computer animations of color markings reveal the function of visual threat signals in Neolamprologus pulcher. Curr Zool 2017; 63:45-54. [PMID: 29491962 PMCID: PMC5804153 DOI: 10.1093/cz/zow086] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 07/19/2016] [Indexed: 11/24/2022] Open
Abstract
Visual signals, including changes in coloration and color patterns, are frequently used by animals to convey information. During contests, body coloration and its changes can be used to assess an opponent's state or motivation. Communication of aggressive propensity is particularly important in group-living animals with a stable dominance hierarchy, as the outcome of aggressive interactions determines the social rank of group members. Neolamprologus pulcher is a cooperatively breeding cichlid showing frequent within-group aggression. Both sexes exhibit two vertical black stripes on the operculum that vary naturally in shape and darkness. During frontal threat displays these patterns are actively exposed to the opponent, suggesting a signaling function. To investigate the role of operculum stripes during contests we manipulated their darkness in computer animated pictures of the fish. We recorded the responses in behavior and stripe darkness of test subjects to which these animated pictures were presented. Individuals with initially darker stripes were more aggressive against the animations and showed more operculum threat displays. Operculum stripes of test subjects became darker after exposure to an animation exhibiting a pale operculum than after exposure to a dark operculum animation, highlighting the role of the darkness of this color pattern in opponent assessment. We conclude that (i) the black stripes on the operculum of N. pulcher are a reliable signal of aggression and dominance, (ii) these markings play an important role in opponent assessment, and (iii) 2D computer animations are well suited to elicit biologically meaningful short-term aggressive responses in this widely used model system of social evolution.
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Affiliation(s)
- Valentina Balzarini
- Institute of Ecology and Evolution, Behavioral Ecology Division, University of Bern, Wohlenstrasse 50a, 3032 Hinterkappelen, Switzerland
| | - Michael Taborsky
- Institute of Ecology and Evolution, Behavioral Ecology Division, University of Bern, Wohlenstrasse 50a, 3032 Hinterkappelen, Switzerland
| | - Fabienne Villa
- Institute of Ecology and Evolution, Behavioral Ecology Division, University of Bern, Wohlenstrasse 50a, 3032 Hinterkappelen, Switzerland
| | - Joachim G. Frommen
- Institute of Ecology and Evolution, Behavioral Ecology Division, University of Bern, Wohlenstrasse 50a, 3032 Hinterkappelen, Switzerland
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14
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Carleton KL, Dalton BE, Escobar-Camacho D, Nandamuri SP. Proximate and ultimate causes of variable visual sensitivities: Insights from cichlid fish radiations. Genesis 2016; 54:299-325. [PMID: 27061347 DOI: 10.1002/dvg.22940] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Revised: 04/01/2016] [Accepted: 04/04/2016] [Indexed: 01/24/2023]
Abstract
Animals vary in their sensitivities to different wavelengths of light. Sensitivity differences can have fitness implications in terms of animals' ability to forage, find mates, and avoid predators. As a result, visual systems are likely selected to operate in particular lighting environments and for specific visual tasks. This review focuses on cichlid vision, as cichlids have diverse visual sensitivities, and considerable progress has been made in determining the genetic basis for this variation. We describe both the proximate and ultimate mechanisms shaping cichlid visual diversity using the structure of Tinbergen's four questions. We describe (1) the molecular mechanisms that tune visual sensitivities including changes in opsin sequence and expression; (2) the evolutionary history of visual sensitivity across the African cichlid flocks; (3) the ontological changes in visual sensitivity and how modifying this developmental program alters sensitivities among species; and (4) the fitness benefits of spectral tuning mechanisms with respect to survival and mating success. We further discuss progress to unravel the gene regulatory networks controlling opsin expression and suggest that a simple genetic architecture contributes to the lability of opsin gene expression. Finally, we identify unanswered questions including whether visual sensitivities are experiencing selection, and whether similar spectral tuning mechanisms shape visual sensitivities of other fishes. genesis 54:299-325, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Karen L Carleton
- Department of Biology, University of Maryland, College Park, Maryland
| | - Brian E Dalton
- Department of Biology, University of Maryland, College Park, Maryland
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15
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Phillips GAC, Carleton KL, Marshall NJ. Multiple Genetic Mechanisms Contribute to Visual Sensitivity Variation in the Labridae. Mol Biol Evol 2015; 33:201-15. [PMID: 26464127 DOI: 10.1093/molbev/msv213] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Coral reefs are one of the most spectrally diverse environments, both in terms of habitat and animal color. Species identity, sex, and camouflage are drivers of the phenotypic diversity seen in coral reef fishes, but how the phenotypic diversity is reflected in the genotype remains to be answered. The labrids are a large, polyphyletic family of coral reef fishes that display a diverse range of colors, including developmental color morphs and extensive behavioral ecologies. Here, we assess the opsin sequence and expression diversity among labrids from the Great Barrier Reef, Australia. We found that labrids express a diverse palette of visual opsins, with gene duplications in both RH2 and LWS genes. The majority of opsins expressed were within the mid-to-long wavelength sensitive classes (RH2 and LWS). Three of the labrid species expressed SWS1 (ultra-violet sensitive) opsins with the majority expressing the violet-sensitive SWS2B gene and none expressing SWS2A. We used knowledge about spectral tuning sites to calculate approximate spectral sensitivities (λmax) for individual species' visual pigments, which corresponded well with previously published λmax values for closely related species (SWS1: 356-370 nm; SWS2B: 421-451 nm; RH2B: 452-492 nm; RH2A: 516-528 nm; LWS1: 554-555 nm; LWS2: 561-562 nm). In contrast to the phenotypic diversity displayed via color patterns and feeding ecology, there was little amino acid diversity within the known opsin sequence tuning sites. However, gene duplications and differential expression provide alternative mechanisms for tuning visual pigments, resulting in variable visual sensitivities among labrid species.
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Affiliation(s)
| | | | - N Justin Marshall
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
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16
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Fisher KJ, Recupero DL, Schrey AW, Draud MJ. Molecular Evidence of Long Wavelength Spectral Sensitivity in the Reverse Sexually Dichromatic Convict Cichlid (Amatitlania nigrofasciata). COPEIA 2015. [DOI: 10.1643/ci-14-088] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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17
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Dalton BE, Loew ER, Cronin TW, Carleton KL. Spectral tuning by opsin coexpression in retinal regions that view different parts of the visual field. Proc Biol Sci 2015; 281:rspb.2014.1980. [PMID: 25377457 DOI: 10.1098/rspb.2014.1980] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Vision frequently mediates critical behaviours, and photoreceptors must respond to the light available to accomplish these tasks. Most photoreceptors are thought to contain a single visual pigment, an opsin protein bound to a chromophore, which together determine spectral sensitivity. Mechanisms of spectral tuning include altering the opsin, changing the chromophore and incorporating pre-receptor filtering. A few exceptions to the use of a single visual pigment have been documented in which a single mature photoreceptor coexpresses opsins that form spectrally distinct visual pigments, and in these exceptions the functional significance of coexpression is unclear. Here we document for the first time photoreceptors coexpressing spectrally distinct opsin genes in a manner that tunes sensitivity to the light environment. Photoreceptors of the cichlid fish, Metriaclima zebra, mix different pairs of opsins in retinal regions that view distinct backgrounds. The mixing of visual pigments increases absorbance of the corresponding background, potentially aiding the detection of dark objects. Thus, opsin coexpression may be a novel mechanism of spectral tuning that could be useful for detecting prey, predators and mates. However, our calculations show that coexpression of some opsins can hinder colour discrimination, creating a trade-off between visual functions.
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Affiliation(s)
- Brian E Dalton
- Department of Biology, University of Maryland, Baltimore County, MD 21250, USA Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - Ellis R Loew
- Department of Biomedical Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Thomas W Cronin
- Department of Biology, University of Maryland, Baltimore County, MD 21250, USA
| | - Karen L Carleton
- Department of Biology, University of Maryland, College Park, MD 20742, USA
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18
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Schluessel V, Kortekamp N, Cortes JAO, Klein A, Bleckmann H. Perception and discrimination of movement and biological motion patterns in fish. Anim Cogn 2015; 18:1077-91. [PMID: 25981056 DOI: 10.1007/s10071-015-0876-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Revised: 04/29/2015] [Accepted: 05/02/2015] [Indexed: 01/29/2023]
Abstract
Vision is of primary importance for many fish species, as is the recognition of movement. With the exception of one study, assessing the influence of conspecific movement on shoaling behaviour, the perception of biological motion in fish had not been studied in a cognitive context. The aim of the present study was therefore to assess the discrimination abilities of two teleost species in regard to simple and complex movement patterns of dots and objects, including biological motion patterns using point and point-light displays (PDs and PLDs). In two-alternative forced-choice experiments, in which choosing the designated positive stimulus was food-reinforced, fish were first tested in their ability to distinguish the video of a stationary black dot on a light background from the video of a moving black dot presented at different frequencies and amplitudes. While all fish succeeded in learning the task, performance declined with decreases in either or both parameters. In subsequent tests, cichlids and damselfish distinguished successfully between the videos of two dots moving at different speeds and amplitudes, between two moving dot patterns (sinus vs. expiring sinus) and between animated videos of two moving organisms (trout vs. eel). Transfer tests following the training of the latter showed that fish were unable to identify the positive stimulus (trout) by means of its PD alone, thereby indicating that the ability of humans to spontaneously recognize an organism based on its biological motion may not be present in fish. All participating individuals successfully discriminated between two PDs and two PLDs after a short period of training, indicating that biological motions presented in form of PLDs are perceived and can be distinguished. Results were the same for the presentation of dark dots on a light background and light dots on a dark background.
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Affiliation(s)
- V Schluessel
- Institute of Zoology, Rheinische Friedrich-Wilhelms-Universität Bonn, Poppelsdorfer Schloss, Meckenheimer Allee 169, 53115, Bonn, Germany,
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19
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York RA, Patil C, Hulsey CD, Streelman JT, Fernald RD. Evolution of bower building in Lake Malawi cichlid fish: phylogeny, morphology, and behavior. Front Ecol Evol 2015. [DOI: 10.3389/fevo.2015.00018] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
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Schluessel V, Beil O, Weber T, Bleckmann H. Symmetry perception in bamboo sharks (Chiloscyllium griseum) and Malawi cichlids (Pseudotropheus sp.). Anim Cogn 2014; 17:1187-205. [DOI: 10.1007/s10071-014-0751-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Revised: 04/07/2014] [Accepted: 04/20/2014] [Indexed: 10/25/2022]
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Pérez i de Lanuza G, Font E. Ultraviolet vision in lacertid lizards: evidence from retinal structure, eye transmittance, SWS1 visual pigment genes, and behaviour. J Exp Biol 2014; 217:2899-909. [DOI: 10.1242/jeb.104281] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Abstract
Ultraviolet (UV) vision and UV colour patches have been reported in a wide range of taxa and are increasingly appreciated as an integral part of vertebrate visual perception and communication systems. Previous studies with Lacertidae, a lizard family with diverse and complex coloration, have revealed the existence of UV-reflecting patches that may function as social signals. However, confirmation of the signalling role of UV coloration requires demonstrating that the lizards are capable of vision in the UV waveband. Here we use a multidisciplinary approach to characterize the visual sensitivity of a diverse sample of lacertid species. Spectral transmission measurements of the ocular media show that wavelengths down to 300 nm are transmitted in all the species sampled. Four retinal oil droplet types can be identified in the lacertid retina. Two types are pigmented and two are colourless. Fluorescence microscopy reveals that a type of colourless droplet is UV-transmitting and may thus be associated with UV-sensitive cones. DNA sequencing shows that lacertids have a functional SWS1 opsin, very similar at 13 critical sites to that in the presumed ancestral vertebrate (which was UV-sensitive) and other UV-sensitive lizards. Finally, males of Podarcis muralis are capable of discriminating between two views of the same stimulus that differ only in the presence/absence of UV radiance. Taken together, these results provide convergent evidence of UV vision in lacertids, very likely by means of an independent photopigment. Moreover, the presence of four oil droplet types suggests that lacertids have a four-cone colour vision system.
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22
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Schluessel V, Kraniotakes H, Bleckmann H. Visual discrimination of rotated 3D objects in Malawi cichlids (Pseudotropheus sp.): a first indication for form constancy in fishes. Anim Cogn 2013; 17:359-71. [DOI: 10.1007/s10071-013-0667-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 07/26/2013] [Accepted: 08/05/2013] [Indexed: 10/26/2022]
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23
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Sabbah S, Hawryshyn CW. What has driven the evolution of multiple cone classes in visual systems: object contrast enhancement or light flicker elimination? BMC Biol 2013; 11:77. [PMID: 23826998 PMCID: PMC3720213 DOI: 10.1186/1741-7007-11-77] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Accepted: 06/27/2013] [Indexed: 11/10/2022] Open
Abstract
Background Two competing theories have been advanced to explain the evolution of multiple cone classes in vertebrate eyes. These two theories have important, but different, implications for our understanding of the design and tuning of vertebrate visual systems. The ‘contrast theory’ proposes that multiple cone classes evolved in shallow-water fish to maximize the visual contrast of objects against diverse backgrounds. The competing ‘flicker theory’ states that multiple cone classes evolved to eliminate the light flicker inherent in shallow-water environments through antagonistic neural interactions, thereby enhancing object detection. However, the selective pressures that have driven the evolution of multiple cone classes remain largely obscure. Results We show that two critical assumptions of the flicker theory are violated. We found that the amplitude and temporal frequency of flicker vary over the visible spectrum, precluding its cancellation by simple antagonistic interactions between the output signals of cones. Moreover, we found that the temporal frequency of flicker matches the frequency where sensitivity is maximal in a wide range of fish taxa, suggesting that the flicker may actually enhance the detection of objects. Finally, using modeling of the chromatic contrast between fish pattern and background under flickering illumination, we found that the spectral sensitivity of cones in a cichlid focal species is optimally tuned to maximize the visual contrast between fish pattern and background, instead of to produce a flicker-free visual signal. Conclusions The violation of its two critical assumptions substantially undermines support for the flicker theory as originally formulated. While this alone does not support the contrast theory, comparison of the contrast and flicker theories revealed that the visual system of our focal species was tuned as predicted by the contrast theory rather than by the flicker theory (or by some combination of the two). Thus, these findings challenge key assumptions of the flicker theory, leaving the contrast theory as the most parsimonious and tenable account of the evolution of multiple cone classes.
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Affiliation(s)
- Shai Sabbah
- Department of Biology, Queen's University, Kingston, Ontario K7L 3N6, Canada.
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24
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Maan ME, Sefc KM. Colour variation in cichlid fish: developmental mechanisms, selective pressures and evolutionary consequences. Semin Cell Dev Biol 2013; 24:516-28. [PMID: 23665150 PMCID: PMC3778878 DOI: 10.1016/j.semcdb.2013.05.003] [Citation(s) in RCA: 112] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Revised: 04/15/2013] [Accepted: 05/01/2013] [Indexed: 12/17/2022]
Abstract
Cichlid fishes constitute one of the most species-rich families of vertebrates. In addition to complex social behaviour and morphological versatility, they are characterised by extensive diversity in colouration, both within and between species. Here, we review the cellular and molecular mechanisms underlying colour variation in this group and the selective pressures responsible for the observed variation. We specifically address the evidence for the hypothesis that divergence in colouration is associated with the evolution of reproductive isolation between lineages. While we conclude that cichlid colours are excellent models for understanding the role of animal communication in species divergence, we also identify taxonomic and methodological biases in the current research effort. We suggest that the integration of genomic approaches with ecological and behavioural studies, across the entire cichlid family and beyond it, will contribute to the utility of the cichlid model system for understanding the evolution of biological diversity.
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Affiliation(s)
- Martine E. Maan
- University of Groningen, Behavioural Biology, PO Box 11103, 9700 CC Groningen, The Netherlands
| | - Kristina M. Sefc
- Institute of Zoology, University of Graz, Universitätsplatz 2, A-8010 Graz, Austria
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25
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Bodaker I, Suzuki MT, Oren A, Béjà O. Dead Sea rhodopsins revisited. ENVIRONMENTAL MICROBIOLOGY REPORTS 2012; 4:617-621. [PMID: 23760932 DOI: 10.1111/j.1758-2229.2012.00377.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Revised: 08/01/2012] [Accepted: 08/01/2012] [Indexed: 06/02/2023]
Abstract
The Dead Sea is a unique hypersaline ecosystem with near toxic magnesium levels (∼2 M), dominance of divalent cations and a slightly acidic pH. Previously, we reported a haloarchaeon related to Halobacterium salinarum to dominate in a microbial bloom that developed in 1992 in the upper water layers of the lake following massive freshwater runoff. Whether this clade also dominated an earlier bloom in 1980-1982 cannot be ascertained as no samples for cultivation-independent analysis were preserved. The presence of the light-driven proton pump bacteriorhodopsin was reported in the 1980-1982 bloom of prokaryotes that had developed in the Dead Sea. To test the hypothesis that bacteriorhodopsin proton pumping may play a major role in determining what type of haloarchaea may dominate in specific bloom conditions, we compared rhodopsin genes recovered from Dead Sea biomass collected in different periods with genes coding for retinal proteins in isolated haloarchaea. Novel bacteriorhodopsin and sensory rhodopsin genes were found in samples collected in 2007 and 2010. The fact that no rhodopsin genes were recovered from samples collected during the 1992 bloom, which was dominated by a single species, suggests that different clades were present in the 1980-1982 and 1992 blooms, and that bacteriorhodopsin proton pumping did not necessarily play a determinative role in the dominance of specific halophiles in the blooms.
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Affiliation(s)
- Idan Bodaker
- Faculty of Biology, Technion - Israel Institute of Technology, Haifa, 32000, Israel
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26
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Shcherbakov D, Knörzer A, Hilbig R, Haas U, Blum M. Near-infrared orientation of Mozambique tilapia Oreochromis mossambicus. ZOOLOGY 2012; 115:233-8. [PMID: 22770589 DOI: 10.1016/j.zool.2012.01.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Revised: 01/13/2012] [Accepted: 01/17/2012] [Indexed: 10/28/2022]
Abstract
Light plays a pivotal role in animal orientation. Aquatic animals face the problem that penetration of light in water is restricted through high attenuation which limits the use of visual cues. In pure water, blue and green light penetrates considerably deeper than red and infrared spectral components. Submicroscopic particles and coloured dissolved organic matter, however, may cause increased scattering and absorption of short-wave components of the solar spectrum, resulting in a relative increase of red and infrared illumination. Here we investigated the potential of near-infrared (NIR) light as a cue for swimming orientation of the African cichlid fish (Cichlidae) Oreochromis mossambicus. A high-throughput semi-automated video tracking assay was used to analyse innate behavioural NIR-sensitivity. Fish revealed a strong preference to swim in the direction of NIR light of a spectral range of 850-950nm at an irradiance similar to values typical of natural surface waters. Our study demonstrates the ability of teleost fish to sense NIR and use it for phototactic swimming orientation.
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Affiliation(s)
- Denis Shcherbakov
- Institute of Zoology, University of Hohenheim, 70593 Stuttgart, Germany.
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27
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Pauers MJ, Kuchenbecker JA, Neitz M, Neitz J. Changes in the colour of light cue circadian activity. Anim Behav 2012; 83:1143-1151. [PMID: 22639465 DOI: 10.1016/j.anbehav.2012.01.035] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The discovery of melanopsin, the non-visual opsin present in intrinsically photosensitive retinal ganglion cells (ipRGCs), has created great excitement in the field of circadian biology. Now, researchers have emphasized melanopsin as the main photopigment governing circadian activity in vertebrates. Circadian biologists have tested this idea under standard laboratory, 12h Light: 12h Dark, lighting conditions that lack the dramatic daily colour changes of natural skylight. Here we used a stimulus paradigm in which the colour of the illumination changed throughout the day, thus mimicking natural skylight, but luminance, sensed intrinsically by melanopsin containing ganglion cells, was kept constant. We show in two species of cichlid, Aequidens pulcher and Labeotropheus fuelleborni, that changes in light colour, not intensity, are the primary determinants of natural circadian activity. Moreover, opponent-cone photoreceptor inputs to ipRGCs mediate the sensation of wavelength change, and not the intrinsic photopigment, melanopsin. These results have implications for understanding the evolutionary biology of non-visual photosensory pathways and answer long-standing questions about the nature and distribution of photopigments in organisms, including providing a solution to the mystery of why nocturnal animals routinely have mutations that interrupt the function of their short wavelength sensitive photopigment gene.
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Affiliation(s)
- Michael J Pauers
- Department of Ophthalmology, University of Washington Medical School, 1959 NE Pacific Street, Seattle, Washington, 98195, USA
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28
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Differences in spectral sensitivity within and among species of darters (genus Etheostoma). Vision Res 2012; 55:19-23. [DOI: 10.1016/j.visres.2011.12.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Revised: 12/10/2011] [Accepted: 12/21/2011] [Indexed: 11/17/2022]
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29
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Miyazaki T, Iwami T. Molecular cloning of cDNA encoding red opsin gene in the retinas of five Antarctic notothenioid fishes. Polar Biol 2011. [DOI: 10.1007/s00300-011-1124-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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30
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Guinea pigs reared in a monochromatic environment exhibit changes in cone density and opsin expression. Exp Eye Res 2011; 93:804-9. [PMID: 21978951 DOI: 10.1016/j.exer.2011.09.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Revised: 09/20/2011] [Accepted: 09/22/2011] [Indexed: 11/23/2022]
Abstract
This study aimed to determine if a monochromatic environment will affect the development of cones in a guinea pig model. Thirty 3-day-old guinea pigs were randomized into three groups and exposed to green, violet, and white light (control) for 8 weeks. The animals were sacrificed and the density of middle-wavelength cones (M cones) and short-wavelength sensitive (S cones) and expression of M-opsin and S-opsin were determined. The density of M cones was increased in the green light group as compared to the control group, and decreased in the violet light group as compared to the control group (both, p < 0.05). There was no significant difference in the density of the S cones among the groups (all, p > 0.05). The density of coexpressing cones in the middle retina was significantly increased in the green light group in comparison to the violet light group (p < 0.01). In addition, there was a significant increase in the level of M-opsin as determined by Western blotting and M-opsin mRNA expression as determined by PCR analysis in the green light group as compared to the control group and a significant decrease in violet light group as compared to the control group (all, p < 0.05). No significant difference in S-opsin level or S-opsin mRNA expression was noted among the groups. We concluded that monochromatic lighting affected the density of cones and expression of opsins in a guinea pig model, and this indicates that the retinal color visual system of the guinea pig possess developmental plasticity.
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Boto L, Cunha C, Doadrio I. A polymorphic microsatellite from the Squalius alburnoides complex (Osteichthyes, Cyprinidae) cloned by serendipity can be useful in genetic analysis of polyploids. Genet Mol Biol 2011; 34:524-8. [PMID: 21931529 PMCID: PMC3168197 DOI: 10.1590/s1415-47572011005000023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2010] [Accepted: 03/23/2011] [Indexed: 11/22/2022] Open
Abstract
A new microsatellite locus (SAS1) for Squalius alburnoides was obtained through cloning by serendipity. The possible usefulness of this new species-specific microsatellite in genetic studies of this hybrid-species complex, was explored. The polymorphism exhibited by SAS1 microsatellite is an important addition to the set of microsatellites previously used in genetic studies in S. alburnoides complex, that mostly relied in markers described for other species. Moreover, the SAS1 microsatellite could be used to identify the parental genomes of the complex, complementing other methods recently described for the same purpose..
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Affiliation(s)
- Luis Boto
- Departamento de Biodiversidad y Biología Evolutiva, Museo Nacional Ciencias Naturales, CSIC, Madrid, Spain
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32
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Pauers MJ. One fish, two fish, red fish, blue fish: geography, ecology, sympatry, and male coloration in the lake Malawi cichlid genus labeotropheus (perciformes: cichlidae). INTERNATIONAL JOURNAL OF EVOLUTIONARY BIOLOGY 2011; 2011:575469. [PMID: 21755046 PMCID: PMC3132605 DOI: 10.4061/2011/575469] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Revised: 02/15/2011] [Accepted: 03/28/2011] [Indexed: 11/20/2022]
Abstract
While sexual selection on male coloration has been important in haplochromine cichlid speciation, few studies to date have examined potential environmental influences on color pattern evolution. Data from multiple sources on male nuptial coloration of the Lake Malawi endemic genus Labeotropheus were used to examine the relationship between color patterns and the environments in which these patterns were found. Red- or carotenoid-pigmented males were concentrated in the northwestern portion of Lake Malawi and were also associated with increasing depth. Further, the presence or absence of L. fuelleborni influenced the coloration of L. trewavasae populations; when L. fuelleborni was present, L. trewavasae males were more likely to exhibit some degree of red coloration. While these results support the idea that sexual selection on male coloration is an important factor in the haplochromine speciation, they also underscore the importance of environmental influences on the evolution of color patterns.
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Affiliation(s)
- Michael J Pauers
- Section of Vertebrate Zoology, Milwaukee Public Museum, 800 West Wells Street, Milwaukee, WI 53233, USA
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33
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Terai Y, Okada N. Speciation of Cichlid Fishes by Sensory Drive. FROM GENES TO ANIMAL BEHAVIOR 2011. [DOI: 10.1007/978-4-431-53892-9_15] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Nagai H, Terai Y, Sugawara T, Imai H, Nishihara H, Hori M, Okada N. Reverse Evolution in RH1 for Adaptation of Cichlids to Water Depth in Lake Tanganyika. Mol Biol Evol 2010; 28:1769-76. [DOI: 10.1093/molbev/msq344] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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35
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Dalton BE, Cronin TW, Marshall NJ, Carleton KL. The fish eye view: are cichlids conspicuous? ACTA ACUST UNITED AC 2010; 213:2243-55. [PMID: 20543123 DOI: 10.1242/jeb.037671] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The extent of animal colouration is determined by an interplay between natural and sexual selection. Both forces probably shape colouration in the speciose, rock-dwelling cichlids of Lake Malawi. Sexual selection is thought to drive male colouration, overcoming natural selection to create conspicuous colour patterns via female mate choice and male-male competition. However, natural selection should make female cichlids cryptic because they mouthbrood their young. We hypothesize that as a result of both sexual and natural selection, males will have colours that are more conspicuous than female colours. Cichlid spectral sensitivity, especially in the ultraviolet, probably influences how colours appear to them. Here we use simple models of the trichromatic colour space of cichlid visual systems to compare the conspicuousness of male and female nuptial colours of nine species. Conspicuousness of colours was evaluated as their Euclidian distance in colour space from environmental backgrounds and from other colours on the same fish. We find in six of the nine species that breeding males have colours that are statistically more conspicuous than female colours. These colours contrast strongly with each other or with the backgrounds, and they fall within a range of spectra best transmitted in the habitat. Female colour distances were sometimes smaller, suggesting that females of some species are more cryptic than males. Therefore, selection can differentially act to generate male colours that are more conspicuous than those in females. However, in two species, females had colours that were more conspicuous than male colours, suggesting that other selective forces and possibly sexual conflicts are acting in this system.
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Affiliation(s)
- Brian E Dalton
- Department of Biology, University of Maryland, Baltimore County, MD 21250, USA
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Lisney TJ, Studd E, Hawryshyn CW. Electrophysiological assessment of spectral sensitivity in adult Nile tilapia Oreochromis niloticus: evidence for violet sensitivity. ACTA ACUST UNITED AC 2010; 213:1453-63. [PMID: 20400629 DOI: 10.1242/jeb.036897] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The cichlid fish radiations of the African Great Lakes are an important model for evolutionary biology. Cichlids have diverse colour vision systems and predominately express three cone visual pigments. However, rare populations of spectrally distinct cones have been found in a number of species, but it is not known whether they contribute to spectral sensitivity. Adult Nile tilapia, Oreochromis niloticus, an ancestral outgroup to the cichlid radiations in the Great Lakes, have three cone types: short-wavelength sensitive (SWS), medium-wavelength sensitive (MWS) and long-wavelength sensitive (LWS) cones, but evidence from microspectrophotometry and cone opsin gene expression suggests they may also have violet-sensitive (VS) cones. We used electrophysiology to assess spectral sensitivity in this species and found evidence of four sensitivity peaks in the ranges 380-420, 440-480, 500-600 and 600-680 nm, with maximal sensitivity at longer wavelengths. The continued presence of a 380-420 nm peak under long-wavelength chromatic adapting backgrounds indicates that this is due to a VS cone mechanism not the beta-band of the LWS cone mechanism. Differences in spectral sensitivity curves recorded at different times of year revealed evidence of A1/A2 shifts. The presence of notches in the sensitivity curves and a multiple-mechanisms model used to assess cone contributions indicated that the curves are the result of four cone mechanisms (VS, SWS, MWS and LWS cones) and that chromatically opponent processes occur between mechanisms. The spectral transmittance of the lens steeply declines between 410-380 nm, limiting the short-wavelength limb of the VS cone. As adults, Nile tilapia appear to possess the necessary retinal mechanisms for colour vision. While maximal sensitivity to longer wavelengths is an adaptation to the wavelengths of light predominantly available in their natural habitats, their broad sensitivity range suggests that Nile tilapia possess a flexible, generalised visual system able to adapt to changes in visual environment in their highly variable natural habitat.
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Affiliation(s)
- T J Lisney
- Department of Biology, Center for Neuroscience Studies, Queen's University, Kingston, Ontario, Canada, K7L 3N6
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O'Quin KE, Hofmann CM, Hofmann HA, Carleton KL. Parallel Evolution of Opsin Gene Expression in African Cichlid Fishes. Mol Biol Evol 2010; 27:2839-54. [DOI: 10.1093/molbev/msq171] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Allelic variation in Malawi cichlid opsins: a tale of two genera. J Mol Evol 2010; 70:593-604. [PMID: 20523974 DOI: 10.1007/s00239-010-9355-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2009] [Accepted: 05/17/2010] [Indexed: 11/27/2022]
Abstract
The role of sequence variation in the spectral tuning of color vision is well established in many systems. This includes the cichlids of Lake Victoria where sequence variation has been linked to environmental light gradients and speciation. The cichlids of Lake Malawi are a similar model for visual evolution, but the role of gene sequence variation in visual tuning between closely related species is unknown. This work describes such variation in multiple species of two rock-dwelling genera: Metriaclima and Labidochromis. Genomic DNA for seven cone opsin genes was sequenced and the structure of the opsin proteins was inferred. Retinal binding pocket polymorphisms were identified and compared to available data regarding spectral absorbance shifts. Sequence variation with known or potential effects on absorbance spectra were found in four genes: SWS1 (UV sensitive), SWS2B (violet sensitive), RH2Abeta (green sensitive), and LWS (red sensitive). Functional variation was distributed such that each genus had both a variable short-wavelength and long-wavelength sensitive opsin. This suggests spectral tuning is important at the margins of the cichlid visual spectrum. Further, there are two SWS1 opsin alleles that differ in sensitivity by 10 nm and are >2 MY divergent. One of these occurs in a haplotype block >1 kb. Potential haplotype blocks were found around the RH2 opsin loci. These data suggest that molecular diversification has resulted in functionally unique alleles and changes to the visual system. These data also suggest that opsin sequence variation tunes spectral sensitivities between closely related species and that the specific regions of spectral tuning are genus-specific.
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Hofmann CM, O’Quin KE, Justin Marshall N, Carleton KL. The relationship between lens transmission and opsin gene expression in cichlids from Lake Malawi. Vision Res 2010; 50:357-63. [DOI: 10.1016/j.visres.2009.12.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2009] [Revised: 12/04/2009] [Accepted: 12/07/2009] [Indexed: 10/20/2022]
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Hofmann CM, O'Quin KE, Marshall NJ, Cronin TW, Seehausen O, Carleton KL. The eyes have it: regulatory and structural changes both underlie cichlid visual pigment diversity. PLoS Biol 2009; 7:e1000266. [PMID: 20027211 PMCID: PMC2790343 DOI: 10.1371/journal.pbio.1000266] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2009] [Accepted: 11/12/2009] [Indexed: 11/18/2022] Open
Abstract
A major goal of evolutionary biology is to unravel the molecular genetic mechanisms that underlie functional diversification and adaptation. We investigated how changes in gene regulation and coding sequence contribute to sensory diversification in two replicate radiations of cichlid fishes. In the clear waters of Lake Malawi, differential opsin expression generates diverse visual systems, with sensitivities extending from the ultraviolet to the red regions of the spectrum. These sensitivities fall into three distinct clusters and are correlated with foraging habits. In the turbid waters of Lake Victoria, visual sensitivity is constrained to longer wavelengths, and opsin expression is correlated with ambient light. In addition to regulatory changes, we found that the opsins coding for the shortest- and longest-wavelength visual pigments have elevated numbers of potentially functional substitutions. Thus, we present a model of sensory evolution in which both molecular genetic mechanisms work in concert. Changes in gene expression generate large shifts in visual pigment sensitivity across the collective opsin spectral range, but changes in coding sequence appear to fine-tune visual pigment sensitivity at the short- and long-wavelength ends of this range, where differential opsin expression can no longer extend visual pigment sensitivity.
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Affiliation(s)
- Christopher M Hofmann
- Department of Biology, University of Maryland, College Park, Maryland, United States of America.
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Hofmann CM, Carleton KL. Gene duplication and differential gene expression play an important role in the diversification of visual pigments in fish. Integr Comp Biol 2009; 49:630-43. [DOI: 10.1093/icb/icp079] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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42
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Wang FY, Yan HY, Chen JSC, Wang TY, Wang D. Adaptation of visual spectra and opsin genes in seabreams. Vision Res 2009; 49:1860-8. [DOI: 10.1016/j.visres.2009.04.023] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2009] [Revised: 04/27/2009] [Accepted: 04/27/2009] [Indexed: 10/20/2022]
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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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Carleton KL, Spady TC, Streelman JT, Kidd MR, McFarland WN, Loew ER. Visual sensitivities tuned by heterochronic shifts in opsin gene expression. BMC Biol 2008; 6:22. [PMID: 18500997 PMCID: PMC2430543 DOI: 10.1186/1741-7007-6-22] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2008] [Accepted: 05/23/2008] [Indexed: 11/11/2022] Open
Abstract
Background Cichlid fishes have radiated into hundreds of species in the Great Lakes of Africa. Brightly colored males display on leks and vie to be chosen by females as mates. Strong discrimination by females causes differential male mating success, rapid evolution of male color patterns and, possibly, speciation. In addition to differences in color pattern, Lake Malawi cichlids also show some of the largest known shifts in visual sensitivity among closely related species. These shifts result from modulated expression of seven cone opsin genes. However, the mechanisms for this modulated expression are unknown. Results In this work, we ask whether these differences might result from changes in developmental patterning of cone opsin genes. To test this, we compared the developmental pattern of cone opsin gene expression of the Nile tilapia, Oreochromis niloticus, with that of several cichlid species from Lake Malawi. In tilapia, quantitative polymerase chain reaction showed that opsin gene expression changes dynamically from a larval gene set through a juvenile set to a final adult set. In contrast, Lake Malawi species showed one of two developmental patterns. In some species, the expressed gene set changes slowly, either retaining the larval pattern or progressing only from larval to juvenile gene sets (neoteny). In the other species, the same genes are expressed in both larvae and adults but correspond to the tilapia adult genes (direct development). Conclusion Differences in visual sensitivities among species of Lake Malawi cichlids arise through heterochronic shifts relative to the ontogenetic pattern of the tilapia outgroup. Heterochrony has previously been shown to be a powerful mechanism for change in morphological evolution. We found that altering developmental expression patterns is also an important mechanism for altering sensory systems. These resulting sensory shifts will have major impacts on visual communication and could help drive cichlid speciation.
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Affiliation(s)
- Karen L Carleton
- Department of Biology, University of Maryland, College Park, MD 20742, USA.
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Hulsey CD, Mims MC, Streelman JT. Do constructional constraints influence cichlid craniofacial diversification? Proc Biol Sci 2007; 274:1867-75. [PMID: 17519189 PMCID: PMC2270932 DOI: 10.1098/rspb.2007.0444] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2007] [Revised: 05/01/2007] [Accepted: 04/02/2007] [Indexed: 11/12/2022] Open
Abstract
Constraints on form should determine how organisms diversify. Owing to competition for the limited space within the body, investment in adjacent structures may frequently represent an evolutionary compromise. For example, evolutionary trade-offs between eye size and jaw muscles in cichlid fish of the African great lakes are thought to represent a constructional constraint that influenced the diversification of these assemblages. To test the evolutionary independence of these structures in Lake Malawi cichlid fish, we measured the mass of the three major adductor mandibulae (AM) muscles and determined the eye volume in 41 species. Using both traditional and novel methodologies to control for resolved and unresolved phylogenetic relationships, we tested the evolutionary independence of these four structures. We found that evolutionary change in the AM muscles was positively correlated, suggesting that competition for space in the head has not influenced diversification among these jaw muscles. Furthermore, there was no negative relationship between change in total AM muscle mass and eye volume, indicating that there has been little effect of the evolution of eye size on AM evolution in Lake Malawi cichlids. The comparative approach used here should provide a robust method to test whether constructional constraints frequently limit phenotypic change in adaptive radiations.
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Affiliation(s)
- C D Hulsey
- School of Biology and Petit Institute of Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332, USA.
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Horth L. Sensory genes and mate choice: Evidence that duplications, mutations, and adaptive evolution alter variation in mating cue genes and their receptors. Genomics 2007; 90:159-75. [PMID: 17544617 DOI: 10.1016/j.ygeno.2007.03.021] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2006] [Revised: 03/05/2007] [Accepted: 03/28/2007] [Indexed: 12/30/2022]
Abstract
Fascinating new data, revealed through gene sequencing, comparative genomics, and genetic engineering, precisely establish which genes are involved in mate choice and mating activity--behaviors that are surprisingly understudied from a genetic perspective. Discussed here are some of the recently identified visual and chemosensory genes that are involved in mate choice and mating behavior. These genes' products are involved in the production, transmission, and receipt of crucial sensory mate-choice cues that affect fitness. This review exposes newfound evidence that alternative splicing, gene-expression pattern changes, and molecular genetic variation in sensory genes are crucial for both intra- and interspecific mate choice and mating success. Many sensory genes have arisen through gene duplications, and data amassed from studies conducted at scales ranging from individual genes to genomic comparisons show that strong, positive Darwinian selection acts on several mating-related genes and that these genes evolve rapidly.
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Affiliation(s)
- Lisa Horth
- Department of Biological Sciences, Old Dominion University, Norfolk, VA 23529, USA.
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Hunt DM, Carvalho LS, Cowing JA, Parry JWL, Wilkie SE, Davies WL, Bowmaker JK. Spectral Tuning of Shortwave-sensitive Visual Pigments in Vertebrates†. Photochem Photobiol 2007; 83:303-10. [PMID: 17576346 DOI: 10.1562/2006-06-27-ir-952] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Of the four classes of vertebrate cone visual pigments, the shortwave-sensitive SWS1 class shows some of the largest shifts in lambda(max), with values ranging in different species from 390-435 nm in the violet region of the spectrum to < 360 nm in the ultraviolet. Phylogenetic evidence indicates that the ancestral pigment most probably had a lambda(max) in the UV and that shifts between violet and UV have occurred many times during evolution. In violet-sensitive (VS) pigments, the Schiff base is protonated whereas in UV-sensitive (UVS) pigments, it is almost certainly unprotonated. The generation of VS pigments in amphibia, birds and mammals from ancestral UVS pigments must involve therefore the stabilization of protonation. Similarly, stabilization must be lost in the evolution of avian UVS pigments from a VS ancestral pigment. The key residues in the opsin protein for these shifts are at sites 86 and 90, both adjacent to the Schiff base and the counterion at Glu113. In this review, the various molecular mechanisms for the UV and violet shifts in the different vertebrate groups are presented and the changes in the opsin protein that are responsible for the spectral shifts are discussed in the context of the structural model of bovine rhodopsin.
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Affiliation(s)
- David M Hunt
- UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK.
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Håstad O, Ernstdotter E, Ödeen A. Ultraviolet vision and foraging in dip and plunge diving birds. Biol Lett 2007; 1:306-9. [PMID: 17148194 PMCID: PMC1617148 DOI: 10.1098/rsbl.2005.0320] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Many fishes are sensitive to ultraviolet (UV) light and display UV markings during courtship. As UV scatters more than longer wavelengths of light, these signals are only effective at short distances, reducing the risk of detection by swimming predators. Such underwater scattering will be insignificant for dip and plunge diving birds, which prey on fishes just below the water surface. One could therefore expect to find adaptations in the eyes of dip and plunge diving birds that tune colour reception to UV signals. We used a molecular method to survey the colour vision tuning of five families of dip or plunge divers and compared the results with those from sister taxa of other foraging methods. We found evidence of extended UV vision only in gulls (Laridae). Based on available evidence, it is more probable that this trait is associated with their terrestrial foraging habits rather than piscivory.
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Affiliation(s)
- Olle Håstad
- Department of Animal Ecology, Evolutionary Biology Centre, Uppsala UniversityNorbyvägen 18D, 752 36 Uppsala, Sweden
| | - Emma Ernstdotter
- Department of Animal Ecology, Evolutionary Biology Centre, Uppsala UniversityNorbyvägen 18D, 752 36 Uppsala, Sweden
| | - Anders Ödeen
- Department of Animal Ecology, Evolutionary Biology Centre, Uppsala UniversityNorbyvägen 18D, 752 36 Uppsala, Sweden
- Department of Biological Sciences, Simon Fraser UniversityBurnaby, British Columbia, Canada V5A 1S6
- Author for correspondence ()
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