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Sample records for wave-sensitive lws opsins

  1. Genomic organization of duplicated short wave-sensitive and long wave-sensitive opsin genes in the green swordtail, Xiphophorus helleri

    PubMed Central

    2010-01-01

    Background Long wave-sensitive (LWS) opsin genes have undergone multiple lineage-specific duplication events throughout the evolution of teleost fishes. LWS repertoire expansions in live-bearing fishes (family Poeciliidae) have equipped multiple species in this family with up to four LWS genes. Given that color vision, especially attraction to orange male coloration, is important to mate choice within poeciliids, LWS opsins have been proposed as candidate genes driving sexual selection in this family. To date the genomic organization of these genes has not been described in the family Poeciliidae, and little is known about the mechanisms regulating the expression of LWS opsins in any teleost. Results Two BAC clones containing the complete genomic repertoire of LWS opsin genes in the green swordtail fish, Xiphophorus helleri, were identified and sequenced. Three of the four LWS loci identified here were linked in a tandem array downstream of two tightly linked short wave-sensitive 2 (SWS2) opsin genes. The fourth LWS opsin gene, containing only a single intron, was not linked to the other three and is the product of a retrotransposition event. Genomic and phylogenetic results demonstrate that the LWS genes described here share a common evolutionary origin with those previously characterized in other poeciliids. Using qualitative RT-PCR and MSP we showed that each of the LWS and SWS2 opsins, as well as three other cone opsin genes and a single rod opsin gene, were expressed in the eyes of adult female and male X. helleri, contributing to six separate classes of adult retinal cone and rod cells with average λmax values of 365 nm, 405 nm, 459 nm, 499 nm, 534 nm and 568 nm. Comparative genomic analysis identified two candidate teleost opsin regulatory regions containing putative CRX binding sites and hormone response elements in upstream sequences of LWS gene regions of seven teleost species, including X. helleri. Conclusions We report the first complete genomic description of LWS and SWS2 genes in poeciliids. These data will serve as a reference for future work seeking to understand the relationship between LWS opsin genomic organization, gene expression, gene family evolution, sexual selection and speciation in this fish family. PMID:20353595

  2. Androgens Increase lws Opsin Expression and Red Sensitivity in Male Three-Spined Sticklebacks

    PubMed Central

    Shao, Yi Ta; Wang, Feng-Yu; Fu, Wen-Chun; Anraku, Kazuhiko; Chen, I-Shiung

    2014-01-01

    Optomotor studies have shown that three-spined sticklebacks (Gasterosteus aculeatus) are more sensitive to red during summer than winter, which may be related to the need to detect the red breeding colour of males. This study aimed to determine whether this change of red light sensitivity is specifically related to reproductive physiology. The mRNA levels of opsin genes were examined in the retinae of sexually mature and immature fish, as well as in sham-operated males, castrated control males, or castrated males implanted with androgen 11-ketoandrostenedione (11 KA), maintained under stimulatory (L16:D8) or inhibitory (L8:D16) photoperiods. In both sexes, red-sensitive opsin gene (lws) mRNA levels were higher in sexually mature than in immature fish. Under L16:D8, lws mRNA levels were higher in intact than in castrated males, and were up-regulated by 11 KA treatment in castrated males. Moreover, electroretinogram data confirmed that sexual maturation resulted in higher relative red spectral sensitivity. Mature males under L16:D8 were more sensitive to red light than males under L8:D16. Red light sensitivity under L16:D8 was diminished by castration, but increased by 11 KA treatment. Thus, in sexually mature male sticklebacks, androgen is a key factor in enhancing sensitivity to red light via regulation of opsin gene expression. This is the first study to demonstrate that sex hormones can regulate spectral vision sensitivity. PMID:24963891

  3. Retinal photoreceptor arrangement, SWS1 and LWS opsin sequence, and electroretinography in the South American marsupial Thylamys elegans (Waterhouse, 1839).

    PubMed

    Palacios, Adrián G; Bozinovic, Francisco; Vielma, Alex; Arrese, Catherine A; Hunt, David M; Peichl, Leo

    2010-05-01

    We studied the retinal photoreceptors in the mouse opossum Thylamys elegans, a nocturnal South American marsupial. A variety of photoreceptor properties and color vision capabilities have been documented in Australian marsupials, and we were interested to establish what similarities and differences this American marsupial showed. Thylamys opsin gene sequencing revealed two cone opsins, a longwave-sensitive (LWS) opsin and a shortwave-sensitive (SWS1) opsin with deduced peak sensitivities at 560 nm and 360 nm (ultraviolet), respectively. Immunocytochemistry located these opsins to separate cone populations, a majority of LWS cones (density range 1,600-5,600/mm(2)) and a minority of SWS1 cones (density range 100-690/mm(2)). With rod densities of 440,000-590,000/mm(2), the cones constituted 0.4-1.2% of the photoreceptors. This is a suitable adaptation to nocturnal vision. Cone densities peaked in a horizontally elongated region ventral to the optic nerve head. In ventral-but not dorsal-retina, roughly 40% of the LWS opsin-expressing cones occurred as close pairs (double cones), and one member of each double cone contained a colorless oil droplet. The corneal electroretinogram (ERG) showed a high scotopic sensitivity with a rod peak sensitivity at 505 nm. At mesopic light levels, the spectral ERG revealed the contributions of a UV-sensitive SWS1 cone mechanism and an LWS cone mechanism with peak sensitivities at 365 nm and 555 nm, respectively, confirming the tuning predictions from the cone opsin sequences. The two spectral cone types provide the basis for dichromatic color vision, or trichromacy if the rods contribute to color processing at mesopic light levels. PMID:20187149

  4. The effect of selection on a long wavelength-sensitive (LWS) opsin gene of Lake Victoria cichlid fishes.

    PubMed

    Terai, Yohey; Mayer, Werner E; Klein, Jan; Tichy, Herbert; Okada, Norihiro

    2002-11-26

    In East African Lake Victoria >200 endemic species of haplochromine fishes have been described on the basis of morphological and behavioral differences. Yet molecular analysis has failed to reveal any species-specific differences among these fishes in either mitochondrial or nuclear genes. Although the genes could be shown to vary, the variations represent trans-species polymorphisms not yet assorted along species lines. Nevertheless, fixed genetic differences must exist between the species at loci responsible for the adaptive characters distinguishing the various forms from one another. Here we describe variation and fixation at the long wavelength-sensitive (LWS) opsin locus, which is selection-driven, adaptive, and if not species- then at least population-specific. Because color is one of the characters distinguishing species of haplochromine fishes and color perception plays an important part in food acquisition and mate choice, we suggest that the observed variation and fixation at the LWS opsin locus may have been involved in the process that has led to the spectacular species divergence of haplochromine fishes in Lake Victoria. PMID:12438648

  5. Ancestral loss of short wave-sensitive cone visual pigment in lorisiform prosimians, contrasting with its strict conservation in other prosimians.

    PubMed

    Kawamura, Shoji; Kubotera, Naoya

    2004-03-01

    Mammals are basically dichromatic in color vision, possessing middle to long wave-sensitive (M/LWS) and the short wave-sensitive (SWS) cone opsins in the retina, whereas some nocturnal mammals lack functional SWS opsins. Prosimians, primitive primates consisting of three extant groups (Lorisiformes, Lemuriformes, and Tarsiiformes), include many nocturnal species. Among nocturnal prosimians, a species of lorisiforms, the greater galago (Otolemur crassicaudatus), is known to lack a functional SWS opsin gene, while lemuriforms and tarsiiforms appear to retain SWS opsins in the retina. It has not been established, however, whether the loss of SWS opsin is a universal phenomenon among lorisiforms and whether the functional SWS opsin genes of lemuriforms and tarsiiforms are under strict or relaxed selective constraint. To gain better insight into an association between nocturnality and loss of SWS function, we isolated and sequenced the SWS opsin genes from two species of lorisiforms, the slow loris (Nycticebus coucang; nocturnal) and the lesser galago (Galago senegalensis; nocturnal), and one species each of lemuriforms and tarsiiforms, the brown lemur (Eulemur fulvus; cathemeral) and the western tarsier ( Tarsius bancanus; nocturnal), respectively. Our sequence analysis revealed that (1) the SWS opsin gene was disrupted in the common ancestor of galagids and lorisids and (2) the rate of nonsynonymous nucleotide substitution has been kept significantly lower than that of synonymous substitution in tarsier and lemur, demonstrating the presence of strict selective constraint on the SWS opsin genes in tarsiiforms and lemuriforms. PMID:15045486

  6. PALMITYLATION OF CONE OPSINS

    PubMed Central

    Ablonczy, Zsolt; Kono, Masahiro; Knapp, Daniel R.; Crouch, Rosalie K.

    2006-01-01

    Palmitylation is a widespread modification in G-protein-coupled receptors and often a dynamic process. In rhodopsins, palmitylation is static on C322/C323. Red/green (M/LWS) cone opsins have no cysteines at corresponding positions and no palmitylation. SWS2 cone opsins have a single corresponding cysteine and mass spectrometric analysis showed partial palmitylation of salamander SWS2 cone opsin. Ultraviolet (SWS1) cone opsins have one corresponding cysteine, but only unpalmitylated opsin was observed for mouse and salamander. The results show that the static palmitylation found on rhodopsin is not found on cone opsins and suggest the possibility of an unidentified role for opsin palmitylation in cones. PMID:16989884

  7. Mix and match color vision: tuning spectral sensitivity by differential opsin gene expression in Lake Malawi cichlids.

    PubMed

    Parry, Juliet W L; Carleton, Karen L; Spady, Tyrone; Carboo, Aba; Hunt, David M; Bowmaker, James K

    2005-10-11

    Cichlid fish of the East African Rift Lakes are renowned for their diversity and offer a unique opportunity to study adaptive changes in the visual system in rapidly evolving species flocks. Since color plays a significant role in mate choice, differences in visual sensitivities could greatly influence and even drive speciation of cichlids. Lake Malawi cichlids inhabiting rock and sand habitats have significantly different cone spectral sensitivities. By combining microspectrophotometry (MSP) of isolated cones, sequencing of opsin genes, and spectral analysis of recombinant pigments, we have established the cone complements of four species of Malawi cichlids. MSP demonstrated that each of these species predominately expresses three cone pigments, although these differ between species to give three spectrally different cone complements. In addition, rare populations of spectrally distinct cones were found. In total, seven spectral classes were identified. This was confirmed by opsin gene sequencing, expression, and in vitro reconstitution. The genes represent the four major classes of cone opsin genes that diverged early in vertebrate evolution. All four species possess a long-wave-sensitive (LWS), three spectrally distinct green-sensitive (RH2), a blue-sensitive (SWS2A), a violet-sensitive (SWS2B), and an ultraviolet-sensitive (SWS1) opsin. However, African cichlids determine their spectral sensitivity by differential expression of primarily only three of the seven available cone opsin genes. Phylogenetic analysis suggests that all percomorph fish have similar potential. PMID:16213819

  8. Retinoic Acid Signaling Regulates Differential Expression of the Tandemly-Duplicated Long Wavelength-Sensitive Cone Opsin Genes in Zebrafish

    PubMed Central

    Frey, Ruth A.; Hunter, Samuel S.; Ashino, Ryuichi; Kawamura, Shoji; Stenkamp, Deborah L.

    2015-01-01

    The signaling molecule retinoic acid (RA) regulates rod and cone photoreceptor fate, differentiation, and survival. Here we elucidate the role of RA in differential regulation of the tandemly-duplicated long wavelength-sensitive (LWS) cone opsin genes. Zebrafish embryos were treated with RA from 48 hours post-fertilization (hpf) to 75 hpf, and RNA was isolated from eyes for microarray analysis. ~170 genes showed significantly altered expression, including several transcription factors and components of cellular signaling pathways. Of interest, the LWS1 opsin gene was strongly upregulated by RA. LWS1 is the upstream member of the tandemly duplicated LWS opsin array and is normally not expressed embryonically. Embryos treated with RA 48 hpf to 100 hpf or beyond showed significant reductions in LWS2-expressing cones in favor of LWS1-expressing cones. The LWS reporter line, LWS-PAC(H) provided evidence that individual LWS cones switched from LWS2 to LWS1 expression in response to RA. The RA signaling reporter line, RARE:YFP indicated that increased RA signaling in cones was associated with this opsin switch, and experimental reduction of RA signaling in larvae at the normal time of onset of LWS1 expression significantly inhibited LWS1 expression. A role for endogenous RA signaling in regulating differential expression of the LWS genes in postmitotic cones was further supported by the presence of an RA signaling domain in ventral retina of juvenile zebrafish that coincided with a ventral zone of LWS1 expression. This is the first evidence that an extracellular signal may regulate differential expression of opsin genes in a tandemly duplicated array. PMID:26296154

  9. Divergent selection for opsin gene variation in guppy (Poecilia reticulata) populations of Trinidad and Tobago

    PubMed Central

    Tezuka, A; Kasagi, S; van Oosterhout, C; McMullan, M; Iwasaki, W M; Kasai, D; Yamamichi, M; Innan, H; Kawamura, S; Kawata, M

    2014-01-01

    The guppy is known to exhibit remarkable interindividual variations in spectral sensitivity of middle to long wavelength-sensitive (M/LWS) cone photoreceptor cells. The guppy has four M/LWS-type opsin genes (LWS-1, LWS-2, LWS-3 and LWS-4) that are considered to be responsible for this sensory variation. However, the allelic variation of the opsin genes, particularly in terms of their absorption spectrum, has not been explored in wild populations. Thus, we examined nucleotide variations in the four M/LWS opsin genes as well as blue-sensitive SWS2-B and ultraviolet-sensitive SWS1 opsin genes for comparison and seven non-opsin nuclear loci as reference genes in 10 guppy populations from various light environments in Trinidad and Tobago. For the first time, we discovered a potential spectral variation (180 Ser/Ala) in LWS-1 that differed at an amino acid site known to affect the absorption spectra of opsins. Based on a coalescent simulation of the nucleotide variation of the reference genes, we showed that the interpopulation genetic differentiation of two opsin genes was significantly larger than the neutral expectation. Furthermore, this genetic differentiation was significantly related to differences in dissolved oxygen (DO) level, and it was not explained by the spatial distance between populations. The DO levels are correlated with eutrophication that possibly affects the color of aquatic environments. These results suggest that the population diversity of opsin genes is significantly driven by natural selection and that the guppy could adapt to various light environments through color vision changes. PMID:24690753

  10. Divergent selection for opsin gene variation in guppy (Poecilia reticulata) populations of Trinidad and Tobago.

    PubMed

    Tezuka, A; Kasagi, S; van Oosterhout, C; McMullan, M; Iwasaki, W M; Kasai, D; Yamamichi, M; Innan, H; Kawamura, S; Kawata, M

    2014-11-01

    The guppy is known to exhibit remarkable interindividual variations in spectral sensitivity of middle to long wavelength-sensitive (M/LWS) cone photoreceptor cells. The guppy has four M/LWS-type opsin genes (LWS-1, LWS-2, LWS-3 and LWS-4) that are considered to be responsible for this sensory variation. However, the allelic variation of the opsin genes, particularly in terms of their absorption spectrum, has not been explored in wild populations. Thus, we examined nucleotide variations in the four M/LWS opsin genes as well as blue-sensitive SWS2-B and ultraviolet-sensitive SWS1 opsin genes for comparison and seven non-opsin nuclear loci as reference genes in 10 guppy populations from various light environments in Trinidad and Tobago. For the first time, we discovered a potential spectral variation (180 Ser/Ala) in LWS-1 that differed at an amino acid site known to affect the absorption spectra of opsins. Based on a coalescent simulation of the nucleotide variation of the reference genes, we showed that the interpopulation genetic differentiation of two opsin genes was significantly larger than the neutral expectation. Furthermore, this genetic differentiation was significantly related to differences in dissolved oxygen (DO) level, and it was not explained by the spatial distance between populations. The DO levels are correlated with eutrophication that possibly affects the color of aquatic environments. These results suggest that the population diversity of opsin genes is significantly driven by natural selection and that the guppy could adapt to various light environments through color vision changes. PMID:24690753

  11. Rapid light-induced shifts in opsin expression: finding new opsins, discerning mechanisms of change, and implications for visual sensitivity.

    PubMed

    Fuller, Rebecca C; Claricoates, Kristin M

    2011-08-01

    Light-induced shifts in cone frequency and opsin expression occur in many aquatic species. Yet little is known about how quickly animals can alter opsin expression and, thereby, track their visual environments. Similarly, little is known about whether adult animals can alter opsin expression or whether shifts in opsin expression are limited to critical developmental windows. We took adult wild-caught bluefin killifish (Lucania goodei) from three different lighting environments (spring, swamp and variable), placed them under two different lighting treatments (clear vs. tea-stained water) and monitored opsin expression over 4 weeks. We measured opsin expression for five previously described opsins (SWS1, SWS2B, SWS2A, RH2-1 and LWS) as well as RH2-2 which we discovered via 454 sequencing. We used two different metrics of opsin expression. We measured expression of each opsin relative to a housekeeping gene and the proportional expression of each opsin relative to the total pool of opsins. Population and lighting environment had large effects on opsin expression which were present at the earliest time points indicating rapid shifts in expression. The two measures of expression produced radically different patterns. Proportional measures indicated large effects of light on SWS1 expression, whereas relative measures indicated no such effect. Instead, light had large effects on the relative expression of SWS2B, RH2-2, RH2-1 and LWS. We suggest that proportional measures of opsin expression are best for making inferences about colour vision, but that measures relative to a housekeeping gene are better for making conclusions about which opsins are differentially regulated. PMID:21749514

  12. Adaptation of visual spectra and opsin genes in seabreams.

    PubMed

    Wang, Feng Yu; Yan, Hong Young; Chen, Johnny Shou-Chung; Wang, Tzi Yuan; Wang, Daryi

    2009-07-01

    Three species of seabreams, Acanthopagrus berda, Acanthopagrus schlegelii and Pagrus major, living at different depths, were chosen to investigate how visual spectra and opsin genes evolve in response to various photic environments. The lambda max of photoreceptors and opsin genes were measured and cloned from these species. Eight to twelve nm spectral shifts in the rod and blue cone cells were observed between the deep-sea, P. major, and shallow-sea species, A. berda and A. schlegelii. Furthermore, the deep-sea P. major has lost its red light vision. Six opsin genes, Rh1, Rh2A, Rh2B, SWS1, SWS2 and LWS, were identified from all three seabream species, with the LWS genes of P. major having undergone pseudogenization. These data indicate that the photic environment of habitats select for the physiology of visual spectra and coding of opsin genes. PMID:19422842

  13. Conservation, Duplication, and Divergence of Five Opsin Genes in Insect Evolution.

    PubMed

    Feuda, Roberto; Marlétaz, Ferdinand; Bentley, Michael A; Holland, Peter W H

    2016-01-01

    Opsin proteins covalently bind to small molecular chromophores and each protein-chromophore complex is sensitive to particular wavelengths of light. Multiple opsins with different wavelength absorbance peaks are required for color vision. Comparing opsin responses is challenging at low light levels, explaining why color vision is often lost in nocturnal species. Here, we investigated opsin evolution in 27 phylogenetically diverse insect species including several transitions between photic niches (nocturnal, diurnal, and crepuscular). We find widespread conservation of five distinct opsin genes, more than commonly considered. These comprise one c-opsin plus four r-opsins (long wavelength sensitive or LWS, blue sensitive, ultra violet [UV] sensitive and the often overlooked Rh7 gene). Several recent opsin gene duplications are also detected. The diversity of opsin genes is consistent with color vision in diurnal, crepuscular, and nocturnal insects. Tests for positive selection in relation to photic niche reveal evidence for adaptive evolution in UV-sensitive opsins in day-flying insects in general, and in LWS opsins of day-flying Lepidoptera specifically. PMID:26865071

  14. Anion sensitivity and spectral tuning of middle- and long-wavelength-sensitive (MWS/LWS) visual pigments.

    PubMed

    Davies, Wayne I L; Wilkie, Susan E; Cowing, Jill A; Hankins, Mark W; Hunt, David M

    2012-07-01

    The long-wavelength-sensitive (LWS) opsins form one of four classes of vertebrate cone visual pigment and exhibit peak spectral sensitivities (λ(max)) that generally range from 525 to 560 nm for rhodopsin/vitamin-A(1) photopigments. Unique amongst the opsin classes, many LWS pigments show anion sensitivity through the interaction of chloride ions with a histidine residue at site 197 (H197) to give a long-wavelength spectral shift in peak sensitivity. Although it has been shown that amino acid substitutions at five sites (180, 197, 277, 285 and 308) are useful in predicting the λ(max) values of the LWS pigment class, some species, such as the elephant shark and most marine mammals, express LWS opsins that possess λ(max) values that are not consistent with this 'five-site' rule, indicating that other interactions may be involved. This study has taken advantage of the natural mutation at the chloride-binding site in the mouse LWS pigment. Through the use of a number of mutant pigments generated by site-directed mutagenesis, a new model has been formulated that takes into account the role of charge and steric properties of the side chains of residues at sites 197 and 308 in the function of the chloride-binding site in determining the peak sensitivity of LWS photopigments. PMID:22349213

  15. Rod Monochromacy and the Coevolution of Cetacean Retinal Opsins

    PubMed Central

    Meredith, Robert W.; Gatesy, John; Emerling, Christopher A.; York, Vincent M.; Springer, Mark S.

    2013-01-01

    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. PMID:23637615

  16. Rod monochromacy and the coevolution of cetacean retinal opsins.

    PubMed

    Meredith, Robert W; Gatesy, John; Emerling, Christopher A; York, Vincent M; Springer, Mark S

    2013-04-01

    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. PMID:23637615

  17. Evolution of opsin expression in birds driven by sexual selection and habitat.

    PubMed

    Bloch, Natasha I

    2015-01-01

    Theories of sexual and natural selection predict coevolution of visual perception with conspecific colour and/or the light environment animals occupy. One way to test these theories is to focus on the visual system, which can be achieved by studying the opsin-based visual pigments that mediate vision. Birds vary greatly in colour, but opsin gene coding sequences and associated visual pigment spectral sensitivities are known to be rather invariant across birds. Here, I studied expression of the four cone opsin genes (Lws, Rh2, Sws2 and Sws1) in 16 species of New World warblers (Parulidae). I found levels of opsin expression vary both across species and between the sexes. Across species, female, but not male Sws2 expression is associated with an index of sexual selection, plumage dichromatism. This fits predictions of classic sexual selection models, in which the sensory system changes in females, presumably impacting female preference, and co-evolves with male plumage. Expression of the opsins at the extremes of the light spectrum, Lws and Uvs, correlates with the inferred light environment occupied by the different species. Unlike opsin spectral tuning, regulation of opsin gene expression allows for fast adaptive evolution of the visual system in response to natural and sexual selection, and in particular, sex-specific selection pressures. PMID:25429020

  18. Evolution of opsin expression in birds driven by sexual selection and habitat

    PubMed Central

    Bloch, Natasha I.

    2015-01-01

    Theories of sexual and natural selection predict coevolution of visual perception with conspecific colour and/or the light environment animals occupy. One way to test these theories is to focus on the visual system, which can be achieved by studying the opsin-based visual pigments that mediate vision. Birds vary greatly in colour, but opsin gene coding sequences and associated visual pigment spectral sensitivities are known to be rather invariant across birds. Here, I studied expression of the four cone opsin genes (Lws, Rh2, Sws2 and Sws1) in 16 species of New World warblers (Parulidae). I found levels of opsin expression vary both across species and between the sexes. Across species, female, but not male Sws2 expression is associated with an index of sexual selection, plumage dichromatism. This fits predictions of classic sexual selection models, in which the sensory system changes in females, presumably impacting female preference, and co-evolves with male plumage. Expression of the opsins at the extremes of the light spectrum, Lws and Uvs, correlates with the inferred light environment occupied by the different species. Unlike opsin spectral tuning, regulation of opsin gene expression allows for fast adaptive evolution of the visual system in response to natural and sexual selection, and in particular, sex-specific selection pressures. PMID:25429020

  19. Euarchontan Opsin Variation Brings New Focus to Primate Origins

    PubMed Central

    Melin, Amanda D.; Wells, Konstans; Moritz, Gillian L.; Kistler, Logan; Orkin, Joseph D.; Timm, Robert M.; Bernard, Henry; Lakim, Maklarin B.; Perry, George H.; Kawamura, Shoji; Dominy, Nathaniel J.

    2016-01-01

    Debate on the adaptive origins of primates has long focused on the functional ecology of the primate visual system. For example, it is hypothesized that variable expression of short- (SWS1) and middle-to-long-wavelength sensitive (M/LWS) opsins, which confer color vision, can be used to infer ancestral activity patterns and therefore selective ecological pressures. A problem with this approach is that opsin gene variation is incompletely known in the grandorder Euarchonta, that is, the orders Scandentia (treeshrews), Dermoptera (colugos), and Primates. The ancestral state of primate color vision is therefore uncertain. Here, we report on the genes (OPN1SW and OPN1LW) that encode SWS1 and M/LWS opsins in seven species of treeshrew, including the sole nocturnal scandentian Ptilocercus lowii. In addition, we examined the opsin genes of the Central American woolly opossum (Caluromys derbianus), an enduring ecological analogue in the debate on primate origins. Our results indicate: 1) retention of ultraviolet (UV) visual sensitivity in C. derbianus and a shift from UV to blue spectral sensitivities at the base of Euarchonta; 2) ancient pseudogenization of OPN1SW in the ancestors of P. lowii, but a signature of purifying selection in those of C. derbianus; and, 3) the absence of OPN1LW polymorphism among diurnal treeshrews. These findings suggest functional variation in the color vision of nocturnal mammals and a distinctive visual ecology of early primates, perhaps one that demanded greater spatial resolution under light levels that could support cone-mediated color discrimination. PMID:26739880

  20. Euarchontan Opsin Variation Brings New Focus to Primate Origins.

    PubMed

    Melin, Amanda D; Wells, Konstans; Moritz, Gillian L; Kistler, Logan; Orkin, Joseph D; Timm, Robert M; Bernard, Henry; Lakim, Maklarin B; Perry, George H; Kawamura, Shoji; Dominy, Nathaniel J

    2016-04-01

    Debate on the adaptive origins of primates has long focused on the functional ecology of the primate visual system. For example, it is hypothesized that variable expression of short- (SWS1) and middle-to-long-wavelength sensitive (M/LWS) opsins, which confer color vision, can be used to infer ancestral activity patterns and therefore selective ecological pressures. A problem with this approach is that opsin gene variation is incompletely known in the grandorder Euarchonta, that is, the orders Scandentia (treeshrews), Dermoptera (colugos), and Primates. The ancestral state of primate color vision is therefore uncertain. Here, we report on the genes (OPN1SW and OPN1LW) that encode SWS1 and M/LWS opsins in seven species of treeshrew, including the sole nocturnal scandentian Ptilocercus lowii. In addition, we examined the opsin genes of the Central American woolly opossum (Caluromys derbianus), an enduring ecological analogue in the debate on primate origins. Our results indicate: 1) retention of ultraviolet (UV) visual sensitivity in C. derbianus and a shift from UV to blue spectral sensitivities at the base of Euarchonta; 2) ancient pseudogenization of OPN1SW in the ancestors of P. lowii, but a signature of purifying selection in those of C. derbianus; and, 3) the absence of OPN1LW polymorphism among diurnal treeshrews. These findings suggest functional variation in the color vision of nocturnal mammals and a distinctive visual ecology of early primates, perhaps one that demanded greater spatial resolution under light levels that could support cone-mediated color discrimination. PMID:26739880

  1. Short- and long-wavelength-sensitive opsins are involved in photoreception both in the retina and throughout the central nervous system of crayfish.

    PubMed

    Kingston, Alexandra C N; Cronin, Thomas W

    2015-12-01

    Crayfish have two classes of photoreceptors in the retinas of their reflecting superposition eyes. Long-wavelength-sensitive photoreceptors, comprised of microvilli from R1-7 cells, make up the main rhabdoms. Eighth retinular cells, located distal to the main rhabdoms, house short-wavelength-sensitive photoreceptors. While the opsin involved in long-wavelength sensitivity has long been known, we present the first description of the short-wavelength-sensitive opsin in the retina of the red swamp crayfish, Procambarus clarkii. The expression patterns of these SWS and LWS opsin proteins in the retina are consistent with the previously described locations of SWS and LWS receptors. Crayfish also have a well-characterized extraocular photoreceptor, called the caudal photoreceptor, located in the sixth abdominal ganglion. To search for retinal opsins in the caudal photoreceptor (and elsewhere in the CNS), we used RT-PCR and immunohistochemical labeling. We found both SWS and LWS opsin transcripts not only in the sixth abdominal ganglion, but also in all ganglia of the nerve cord. Immunolabeling shows that both opsins are expressed in nerve fibers that extend from the brain through the entire length of the CNS. Thus, the same two photopigments are used both for vision in the retina and for extraocular functions throughout the CNS of crayfish. PMID:26445969

  2. Divergence in cis-regulatory sequences surrounding the opsin gene arrays of African cichlid fishes

    PubMed Central

    2011-01-01

    Background Divergence within cis-regulatory sequences may contribute to the adaptive evolution of gene expression, but functional alleles in these regions are difficult to identify without abundant genomic resources. Among African cichlid fishes, the differential expression of seven opsin genes has produced adaptive differences in visual sensitivity. Quantitative genetic analysis suggests that cis-regulatory alleles near the SWS2-LWS opsins may contribute to this variation. Here, we sequence BACs containing the opsin genes of two cichlids, Oreochromis niloticus and Metriaclima zebra. We use phylogenetic footprinting and shadowing to examine divergence in conserved non-coding elements, promoter sequences, and 3'-UTRs surrounding each opsin in search of candidate cis-regulatory sequences that influence cichlid opsin expression. Results We identified 20 conserved non-coding elements surrounding the opsins of cichlids and other teleosts, including one known enhancer and a retinal microRNA. Most conserved elements contained computationally-predicted binding sites that correspond to transcription factors that function in vertebrate opsin expression; O. niloticus and M. zebra were significantly divergent in two of these. Similarly, we found a large number of relevant transcription factor binding sites within each opsin's proximal promoter, and identified five opsins that were considerably divergent in both expression and the number of transcription factor binding sites shared between O. niloticus and M. zebra. We also found several microRNA target sites within the 3'-UTR of each opsin, including two 3'-UTRs that differ significantly between O. niloticus and M. zebra. Finally, we examined interspecific divergence among 18 phenotypically diverse cichlids from Lake Malawi for one conserved non-coding element, two 3'-UTRs, and five opsin proximal promoters. We found that all regions were highly conserved with some evidence of CRX transcription factor binding site turnover. We also found three SNPs within two opsin promoters and one non-coding element that had weak association with cichlid opsin expression. Conclusions This study is the first to systematically search the opsins of cichlids for putative cis-regulatory sequences. Although many putative regulatory regions are highly conserved across a large number of phenotypically diverse cichlids, we found at least nine divergent sequences that could contribute to opsin expression differences in cis and stand out as candidates for future functional analyses. PMID:21554730

  3. The NASA LWS Sentinels Mission

    NASA Astrophysics Data System (ADS)

    Lin, Robert P.; Science, Sentinels; DefinitionTeam, Technology

    2006-06-01

    One of the primary goals of NASA's Sentinels mission, the heliospheric element of the integrated LWS (Living With a Star) program, is to provide the observations necessary for an understanding of the physics of the Sun/inner heliosphere processes that produce Solar Energetic Particle (SEP) events, so the requirements for eventual predictive capability can be defined. We present the results of the study by the Sentinels Science and Technology Definition Team (STDT) that recommends a combination of the Inner Heliosphere Sentinels (IHS),consisting of four identical spacecraft that utilize Venus gravity assists to achieve 0.25-0.75 AU orbits, primarily for in situ particles and fields measurements; a Near-Earth Sentinel (NES) with a spectroscopic coronagraph to provide the physical conditions in the SEP acceleration region and a wide field (>0.3AU) coronagraph to connect to the HIS measurements, and a Farside Sentinel (FS) with a magnetograph to provide near global photospheric magnetic field measurements for modeling the structure of the inner heliosphere. We show how the combined measurements are designed to lead to an understanding of SEP origin and to improve our predictive capability for large SEP events.

  4. Opsin evolution in the Ambulacraria.

    PubMed

    D'Aniello, S; Delroisse, J; Valero-Gracia, A; Lowe, E K; Byrne, M; Cannon, J T; Halanych, K M; Elphick, M R; Mallefet, J; Kaul-Strehlow, S; Lowe, C J; Flammang, P; Ullrich-Lter, E; Wanninger, A; Arnone, M I

    2015-12-01

    Opsins - G-protein coupled receptors involved in photoreception - have been extensively studied in the animal kingdom. The present work provides new insights into opsin-based photoreception and photoreceptor cell evolution with a first analysis of opsin sequence data for a major deuterostome clade, the Ambulacraria. Systematic data analysis, including for the first time hemichordate opsin sequences and an expanded echinoderm dataset, led to a robust opsin phylogeny for this cornerstone superphylum. Multiple genomic and transcriptomic resources were surveyed to cover each class of Hemichordata and Echinodermata. In total, 119 ambulacrarian opsin sequences were found, 22 new sequences in hemichordates and 97 in echinoderms (including 67 new sequences). We framed the ambulacrarian opsin repertoire within eumetazoan diversity by including selected reference opsins from non-ambulacrarians. Our findings corroborate the presence of all major ancestral bilaterian opsin groups in Ambulacraria. Furthermore, we identified two opsin groups specific to echinoderms. In conclusion, a molecular phylogenetic framework for investigating light-perception and photobiological behaviors in marine deuterostomes has been obtained. PMID:26472700

  5. Ciliary Transport of Opsin

    PubMed Central

    Williams, David S.

    2010-01-01

    As part of the renewal of photoreceptor outer segment disk membranes, membrane proteins are transported along the region of the cilium, connecting the inner and outer segments. Genetics studies have indicated the role of motor proteins in this transport. Direct analysis of live cells is needed to increase our understanding of the transport mechanisms further. Here, we show that transfection of hTERT-RPE1 cells with constructs encoding RHO-EGFP, but not RHO-mCherry, results in the distribution of fluorescently-tagged opsin in the plasma membrane. When the cells have differentiated and possess cilia, a portion of the RHO-EGFP was observed along the cilia. Due to the remarkable conservation of ciliary protein function, this system of Rho-Egfp transfected hTERT-RPE1 cells provides a valid model with which to study the ciliary transport of opsin directly in live cells. PMID:20238016

  6. Molecular and functional characterization of opsins in barfin flounder (Verasper moseri).

    PubMed

    Kasagi, Satoshi; Mizusawa, Kanta; Murakami, Naoto; Andoh, Tadashi; Furufuji, Sumihisa; Kawamura, Shoji; Takahashi, Akiyoshi

    2015-02-10

    Green light irradiation facilitates the somatic growth of barfin flounder (Verasper moseri). However, the V. moseri visual system, which may be associated with somatic growth by acting on the endocrine system upon exposure to this particular wavelength, remains largely unexplored. Herein, we characterized the visual opsin repertoire of V. moseri to understand the molecular basis underlying this effect. The five types of visual opsins that are found in vertebrates were cloned from RNA that was extracted from the eyes of V. moseri. Notably, V. moseri possessed one pseudogene (RH2-A) and two intact (RH2-B and RH2-C) copies of "green-sensitive" opsin genes. The wavelengths of maximum absorption spectra (λmax) for each of the reconstituted photopigments were 552nm for "red-sensitive" LWS, 506nm for RH2-B, 490nm for RH2-C, 482nm and 416nm for "blue-sensitive" SWS2A and SWS2B, respectively, 367nm for "ultraviolet-sensitive" SWS1, and 494nm for "dim-light sensitive rhodopsin" RH1. The λmax of SWS2A was longer than that of any other reported vertebrate SWS2 opsin. By measuring the expression level of these opsin genes with quantitative RT-PCR in 3-, 15-, and 27-month-old fish, we found that RH2-B and SWS2A were expressed at a constant level, whereas the expression of LWS, RH2-C, SWS2B, and SWS1 opsin genes decreased, and that of RH1 increased with age. Barfin flounders inhabit inshore waters at a young age and expand their habitat to deep sea areas as they age, and green light is relatively abundant in deep water compared to the lights of other wavelengths in shallow water. Our results indicate that gene repertoire and expression profile of the opsin genes of barfin flounder are adaptive to their habitat shift that occurs during development, with some opsins acquiring a distinct λmax. PMID:25433330

  7. The LWS TR&T Program

    NASA Astrophysics Data System (ADS)

    Sibeck, D.

    NASA's Living With a Star (LWS) Targetted Research and Technology (TR&T) program focuses on space science research areas with the potential for societal impact, e.g. forecasting variations in the solar EUV radiation and corresponding ionospheric effects, coronal mass ejections and corresponding geomagnetic and auroral activity, ionospheric radio propagation, variations in radiation belt particle intensity, and the influence of space weather upon the Earth's climate. Examples of LWS-funded research projects in each area will be given. With the guidance of an initial Science Definition Team and an ongoing Steering Committee with rotating membership, the TR&T program will set research objectives, encourage cross-disciplinary research and end-to-end modeling efforts, and define the metrics needed to evaluate these efforts. The program will provide a publically-accessible WWW site to host tools and data sets developed by the program, and may institute a series of workshops.

  8. Evolution and functional diversity of jellyfish opsins.

    PubMed

    Suga, Hiroshi; Schmid, Volker; Gehring, Walter J

    2008-01-01

    Cnidaria are the most basal animal phylum possessing complex eyes [1]. Their eyes predominantly use ciliary photoreceptor cells (c-PRCs) like vertebrates, whereas insect eyes use rhabdomeric photoreceptor cells (r-PRCs) [1-4]. These two cell types show not only different cytoarchitectures but distinct phototransduction cascades, which are triggered by the respective types of opsins (e.g., [5]), ciliary opsins (c-opsins) and rhabdomeric opsins (r-opsins) [6]. Recent reports suggested that the c- and r-PRCs and their respective opsins diverged at least before the deuterostome-protostome split [7-9]. To study the earlier evolution of animal PRCs and opsins, we investigated two hydrozoan jellyfishes. We report here the first-characterized cnidarian opsins. Molecular phylogeny revealed that the cloned 20 jellyfish opsins, together with all the opsins from a hydra and some from a sea anemone, are more closely related to the c-opsins than to any other major opsin subfamily, indicating that the divergence of c- and r-opsins antedates the Cnidaria-Bilateria split. Possible scenarios of animal PRC evolution are discussed. Furthermore, Cladonema opsins show several distinct tissue- and stage-specific expression patterns. The expression of specific opsins in the eyes suggests a role in vision, whereas that in the gonads suggests a role in light-controlled release of gametes. PMID:18160295

  9. SWS and LWS observations of Cassiopeia A

    NASA Technical Reports Server (NTRS)

    Unger, S. J.; Pequignot, D.; Cox, P.; Haas, M. R.; Baluteau, J. P.; Lahuis, F.; Emery, R. J.; Morisset, C.

    1997-01-01

    The observations of the Casssiopeia A supernova remnant performed with the short wavelength spectrometer (SWS) and the long wavelength spectrometer (LWS), onboard the Infrared Space Observatory (ISO), are reported on. Broad O III 52 micrometer and 88 micrometer and O I 63 micrometer emission lines were detected. The far infrared O III lines fit the model of a spherical shell with central velocity redshifted by 770 +/- 40 km/s. A pronounced density contrast between the front and back of the shell was detected.

  10. Variable light environments induce plastic spectral tuning by regional opsin coexpression in the African cichlid fish, Metriaclima zebra.

    PubMed

    Dalton, Brian E; Lu, Jessica; Leips, Jeff; Cronin, Thomas W; Carleton, Karen L

    2015-08-01

    Critical behaviours such as predation and mate choice often depend on vision. Visual systems are sensitive to the spectrum of light in their environment, which can vary extensively both within and among habitats. Evolutionary changes in spectral sensitivity contribute to divergence and speciation. Spectral sensitivity of the retina is primarily determined by visual pigments, which are opsin proteins bound to a chromophore. We recently discovered that photoreceptors in different regions of the retina, which view objects against distinct environmental backgrounds, coexpress different pairs of opsins in an African cichlid fish, Metriaclima zebra. This coexpression tunes the sensitivity of the retinal regions to the corresponding backgrounds and may aid in detection of dark objects, such as predators. Although intraretinal regionalization of spectral sensitivity in many animals correlates with their light environments, it is unknown whether variation in the light environment induces developmentally plastic alterations of intraretinal sensitivity regions. Here, we demonstrate with fluorescent insitu hybridization and qPCR that the spectrum and angle of environmental light both influence the development of spectral sensitivity regions by altering the distribution and level of opsins across the retina. Normally, M.zebra coexpresses LWS opsin with RH2A? opsin in double cones of the ventral but not the dorsal retina. However, when illuminated from below throughout development, adult M.zebra coexpressed LWS and RH2A? in double cones both dorsally and ventrally. Thus, environmental background spectra alter the spectral sensitivity pattern that develops across the retina, potentially influencing behaviours and related evolutionary processes such as courtship and speciation. PMID:26175094

  11. Three cone opsin genes determine the properties of the visual spectra in the Japanese anchovy, Engraulis japonicus (Engraulidae, Teleostei).

    PubMed

    Kondrashev, Sergei L; Miyazaki, Taeko; Lamash, Nina E; Tsuchiya, Tohru

    2013-03-15

    A complement of cone visual pigments was identified in the Japanese anchovy Engraulis japonicus, one of the engraulid fish species that has a retina specialized for polarization and color vision. The nature of the chromophore bound to opsin proteins was investigated using high performance liquid chromatography. The opsin genes were then cloned and sequenced, and the absorption spectra of different types of cones were obtained by microspectrophotometry. Two green (EJ-RH2-1, EJ-RH2-2) and one red (EJ-LWS) cone opsin genes were identified and are presumably related to the vitamin A1-based visual pigments (i.e. rhodopsins) with ?max values of 492, 474 and 512 nm, respectively. The long and short cones from the ventro-temporal retinal zone consisted of a pure population of RH2 class gene-based pigments (?max=492 nm). The long and short cones from other retinal areas and the lateral components of the triple cones possessed a mixture of RH2 and LWS class gene-based pigments that exhibited a ?max of ~502 nm. The central component of the triple cones contained only RH2 class gene-based pigments (?max=474 nm). Thus, E. japonicus possesses a middle-wave range of spectral sensitivity and acquires different color vision systems in distinct visual fields. PMID:23197087

  12. Intraspecific cone opsin expression variation in the cichlids of Lake Malawi.

    PubMed

    Smith, Adam R; D'Annunzio, Lindsay; Smith, Abbi E; Sharma, Anit; Hofmann, Christopher M; Marshall, N J; Carleton, Karen L

    2011-01-01

    The expression of cone opsin genes is a primary determinant of the characteristics of colour vision. Interspecific variation in opsin expression is common in African cichlids. It is correlated with foraging among cichlids from Lake Malawi, and with ambient light environment among cichlids from Lake Victoria. In this study, we tested whether gene expression varied within species such that it might be important in contributing to divergence. We hypothesized that light attenuation with depth would be correlated with predictable changes in gene expression in Lake Malawi, and that this variation would tune visual sensitivities to match the ambient light environment. We observed significant differences in cone opsin expression in three different comparisons among populations of the same species. Higher LWS expression was found in shallow versus deep Copadichromis eucinostomus. In Metriaclima zebra, individuals from Zimbawe Rock expressed significantly more SWS2B than those from Thumbi West Island, although these locales have similar ambient light environments. Finally, Tropheops gracilior from deeper water had significantly more variation in expression than their shallow counterparts. These results support that gene expression varies significantly between populations of the same species. Surprisingly, these results could not be explained by predicted visual performance as models predicted that differential expression patterns did not confer sensitivity advantages at different depths. This suggested that expression variation did not confer a local sensitivity advantage. Therefore, our findings were contrary to a primary requirement of the sensory bias hypothesis. As such, other explanations for intraspecific gene expression variation need to be tested. PMID:21091561

  13. Opsin vs opsin: New materials for biotechnological applications

    NASA Astrophysics Data System (ADS)

    Alfinito, Eleonora; Reggiani, Lino

    2014-08-01

    The need of new diagnostic methods satisfying, as an early detection, a low invasive procedure and a cost-efficient value, is orienting the technological research toward the use of bio-integrated devices, in particular, bio-sensors. The set of know-why necessary to achieve this goal is wide, from biochemistry to electronics and is summarized in an emerging branch of electronics, called proteotronics. Proteotronics is here applied to state a comparative analysis of the electrical responses coming from type-1 and type-2 opsins. In particular, the procedure is used as an early investigation of a recently discovered family of opsins, the proteorhodopsins activated by blue light, BPRs. The results reveal some interesting and unexpected similarities between proteins of the two families, suggesting the global electrical response are not strictly linked to the class identity.

  14. Opsin vs opsin: New materials for biotechnological applications

    SciTech Connect

    Alfinito, Eleonora; Reggiani, Lino

    2014-08-14

    The need of new diagnostic methods satisfying, as an early detection, a low invasive procedure and a cost-efficient value, is orienting the technological research toward the use of bio-integrated devices, in particular, bio-sensors. The set of know-why necessary to achieve this goal is wide, from biochemistry to electronics and is summarized in an emerging branch of electronics, called proteotronics. Proteotronics is here applied to state a comparative analysis of the electrical responses coming from type-1 and type-2 opsins. In particular, the procedure is used as an early investigation of a recently discovered family of opsins, the proteorhodopsins activated by blue light, BPRs. The results reveal some interesting and unexpected similarities between proteins of the two families, suggesting the global electrical response are not strictly linked to the class identity.

  15. LWS/SET Technology Experiment Carrier

    NASA Technical Reports Server (NTRS)

    Sherman, Barry; Giffin, Geoff

    2002-01-01

    This paper examines the approach taken to building a low-cost, modular spacecraft bus that can be used to support a variety of technology experiments in different space environments. It describes the techniques used and design drivers considered to ensure experiment independence from as yet selected host spacecraft. It describes the technology experiment carriers that will support NASA's Living With a Star Space Environment Testbed space missions. NASA has initiated the Living With a Star (LWS) Program to develop a better scientific understanding to address the aspects of the connected Sun-Earth system that affect life and society. A principal goal of the program is to bridge the gap between science, engineering, and user application communities. The Space Environment Testbed (SET) Project is one element of LWS. The Project will enable future science, operational, and commercial objectives in space and atmospheric environments by improving engineering approaches to the accommodation and/or mitigation of the effects of solar variability on technological systems. The SET Project is highly budget constrained and must seek to take advantage of as yet undetermined partnering opportunities for access to space. SET will conduct technology validation experiments hosted on available flight opportunities. The SET Testbeds will be developed in a manner that minimizes the requirements for accommodation, and will be flown as flight opportunities become available. To access the widest range of flight opportunities, two key development requirements are to maintain flexibility with respect to accommodation constraints and to have the capability to respond quickly to flight opportunities. Experiments, already developed to the technology readiness level of needing flight validation in the variable Sun-Earth environment, will be selected on the basis of the need for the subject technology, readiness for flight, need for flight resources and particular orbit. Experiments will be accumulated by the Project and manifested for specific flight opportunities as they become available. The SET Carrier is designed to present a standard set of interfaces to SET technology experiments and to be modular and flexible enough to interface to a variety of possible host spacecraft. The Carrier will have core components and mission unique components. Once the core carrier elements have been developed, only the mission unique components need to be defined and developed for any particular mission. This approach will minimize the mission specific cost and development schedule for a given flight opportunity. The standard set of interfaces provided by SET to experiments allows them to be developed independent of the particulars of a host spacecraft. The Carrier will provide the power, communication, and the necessary monitoring features to operate experiments. The Carrier will also provide all of the mechanical assemblies and harnesses required to adapt experiments to a particular host. Experiments may be hosted locally with the Carrier or remotely on the host spacecraft. The Carrier design will allow a single Carrier to support a variable number of experiments and will include features that support the ability to incrementally add experiments without disturbing the core architecture.

  16. Diversity of Active States in TMT Opsins

    PubMed Central

    Sakai, Kazumi; Yamashita, Takahiro; Imamoto, Yasushi; Shichida, Yoshinori

    2015-01-01

    Opn3/TMT opsins belong to one of the opsin groups with vertebrate visual and non-visual opsins, and are widely distributed in eyes, brains and other internal organs in various vertebrates and invertebrates. Vertebrate Opn3/TMT opsins are further classified into four groups on the basis of their amino acid identities. However, there is limited information about molecular properties of these groups, due to the difficulty in preparing the recombinant proteins. Here, we successfully expressed recombinant proteins of TMT1 and TMT2 opsins of medaka fish (Oryzias latipes) in cultured cells and characterized their molecular properties. Spectroscopic and biochemical studies demonstrated that TMT1 and TMT2 opsins functioned as blue light-sensitive Gi/Go-coupled receptors, but exhibited spectral properties and photo-convertibility of the active state different from each other. TMT1 opsin forms a visible light-absorbing active state containing all-trans-retinal, which can be photo-converted to 7-cis- and 9-cis-retinal states in addition to the original 11-cis-retinal state. In contrast, the active state of TMT2 opsin is a UV light-absorbing state having all-trans-retinal and does not photo-convert to any other state, including the original 11-cis-retinal state. Thus, TMT opsins are diversified so as to form a different type of active state, which may be responsible for their different functions. PMID:26491964

  17. Shedding new light on opsin evolution

    PubMed Central

    Porter, Megan L.; Blasic, Joseph R.; Bok, Michael J.; Cameron, Evan G.; Pringle, Thomas; Cronin, Thomas W.; Robinson, Phyllis R.

    2012-01-01

    Opsin proteins are essential molecules in mediating the ability of animals to detect and use light for diverse biological functions. Therefore, understanding the evolutionary history of opsins is key to understanding the evolution of light detection and photoreception in animals. As genomic data have appeared and rapidly expanded in quantity, it has become possible to analyse opsins that functionally and histologically are less well characterized, and thus to examine opsin evolution strictly from a genetic perspective. We have incorporated these new data into a large-scale, genome-based analysis of opsin evolution. We use an extensive phylogeny of currently known opsin sequence diversity as a foundation for examining the evolutionary distributions of key functional features within the opsin clade. This new analysis illustrates the lability of opsin protein-expression patterns, site-specific functionality (i.e. counterion position) and G-protein binding interactions. Further, it demonstrates the limitations of current model organisms, and highlights the need for further characterization of many of the opsin sequence groups with unknown function. PMID:22012981

  18. Vision for the Future of Lws TR&T

    NASA Astrophysics Data System (ADS)

    Schwadron, N.; Mannucci, A. J.; Antiochos, S. K.; Bhattacharjee, A.; Gombosi, T. I.; Gopalswamy, N.; Kamalabadi, F.; Linker, J.; Pilewskie, P.; Pulkkinen, A. A.; Spence, H. E.; Tobiska, W. K.; Weimer, D. R.; Withers, P.; Bisi, M. M.; Kuznetsova, M. M.; Miller, K. L.; Moretto, T.; Onsager, T. G.; Roussev, I. I.; Viereck, R. A.

    2014-12-01

    The Living With a Star (LWS) program addresses acute societal needs for understanding the effects of space weather and developing scientific knowledge to support predictive capabilities. Our society's heavy reliance on technologies affected by the space environment, an enormous number of airline customers, interest in space tourism, and the developing plans for long-duration human exploration space missions are clear examples that demonstrate urgent needs for space weather models and detailed understanding of space weather effects and risks. Since its inception, the LWS program has provided a vehicle to innovate new mechanisms for conducting research, building highly effective interdisciplinary teams, and ultimately in developing the scientific understanding needed to transition research tools into operational models that support the predictive needs of our increasingly space-reliant society. The advances needed require broad-based observations that cannot be obtained by large missions alone. The Decadal Survey (HDS, 2012) outlines the nation's needs for scientific development that will build the foundation for tomorrow's space weather services. Addressing these goals, LWS must develop flexible pathways to space utilizing smaller, more diverse and rapid development of observational platforms. Expanding utilization of ground-based assets and shared launches will also significantly enhance opportunities to fulfill the growing LWS data needs. Partnerships between NASA divisions, national/international agencies, and with industry will be essential for leveraging resources to address increasing societal demand for space weather advances. Strengthened connections to user communities will enhance the quality and impact of deliverables from LWS programs. Thus, we outline the developing vision for the future of LWS, stressing the need for deeper scientific understanding to improve forecasting capabilities, for more diverse data resources, and for project deliverables that address the growing needs of user communities.

  19. Analysis of the opsin repertoire in the tardigrade Hypsibius dujardini provides insights into the evolution of opsin genes in panarthropoda.

    PubMed

    Hering, Lars; Mayer, Georg

    2014-09-01

    Screening of a deeply sequenced transcriptome using Illumina sequencing as well as the genome of the tardigrade Hypsibius dujardini revealed a set of five opsin genes. To clarify the phylogenetic position of these genes and to elucidate the evolutionary history of opsins in Panarthropoda (Onychophora + Tardigrada + Arthropoda), we reconstructed the phylogeny of broadly sampled metazoan opsin genes using maximum likelihood and Bayesian inference methods in conjunction with carefully selected substitution models. According to our findings, the opsin repertoire of H. dujardini comprises representatives of all three major bilaterian opsin clades, including one r-opsin, three c-opsins, and a Group 4 opsin (neuropsin/opsin-5). The identification of the tardigrade ortholog of neuropsin/opsin-5 is the first record of this opsin type in a protostome, but our screening of available metazoan genomes revealed that it is also present in other protostomes. Our opsin phylogeny further suggests that two r-opsins, including an "arthropsin," were present in the last common ancestor of Panarthropoda. Although both r-opsin lineages were retained in Onychophora and Arthropoda, the arthropsin was lost in Tardigrada. The single (most likely visual) r-opsin found in H. dujardini supports the hypothesis of monochromatic vision in the panarthropod ancestor, whereas two duplications of the ancestral panarthropod c-opsin have led to three c-opsins in tardigrades. Although the early-branching nodes are unstable within the metazoans, our findings suggest that the last common ancestor of Bilateria possessed six opsins: Two r-opsins, one c-opsin, and three Group 4 opsins, one of which (Go opsin) was lost in the ecdysozoan lineage. PMID:25193307

  20. Analysis of the Opsin Repertoire in the Tardigrade Hypsibius dujardini Provides Insights into the Evolution of Opsin Genes in Panarthropoda

    PubMed Central

    Hering, Lars; Mayer, Georg

    2014-01-01

    Screening of a deeply sequenced transcriptome using Illumina sequencing as well as the genome of the tardigrade Hypsibius dujardini revealed a set of five opsin genes. To clarify the phylogenetic position of these genes and to elucidate the evolutionary history of opsins in Panarthropoda (Onychophora + Tardigrada + Arthropoda), we reconstructed the phylogeny of broadly sampled metazoan opsin genes using maximum likelihood and Bayesian inference methods in conjunction with carefully selected substitution models. According to our findings, the opsin repertoire of H. dujardini comprises representatives of all three major bilaterian opsin clades, including one r-opsin, three c-opsins, and a Group 4 opsin (neuropsin/opsin-5). The identification of the tardigrade ortholog of neuropsin/opsin-5 is the first record of this opsin type in a protostome, but our screening of available metazoan genomes revealed that it is also present in other protostomes. Our opsin phylogeny further suggests that two r-opsins, including an arthropsin, were present in the last common ancestor of Panarthropoda. Although both r-opsin lineages were retained in Onychophora and Arthropoda, the arthropsin was lost in Tardigrada. The single (most likely visual) r-opsin found in H. dujardini supports the hypothesis of monochromatic vision in the panarthropod ancestor, whereas two duplications of the ancestral panarthropod c-opsin have led to three c-opsins in tardigrades. Although the early-branching nodes are unstable within the metazoans, our findings suggest that the last common ancestor of Bilateria possessed six opsins: Two r-opsins, one c-opsin, and three Group 4 opsins, one of which (Go opsin) was lost in the ecdysozoan lineage. PMID:25193307

  1. Broad-Band Activatable White-Opsin

    PubMed Central

    Batabyal, Subrata; Cervenka, Gregory; Ha, Ji Hee; Kim, Young-tae; Mohanty, Samarendra

    2015-01-01

    Currently, the use of optogenetic sensitization of retinal cells combined with activation/inhibition has the potential to be an alternative to retinal implants that would require electrodes inside every single neuron for high visual resolution. However, clinical translation of optogenetic activation for restoration of vision suffers from the drawback that the narrow spectral sensitivity of an opsin requires active stimulation by a blue laser or a light emitting diode with much higher intensities than ambient light. In order to allow an ambient light-based stimulation paradigm, we report the development of a white-opsin that has broad spectral excitability in the visible spectrum. The cells sensitized with white-opsin showed excitability at an order of magnitude higher with white light compared to using only narrow-band light components. Further, cells sensitized with white-opsin produced a photocurrent that was five times higher than Channelrhodopsin-2 under similar photo-excitation conditions. The use of fast white-opsin may allow opsin-sensitized neurons in a degenerated retina to exhibit a higher sensitivity to ambient white light. This property, therefore, significantly lowers the activation threshold in contrast to conventional approaches that use intense narrow-band opsins and light to activate cellular stimulation. PMID:26360377

  2. The Microbial Opsin Family of Optogenetic Tools

    PubMed Central

    Zhang, Feng; Vierock, Johannes; Yizhar, Ofer; Fenno, Lief E.; Tsunoda, Satoshi; Kianianmomeni, Arash; Prigge, Matthias; Berndt, Andre; Cushman, John; Polle, Jürgen; Magnuson, Jon; Hegemann, Peter; Deisseroth, Karl

    2014-01-01

    The capture and utilization of light is an exquisitely evolved process. The single-component microbial opsins, although more limited than multicomponent cascades in processing, display unparalleled compactness and speed. Recent advances in understanding microbial opsins have been driven by molecular engineering for optogenetics and by comparative genomics. Here we provide a Primer on these light-activated ion channels and pumps, describe a group of opsins bridging prior categories, and explore the convergence of molecular engineering and genomic discovery for the utilization and understanding of these remarkable molecular machines. PMID:22196724

  3. The Microbial Opsin Family of Optogenetic Tools

    SciTech Connect

    Zhang, Feng; Vierock, Johannes; Yizhar, Ofer; Fenno, Lief E.; Tsunoda, Satoshi; Kianianmomeni, Arash; Prigge, Matthias; Berndt, Andre; Cushman, John C.; Polle, Juergen E.; Magnuson, Jon K.; Hegemann, Peter; Deisseroth, Karl

    2011-12-23

    The capture and utilization of light is an exquisitely evolved process. The single-component microbial opsins, although more limited than multicomponent cascades in processing, display unparalleled compactness and speed. Recent advances in understanding microbial opsins have been driven by molecular engineering for optogenetics and by comparative genomics. Here we provide a Primer on these light-activated ion channels and pumps, describe a group of opsins bridging prior categories, and explore the convergence of molecular engineering and genomic discovery for the utilization and understanding of these remarkable molecular machines.

  4. Involvement of opsins in mammalian sperm thermotaxis

    PubMed Central

    Pérez-Cerezales, Serafín; Boryshpolets, Sergii; Afanzar, Oshri; Brandis, Alexander; Nevo, Reinat; Kiss, Vladimir; Eisenbach, Michael

    2015-01-01

    A unique characteristic of mammalian sperm thermotaxis is extreme temperature sensitivity, manifested by the capacity of spermatozoa to respond to temperature changes of <0.0006 °C as they swim their body-length distance. The identity of the sensing system that confers this exceptional sensitivity on spermatozoa is not known. Here we show that the temperature-sensing system of mammalian spermatozoa involves opsins, known to be G-protein-coupled receptors that act as photosensors in vision. We demonstrate by molecular, immunological, and functional approaches that opsins are present in human and mouse spermatozoa at specific sites, which depend on the species and the opsin type, and that they are involved in sperm thermotaxis via two signalling pathways—the phospholipase C and the cyclic-nucleotide pathways. Our results suggest that, depending on the context and the tissue, mammalian opsins act not only as photosensors but also as thermosensors. PMID:26537127

  5. Metazoan opsin evolution reveals a simple route to animal vision

    PubMed Central

    Feuda, Roberto; Hamilton, Sinead C.; McInerney, James O.; Pisani, Davide

    2012-01-01

    All known visual pigments in Neuralia (Cnidaria, Ctenophora, and Bilateria) are composed of an opsin (a seven-transmembrane G protein-coupled receptor), and a light-sensitive chromophore, generally retinal. Accordingly, opsins play a key role in vision. There is no agreement on the relationships of the neuralian opsin subfamilies, and clarifying their phylogeny is key to elucidating the origin of this protein family and of vision. We used improved methods and data to resolve the opsin phylogeny and explain the evolution of animal vision. We found that the Placozoa have opsins, and that the opsins share a common ancestor with the melatonin receptors. Further to this, we found that all known neuralian opsins can be classified into the same three subfamilies into which the bilaterian opsins are classified: the ciliary (C), rhabdomeric (R), and go-coupled plus retinochrome, retinal G protein-coupled receptor (Go/RGR) opsins. Our results entail a simple scenario of opsin evolution. The first opsin originated from the duplication of the common ancestor of the melatonin and opsin genes in a eumetazoan (Placozoa plus Neuralia) ancestor, and an inference of its amino acid sequence suggests that this protein might not have been light-sensitive. Two more gene duplications in the ancestral neuralian lineage resulted in the origin of the R, C, and Go/RGR opsins. Accordingly, the first animal with at least a C, an R, and a Go/RGR opsin was a neuralian progenitor. PMID:23112152

  6. Metazoan opsin evolution reveals a simple route to animal vision.

    PubMed

    Feuda, Roberto; Hamilton, Sinead C; McInerney, James O; Pisani, Davide

    2012-11-13

    All known visual pigments in Neuralia (Cnidaria, Ctenophora, and Bilateria) are composed of an opsin (a seven-transmembrane G protein-coupled receptor), and a light-sensitive chromophore, generally retinal. Accordingly, opsins play a key role in vision. There is no agreement on the relationships of the neuralian opsin subfamilies, and clarifying their phylogeny is key to elucidating the origin of this protein family and of vision. We used improved methods and data to resolve the opsin phylogeny and explain the evolution of animal vision. We found that the Placozoa have opsins, and that the opsins share a common ancestor with the melatonin receptors. Further to this, we found that all known neuralian opsins can be classified into the same three subfamilies into which the bilaterian opsins are classified: the ciliary (C), rhabdomeric (R), and go-coupled plus retinochrome, retinal G protein-coupled receptor (Go/RGR) opsins. Our results entail a simple scenario of opsin evolution. The first opsin originated from the duplication of the common ancestor of the melatonin and opsin genes in a eumetazoan (Placozoa plus Neuralia) ancestor, and an inference of its amino acid sequence suggests that this protein might not have been light-sensitive. Two more gene duplications in the ancestral neuralian lineage resulted in the origin of the R, C, and Go/RGR opsins. Accordingly, the first animal with at least a C, an R, and a Go/RGR opsin was a neuralian progenitor. PMID:23112152

  7. Opsin Expression in Human Epidermal Skin

    PubMed Central

    Haltaufderhyde, Kirk; Ozdeslik, Rana N; Wicks, Nadine L; Najera, Julia A; Oancea, Elena

    2015-01-01

    Human skin is constantly exposed to solar light containing visible and ultraviolet radiation (UVR), a powerful skin carcinogen. UVR elicits cellular responses in epidermal cells via several mechanisms: direct absorption of short-wavelength UVR photons by DNA, oxidative damage caused by long-wavelength UVR, and, as we recently demonstrated, via a retinal-dependent G protein-coupled signaling pathway. Because the human epidermis is exposed to a wide range of light wavelengths, we investigated whether opsins, light-activated receptors that mediate photoreception in the eye, are expressed in epidermal skin to potentially serve as photosensors. Here we show that four opsinsOPN1-SW, OPN2, OPN3 and OPN5are expressed in the two major human epidermal cell types, melanocytes and keratinocytes, and the mRNA expression profile of these opsins does not change in response to physiological UVR doses. We detected two OPN3 splice variants present in similar amounts in both cell types and three OPN5 splice isoforms, two of which encode truncated proteins. Notably, OPN2 and OPN3 mRNA were significantly more abundant than other opsins and encoded full-length proteins. Our results demonstrate that opsins are expressed in epidermal skin cells and suggest that they might initiate lightinduced signaling pathways, possibly contributing to UVR phototransduction. PMID:25267311

  8. The vertebrate ancestral repertoire of visual opsins, transducin alpha subunits and oxytocin/vasopressin receptors was established by duplication of their shared genomic region in the two rounds of early vertebrate genome duplications

    PubMed Central

    2013-01-01

    Background Vertebrate color vision is dependent on four major color opsin subtypes: RH2 (green opsin), SWS1 (ultraviolet opsin), SWS2 (blue opsin), and LWS (red opsin). Together with the dim-light receptor rhodopsin (RH1), these form the family of vertebrate visual opsins. Vertebrate genomes contain many multi-membered gene families that can largely be explained by the two rounds of whole genome duplication (WGD) in the vertebrate ancestor (2R) followed by a third round in the teleost ancestor (3R). Related chromosome regions resulting from WGD or block duplications are said to form a paralogon. We describe here a paralogon containing the genes for visual opsins, the G-protein alpha subunit families for transducin (GNAT) and adenylyl cyclase inhibition (GNAI), the oxytocin and vasopressin receptors (OT/VP-R), and the L-type voltage-gated calcium channels (CACNA1-L). Results Sequence-based phylogenies and analyses of conserved synteny show that the above-mentioned gene families, and many neighboring gene families, expanded in the early vertebrate WGDs. This allows us to deduce the following evolutionary scenario: The vertebrate ancestor had a chromosome containing the genes for two visual opsins, one GNAT, one GNAI, two OT/VP-Rs and one CACNA1-L gene. This chromosome was quadrupled in 2R. Subsequent gene losses resulted in a set of five visual opsin genes, three GNAT and GNAI genes, six OT/VP-R genes and four CACNA1-L genes. These regions were duplicated again in 3R resulting in additional teleost genes for some of the families. Major chromosomal rearrangements have taken place in the teleost genomes. By comparison with the corresponding chromosomal regions in the spotted gar, which diverged prior to 3R, we could time these rearrangements to post-3R. Conclusions We present an extensive analysis of the paralogon housing the visual opsin, GNAT and GNAI, OT/VP-R, and CACNA1-L gene families. The combined data imply that the early vertebrate WGD events contributed to the evolution of vision and the other neuronal and neuroendocrine functions exerted by the proteins encoded by these gene families. In pouched lamprey all five visual opsin genes have previously been identified, suggesting that lampreys diverged from the jawed vertebrates after 2R. PMID:24180662

  9. The Comb Jelly Opsins and the Origins of Animal Phototransduction

    PubMed Central

    Feuda, Roberto; Rota-Stabelli, Omar; Oakley, Todd H.; Pisani, Davide

    2014-01-01

    Opsins mediate light detection in most animals, and understanding their evolution is key to clarify the origin of vision. Despite the public availability of a substantial collection of well-characterized opsins, early opsin evolution has yet to be fully understood, in large part because of the high level of divergence observed among opsins belonging to different subfamilies. As a result, different studies have investigated deep opsin evolution using alternative data sets and reached contradictory results. Here, we integrated the data and methods of three, key, recent studies to further clarify opsin evolution. We show that the opsin relationships are sensitive to outgroup choice; we generate new support for the existence of Rhabdomeric opsins in Cnidaria (e.g., corals and jellyfishes) and show that all comb jelly opsins belong to well-recognized opsin groups (the Go-coupled opsins or the Ciliary opsins), which are also known in Bilateria (e.g., humans, fruit flies, snails, and their allies) and Cnidaria. Our results are most parsimoniously interpreted assuming a traditional animal phylogeny where Ctenophora are not the sister group of all the other animals. PMID:25062921

  10. The comb jelly opsins and the origins of animal phototransduction.

    PubMed

    Feuda, Roberto; Rota-Stabelli, Omar; Oakley, Todd H; Pisani, Davide

    2014-08-01

    Opsins mediate light detection in most animals, and understanding their evolution is key to clarify the origin of vision. Despite the public availability of a substantial collection of well-characterized opsins, early opsin evolution has yet to be fully understood, in large part because of the high level of divergence observed among opsins belonging to different subfamilies. As a result, different studies have investigated deep opsin evolution using alternative data sets and reached contradictory results. Here, we integrated the data and methods of three, key, recent studies to further clarify opsin evolution. We show that the opsin relationships are sensitive to outgroup choice; we generate new support for the existence of Rhabdomeric opsins in Cnidaria (e.g., corals and jellyfishes) and show that all comb jelly opsins belong to well-recognized opsin groups (the Go-coupled opsins or the Ciliary opsins), which are also known in Bilateria (e.g., humans, fruit flies, snails, and their allies) and Cnidaria. Our results are most parsimoniously interpreted assuming a traditional animal phylogeny where Ctenophora are not the sister group of all the other animals. PMID:25062921

  11. Losses of functional opsin genes, short-wavelength cone photopigments, and color vision--a significant trend in the evolution of mammalian vision.

    PubMed

    Jacobs, Gerald H

    2013-03-01

    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. PMID:23286388

  12. Cubozoan genome illuminates functional diversification of opsins and photoreceptor evolution.

    PubMed

    Liegertov, Michaela; Pergner, Ji?; Kozmikov, Iryna; Fabian, Peter; Pombinho, Antonio R; Strnad, Hynek; Pa?es, Jan; Vl?ek, ?estmr; Bart?n?k, Petr; Kozmik, Zbyn?k

    2015-01-01

    Animals sense light primarily by an opsin-based photopigment present in a photoreceptor cell. Cnidaria are arguably the most basal phylum containing a well-developed visual system. The evolutionary history of opsins in the animal kingdom has not yet been resolved. Here, we study the evolution of animal opsins by genome-wide analysis of the cubozoan jellyfish Tripedalia cystophora, a cnidarian possessing complex lens-containing eyes and minor photoreceptors. A large number of opsin genes with distinct tissue- and stage-specific expression were identified. Our phylogenetic analysis unequivocally classifies cubozoan opsins as a sister group to c-opsins and documents lineage-specific expansion of the opsin gene repertoire in the cubozoan genome. Functional analyses provided evidence for the use of the Gs-cAMP signaling pathway in a small set of cubozoan opsins, indicating the possibility that the majority of other cubozoan opsins signal via distinct pathways. Additionally, these tests uncovered subtle differences among individual opsins, suggesting possible fine-tuning for specific photoreceptor tasks. Based on phylogenetic, expression and biochemical analysis we propose that rapid lineage- and species-specific duplications of the intron-less opsin genes and their subsequent functional diversification promoted evolution of a large repertoire of both visual and extraocular photoreceptors in cubozoans. PMID:26154478

  13. The Living With a Star (LWS) Sentinels Mission

    NASA Technical Reports Server (NTRS)

    Szabo, A.

    2005-01-01

    The Sentinels Mission, the heliospheric element of the NASA Living With a Star (LWS) program, is still rapidly evolving, especially as the Sentinels Science and Technology Definition Team is progressing with its work. With the Solar Dynamics Observatory, the solar component, and the Geospace elements taking a more finalized form, it becomes clearer what scientific and measurement objectives will be necessary to establish the solar-geospace connection in order to achieve the goals of the LWS program. Possible, early formulation designs of the Sentinels mission will be presented that includes the Inner Heliospheric Mappers, a four spacecraft mission to observe the inner heliosphere between 0.25 and 1.0 AUs along with a Far Side Sentinel that will perform remote solar observations from nearly the opposite side of the Sun. Moreover, the complementarity of the various planned international missions (e.g., ESA Solar Orbiter, and Beppi Colombo) along with NASA planetary projects (e.g., Mars program and MESSENGER) will be discussed and how they can form a coherent system. Finally, the importance of already available heliospheric data will be emphasized.

  14. The NASA living with a star (LWS) sentinels mission

    NASA Astrophysics Data System (ADS)

    Lin, R. P.; Szabo, A.

    2005-08-01

    The NASA Living With a Star (LWS) Sentinels mission is presently being defined by its Science and Technology Definition Team (STDT). Sentinels is the third element of the LWS program. Its primary scientific objective is to discover, understand and model the connection between solar phenomena and the interplanetary/geospace disturbances, specifically, the heliospheric initiation, propagation and solar connection of those energetic phenomena that adversely affect space exploration and life and society here on Earth. Sentinels will play a particularly important role in support of NASA's new Vision for Space Exploration (VSE), in providing key new measurements required to understand the production of Solar Energetic Particles (SEPs) that are hazardous to human and robotic missions to the Moon and Mars. Here we describe the planning for Sentinels, and the preliminary design of the first phase, the Inner Heliosphere Sentinels, a four spacecraft mission to provide multi-point longitudinally and radially distributed in situ observations of SEPs, plasma, fields, and X-rays/gamma-rays/neutrons in the inner heliosphere (~0.25-0.76 AU), close to the site of SEP acceleration and rapid transient evolution.

  15. The Living With a Star (LWS) Sentinels Mission

    NASA Astrophysics Data System (ADS)

    Szabo, A.

    2005-05-01

    The Sentinels Mission, the heliospheric element of the NASA Living With a Star (LWS) program, is still rapidly evolving, especially as the Sentinels Science and Technology Definition Team is progressing with its work. With the Solar Dynamics Observatory, the solar component, and the Geospace elements taking a more finalized form, it becomes clearer what scientific and measurement objectives will be necessary to establish the solar-geospace connection in order to achieve the goals of the LWS program. Possible, early formulation designs of the Sentinels mission will be presented that includes the Inner Heliospheric Mappers, a four spacecraft mission to observe the inner heliosphere between 0.25 and 1.0 AUs along with a Far Side Sentinel that will perform remote solar observations from nearly the opposite side of the Sun. Moreover, the complementarity of the various planned international missions (e.g., ESA Solar Orbiter, and Beppi Colombo) along with NASA planetary projects (e.g., Mars program and MESSENGER) will be discussed and how they can form a coherent system. Finally, the importance of already available heliospheric data will be emphasized.

  16. A mammalian neural tissue opsin (Opsin 5) is a deep brain photoreceptor in birds

    PubMed Central

    Nakane, Yusuke; Ikegami, Keisuke; Ono, Hiroko; Yamamoto, Naoyuki; Yoshida, Shosei; Hirunagi, Kanjun; Ebihara, Shizufumi; Kubo, Yoshihiro; Yoshimura, Takashi

    2010-01-01

    It has been known for many decades that nonmammalian vertebrates detect light by deep brain photoreceptors that lie outside the retina and pineal organ to regulate seasonal cycle of reproduction. However, the identity of these photoreceptors has so far remained unclear. Here we report that Opsin 5 is a deep brain photoreceptive molecule in the quail brain. Expression analysis of members of the opsin superfamily identified as Opsin 5 (OPN5; also known as Gpr136, Neuropsin, PGR12, and TMEM13) mRNA in the paraventricular organ (PVO), an area long believed to be capable of phototransduction. Immunohistochemistry identified Opsin 5 in neurons that contact the cerebrospinal fluid in the PVO, as well as fibers extending to the external zone of the median eminence adjacent to the pars tuberalis of the pituitary gland, which translates photoperiodic information into neuroendocrine responses. Heterologous expression of Opsin 5 in Xenopus oocytes resulted in light-dependent activation of membrane currents, the action spectrum of which showed peak sensitivity (λmax) at ∼420 nm. We also found that short-wavelength light, i.e., between UV-B and blue light, induced photoperiodic responses in eye-patched, pinealectomized quail. Thus, Opsin 5 appears to be one of the deep brain photoreceptive molecules that regulates seasonal reproduction in birds. PMID:20679218

  17. Multiple rod-cone and cone-rod photoreceptor transmutations in snakes: evidence from visual opsin gene expression.

    PubMed

    Simões, Bruno F; Sampaio, Filipa L; Loew, Ellis R; Sanders, Kate L; Fisher, Robert N; Hart, Nathan S; Hunt, David M; Partridge, Julian C; Gower, David J

    2016-01-27

    In 1934, Gordon Walls forwarded his radical theory of retinal photoreceptor 'transmutation'. This proposed that rods and cones used for scotopic and photopic vision, respectively, were not fixed but could evolve into each other via a series of morphologically distinguishable intermediates. Walls' prime evidence came from series of diurnal and nocturnal geckos and snakes that appeared to have pure-cone or pure-rod retinas (in forms that Walls believed evolved from ancestors with the reverse complement) or which possessed intermediate photoreceptor cells. Walls was limited in testing his theory because the precise identity of visual pigments present in photoreceptors was then unknown. Subsequent molecular research has hitherto neglected this topic but presents new opportunities. We identify three visual opsin genes, rh1, sws1 and lws, in retinal mRNA of an ecologically and taxonomically diverse sample of snakes central to Walls' theory. We conclude that photoreceptors with superficially rod- or cone-like morphology are not limited to containing scotopic or photopic opsins, respectively. Walls' theory is essentially correct, and more research is needed to identify the patterns, processes and functional implications of transmutation. Future research will help to clarify the fundamental properties and physiology of photoreceptors adapted to function in different light levels. PMID:26817768

  18. Multiple rodcone and conerod photoreceptor transmutations in snakes: Evidence from visual opsin gene expression

    USGS Publications Warehouse

    Simoe, Bruno F; Sampaio, Filipa L.; Loew, Ellis R.; Sanders, Kate L.; Fisher, Robert N.; Hart, Nathan S.; Hunt, David M.; Partridge, Julian C.; Gower, David J.

    2016-01-01

    In 1934, Gordon Walls forwarded his radical theory of retinal photoreceptor transmutation. This proposed that rods and cones used for scotopic and photopic vision, respectively, were not fixed but could evolve into each other via a series of morphologically distinguishable intermediates. Walls' prime evidence came from series of diurnal and nocturnal geckos and snakes that appeared to have pure-cone or pure-rod retinas (in forms that Walls believed evolved from ancestors with the reverse complement) or which possessed intermediate photoreceptor cells. Walls was limited in testing his theory because the precise identity of visual pigments present in photoreceptors was then unknown. Subsequent molecular research has hitherto neglected this topic but presents new opportunities. We identify three visual opsin genes,rh1,sws1andlws, in retinal mRNA of an ecologically and taxonomically diverse sample of snakes central to Walls' theory. We conclude that photoreceptors with superficially rod- or cone-like morphology are not limited to containing scotopic or photopic opsins, respectively. Walls' theory is essentially correct, and more research is needed to identify the patterns, processes and functional implications of transmutation. Future research will help to clarify the fundamental properties and physiology of photoreceptors adapted to function in different light levels.

  19. The Dynamic Evolutionary History of Pancrustacean Eyes and Opsins.

    PubMed

    Henze, Miriam J; Oakley, Todd H

    2015-11-01

    Pancrustacea (Hexapoda plus Crustacea) display an enormous diversity of eye designs, including multiple types of compound eyes and single-chambered eyes, often with color vision and/or polarization vision. Although the eyes of some pancrustaceans are well-studied, there is still much to learn about the evolutionary paths to this amazing visual diversity. Here, we examine the evolutionary history of eyes and opsins across the principle groups of Pancrustacea. First, we review the distribution of lateral and median eyes, which are found in all major pancrustacean clades (Oligostraca, Multicrustacea, and Allotriocarida). At the same time, each of those three clades has taxa that lack lateral and/or median eyes. We then compile data on the expression of visual r-opsins (rhabdomeric opsins) in lateral and median eyes across Pancrustacea and find no evidence for ancient opsin clades expressed in only one type of eye. Instead, opsin clades with eye-specific expression are products of recent gene duplications, indicating a dynamic past, during which opsins often changed expression from one type of eye to another. We also investigate the evolutionary history of peropsins and r-opsins, which are both known to be expressed in eyes of arthropods. By searching published transcriptomes, we discover for the first time crustacean peropsins and suggest that previously reported odonate opsins may also be peropsins. Finally, from analyzing a reconciled, phylogenetic tree of arthropod r-opsins, we infer that the ancestral pancrustacean had four visual opsin genes, which we call LW2, MW1, MW2, and SW. These are the progenitors of opsin clades that later were variously duplicated or lost during pancrustacean evolution. Together, our results reveal a particularly dynamic history, with losses of eyes, duplication and loss of opsin genes, and changes in opsin expression between types of eyes. PMID:26319405

  20. The Living with a Star (LWS) Sentinels Mission

    NASA Astrophysics Data System (ADS)

    Lin, R. P.

    2004-12-01

    NASA has recently formed a Science and Technology Definition Team (STDT) to define the Sentinels mission, the heliospheric element of the integrated LWS program. The objective of the Sentinels is to discover, understand and model the connection between solar events such as flares and coronal mass ejections (CMEs) and heliospheric and magnetospheric events, such as Solar Particle Events (SPEs), that can adversely impact life and society. Moreover, Sentinels is also relevant for the new NASA exploration initiative to the Moon and beyond. The primary objective of Sentinels is to provide the observations necessary for an understanding of the physics of the Sun/inner heliosphere processes that affect the solar system, so the requirements for eventual predictive capability can be defined. I will describe the preliminary scientific planning to implement the Sentinels mission.

  1. Carrier Plus: A Sensor Payload for Living With a Star Space Environment Testbed (LWS/SET)

    NASA Technical Reports Server (NTRS)

    Marshall, Cheryl; Moss, Steven; Howard, Regan; LaBel, Kenneth; Grycewicz, Tom; Barth, Janet; Brewer, Dana

    2003-01-01

    The paper discusses the following: 1. Living with a Star (LWS) program: space environment testbed (SET); natural space environment. 2. Carrier plus: goals and benefits. 3. ON-orbit sensor measurements. 4. Carrier plus architecture. 5. Participation in carrier plus.

  2. Opsin clines in butterflies suggest novel roles for insect photopigments.

    PubMed

    Frentiu, Francesca D; Yuan, Furong; Savage, Wesley K; Bernard, Gary D; Mullen, Sean P; Briscoe, Adriana D

    2015-02-01

    Opsins are ancient molecules that enable animal vision by coupling to a vitamin-derived chromophore to form light-sensitive photopigments. The primary drivers of evolutionary diversification in opsins are thought to be visual tasks related to spectral sensitivity and color vision. Typically, only a few opsin amino acid sites affect photopigment spectral sensitivity. We show that opsin genes of the North American butterfly Limenitis arthemis have diversified along a latitudinal cline, consistent with natural selection due to environmental factors. We sequenced single nucleotide (SNP) polymorphisms in the coding regions of the ultraviolet (UVRh), blue (BRh), and long-wavelength (LWRh) opsin genes from ten butterfly populations along the eastern United States and found that a majority of opsin SNPs showed significant clinal variation. Outlier detection and analysis of molecular variance indicated that many SNPs are under balancing selection and show significant population structure. This contrasts with what we found by analysing SNPs in the wingless and EF-1 alpha loci, and from neutral amplified fragment length polymorphisms, which show no evidence of significant locus-specific or genome-wide structure among populations. Using a combination of functional genetic and physiological approaches, including expression in cell culture, transgenic Drosophila, UV-visible spectroscopy, and optophysiology, we show that key BRh opsin SNPs that vary clinally have almost no effect on spectral sensitivity. Our results suggest that opsin diversification in this butterfly is more consistent with natural selection unrelated to spectral tuning. Some of the clinally varying SNPs may instead play a role in regulating opsin gene expression levels or the thermostability of the opsin protein. Lastly, we discuss the possibility that insect opsins might have important, yet-to-be elucidated, adaptive functions in mediating animal responses to abiotic factors, such as temperature or photoperiod. PMID:25371434

  3. Keck LWS Mid-IR Observations of Nearby LLAGN

    NASA Astrophysics Data System (ADS)

    Grossan, B.

    2002-12-01

    We present new Keck LWS Mid-IR (MIR) imaging observations of a sample of LLAGN. Our results show that nuclear 10 micron fluxes of NGC4203 and NGC4736, along with three other LLGN from previous work, correlate with X-ray flux with the same relation as more luminous Seyferts and quasars. The nuclear emission of our objects is clearly differentiated from that of starburst activity on a plot of MIR vs. X-ray flux. Because X-ray and MIR fluxes are nearly insensitive to dust extinction, this behavior suggests the same continuum origin for our LLAGN sample as for Seyferts. MIR images of the nucleus of M81 show clearly extended, elliptical structure roughly 3.5" across the long axis ( 70 pc at the source), confirming earlier, lower resolution measurements at Palomar. This structure, the relative MIR and X-ray nuclear fluxes, the lack of stellar emission sufficient to power the MIR flux, and a weak UV continuum, are evidence for material within the nucleus extinguishing an AGN which powers the MIR emission. A unified model torus may be the origin of the extinction. The author gratefully acknowledges the support of the American Astronomical Society and the LBNL Institute for Nuclear and Particle Astrophysics (INPA) for this work.

  4. ISO LWS observations of planetary nebula fine-structure lines

    NASA Astrophysics Data System (ADS)

    Liu, X.-W.; Barlow, M. J.; Cohen, M.; Danziger, I. J.; Luo, S.-G.; Baluteau, J. P.; Cox, P.; Emery, R. J.; Lim, T.; Péquignot, D.

    2001-05-01

    We have obtained 43-198μm far-infrared (IR) spectra for a sample of 51 Galactic planetary nebulae (PN) and protoplanetary nebulae (PPN), using the Long Wavelength Spectrometer (LWS) on board the Infrared Space Observatory (ISO). Spectra were also obtained of the former PN candidate Lo 14. The spectra yield fluxes for the fine-structure lines [Nii] 122μm, [Niii] 57μm and [Oiii] 52 and 88μm emitted in the ionized regions and the [Oi] 63- and 146-μm and [Cii] 158-μm lines from the photodissociation regions (PDRs), which have been used to determine electron densities and ionic abundances for the ionized regions and densities, temperatures and gas masses for the PDRs. The strong [Niii] and [Oiii] emission lines detected in the LWS spectrum taken centred on Lo 14 could be associated with the nearby strong radio and infrared source G 331.5-0.1. We find that the electron densities yielded by the [Oiii] 88μm/52μm doublet ratio are systematically lower than those derived from the optical [Ariv] λ4740/λ4711 and [Cliii] λ5537/λ5517 doublet ratios, which have much higher critical densities than the 52- and 88-μm lines, suggesting the presence of density inhomogeneities in the nebulae. Ionic abundances, N+/H+, N2+/H+ and O2+/H+, as well as the N2+/O2+ abundance ratio, which provides a good approximation to the N/O elemental abundance ratio, are derived. Although ionic abundances relative to H+ deduced from the far-IR fine-structure lines are sensitive to the adopted electron density and the presence of density inhomogeneities, the strong dependence on the nebular physical conditions is largely cancelled out when N2+/O2+ is calculated from the 57μm/(52μm+88μm) flux ratio, owing to the similarity of the critical densities of the lines involved. The temperatures and densities of the PDRs around 24 PN have been determined from the observed [Oi] and [Cii] line intensity ratios. Except for a few objects, the deduced temperatures fall between 200 and 500K, peaking around 250K. The densities of the PDRs vary from 104-105cm-3, reaching 3×105cm-3 in some young compact PN. With a derived temperature of 1600K and a density of 105cm-3, the PDR of NGC 7027 is one of the warmest and at the same time one of the densest amongst the nebulae studied. For most of the PN studied, the [Cii]-emitting regions contain only modest amounts of material, with gas masses <~0.1Msolar. Exceptional large PDR masses are found for a few nebulae, including NGC 7027, the bipolar nebulae M2-9 and NGC 6302, the young dense planetary nebulae BD+30°3639, IC 418 and NGC 5315, and the old, probably recombining, nebulae IC 4406 and NGC 6072.

  5. Carrier Plus: A sensor payload for Living With a Star Space Environment Testbed (LWS/SET)

    NASA Technical Reports Server (NTRS)

    Marshall, Cheryl J.; Moss, Steven; Howard, Regan; LaBel, Kenneth A.; Grycewicz, Tom; Barth, Janet L.; Brewer, Dana

    2003-01-01

    The Defense Threat Reduction Agency (DTR4) and National Aeronautics and Space Administration (NASA) Goddard Space Flight Center are collaborating to develop the Carrier Plus sensor experiment platform as a capability of the Space Environments Testbed (SET). The Space Environment Testbed (SET) provides flight opportunities for technology experiments as part of NASA's Living With a Star (LWS) program. The Carrier Plus will provide new capability to characterize sensor technologies such as state-of-the-art visible focal plane arrays (FPAs) in a natural space radiation environment. The technical objectives include on-orbit validation of recently developed FPA technologies and performance prediction methodologies, as well as characterization of the FPA radiation response to total ionizing dose damage, displacement damage and transients. It is expected that the sensor experiment will carry 4-6 FPAs and associated radiation correlative environment monitors (CEMs) for a 2006-2007 launch. Sensor technology candidates may include n- and p-charge coupled devices (CCDs), active pixel sensors (APS), and hybrid CMOS arrays. The presentation will describe the Carrier Plus goals and objectives, as well as provide details about the architecture and design. More information on the LWS program can be found at http://lws.gsfc.nasa.gov/. Business announcements for LWS/SET and program briefings are posted at http://lws-set.gsfc.nasa.gov

  6. Opsin gene duplication and divergence in ray-finned fish.

    PubMed

    Rennison, Diana J; Owens, Gregory L; Taylor, John S

    2012-03-01

    Opsin gene sequences were first reported in the 1980s. The goal of that research was to test the hypothesis that human opsins were members of a single gene family and that variation in human color vision was mediated by mutations in these genes. While the new data supported both hypotheses, the greatest contribution of this work was, arguably, that it provided the data necessary for PCR-based surveys in a diversity of other species. Such studies, and recent whole genome sequencing projects, have uncovered exceptionally large opsin gene repertoires in ray-finned fishes (taxon, Actinopterygii). Guppies and zebrafish, for example, have 10 visual opsin genes each. Here we review the duplication and divergence events that have generated these gene collections. Phylogenetic analyses revealed that large opsin gene repertories in fish have been generated by gene duplication and divergence events that span the age of the ray-finned fishes. Data from whole genome sequencing projects and from large-insert clones show that tandem duplication is the primary mode of opsin gene family expansion in fishes. In some instances gene conversion between tandem duplicates has obscured evolutionary relationships among genes and generated unique key-site haplotypes. We mapped amino acid substitutions at so-called key-sites onto phylogenies and this exposed many examples of convergence. We found that dN/dS values were higher on the branches of our trees that followed gene duplication than on branches that followed speciation events, suggesting that duplication relaxes constraints on opsin sequence evolution. Though the focus of the review is opsin sequence evolution, we also note that there are few clear connections between opsin gene repertoires and variation in spectral environment, morphological traits, or life history traits. PMID:22178363

  7. Living with a Star (LWS) Space Environment Testbeds (SET), Mission Carrier Overview and Capabilities

    NASA Technical Reports Server (NTRS)

    Patschke, Robert; Barth, Janet; Label, Ken; Mariano, Carolyn; Pham, Karen; Brewer, Dana; Cuviello, Michael; Kobe, David; Wu, Carl; Jarosz, Donald

    2004-01-01

    NASA has initiated the Living With a Star (LWS) Program to develop the scientific understanding to address the aspects of the Connected Sun-Earth system that affect life and society. A goal of the program is to bridge the gap between science, engineering, and user application communities. This will enable future science, operational, and commercial objectives in space and atmospheric environments by improving engineering approaches to the accommodation and/or mitigation of the effects of solar variability on technological systems. The three program elements of the LWS Program are Science Missions; Targeted Research and Technology; and Space Environment Testbeds (SETS). SET is an ideal platform for small experiments performing research on space environment effects on technologies and on the mitigation of space weather effects. A short description of the LWS Program will be given, and the SET will be described in detail, giving the mission objectives, available carrier services, and upcoming flight opportunities.

  8. Characterization of the long-wavelength opsin from Mecoptera and Siphonaptera: does a flea see?

    PubMed

    Taylor, Sean D; de la Cruz, Katharina Dittmar; Porter, Megan L; Whiting, Michael F

    2005-05-01

    Mecoptera and Siphonaptera represent two insect orders that have largely been overlooked in the study of insect vision. Recent phylogenetic evidence demonstrates that Mecoptera (scorpionflies) is paraphyletic, with the order Siphonaptera (fleas) nesting as sister to the family Boreidae (snow fleas), showing an evolutionary trend towards reduction in gross eye morphology within fleas. We provide the first molecular characterization of long-wavelength opsins from these three lineages (opsin gene from fleas [FL-Opsin], the Boreidae [B-Opsin], and a mecopteran family [M-Opsin]) and assess the effects of loss of visual acuity on the structure and function of the opsin gene. Phylogenetic analysis implies a physiological sensitivity in the red-green spectrum for these opsins. Analysis of intron splice sites reveals a high degree of similarity between FL-Opsin and B-Opsin as well as conserved splice sites across insect blue-green and long-wavelength opsins. Calculated rates of evolution and tests for destabilizing selection indicate that FL-Opsin, B-Opsin, and M-Opsin are evolving at similar rates with no radical selective pressures, implying conservative evolution and functional constraint across all three lineages. PMID:15703237

  9. Opsin co-expression in Limulus photoreceptors: differential regulation by light and a circadian clock

    PubMed Central

    Katti, C.; Kempler, K.; Porter, M. L.; Legg, A.; Gonzalez, R.; Garcia-Rivera, E.; Dugger, D.; Battelle, B.-A.

    2010-01-01

    A long-standing concept in vision science has held that a single photoreceptor expresses a single type of opsin, the protein component of visual pigment. However, the number of examples in the literature of photoreceptors from vertebrates and invertebrates that break this rule is increasing. Here, we describe a newly discovered Limulus opsin, Limulus opsin5, which is significantly different from previously characterized Limulus opsins, opsins1 and 2. We show that opsin5 is co-expressed with opsins1 and 2 in Limulus lateral and ventral eye photoreceptors and provide the first evidence that the expression of co-expressed opsins can be differentially regulated. We show that the relative levels of opsin5 and opsin1 and 2 in the rhabdom change with a diurnal rhythm and that their relative levels are also influenced by the animal's central circadian clock. An analysis of the sequence of opsin5 suggests it is sensitive to visible light (400700 nm) but that its spectral properties may be different from that of opsins1 and 2. Changes in the relative levels of these opsins may underlie some of the dramatic daynight changes in Limulus photoreceptor function and may produce a diurnal change in their spectral sensitivity. PMID:20639420

  10. Extraordinary diversity of visual opsin genes in dragonflies

    PubMed Central

    Futahashi, Ryo; Kawahara-Miki, Ryouka; Kinoshita, Michiyo; Yoshitake, Kazutoshi; Yajima, Shunsuke; Arikawa, Kentaro; Fukatsu, Takema

    2015-01-01

    Dragonflies are colorful and large-eyed animals strongly dependent on color vision. Here we report an extraordinary large number of opsin genes in dragonflies and their characteristic spatiotemporal expression patterns. Exhaustive transcriptomic and genomic surveys of three dragonflies of the family Libellulidae consistently identified 20 opsin genes, consisting of 4 nonvisual opsin genes and 16 visual opsin genes of 1 UV, 5 short-wavelength (SW), and 10 long-wavelength (LW) type. Comprehensive transcriptomic survey of the other dragonflies representing an additional 10 families also identified as many as 15–33 opsin genes. Molecular phylogenetic analysis revealed dynamic multiplications and losses of the opsin genes in the course of evolution. In contrast to many SW and LW genes expressed in adults, only one SW gene and several LW genes were expressed in larvae, reflecting less visual dependence and LW-skewed light conditions for their lifestyle under water. In this context, notably, the sand-burrowing or pit-dwelling species tended to lack SW gene expression in larvae. In adult visual organs: (i) many SW genes and a few LW genes were expressed in the dorsal region of compound eyes, presumably for processing SW-skewed light from the sky; (ii) a few SW genes and many LW genes were expressed in the ventral region of compound eyes, probably for perceiving terrestrial objects; and (iii) expression of a specific LW gene was associated with ocelli. Our findings suggest that the stage- and region-specific expressions of the diverse opsin genes underlie the behavior, ecology, and adaptation of dragonflies. PMID:25713365

  11. Extraordinary diversity of visual opsin genes in dragonflies.

    PubMed

    Futahashi, Ryo; Kawahara-Miki, Ryouka; Kinoshita, Michiyo; Yoshitake, Kazutoshi; Yajima, Shunsuke; Arikawa, Kentaro; Fukatsu, Takema

    2015-03-17

    Dragonflies are colorful and large-eyed animals strongly dependent on color vision. Here we report an extraordinary large number of opsin genes in dragonflies and their characteristic spatiotemporal expression patterns. Exhaustive transcriptomic and genomic surveys of three dragonflies of the family Libellulidae consistently identified 20 opsin genes, consisting of 4 nonvisual opsin genes and 16 visual opsin genes of 1 UV, 5 short-wavelength (SW), and 10 long-wavelength (LW) type. Comprehensive transcriptomic survey of the other dragonflies representing an additional 10 families also identified as many as 15-33 opsin genes. Molecular phylogenetic analysis revealed dynamic multiplications and losses of the opsin genes in the course of evolution. In contrast to many SW and LW genes expressed in adults, only one SW gene and several LW genes were expressed in larvae, reflecting less visual dependence and LW-skewed light conditions for their lifestyle under water. In this context, notably, the sand-burrowing or pit-dwelling species tended to lack SW gene expression in larvae. In adult visual organs: (i) many SW genes and a few LW genes were expressed in the dorsal region of compound eyes, presumably for processing SW-skewed light from the sky; (ii) a few SW genes and many LW genes were expressed in the ventral region of compound eyes, probably for perceiving terrestrial objects; and (iii) expression of a specific LW gene was associated with ocelli. Our findings suggest that the stage- and region-specific expressions of the diverse opsin genes underlie the behavior, ecology, and adaptation of dragonflies. PMID:25713365

  12. The Evolution and Expression of the Moth Visual Opsin Family

    PubMed Central

    Fu, Xiaowei; Murphy, Robert W.; Wu, Kongming

    2013-01-01

    Because visual genes likely evolved in response to their ambient photic environment, the dichotomy between closely related nocturnal moths and diurnal butterflies forms an ideal basis for investigating their evolution. To investigate whether the visual genes of moths are associated with nocturnal dim-light environments or not, we cloned long-wavelength (R), blue (B) and ultraviolet (UV) opsin genes from 12 species of wild-captured moths and examined their evolutionary functions. Strong purifying selection appeared to constrain the functions of the genes. Dark-treatment altered the levels of mRNA expression in Helicoverpa armigera such that R and UV opsins were up-regulated after dark-treatment, the latter faster than the former. In contrast, B opsins were not significantly up-regulated. Diel changes of opsin mRNA levels in both wild-captured and lab-reared individuals showed no significant fluctuation within the same group. However, the former group had significantly elevated levels of expression compared with the latter. Consequently, environmental conditions appeared to affect the patterns of expression. These findings and the proportional expression of opsins suggested that moths potentially possessed color vision and the visual system played a more important role in the ecology of moths than previously appreciated. This aspect did not differ much from that of diurnal butterflies. PMID:24205129

  13. A novel rod-like opsin isolated from the extra-retinal photoreceptors of teleost fish.

    PubMed

    Philp, A R; Bellingham, J; Garcia-Fernandez, J; Foster, R G

    2000-02-25

    We have isolated a novel opsin from the pineal complex of Atlantic salmon (Salmo salar) and from the brain of the puffer fish (Fugu rubripes). These extra-retinal opsins share approximately 74% identity at the nucleotide and amino acid level with rod-opsins from the retina of these species. By PCR, we have determined that the novel rod-like opsin is not expressed in the salmon retina, and the retinal rod-opsin is not expressed in the salmon pineal. Phylogenetic analysis suggests that the rod-like opsins arose from a gene duplication event approximately 205 million years ago, a time of considerable adaptive radiation of the bony fish. In view of the large differences in the coding sequences of the pineal/brain rod-like opsins, their extra-retinal sites of expression, and phylogenetic position we have termed these novel opsins 'extra-retinal rod-like opsins' (ERrod-like opsins). We speculate that the differences between retinal rod-opsins and ERrod-like opsins have arisen from their differing photosensory roles and/or genetic drift after the gene duplication event in the Triassic. PMID:10692583

  14. Reduced opsin gene expression in a cave-dwelling fish

    PubMed Central

    Tobler, Michael; Coleman, Seth W.; Perkins, Brian D.; Rosenthal, Gil G.

    2010-01-01

    Regressive evolution of structures associated with vision in cave-dwelling organisms is the focus of intense research. Most work has focused on differences between extreme visual phenotypes: sighted, surface animals and their completely blind, cave-dwelling counterparts. We suggest that troglodytic systems, comprising multiple populations that vary along a gradient of visual function, may prove critical in understanding the mechanisms underlying initial regression in visual pathways. Gene expression assays of natural and laboratory-reared populations of the Atlantic molly (Poecilia mexicana) revealed reduced opsin expression in cave-dwelling populations compared with surface-dwelling conspecifics. Our results suggest that the reduction in opsin expression in cave-dwelling populations is not phenotypically plastic but reflects a hardwired system not rescued by exposure to light during retinal ontogeny. Changes in opsin gene expression may consequently represent a first evolutionary step in the regression of eyes in cave organisms. PMID:19740890

  15. Parallel evolution of opsin gene expression in African cichlid fishes.

    PubMed

    O'Quin, Kelly E; Hofmann, Christopher M; Hofmann, Hans A; Carleton, Karen L

    2010-12-01

    Phenotypic evolution may occur either through alterations to the structure of protein-coding genes or their expression. Evidence for which of these two mechanisms more commonly contribute to the evolution of a phenotype can be garnered from examples of parallel and convergent evolution. The visual system of East African cichlid fishes is an excellent system with which to address this question. Cichlid fishes from Lakes Malawi (LM) and Victoria together exhibit three diverse palettes of coexpressed opsins and several important protein-coding mutations that both shift spectral sensitivity. Here we assess both opsin expression and protein-coding diversity among cichlids from a third rift lake, Lake Tanganyika (LT). We found that Tanganyikan cichlids exhibit three palettes of coexpressed opsins that largely overlap the short-, middle-, and long-wavelength-sensitive palettes of LM cichlids. Bayesian phenotypic clustering and ancestral state reconstructions both support the parallel evolution of the short- and middle-wavelength palettes among cichlids from LT and LM. In each case, these transitions occurred from different ancestors that expressed the same long-wavelength palette. We also identified similar but distinct patterns of correlated evolution between opsin expression, diet, and lens transmittance among cichlids from LT and LM as well. In contrast to regulatory changes, we identified few functional or potentially functional mutations in the protein-coding sequences of three variable opsins, with the possible exception of the SWS1 (ultraviolet) opsin. These results underscore the important contribution that gene regulation can make to rapid phenotypic evolution and adaptation. PMID:20601410

  16. Vertebrate ancient opsin and melanopsin: divergent irradiance detectors.

    PubMed

    Davies, Wayne L; Hankins, Mark W; Foster, Russell G

    2010-11-01

    Both vertebrates and invertebrates respond to light by utilising a wide-ranging array of photosensory systems, with diverse photoreceptor organs expressing a characteristic photopigment, itself consisting of an opsin apoprotein linked to a light-sensitive retinoid chromophore based on vitamin A. In the eye, the pigments expressed in both cone and rod photoreceptors have been studied in great depth and mediate contrast perception, measurement of the spectral composition of environmental light, and thus classical image forming vision. By contrast, the molecular basis for non-visual and extraocular photoreception is far less understood; however, two photopigment genes have become the focus of much study, the vertebrate ancient (va) opsin and melanopsin (opn4). In this review, we discuss the history of discovery for each gene, as well as focusing on the evolution, expression profile, functional role and broader physiological significance of each photopigment. Recently, it has been suggested independently by Arendt et al. and Lamb that an ancestral opsin bifurcated in early metazoans and evolved into two quite different photopigments, one expressed in rhabdomeric photoreceptors and the other in ciliary photoreceptors. This interpretation of the evolution of the metazoan eye has provided a powerful framework for understanding photobiological organization. Their proposal, however, does not encompass all current experimental observations that would be consistent with what we term a central "Evolution of Photosensory Opsins with Common Heredity (EPOCH)" hypothesis to explain the complexity of animal photosensory systems. Clearly, many opsin genes (e.g. va opsin) simply do not fit neatly within this scheme. Thus, the review concludes with a discussion of these anomalies and their context regarding the phylogeny of photoreceptor and photopigment development. PMID:20922256

  17. Opsin phylogeny and evolution: a model for blue shifts in wavelength regulation.

    PubMed

    Chang, B S; Crandall, K A; Carulli, J P; Hartl, D L

    1995-03-01

    The vast diversity in spectral sensitivities in the vision of many organisms is mediated mostly (although not entirely) through variation in the photosensitive visual pigments (opsins) of the eye. Specifically, shifts in absorption maxima of visual pigments are thought to be a result of interactions within the binding pocket of the opsin, between amino acid side chains and the retinal chromophore, However, it has proven difficult to identify specific amino acid residues important in determining wavelength absorption maxima, especially for some of the short wavelength (blue) opsins. In this paper, a comparative phylogenetic approach was applied to opsin protein sequence data to identify residues important in opsin wavelength regulation. In essence, this approach consisted of interpreting evolutionary history as a series of experiments in which natural selection has repeatedly favored amino acid replacements of certain residues to shift the opsin absorption spectra to either shorter or longer wavelengths. Opsin protein sequences were obtained from GenBank, aligned, and used to reconstruct a phylogenetic tree. Amino acid replacements were traced along the branches of this opsin tree, focusing only on residues likely to reside within the chromophore-binding pocket. A number of functionally convergent, nonconservative amino acid replacements in independently evolved opsins with similar shifts in spectral properties were identified. In short, reconstruction of the phylogeny of the opsin molecule allowed us to track amino acid substitutions in specific sites within the opsin and to target those particular substitutions that are repeatedly associated with marked changes in peak absorbance, shifting the spectral sensitivity of the opsin toward shorter or longer wavelengths. Based on these results, we propose a model for blue shifts of opsin absorption spectra. Amino acid replacements of four polar and charged residues near the protonated Schiff base (SBH+) end of the chromophore are proposed to result in blue shifts of the opsin absorption spectra. This model may explain some of the diversity of blue opsins apparent in both vertebrates and invertebrates. PMID:7620634

  18. Implications of the ISO LWS spectrum of the prototypical ultraluminous galaxy: ARP 220

    NASA Technical Reports Server (NTRS)

    Fischer, J.; Satyapal, S.; Luhman, M. L.; Melnick, G.; Cox, P.; Cernicharo, J.; Stacey, G. J.; Smith, H. A.; Lord, S. D.; Greenhouse, M. A.

    1997-01-01

    The low resolution far infrared spectrum of the galaxy Arp 220, obtained with the low wavelength spectrometer (LWS) onboard the Infrared Space Observatory (ISO), is presented. The spectrum is dominated by the OH, H2O, CH, NH3 and O I absorption lines. The upper limits on the far infrared fine structure lines indicate a softer radiation in Arp 220 than in starburst galaxies.

  19. Variations in Opsin Coding Sequences Cause X-Linked Cone Dysfunction Syndrome with Myopia and Dichromacy

    PubMed Central

    McClements, Michelle; Davies, Wayne I. L.; Michaelides, Michel; Young, Terri; Neitz, Maureen; MacLaren, Robert E.; Moore, Anthony T.; Hunt, David M.

    2013-01-01

    Purpose. To determine the role of variant L opsin haplotypes in seven families with Bornholm Eye Disease (BED), a cone dysfunction syndrome with dichromacy and myopia. Methods. Analysis of the opsin genes within the L/M opsin array at Xq28 included cloning and sequencing of an exon 3-5 gene fragment, long range PCR to establish gene order, and quantitative PCR to establish gene copy number. In vitro expression of normal and variant opsins was performed to examine cellular trafficking and spectral sensitivity of pigments. Results. All except one of the BED families possessed L opsin genes that contained a rare exon 3 haplotype. The exception was a family with the deleterious Cys203Arg substitution. Two rare exon 3 haplotypes were found and, where determined, these variant opsin genes were in the first position in the array. In vitro expression in transfected cultured neuronal cells showed that the variant opsins formed functional pigments, which trafficked to the cell membranes. The variant opsins were, however, less stable than wild type. Conclusions. It is concluded that the variant L opsin haplotypes underlie BED. The reduction in the amount of variant opsin produced in vitro compared with wild type indicates a possible disease mechanism. Alternatively, the recently identified defective splicing of exon 3 of the variant opsin transcript may be involved. Both mechanisms explain the presence of dichromacy and cone dystrophy. Abnormal pigment may also underlie the myopia that is invariably present in BED subjects. PMID:23322568

  20. Restoration of Vision with Ectopic Expression of Human Rod Opsin

    PubMed Central

    Cehajic-Kapetanovic, Jasmina; Eleftheriou, Cyril; Allen, Annette E.; Milosavljevic, Nina; Pienaar, Abigail; Bedford, Robert; Davis, Katherine E.; Bishop, Paul N.; Lucas, Robert J.

    2015-01-01

    Summary Many retinal dystrophies result in photoreceptor loss, but the inner retinal neurons can survive, making them potentially amenable to emerging optogenetic therapies. Here, we show that ectopically expressed human rod opsin, driven by either a non-selective or ON-bipolar cell-specific promoter, can function outside native photoreceptors and restore visual function in a mouse model of advanced retinal degeneration. Electrophysiological recordings from retinal explants and the visual thalamus revealed changes in firing (increases and decreases) induced by simple light pulses, luminance increases, and naturalistic movies in treated mice. These responses could be elicited at light intensities within the physiological range and substantially below those required by other optogenetic strategies. Mice with rod opsin expression driven by the ON-bipolar specific promoter displayed behavioral responses to increases in luminance, flicker, coarse spatial patterns, and elements of a natural movie at levels of contrast and illuminance (≈50–100 lux) typical of natural indoor environments. These data reveal that virally mediated ectopic expression of human rod opsin can restore vision under natural viewing conditions and at moderate light intensities. Given the inherent advantages in employing a human protein, the simplicity of this intervention, and the quality of vision restored, we suggest that rod opsin merits consideration as an optogenetic actuator for treating patients with advanced retinal degeneration. PMID:26234216

  1. Vertebrate ancient opsin photopigment spectra and the avian photoperiodic response

    PubMed Central

    Davies, Wayne I. L.; Turton, Michael; Peirson, Stuart N.; Follett, Brian K.; Halford, Stephanie; Garcia-Fernandez, Jose M.; Sharp, Peter J.; Hankins, Mark W.; Foster, Russell G.

    2012-01-01

    In mammals, photoreception is restricted to cones, rods and a subset of retinal ganglion cells. By contrast, non-mammalian vertebrates possess many extraocular photoreceptors but in many cases the role of these photoreceptors and their underlying photopigments is unknown. In birds, deep brain photoreceptors have been shown to sense photic changes in daylength (photoperiod) and mediate seasonal reproduction. Nonetheless, the specific identity of the opsin photopigment sensor involved has remained elusive. Previously, we showed that vertebrate ancient (VA) opsin is expressed in avian hypothalamic neurons and forms a photosensitive molecule. However, a direct functional link between VA opsin and the regulation of seasonal biology was absent. Here, we report the in vivo and in vitro absorption spectra (?max = ?490 nm) for chicken VA photopigments. Furthermore, the spectral sensitivity of these photopigments match the peak absorbance of the avian photoperiodic response (?max = 492 nm) and permits maximum photon capture within the restricted light environment of the hypothalamus. Such a correspondence argues strongly that VA opsin plays a key role in regulating seasonal reproduction in birds. PMID:22031722

  2. Expression Dynamics and Protein Localization of Rhabdomeric Opsins in Platynereis Larvae

    PubMed Central

    Randel, Nadine; Bezares-Caldern, Luis A.; Ghmann, Martin; Shahidi, Rza; Jkely, Gspr

    2013-01-01

    The larval stages of polychaete annelids are often responsive to light and can possess one to six eyes. The early trochophore larvae of the errant annelid Platynereis dumerilii have a single pair of ventral eyespots, whereas older nectochaete larvae have an additional two pairs of dorsal eyes that will develop into the adult eyes. Early Platynereis trochophores show robust positive phototaxis starting on the first day of development. Even though the mechanism of phototaxis in Platynereis early trochophore larvae is well understood, no photopigment (opsin) expression has yet been described in this stage. In late trochophore larvae, a rhabdomeric-type opsin, r-opsin1, expressed in both the eyespots and the adult eyes has already been reported. Here, we identify another Platynereis rhabdomeric opsin, r-opsin3, that is expressed in a single photoreceptor in the eyespots in early trochophores, suggesting that it mediates early larval phototaxis. We also show that r-opsin1 and r-opsin3 are expressed in adjacent photoreceptor cells in the eyespots in later stages, indicating that a second eyespot-photoreceptor differentiates in late trochophore larvae. Using serial transmission electron microscopy (TEM), we identified and reconstructed both photoreceptors and a pigment cell in the late larval eyespot. We also characterized opsin expression in the adult eyes and found that the two opsins co-express there in several photoreceptor cells. Using antibodies recognizing r-opsin1 and r-opsin3 proteins, we demonstrate that both opsins localize to the rhabdomere in all six eyes. In addition, we found that r-opsin1 mRNA is localized to, and translated in, the projections of the adult eyes. The specific changes we describe in opsin transcription and translation and in the cellular complement suggest that the six larval eyes undergo spectral and functional maturation during the early planktonic phase of the Platynereis life cycle. PMID:23667045

  3. Characterisation and localisation of the opsin protein repertoire in the brain and retinas of a spider and an onychophoran

    PubMed Central

    2013-01-01

    Background Opsins have been found in the majority of animals and their most apparent functions are related to vision and light-guided behaviour. As an increasing number of sequences have become available it has become clear that many opsin-like transcripts are expressed in tissues other than the eyes. Opsins can be divided into three main groups: rhabdomeric opsins (r-opsins), ciliary opsins (c-opsins) and group 4 opsins. In arthropods, the main focus has been on the r-opsins involved in vision. However, with increased sequencing it is becoming clear that arthropods also possess opsins of the c-type, group 4 opsins and the newly discovered arthropsins but the functions of these opsins are unknown in arthropods and data on their localisation is limited or absent. Results We identified opsins from the spider Cupiennius salei and the onychophoran Euperipatoides kanangrensis and characterised the phylogeny and localisation of these transcripts. We recovered all known visual opsins in C. salei, and in addition found a peropsin, a c-opsin and an opsin resembling Daphnia pulex arthropsin. The peropsin was expressed in all eye types except the anterior median eyes. The arthropsin and the c-opsin were expressed in the central nervous system but not the eyes. In E. kanangrensis we found: a c-opsin; an opsin resembling D. pulex arthropsins; and an r-opsin with high sequence similarity to previously published onychophoran onychopsins. The E. kanangrensis c-opsin and onychopsin were expressed in both the eyes and the brain but the arthropsin only in the brain. Conclusion Our novel finding that opsins of both the ciliary and rhabdomeric type are present in the onychophoran and a spider suggests that these two types of opsins were present in the last common ancestor of the Onychophora and Euarthropoda. The expression of the c-opsin in the eye of an onychophoran indicates that c-opsins may originally have been involved in vision in the arthropod clade. The lack of c-opsin expression in the spider retina suggests that the role for c-opsin in vision was lost in the euarthropods. Our discovery of arthropsin in onychophorans and spiders dates the emergence of arthropsin to the common ancestor of Onychophora and Euarthropoda and their expression in the brain suggests a non-visual function. PMID:24010579

  4. Explaining the mobility of retinal in activated rhodopsin and opsin.

    PubMed

    Mertz, Blake; Feng, Jun; Corcoran, Conor; Neeley, Brandon

    2015-11-01

    Rhodopsin, the mammalian dim light photoreceptor, is the canonical model for G protein-coupled receptors. Activation of rhodopsin occurs when the covalently bound inverse agonist, retinal, absorbs a photon and undergoes an 11-cis to all-trans isomerization. Two critical components of the visual cycle occur with the (1) hydrolytic release of all-trans retinaldehyde and subsequent (2) uptake of 11-cis retinaldehyde to reform the Schiff base linkage in the apoprotein opsin. Two pores on the surface of opsin are connected via the retinal channel, as discovered upon solution of the X-ray crystal structure (Park et al., Nature, 2008), and could serve as potential entryways for uptake and release. Using molecular dynamics simulations, we examined the behavior of rhodopsin in the Meta-II conformation (active) under Meta-I conditions (inactive), and discovered that the retinal binding pocket is flexible enough to allow a 180 rotation along the long axis of the retinal polyene chain. This result reconciles a discrepancy between the known polyene chain orientation from crystallographic and spectroscopic studies and opens the door for further investigation into the intermolecular interactions between the retinal ligand and the apoprotein opsin. Subsequent docking studies of both isomers of retinal into the opsin channel were then conducted to identify the mechanism for uptake and release. Our results suggest that retinal undergoes unidirectional uptake through Pore A and release through Pore B, and that aromatic sidechain interactions play a key role in stabilizing retinal within the opsin channel. These findings are significant in developing our understanding of the retinoid cycle and how ligand-receptor interactions in rhodopsin relate to G protein-coupled receptor activation. PMID:26248892

  5. Chemical name to structure: OPSIN, an open source solution.

    PubMed

    Lowe, Daniel M; Corbett, Peter T; Murray-Rust, Peter; Glen, Robert C

    2011-03-28

    We have produced an open source, freely available, algorithm (Open Parser for Systematic IUPAC Nomenclature, OPSIN) that interprets the majority of organic chemical nomenclature in a fast and precise manner. This has been achieved using an approach based on a regular grammar. This grammar is used to guide tokenization, a potentially difficult problem in chemical names. From the parsed chemical name, an XML parse tree is constructed that is operated on in a stepwise manner until the structure has been reconstructed from the name. Results from OPSIN on various computer generated name/structure pair sets are presented. These show exceptionally high precision (99.8%+) and, when using general organic chemical nomenclature, high recall (98.7-99.2%). This software can serve as the basis for future open source developments of chemical name interpretation. PMID:21384929

  6. Visual sensitivities tuned by heterochronic shifts in opsin gene expression

    PubMed Central

    Carleton, Karen L; Spady, Tyrone C; Streelman, J Todd; Kidd, Michael R; McFarland, William N; Loew, Ellis R

    2008-01-01

    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. PMID:18500997

  7. The Opsin Shift and Mechanism of Spectral Tuning of Rhodopsin

    PubMed Central

    Rajamani, Ramkumar; Lin, Yen-lin

    2010-01-01

    Molecular dynamics simulations and combined quantum mechanical and molecular mechanical (QM/MM) calculations have been performed to investigate the mechanism of the opsin shift and spectral tuning in rhodopsin. A red shift of ?980 cm?1 was estimated in the transfer of the chromophore from methanol solution environment to the protonated Schiff base binding site of the opsin. The conformational change from a 6-s-cis-all-trans configuration in solution to the 6-s-cis-11-cis conformer contributes additional ?200 cm?1 and the remaining effects were attributed to dispersion interactions with the aromatic residues in the binding site. An opsin shift of 2100 cm?1 was obtained, in reasonable accord with experiment (2730 cm?1). Dynamics simulations revealed that the 6-s-cis bond can occupy two main conformations for the ?-ionone ring, resulting a weighted average dihedral angle of about 50, which may be compared with the experimental estimate of ?28 from solid-state NMR and Raman data. We investigated a series of four single-mutations, including E113D, A292S, T118A and A269T, which are located near the protonated Schiff base, along the polyene chain of retinal and close to the ionone ring. The computational results on absorption energy shift provided insights into the mechanism of spectral tuning, which involves all means of electronic structural effects, including the stabilization or destabilization of either the ground or the electronically excited state of the retinal protonated Schiff base. PMID:20941732

  8. Selective Protonation of Acidic Residues Triggers Opsin Activation.

    PubMed

    Lans, Isaias; Dalton, James A R; Giraldo, Jess

    2015-07-30

    Rhodopsin, the visual pigment in the retina, is a Class A G protein-coupled receptor (GPCR) covalently bound to retinal chromophore. In dark conditions, retinal is in the cis-isomeric state, stabilizing the rhodopsin inactive state as an inverse agonist. After light absorption, retinal undergoes an isomerization photoreaction to trans-retinal, which includes a conformational change of the receptor to its active state. In the absence of retinal, the apoprotein opsin presents a low level of constitutive activity, which depends on pH, with higher propensity of activation at acidic pH. To examine the effect and the underlying mechanism that protonation may have on opsin activation, a number of MD simulations were run varying the number and identity of acidic residues selected for protonation. Results show that the combined protonation of D83, E113, and E247 is of special relevance for the induction of receptor activation. Subsequent conformational analysis of the MD trajectories provides a structural mechanistic insight into the opsin activation process. Furthermore, because protonation seems to be a determining step in the activation of other GPCRs, the methodology and rationale used herein can be extended to mechanistic studies of GPCRs in general. PMID:26140747

  9. True blue: S-opsin is widely expressed in different animal species.

    PubMed

    Amann, B; Hirmer, S; Hauck, S M; Kremmer, E; Ueffing, M; Deeg, C A

    2014-02-01

    Colour vision in animals is an interesting, fascinating subject. In this study, we examined a wide variety of species for expression of S-opsin (blue sensitive) and M-/L-opsin (green-red sensitive) in retinal cones using two novel monoclonal antibodies specific for peptides from human opsins. Mouse, rat and hare did not express one of the investigated epitopes, but we could clearly prove existence of cones through peanut agglutinin labelling. Retinas of guinea pig, dog, wolf, marten, cat, roe deer, pig and horse were positive for S-opsin, but not for M-/L-opsin. Nevertheless all these species are clearly at least dichromats, because we could detect further S-opsin negative cones by labelling with cone arrestin specific antibody. In contrast, pheasant and char had M-/L-opsin positive cones, but no S-opsin expressing cones. Sheep, cattle, monkey, men, pigeon, duck and chicken were positive for both opsins. Visual acuity analyzed through density of retinal ganglion cells revealed least visual discrimination by horses and highest resolution in pheasant and pigeon. Most mammals studied are dichromats with visual perception similar to red-green blind people. PMID:23173557

  10. Co-expression of three opsins in cone photoreceptors of the salamander, Ambystoma tigrinum

    PubMed Central

    Isayama, Tomoki; Chen, Ying; Kono, Masahiro; Fabre, Eduard; Slavsky, Michael; DeGrip, Willem J.; Ma, Jian-Xing; Crouch, Rosalie K.; Makino, Clint L.

    2014-01-01

    Whereas more than one type of visual opsin is present in the retina of most vertebrates, it was thought that each type of photoreceptor expressed only one opsin. However, evidence has accumulated that some photoreceptors contain more than one opsin, in many cases as a result of a developmental transition from the expression of one opsin to another. The salamander UV-sensitive (UV) cone is particularly notable because it contains three opsins (Makino and Dodd, 1996; J Gen Physiol 108:2734). Two opsin types are expressed at levels more than a hundred times lower than that of the primary opsin. Here, immunohistochemical experiments identified the primary component as a UV cone opsin and the two minor components as the short wavelength-sensitive (S) and long wavelength-sensitive (L) cone opsins. Based on single cell recordings of 156 photoreceptors, the presence of three components in UV cones of hatchlings and terrestrial adults ruled out a developmental transition. There was no evidence for multiple opsin types within rods or S cones. But immunohistochemistry and partial bleaching in conjunction with single cell recording revealed that both single and double L cones contained low levels of short wavelength-sensitive pigments in addition to the main L visual pigment. These results raise the possibility that co-expression of multiple opsins in other vertebrates was overlooked because a minor component absorbing at short wavelengths was masked by the main visual pigment or because the expression level of a component absorbing at long wavelengths was exceedingly low. PMID:24374736

  11. Molecular characterization of visual pigments in Branchiopoda and the evolution of opsins in Arthropoda.

    PubMed

    Kashiyama, Kazuyuki; Seki, Takaharu; Numata, Hideharu; Goto, Shin G

    2009-02-01

    Studies on color vision in invertebrates have focused primarily on insect visual pigments, with little attention given to crustacean visual pigments. None of the blue-green-, blue-, or ultraviolet (UV)-sensitive-opsins have been identified in crustaceans. In addition, the discussion of visual pigments has been limited to long-wavelength-sensitive opsins in Pancrustacea. Here, we focused on Branchiopoda (Crustacea), which is a sister group of Hexapoda including insects. In the tadpole shrimp Triops granarius, the visual pigment chromophore was retinal. Multiple opsins were isolated from each of three branchiopod species, T. granarius, Triops longicaudatus, and the fairy shrimp Branchinella kugenumaensis (five, five, and four opsins from these species, respectively). Phylogenetic analyses and the presence of a lysine residue corresponding to position 90 in bovine rhodopsin suggested that three of the branchiopod opsins comprise UV-sensitive pigments. In addition, the phylogenetic relationships between insect and branchiopod UV-sensitive opsins revealed that the divergence of blue- and UV-sensitive pigments predates the Branchiopoda and Insecta divergence. The other branchiopod opsins show distant relationships to other known insect opsins and form novel clusters. The present results strongly suggest that the ancestral arthropod of the Chelicerata-Pancrustacea lineages possessed at least four types of opsins. The ancestors of Pancrustacea and the Insecta-Branchiopoda lineages possessed at least five and six types of opsins, respectively. Our results suggest that in the evolutionary process associated with each lineage, several opsins appeared and diversified with repeated gene duplication, of which some have been lost in some taxa. PMID:18984904

  12. Ocular and Extraocular Expression of Opsins in the Rhopalium of Tripedalia cystophora (Cnidaria: Cubozoa)

    PubMed Central

    Bielecki, Jan; Zaharoff, Alexander K.; Leung, Nicole Y.; Garm, Anders; Oakley, Todd H.

    2014-01-01

    A growing body of work on the neuroethology of cubozoans is based largely on the capabilities of the photoreceptive tissues, and it is important to determine the molecular basis of their light sensitivity. The cubozoans rely on 24 special purpose eyes to extract specific information from a complex visual scene to guide their behavior in the habitat. The lens eyes are the most studied photoreceptive structures, and the phototransduction in the photoreceptor cells is based on light sensitive opsin molecules. Opsins are photosensitive transmembrane proteins associated with photoreceptors in eyes, and the amino acid sequence of the opsins determines the spectral properties of the photoreceptors. Here we show that two distinct opsins (Tripedalia cystophora-lens eye expressed opsin and Tripedalia cystophora-neuropil expressed opsin, or Tc-leo and Tc-neo) are expressed in the Tripedalia cystophora rhopalium. Quantitative PCR determined the level of expression of the two opsins, and we found Tc-leo to have a higher amount of expression than Tc-neo. In situ hybridization located Tc-leo expression in the retinal photoreceptors of the lens eyes where the opsin is involved in image formation. Tc-neo is expressed in a confined part of the neuropil and is probably involved in extraocular light sensation, presumably in relation to diurnal activity. PMID:24901369

  13. Opsin evolution and expression in Arthropod compound Eyes and Ocelli: Insights from the cricket Gryllus bimaculatus

    PubMed Central

    2012-01-01

    Background Opsins are key proteins in animal photoreception. Together with a light-sensitive group, the chromophore, they form visual pigments which initiate the visual transduction cascade when photoactivated. The spectral absorption properties of visual pigments are mainly determined by their opsins, and thus opsins are crucial for understanding the adaptations of animal eyes. Studies on the phylogeny and expression pattern of opsins have received considerable attention, but our knowledge about insect visual opsins is still limited. Up to now, researchers have focused on holometabolous insects, while general conclusions require sampling from a broader range of taxa. We have therefore investigated visual opsins in the ocelli and compound eyes of the two-spotted cricket Gryllus bimaculatus, a hemimetabolous insect. Results Phylogenetic analyses place all identified cricket sequences within the three main visual opsin clades of insects. We assign three of these opsins to visual pigments found in the compound eyes with peak absorbances in the green (515 nm), blue (445 nm) and UV (332 nm) spectral range. Their expression pattern divides the retina into distinct regions: (1) the polarization-sensitive dorsal rim area with blue- and UV-opsin, (2) a newly-discovered ventral band of ommatidia with blue- and green-opsin and (3) the remainder of the compound eye with UV- and green-opsin. In addition, we provide evidence for two ocellar photopigments with peak absorbances in the green (511 nm) and UV (350 nm) spectral range, and with opsins that differ from those expressed in the compound eyes. Conclusions Our data show that cricket eyes are spectrally more specialized than has previously been assumed, suggesting that similar adaptations in other insect species might have been overlooked. The arrangement of spectral receptor types within some ommatidia of the cricket compound eyes differs from the generally accepted pattern found in holometabolous insect taxa and awaits a functional explanation. From the opsin phylogeny, we conclude that gene duplications, which permitted differential opsin expression in insect ocelli and compound eyes, occurred independently in several insect lineages and are recent compared to the origin of the eyes themselves. PMID:22935102

  14. 2006 LWS TR&T Solar Wind Focused Science Topic Team: Overview of Current Results

    NASA Astrophysics Data System (ADS)

    Miralles, M. P.; LWS Tr&T Solar Wind Fst Team

    2008-12-01

    We present a summary of the research conducted by the members of the 2006 LWS TR&T Solar Wind Focused Science Topic (FST) Team on the physical processes that heat and accelerate the solar wind. The Team applied a combination of theoretical studies, numerical simulations, and observations for their investigation of the role of energy sources and kinetic mechanisms responsible for the heating and acceleration of the solar wind. In particular, the FST Team examined magnetic reconnection, waves, and turbulence as possible heating mechanisms. Plasma properties and their evolution over the solar cycle, determined from the analysis of remote and in situ measurements of solar wind source regions and streams, are being used to constrain the models. The consistency of candidate theoretical models with existing observational data for the solar wind will be discussed.

  15. Modeling Active Region Evolution - A New LWS TR and T Strategic Capability Model Suite

    NASA Technical Reports Server (NTRS)

    MacNeice, Peter

    2012-01-01

    In 2006 the LWS TR&T Program funded us to develop a strategic capability model of slowly evolving coronal active regions. In this poster we report on the overall design, and status of our new modeling suite. Our design features two coronal field models, a non-linear force free field model and a global 3D MHD code. The suite includes supporting tools and a user friendly GUI which will enable users to query the web for relevant magnetograms, download them, process them to synthesize a sequence of photospheric magnetograms and associated photospheric flow field which can then be applied to drive the coronal model innner boundary, run the coronal models and finally visualize the results.

  16. The ISO-LWS map of the Serpens cloud core. II. The line spectra

    NASA Astrophysics Data System (ADS)

    Larsson, B.; Liseau, R.; Men'shchikov, A. B.

    2002-05-01

    We present spectrophotometric ISO imaging with the LWS and the CAM-CVF of the Serpens molecular cloud core. The LWS map is centred on the far infrared and submillimetre source FIRS 1/SMM 1 and its size is 8',x 8'. The fine structure line emission in [O I] 63 mu m and [C II] 157 mu m is extended on the arcminute scale and can be successfully modelled to originate in a PDR with G0 = 15 +/- 10 and n(H2) in the range of (104-105) cm-3. Extended emission might also be observed in the rotational line emission of H2O and high-J CO. However, lack of sufficient angular resolution prevents us from excluding the possibility that the emssion regions of these lines are point like, which could be linked to the embedded objects SMM 9/S 68 and SMM 4. Toward the Class 0 source SMM 1, the LWS observations reveal, in addition to fine structure line emission, a rich spectrum of molecular lines, superposed onto a strong, optically thick dust continuum (Larsson et al. \\cite{Lar00}). The sub-thermally excited and optically thick CO, H2O and OH lines are tracing an about 103 AU source with temperatures higher than 300 K and densities above 106 cm-3 (M=0.01 Msun). The molecular abundances, X=N(mol)/N(H2), are X=(1, 0.1, 0.02, ge 0.025) x 10-4 for CO, H2O, OH and 13CO, respectively. Our data are consistent with an ortho-to-para ratio of 3 for H2O. OH appears highly overabundant, which we tentatively ascribe to an enhanced (X-ray) ionisation rate in the Serpens cloud core (zeta >> 10-18 s-1). We show that geometry is of concern for the correct interpretation of the data and based on 2D-radiative transfer modelling of the disk/torus around SMM 1, which successfully reproduces the entire observed SED and the observed line profiles of low-to-mid-J CO isotopomers, we can exclude the disk to be the source of the LWS-molecular line emission. The same conclusion applies to models of dynamical collapse (``inside-out'' infall). The 6{' '} pixel resolution of the CAM-CVF permits us to see that the region of rotational H2 emission is offset from SMM 1 by 30{' '}, at position angle 340deg, which is along the known jet flow from the Class 0 object. This H2 gas is extinguished by AV = 4.5 mag and at a temperature of 10310 K, which suggests that the heating of the gas is achieved through relatively slow shocks. Although we are not able to establish any firm conclusion regarding the detailed nature of the shock waves, our observations of the molecular line emission from SMM 1 are to a limited extent explainable in terms of an admixture of J-shocks and of C-shocks, the latter with speeds of about (15-20) km s-1, whereas dynamical infall is not directly revealed by our data. Based on observations with ISO, an ESA project with instruments funded by ESA Member States (especially the PI countries: France, Germany, The Netherlands and the UK) and with the participation of ISAS and NASA.

  17. ISO-LWS observations of Herbig Ae/Be stars. I. Fine structure lines

    NASA Astrophysics Data System (ADS)

    Lorenzetti, D.; Tommasi, E.; Giannini, T.; Nisini, B.; Benedettini, M.; Pezzuto, S.; Strafella, F.; Barlow, M.; Clegg, P. E.; Cohen, M.; di Giorgio, A. M.; Liseau, R.; Molinari, S.; Palla, F.; Saraceno, P.; Smith, H. A.; Spinoglio, L.; White, G. J.

    1999-06-01

    We present the results of the first spectrophotometric survey of a sample of eleven Herbig Ae/Be stars (HAEBE) obtained with the Long Wavelength Spectrometer (LWS) on board the Infrared Space Observatory (ISO). The [OI] 63mu m and the [CII] 158mu m lines are observed in all the investigated sources, while the [OI] 145mu m transition, due to its relative faintness, sometimes remains undetected. By comparing line intensity ratios with model predictions, photodissociation, due to the UV photons from the central star, results the dominating excitation mechanism although contributions of C-shocks to the [OI] emission cannot be ruled out. A clear example for the presence of a photodissociation region (PDR) illuminated by an HAEBE is shown by LWS spectroscopic mapping of NGC 7129. Some diagnostic probes of the radiation field and density are provided for the objects in our sample: these substantially agree with the known characteristics of both the star and its circumstellar environment, although the observed ratio [OI]63/[OI]145 tends to be smaller than predicted by PDR models. The most likely explanation for this behaviour is self-absorption at 63mu m by cold atomic oxygen. Fine structure lines of the ionised species [OIII], [NII] were detected whenever the star had a spectral type of B0 or earlier; in particular, around the star CoD-42(deg) 11721, besides a compact HII region, evidence is given for an extended low electron density ionised region. Finally, molecular line emission is associated with stars powering a CO outflow, and clumpy PDR models, better than C-shock models, predict for them relative cooling (CO vs OI and CO vs OH) similar to the observed ones. Based on observations with ISO, an ESA project with instruments funded by ESA Member States and with the participation of ISAS and NASA}

  18. Spectral tuning by opsin coexpression in retinal regions that view different parts of the visual field

    PubMed Central

    Dalton, Brian E.; Loew, Ellis R.; Cronin, Thomas W.; Carleton, Karen L.

    2014-01-01

    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. PMID:25377457

  19. Molecular expression of opsin gene in growing juvenile mackerel ( Scomber japonicus Houttuyn)

    NASA Astrophysics Data System (ADS)

    Kim, Eung-Oh; Yoon, Seong-Jong; Park, Kyoung-Hyun; Kim, Dae-Hyun; Do, Jeung-Wan; Cho, Eun-Seob

    2009-12-01

    Fish have developed color vision that is closely adapted to their photic environments, where both spectral sensitivity and the number of visual opsins are influenced. The mackerel used in this study is one of the most important fishery stocks in Korea. The opsin gene of the mackerel juveniles after 20 days in hatching was isolated and characterized based on the molecular study of visual photoreceptor. The full-length mackerel opsin gene was obtained by PCR amplification of genomic DNA, as well as cDNA synthesis. Sequence analysis of the opsin gene showed that it contained a 1,080 bp open reading frame encoding 360 amino acids. Based on Schiffs base formation (S114, K119), glycosylation (E3, F37) and palmitoylation (S281, 282), the deduced amino acid sequence had a typical rod opsin. The mackerel and Gempylus serpens showed 73.7% DNA homology on opsin gene, which was higher than any other of investigated species. In the analysis of phylogenetic relationship, the genetic placement of the mackerel is closer to that of Scombroidei than Labroidei, with supporting somewhat strong bootstrap value. In the analysis of Northern and RT-PCR, the probed products were observed only in rapidly growing juveniles. These findings indicate that in mackerel opsin mRNA expression can be detected in day-20 hatching larvae. It may play an important role in stimulating growth hormone.

  20. Spectral tuning by opsin coexpression in retinal regions that view different parts of the visual field.

    PubMed

    Dalton, Brian E; Loew, Ellis R; Cronin, Thomas W; Carleton, Karen L

    2014-12-22

    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. PMID:25377457

  1. Variation in opsin genes correlates with signalling ecology in North American fireflies.

    PubMed

    Sander, S E; Hall, D W

    2015-09-01

    Genes underlying signal reception should evolve to maximize signal detection in a particular environment. In animals, opsins, the protein component of visual pigments, are predicted to evolve according to this expectation. Fireflies are known for their bioluminescent mating signals. The eyes of nocturnal species are expected to maximize the detection of conspecific signal colours emitted in the typical low-light environment. This is not expected for species that have transitioned to diurnal activity in bright daytime environments. Here, we test the hypothesis that opsin gene sequence plays a role in modifying firefly eye spectral sensitivity. We use genome and transcriptome sequencing in four firefly species, transcriptome sequencing in six additional species and targeted gene sequencing in 28 other species to identify all opsin genes present in North American fireflies and to elucidate amino acid sites under positive selection. We also determine whether amino acid substitutions in opsins are linked to evolutionary changes in signal mode, signal colour and light environment. We find only two opsins, one long wavelength and one ultraviolet, in all firefly species and identify 25 candidate sites that may be involved in determining spectral sensitivity. In addition, we find elevated rates of evolution at transitions to diurnal activity, and changes in selective constraint on long wavelength opsin associated with changes in light environment. Our results suggest that changes in eye spectral sensitivity are at least partially due to opsin sequence. Fireflies continue to be a promising system in which to investigate the evolution of signals, receptors and signalling environments. PMID:26289828

  2. Parapinopsin, a novel catfish opsin localized to the parapineal organ, defines a new gene family.

    PubMed

    Blackshaw, S; Snyder, S H

    1997-11-01

    Multiple sites of extraretinal photoreception are present in vertebrates, but the molecular basis of extraretinal phototransduction is poorly understood. This study reports the cloning of the first opsin specifically expressed in the directly photosensitive pineal and parapineal of cold-blooded vertebrates. This opsin, identified in channel catfish and termed parapinopsin, defines a new gene family of vertebrate photopigments and is expressed in a majority of parapinealocytes and a subset of pineal photoreceptor cells. Parapinopsin shows a caudal-rostral gradient of expression within the pineal organ. This study also reports the cloning of partial cDNAs encoding the channel catfish orthologues of rhodopsin and the red cone pigment-the full complement of retinal opsins in the species. In situ hybridization studies using probes derived from these retinal opsins, together with parapinopsin, reveal no expression of retinal opsins in pineal and parapineal organ and no expression of any opsin tested in the "deep brain," iris, or dermal melanophores. These data imply that phototransduction in these sites of extraretinal photoreception must be mediated by novel opsins. PMID:9334384

  3. Three Different Cone Opsin Gene Array Mutational Mechanisms with GenotypePhenotype Correlation and Functional Investigation of Cone Opsin Variants

    PubMed Central

    Gardner, Jessica C; Liew, Gerald; Quan, Ying-Hua; Ermetal, Burcu; Ueyama, Hisao; Davidson, Alice E; Schwarz, Nele; Kanuga, Naheed; Chana, Ravinder; Maher, Eamonn R; Webster, Andrew R; Holder, Graham E; Robson, Anthony G; Cheetham, Michael E; Liebelt, Jan; Ruddle, Jonathan B; Moore, Anthony T; Michaelides, Michel; Hardcastle, Alison J

    2014-01-01

    Mutations in the OPN1LW (L-) and OPN1MW (M-)cone opsin genes underlie a spectrum of cone photoreceptor defects from stationary loss of color vision to progressive retinal degeneration. Genotypes of 22 families with a range of cone disorders were grouped into three classes: deletions of the locus control region (LCR); missense mutation (p.Cys203Arg) in an L-/M-hybrid gene; and exon 3 single-nucleotide polymorphism (SNP) interchange haplotypes in an otherwise normal gene array. Moderate-to-high myopia was observed in all mutation categories. Individuals with LCR deletions or p.Cys203Arg mutations were more likely to have nystagmus and poor vision, with disease progression in some p.Cys203Arg patients. Three disease-associated exon 3 SNP haplotypes encoding LIAVA, LVAVA, or MIAVA were identified in our cohort. These patients were less likely to have nystagmus but more likely to show progression, with all patients over the age of 40 years having marked macular abnormalities. Previously, the haplotype LIAVA has been shown to result in exon 3 skipping. Here, we show that haplotypes LVAVA and MIAVA also result in aberrant splicing, with a residual low level of correctly spliced cone opsin. The OPN1LW/OPN1MW:c.532A>G SNP, common to all three disease-associated haplotypes, appears to be principally responsible for this mutational mechanism. PMID:25168334

  4. Three different cone opsin gene array mutational mechanisms with genotype-phenotype correlation and functional investigation of cone opsin variants.

    PubMed

    Gardner, Jessica C; Liew, Gerald; Quan, Ying-Hua; Ermetal, Burcu; Ueyama, Hisao; Davidson, Alice E; Schwarz, Nele; Kanuga, Naheed; Chana, Ravinder; Maher, Eamonn R; Webster, Andrew R; Holder, Graham E; Robson, Anthony G; Cheetham, Michael E; Liebelt, Jan; Ruddle, Jonathan B; Moore, Anthony T; Michaelides, Michel; Hardcastle, Alison J

    2014-11-01

    Mutations in the OPN1LW (L-) and OPN1MW (M-)cone opsin genes underlie a spectrum of cone photoreceptor defects from stationary loss of color vision to progressive retinal degeneration. Genotypes of 22 families with a range of cone disorders were grouped into three classes: deletions of the locus control region (LCR); missense mutation (p.Cys203Arg) in an L-/M-hybrid gene; and exon 3 single-nucleotide polymorphism (SNP) interchange haplotypes in an otherwise normal gene array. Moderate-to-high myopia was observed in all mutation categories. Individuals with LCR deletions or p.Cys203Arg mutations were more likely to have nystagmus and poor vision, with disease progression in some p.Cys203Arg patients. Three disease-associated exon 3 SNP haplotypes encoding LIAVA, LVAVA, or MIAVA were identified in our cohort. These patients were less likely to have nystagmus but more likely to show progression, with all patients over the age of 40 years having marked macular abnormalities. Previously, the haplotype LIAVA has been shown to result in exon 3 skipping. Here, we show that haplotypes LVAVA and MIAVA also result in aberrant splicing, with a residual low level of correctly spliced cone opsin. The OPN1LW/OPN1MW:c.532A>G SNP, common to all three disease-associated haplotypes, appears to be principally responsible for this mutational mechanism. PMID:25168334

  5. Retinal cone photoreceptors of the deer mouse Peromyscus maniculatus: development, topography, opsin expression and spectral tuning.

    PubMed

    Arbogast, Patrick; Glsmann, Martin; Peichl, Leo

    2013-01-01

    A quantitative analysis of photoreceptor properties was performed in the retina of the nocturnal deer mouse, Peromyscus maniculatus, using pigmented (wildtype) and albino animals. The aim was to establish whether the deer mouse is a more suitable model species than the house mouse for photoreceptor studies, and whether oculocutaneous albinism affects its photoreceptor properties. In retinal flatmounts, cone photoreceptors were identified by opsin immunostaining, and their numbers, spectral types, and distributions across the retina were determined. Rod photoreceptors were counted using differential interference contrast microscopy. Pigmented P. maniculatus have a rod-dominated retina with rod densities of about 450.000/mm(2) and cone densities of 3000-6500/mm(2). Two cone opsins, shortwave sensitive (S) and middle-to-longwave sensitive (M), are present and expressed in distinct cone types. Partial sequencing of the S opsin gene strongly supports UV sensitivity of the S cone visual pigment. The S cones constitute a 5-15% minority of the cones. Different from house mouse, S and M cone distributions do not have dorsoventral gradients, and coexpression of both opsins in single cones is exceptional (<2% of the cones). In albino P. maniculatus, rod densities are reduced by approximately 40% (270.000/mm(2)). Overall, cone density and the density of cones exclusively expressing S opsin are not significantly different from pigmented P. maniculatus. However, in albino retinas S opsin is coexpressed with M opsin in 60-90% of the cones and therefore the population of cones expressing only M opsin is significantly reduced to 5-25%. In conclusion, deer mouse cone properties largely conform to the general mammalian pattern, hence the deer mouse may be better suited than the house mouse for the study of certain basic cone properties, including the effects of albinism on cone opsin expression. PMID:24260509

  6. Optogenetics: 10 years of microbial opsins in neuroscience

    PubMed Central

    Deisseroth, Karl

    2016-01-01

    Over the past 10 years, the development and convergence of microbial opsin engineering, modular genetic methods for cell-type targeting and optical strategies for guiding light through tissue have enabled versatile optical control of defined cells in living systems, defining modern optogenetics. Despite widespread recognition of the importance of spatiotemporally precise causal control over cellular signaling, for nearly the first half (2005–2009) of this 10-year period, as optogenetics was being created, there were difficulties in implementation, few publications and limited biological findings. In contrast, the ensuing years have witnessed a substantial acceleration in the application domain, with the publication of thousands of discoveries and insights into the function of nervous systems and beyond. This Historical Commentary reflects on the scientific landscape of this decade-long transition. PMID:26308982

  7. The amino terminus of opsin translocates "posttranslationally" as efficiently as cotranslationally.

    PubMed

    Kanner, Elliott M; Klein, Irene K; Friedlander, Martin; Simon, Sanford M

    2002-06-18

    Opsin, a member of the G-protein-coupled receptor family, is a polytopic membrane protein that does not encode a cleaved amino-terminal signal sequence. The amino terminus of opsin precedes the first known targeting information, suggesting that it translocates across the endoplasmic reticulum (ER) membrane after synthesis, uncoupled from translation. However, translocation across the mammalian ER is believed to be coupled to protein synthesis. In this study we show that opsin, within a range of nascent peptide lengths, targets and translocates equally efficiently co- and posttranslationally. Longer nascent opsin peptides have a lower efficiency of cotranslational translocation but an even lower efficiency of posttranslational translocation. We also show that SRP is required for both co- and posttranslational targeting. PMID:12056902

  8. Implications of the ISO-LWS Spectrum of the Prototypical Ultraluminous Galaxy ARP 220

    NASA Astrophysics Data System (ADS)

    Fischer, J.; Satyapal, S.; Luhman, M. L.; Melnick, G.; Cox, P.; Cernicharo, J.; Stacey, G. J.; Smith, H. A.; Lord, S. D.; Greenhouse, M. A.

    We present a low resolution (R = lambda / delta lambda ~200) far-infrared (43-197 pirn) spectrum of the ultraluminous galaxy Arp 220, obtained from deep full-range scans using the Long Wavelength Spectrometer (LWS) aboard the Infrared Space Observatory (ISO). The spectrum is vastly different from the spectra of less luminous IR bright galaxies: the fine-structure lines that are typical of IR bright galaxies are weak or absent and the spectrum is dominated by absorption lines of OH, H20, CH, NH3 and [O I]. From the 43-197 um continuum fit we derive that the optical depth of the thermal dust emission, tau_dust is about unity at 150 um. From our continuum fit we derive a Lyman continuum production rate of Q = 9 x 10^54 sec-1 and our simple spherical radiative transfer solution indicates a cool central source. The upper limits on the FIR fine-structure lines indicate a softer radiation field in Arp 220 than in starburst galaxies such as M82 or in AGN. The low L[CII] 158 / L FIR ratio in Arp 220 cannot be easily explained by dust obscuration or saturation effects. These results may be explained by a starburst model with a low upper mass cutoff or by unusually high dust absorption of UV photons within the ionized regions of a starburst or AGN.

  9. NASA's Living With a Star (LWS) Sentinels Mission to Understand the Origin of Solar Energetic Particles

    NASA Astrophysics Data System (ADS)

    Mewaldt, R. A.; Lin, R. P.; Szabo, A.

    2006-05-01

    One of the primary goals of NASA's Sentinels mission, the heliospheric element of the integrated LWS program, is to provide observations necessary for understanding the physics of solar/inner heliosphere processes that produce solar energetic particle (SEP) events, so that requirements for eventual predictive capability can be defined. We present the results of a study by the Sentinels Science and Technology Definition Team (STDT) that recommends the following program: (a) four identical Inner Heliosphere Sentinels (IHS) spacecraft that utilize Venus gravity assists to achieve 0.25-0.7 AU orbits, primarily for in situ particles and fields measurements; (b) a Near-Earth Sentinel (NES) with a spectroscopic coronagraph to provide the physical conditions in the SEP acceleration region and a wide field (>~0.3 AU) coronagraph to connect to the IHS measurements; and (3) a Farside Sentinel (FS) with a magnetograph to provide near global photospheric magnetic field measurements for modeling the structure of the inner heliosphere. From their multiple vantage points, distributed in radius and longitude, the four IHS spacecraft will be able to study the injection, acceleration, and transport of SEPs with unprecedented precision, which should resolve issues that have arisen from SEP timing studies at 1 AU. We illustrate how these combined measurements will lead to an understanding of SEP origin and improve our predictive capability for large SEP events.

  10. Exploring the inner heliosphere with the NASA Living With a Star (LWS) Sentinels mission

    NASA Astrophysics Data System (ADS)

    Lin, R. P.; Sentinels Team

    We present the results of the study by the Science and Technology Definition Team STDT to define the NASA Sentinels mission the heliospheric element of the integrated LWS program The objective of the Sentinels is to discover understand and model the connection between solar events such as flares and coronal mass ejections CMEs and heliospheric and magnetospheric events such as Solar Particle Events SPEs that can adversely impact life and society in particular NASA s exploration initiative to the Moon Mars and beyond The primary objective of Sentinels is to provide the observations necessary for an understanding of the physics of the Sun inner heliosphere processes that affect the solar system so the requirements for eventual predictive capability can be defined This can be achieved with a combination of the Inner Heliosphere Sentinels consisting of four identical spacecraft that utilize Venus gravity assists to achieve 0 25-0 75 AU orbits primarily for in situ particles and fields measurements a Near-Earth Sentinel with spectroscopic and wide field sim 0 3 AU coronagraphs and a Farside Sentinel with a magnetograph to provide near global photospheric magnetic field measurements for modeling

  11. Constitutive activation of phototransduction by K296E opsin is not a cause of photoreceptor degeneration.

    PubMed Central

    Li, T; Franson, W K; Gordon, J W; Berson, E L; Dryja, T P

    1995-01-01

    The missense mutation Lys-296-->Glu (K296E) in the rhodopsin gene produces an opsin with no chromophore binding site and therefore is not activated by light. Nevertheless, the mutant opsin constitutively activates transducin in vitro and causes photoreceptor degeneration in vivo, possibly by continuously activating the phototransduction cascade, analogous to constant exposure to environmental light. We studied the K296E mutation in eight lines of transgenic mice. Each line developed photoreceptor degeneration with the rate of degeneration increasing monotonically as the ratio of mutant:wild-type opsin mRNA increased. At no time in the course of degeneration was there endogenous light adaptation in the retina as measured by the electroretinogram. The mutant opsin was found to be invariably phosphorylated and stably bound to arrestin. Light-independent activation of transducin was demonstrated only after the removal of arrestin and dephosphorylation of K296E opsin. Thus, K296E opsin in vivo does not activate the phototransduction cascade because it is shut off by photoreceptor inactivation mechanisms. Our data show that the K296E mutation does not cause photoreceptor degeneration by continuous activation of phototransduction. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:7724596

  12. Broadband activation by white-opsin lowers intensity threshold for cellular stimulation

    PubMed Central

    Batabyal, Subrata; Cervenka, Gregory; Birch, David; Kim, Young-tae; Mohanty, Samarendra

    2015-01-01

    Photoreceptors, which initiate the conversion of ambient light to action potentials via retinal circuitry, degenerate in retinal diseases such as retinitis pigmentosa and age related macular degeneration leading to loss of vision. Current prosthetic devices using arrays consisting of electrodes or LEDs (for optogenetic activation of conventional narrow-band opsins) have limited spatial resolution and can cause damage to retinal circuits by mechanical or photochemical (by absorption of intense narrow band light) means. Here, we describe a broad-band light activatable white-opsin for generating significant photocurrent at white light intensity levels close to ambient daylight conditions. White-opsin produced an order of magnitude higher photocurrent in response to white light as compared to narrow-band opsin channelrhodopsin-2, while maintaining the ms-channel kinetics. High fidelity of peak-photocurrent (both amplitude and latency) of white-opsin in response to repetitive white light stimulation of varying pulse width was observed. The significantly lower intensity stimulation required for activating white-opsin sensitized cells may facilitate ambient white light-based restoration of vision for patients with widespread photoreceptor degeneration. PMID:26658483

  13. Broadband activation by white-opsin lowers intensity threshold for cellular stimulation.

    PubMed

    Batabyal, Subrata; Cervenka, Gregory; Birch, David; Kim, Young-Tae; Mohanty, Samarendra

    2015-01-01

    Photoreceptors, which initiate the conversion of ambient light to action potentials via retinal circuitry, degenerate in retinal diseases such as retinitis pigmentosa and age related macular degeneration leading to loss of vision. Current prosthetic devices using arrays consisting of electrodes or LEDs (for optogenetic activation of conventional narrow-band opsins) have limited spatial resolution and can cause damage to retinal circuits by mechanical or photochemical (by absorption of intense narrow band light) means. Here, we describe a broad-band light activatable white-opsin for generating significant photocurrent at white light intensity levels close to ambient daylight conditions. White-opsin produced an order of magnitude higher photocurrent in response to white light as compared to narrow-band opsin channelrhodopsin-2, while maintaining the ms-channel kinetics. High fidelity of peak-photocurrent (both amplitude and latency) of white-opsin in response to repetitive white light stimulation of varying pulse width was observed. The significantly lower intensity stimulation required for activating white-opsin sensitized cells may facilitate ambient white light-based restoration of vision for patients with widespread photoreceptor degeneration. PMID:26658483

  14. X-Linked Cone Dystrophy Caused by Mutation of the Red and Green Cone Opsins

    PubMed Central

    Gardner, Jessica C.; Webb, Tom R.; Kanuga, Naheed; Robson, Anthony G.; Holder, Graham E.; Stockman, Andrew; Ripamonti, Caterina; Ebenezer, Neil D.; Ogun, Olufunmilola; Devery, Sophie; Wright, Genevieve A.; Maher, Eamonn R.; Cheetham, Michael E.; Moore, Anthony T.; Michaelides, Michel; Hardcastle, Alison J.

    2010-01-01

    X-linked cone and cone-rod dystrophies (XLCOD and XLCORD) are a heterogeneous group of progressive disorders that solely or primarily affect cone photoreceptors. Mutations in exon ORF15 of the RPGR gene are the most common underlying cause. In a previous study, we excluded RPGR exon ORF15 in some families with XLCOD. Here, we report genetic mapping of XLCOD to Xq26.1-qter. Asignificant LOD score was detected with marker DXS8045 (Zmax = 2.41 [? = 0.0]). The disease locus encompasses the cone opsin gene array on Xq28. Analysis of the array revealed a missense mutation (c. 529T>C [p. W177R]) in exon 3 of both the long-wavelength-sensitive (LW, red) and medium-wavelength-sensitive (MW, green) cone opsin genes that segregated with disease. Both exon 3 sequences were identical and were derived from the MW gene as a result of gene conversion. The amino acid W177 is highly conserved in visual and nonvisual opsins across species. We show that W177R in MW opsin and the equivalent W161R mutation in rod opsin result in protein misfolding and retention in the endoplasmic reticulum. We also demonstrate that W177R misfolding, unlike the P23H mutation in rod opsin that causes retinitis pigmentosa, is not rescued by treatment with the pharmacological chaperone 9-cis-retinal. Mutations in the LW/MW cone opsin gene array can, therefore, lead to a spectrum of disease, ranging from color blindness to progressive cone dystrophy (XLCOD5). PMID:20579627

  15. Chromatic Properties of Horizontal and Ganglion Cell Responses Follow a Dual Gradient in Cone Opsin Expression

    PubMed Central

    Yin, Lu; Smith, Robert G; Sterling, Peter; Brainard, David H.

    2007-01-01

    In guinea pig retina, immunostaining reveals a dual gradient of opsins: cones expressing opsin sensitive to medium wavelengths (M) predominate in the upper retina, whereas cones expressing opsin sensitive to shorter wavelengths (S) predominate in the lower retina. Whether these gradients correspond to functional gradients in postreceptoral neurons is essentially unknown. Using monochromatic flashes, we measured the relative weights with which M, S, and rod signals contribute to horizontal cell responses. For a background that produced 4.76 log10 photoisomerizations per rod per second (Rh*/rod/s), mean weights in superior retina were 52% (M), 2% (S), and 46% (rod). Mean weights in inferior retina were 9% (M), 50% (S), and 41% (rod). In superior retina, cone opsin weights agreed quantitatively with relative pigment density estimates from immunostaining. In inferior retina, cone opsin weights agreed qualitatively with relative pigment density estimates, but quantitative comparison was impossible because individual cones coexpress both opsins to varying and unquantifiable degrees. We further characterized the functional gradients in horizontal and brisk-transient ganglion cells using flickering stimuli produced by various mixtures of blue and green primary lights. Cone weights for both cell types resembled those obtained for horizontal cells using monochromatic flashes. Because the brisk-transient ganglion cell is thought to mediate behavioral detection of luminance contrast, our results are consistent with the hypothesis that the dual gradient of cone opsins assists achromatic contrast detection against different spectral backgrounds. In our preparation, rod responses did not completely saturate, even at background light levels typical of outdoor sunlight (5.14 log10 Rh*/rod/s). PMID:17122060

  16. Brain area-specific diurnal and photic regulation of val-opsinA and val-opsinB genes in the zebrafish.

    PubMed

    Hang, Chong Yee; Kitahashi, Takashi; Parhar, Ishwar S

    2015-05-01

    Zebrafish possess two isoforms of vertebrate ancient long (VAL)-opsin, val-opsinA (valopa) and val-opsinB (valopb), which probably mediate non-visual responses to light. To understand the diurnal and light-sensitive regulation of the valop genes in different cell groups, the current study used real-time quantitative PCR to examine the diurnal changes of valopa and b mRNA levels in different brain areas of adult male zebrafish. Furthermore, effects of the extended exposure to light or dark condition, luminous levels and the treatment with a melatonin receptor agonist or antagonist on valop transcription were examined. In the thalamus, valop mRNA levels showed significant diurnal changes; valopa peaked in the evening, while valopb peaked in the morning. The diurnal change of valopa mRNA levels occurred independent of light conditions, whereas that of valopb mRNA levels were regulated by light. A melatonin receptor agonist or antagonist did not affect the changes of valop mRNA levels. In contrast, the midbrain and hindbrain showed arrhythmic valop mRNA levels under light and dark cycles. The differential diurnal regulation of the valopa and b genes in the thalamus and the arrhythmic expression in the midbrain and hindbrain suggest involvement of deep brain VAL-opsin in time- and light-dependent physiology. We show diurnal expression changes of vertebrate ancient long (VAL) opsin genes (valopa and valopb), depending on brain area, time of day and light condition, in the adult male zebrafish. Differential regulation of the valop genes in the thalamus and arrhythmic expression in the midbrain and hindbrain suggest their involvement in time- and light-dependent physiology to adjust to environmental changes. PMID:25727787

  17. Crepuscular Behavioral Variation and Profiling of Opsin Genes in Anopheles gambiae and Anopheles stephensi (Diptera: Culicidae)

    PubMed Central

    Jenkins, Adam M.; Muskavitch, Marc A. T.

    2015-01-01

    We understand little about photopreference and the molecular mechanisms governing vision-dependent behavior in vector mosquitoes. Investigations of the influence of photopreference on adult mosquito behaviors such as endophagy and exophagy and endophily and exophily will enhance our ability to develop and deploy vector-targeted interventions and monitoring techniques. Our laboratory-based analyses have revealed that crepuscular period photopreference differs between An. gambiae and An. stephensi. We employed qRT-PCR to assess crepuscular transcriptional expression patterns of long wavelength-, short wavelength-, and ultraviolet wavelength-sensing opsins (i.e., rhodopsin-class G-protein coupled receptors) in An. gambiae and in An. stephensi. Transcript levels do not exhibit consistent differences between species across diurnal cycles, indicating that differences in transcript abundances within this gene set are not correlated with these behavioral differences. Using developmentally staged and gender-specific RNAseq data sets in An. gambiae, we show that long wavelength-sensing opsins are expressed in two different patterns (one set expressed during larval stages, and one set expressed during adult stages), while short wavelength- and ultraviolet wavelength-sensing opsins exhibit increased expression during adult stages. Genomic organization of An. gambiae opsins suggests paralogous gene expansion of long wavelength-sensing opsins in comparison with An. stephensi. We speculate that this difference in gene number may contribute to variation between these species in photopreference behavior (e.g., visual sensitivity). PMID:26334802

  18. Diurnal lighting patterns and habitat alter opsin expression and colour preferences in a killifish

    PubMed Central

    Johnson, Ashley M.; Stanis, Shannon; Fuller, Rebecca C.

    2013-01-01

    Spatial variation in lighting environments frequently leads to population variation in colour patterns, colour preferences and visual systems. Yet lighting conditions also vary diurnally, and many aspects of visual systems and behaviour vary over this time scale. Here, we use the bluefin killifish (Lucania goodei) to compare how diurnal variation and habitat variation (clear versus tannin-stained water) affect opsin expression and the preference to peck at different-coloured objects. Opsin expression was generally lowest at midnight and dawn, and highest at midday and dusk, and this diurnal variation was many times greater than variation between habitats. Pecking preference was affected by both diurnal and habitat variation but did not correlate with opsin expression. Rather, pecking preference matched lighting conditions, with higher preferences for blue at noon and for red at dawn/dusk, when these wavelengths are comparatively scarce. Similarly, blue pecking preference was higher in tannin-stained water where blue wavelengths are reduced. In conclusion, L. goodei exhibits strong diurnal cycles of opsin expression, but these are not tightly correlated with light intensity or colour. Temporally variable pecking preferences probably result from lighting environment rather than from opsin production. These results may have implications for the colour pattern diversity observed in these fish. PMID:23698009

  19. Diurnal lighting patterns and habitat alter opsin expression and colour preferences in a killifish.

    PubMed

    Johnson, Ashley M; Stanis, Shannon; Fuller, Rebecca C

    2013-07-22

    Spatial variation in lighting environments frequently leads to population variation in colour patterns, colour preferences and visual systems. Yet lighting conditions also vary diurnally, and many aspects of visual systems and behaviour vary over this time scale. Here, we use the bluefin killifish (Lucania goodei) to compare how diurnal variation and habitat variation (clear versus tannin-stained water) affect opsin expression and the preference to peck at different-coloured objects. Opsin expression was generally lowest at midnight and dawn, and highest at midday and dusk, and this diurnal variation was many times greater than variation between habitats. Pecking preference was affected by both diurnal and habitat variation but did not correlate with opsin expression. Rather, pecking preference matched lighting conditions, with higher preferences for blue at noon and for red at dawn/dusk, when these wavelengths are comparatively scarce. Similarly, blue pecking preference was higher in tannin-stained water where blue wavelengths are reduced. In conclusion, L. goodei exhibits strong diurnal cycles of opsin expression, but these are not tightly correlated with light intensity or colour. Temporally variable pecking preferences probably result from lighting environment rather than from opsin production. These results may have implications for the colour pattern diversity observed in these fish. PMID:23698009

  20. Spectral sensitivity in Onychophora (velvet worms) revealed by electroretinograms, phototactic behaviour and opsin gene expression.

    PubMed

    Beckmann, Holger; Hering, Lars; Henze, Miriam J; Kelber, Almut; Stevenson, Paul A; Mayer, Georg

    2015-03-01

    Onychophorans typically possess a pair of simple eyes, inherited from the last common ancestor of Panarthropoda (Onychophora+Tardigrada+Arthropoda). These visual organs are thought to be homologous to the arthropod median ocelli, whereas the compound eyes probably evolved in the arthropod lineage. To gain insights into the ancestral function and evolution of the visual system in panarthropods, we investigated phototactic behaviour, opsin gene expression and the spectral sensitivity of the eyes in two representative species of Onychophora: Euperipatoides rowelli (Peripatopsidae) and Principapillatus hitoyensis (Peripatidae). Our behavioural analyses, in conjunction with previous data, demonstrate that both species exhibit photonegative responses to wavelengths ranging from ultraviolet to green light (370-530?nm), and electroretinograms reveal that the onychophoran eye is maximally sensitive to blue light (peak sensitivity ?480?nm). Template fits to these sensitivities suggest that the onychophoran eye is monochromatic. To clarify which type of opsin the single visual pigment is based on, we localised the corresponding mRNA in the onychophoran eye and brain using in situ hybridization. Our data show that the r-opsin gene (onychopsin) is expressed exclusively in the photoreceptor cells of the eye, whereas c-opsin mRNA is confined to the optic ganglion cells and the brain. Together, our findings suggest that the onychopsin is involved in vision, whereas c-opsin might have a photoreceptive, non-visual function in onychophorans. PMID:25617459

  1. The hypothalamic photoreceptors regulating seasonal reproduction in birds: a prime role for VA opsin.

    PubMed

    Garca-Fernndez, Jos M; Cernuda-Cernuda, Rafael; Davies, Wayne I L; Rodgers, Jessica; Turton, Michael; Peirson, Stuart N; Follett, Brian K; Halford, Stephanie; Hughes, Steven; Hankins, Mark W; Foster, Russell G

    2015-04-01

    Extraretinal photoreceptors located within the medio-basal hypothalamus regulate the photoperiodic control of seasonal reproduction in birds. An action spectrum for this response describes an opsin photopigment with a ?max of ? 492 nm. Beyond this however, the specific identity of the photopigment remains unresolved. Several candidates have emerged including rod-opsin; melanopsin (OPN4); neuropsin (OPN5); and vertebrate ancient (VA) opsin. These contenders are evaluated against key criteria used routinely in photobiology to link orphan photopigments to specific biological responses. To date, only VA opsin can easily satisfy all criteria and we propose that this photopigment represents the prime candidate for encoding daylength and driving seasonal breeding in birds. We also show that VA opsin is co-expressed with both gonadotropin-releasing hormone (GnRH) and arginine-vasotocin (AVT) neurons. These new data suggest that GnRH and AVT neurosecretory pathways are endogenously photosensitive and that our current understanding of how these systems are regulated will require substantial revision. PMID:25448788

  2. Crepuscular Behavioral Variation and Profiling of Opsin Genes in Anopheles gambiae and Anopheles stephensi (Diptera: Culicidae).

    PubMed

    Jenkins, Adam M; Muskavitch, Marc A T

    2015-05-01

    We understand little about photo-preference and the molecular mechanisms governing vision-dependent behavior in vector mosquitoes. Investigations of the influence of photo-preference on adult mosquito behaviors such as endophagy and exophagy and endophily and exophily will enhance our ability to develop and deploy vector-targeted interventions and monitoring techniques. Our laboratory-based analyses have revealed that crepuscular period photo-preference differs between An. gambiae and An. stephensi. We employed qRT-PCR to assess crepuscular transcriptional expression patterns of long wavelength-, short wavelength-, and ultraviolet wavelength-sensing opsins (i.e., rhodopsin-class G-protein coupled receptors) in An. gambiae and in An. stephensi. Transcript levels do not exhibit consistent differences between species across diurnal cycles, indicating that differences in transcript abundances within this gene set are not correlated with these behavioral differences. Using developmentally staged and gender-specific RNAseq data sets in An. gambiae, we show that long wavelength-sensing opsins are expressed in two different patterns (one set expressed during larval stages, and one set expressed during adult stages), while short wavelength- and ultraviolet wavelength-sensing opsins exhibit increased expression during adult stages. Genomic organization of An. gambiae opsins suggests paralogous gene expansion of long wavelength-sensing opsins in comparison with An. stephensi. We speculate that this difference in gene number may contribute to variation between these species in photo-preference behavior (e.g., visual sensitivity). PMID:26334802

  3. Regeneration of bovine and octopus opsins in situ with natural and artificial retinals

    SciTech Connect

    Koutalos, Y.; Ebrey, T.G.; Tsuda, M.; Odashima, K.; Lien, T.; Park, M.H.; Shimizu, N.; Derguini, F.; Nakanishi, K.; Gilson, H.R.; Honig, B. )

    1989-03-21

    The authors consider the problem of color regulation in visual pigments for both bovine rhodopsin and octopus rhodopsin. Both pigments have 11-cis-retinal as their chromophore. These rhodopsins were bleached in their native membranes, and the opsins were regenerated with natural and artificial chromophores. Both bovine and octopus opsins were regenerated with the 9-cis- and 11-cis-retinal isomers, but the octopus opsin was additionally regenerated with the 13-cis and all-trans isomers. Titration of the octopus opsin with 11-cis-retinal gave an extinction coefficient for octopus rhodopsin of 27,000 {plus minus} 3,000 M{sup {minus}1} cm{sup {minus}1} at 475 nm. The absorption maxima of bovine artificial pigments formed by regenerating opsin with the 11-cis dihydro series of chromophores support a color regulation model for bovine rhodopsin in which the chromophore-binding site of the protein has two negative charges: one directly hydrogen bonded to the Schiff base nitrogen and another near carbon-13. Formation of octopus artificial pigments with both all-trans and 11-cis dihydro chromophores leads to a similar model for octopus rhodopsin and metarhodopsin: there are two negative charges in the chromophore-binding site, one directly hydrogen bonded to the Schiff base nitrogen and a second near carbon-13. The interaction of this second charge with the chromophore in octopus rhodopsin is weaker than in bovine, while in metarhodopsin it is as strong as in bovine.

  4. Broad-band opsin for effective stimulation of cells by white light

    NASA Astrophysics Data System (ADS)

    Batabyal, Subrata; Cervenka, Gregory; Kim, Young-Tae; Mohanty, Samarendra

    2015-03-01

    Currently, use of optogenetic sensitization of retinal cells combined with activation/inhibition has potential as alternative to retinal implants that would have required electrodes inside every single neuron for high visual resolution. However, clinical translation of optogenetic activation for restoration of vision suffers from the drawback that narrow spectral sensitivity of opsin requires active stimulation by blue laser or LED having intensity much higher than ambient light. In order to allow ambient-light based stimulation paradigm, here we report development of broad-band opsin that has broad spectral excitability in the entire visible spectrum. The cells sensitized with the broad-band opsin showed order of magnitude higher excitability with white light as compared to that using only the narrow-band light components. The use of broad-band opsin construct will allow higher sensitivity of the opsin-sensitized neurons in degenerated retina to ambient white light, and therefore, significantly lower activation-threshold in contrast to conventional approach of intense, narrow-band light based active-stimulation.

  5. The Verriest Lecture: Short-wave-sensitive cone pathways across the life span.

    PubMed

    Werner, John S

    2016-03-01

    Structurally and functionally, the short-wave-sensitive (S) cone pathways are thought to decline more rapidly with normal aging than the middle- and long-wave-sensitive cone pathways. This would explain the celebrated results by Verriest and others demonstrating that the largest age-related color discrimination losses occur for stimuli on a tritan axis. Here, we challenge convention, arguing from psychophysical data that selective S-cone pathway losses do not cause declines in color discrimination. We show substantial declines in chromatic detection and discrimination, as well as in temporal and spatial vision tasks, that are mediated by S-cone pathways. These functional losses are not, however, unique to S-cone pathways. Finally, despite reduced photon capture by S cones, their postreceptoral pathways provide robust signals for the visual system to renormalize itself to maintain nearly stable color perception across the life span. PMID:26974914

  6. Opsin expression in Limulus eyes: a UV opsin is expressed in each eye type and co-expressed with a visible light-sensitive opsin in ventral larval eyes.

    PubMed

    Battelle, Barbara-Anne; Kempler, Karen E; Harrison, Alexandra; Dugger, Donald R; Payne, Richard

    2014-09-01

    The eyes of the horseshoe crab, Limulus polyphemus, are a model for studies of visual function and the visual systems of euarthropods. Much is known about the structure and function of L. polyphemus photoreceptors, much less about their photopigments. Three visible-light-sensitive L. polyphemus opsins were characterized previously (LpOps1, 2 and 5). Here we characterize a UV opsin (LpUVOps1) that is expressed in all three types of L. polyphemus eyes. It is expressed in most photoreceptors in median ocelli, the only L. polyphemus eyes in which UV sensitivity was previously detected, and in the dendrite of eccentric cells in lateral compound eyes. Therefore, eccentric cells, previously thought to be non-photosensitive second-order neurons, may actually be UV-sensitive photoreceptors. LpUVOps1 is also expressed in small photoreceptors in L. polyphemus ventral larval eyes, and intracellular recordings from these photoreceptors confirm that LpUVOps1 is an active, UV-sensitive photopigment. These photoreceptors also express LpOps5, which we demonstrate is an active, long-wavelength-sensitive photopigment. Thus small photoreceptors in ventral larval eyes, and probably those of the other larval eyes, have dual sensitivity to UV and visible light. Interestingly, the spectral tuning of small ventral photoreceptors may change day to night, because the level of LpOps5 in their rhabdoms is lower during the day than during the night, whereas LpUVOps1 levels show no diurnal change. These and previous findings show that opsin co-expression and the differential regulation of co-expressed opsins in rhabdoms is a common feature of L. polyphemus photoreceptors. PMID:24948643

  7. Opsin expression in Limulus eyes: a UV opsin is expressed in each eye type and co-expressed with a visible light-sensitive opsin in ventral larval eyes

    PubMed Central

    Battelle, Barbara-Anne; Kempler, Karen E.; Harrison, Alexandra; Dugger, Donald R.; Payne, Richard

    2014-01-01

    The eyes of the horseshoe crab, Limulus polyphemus, are a model for studies of visual function and the visual systems of euarthropods. Much is known about the structure and function of L. polyphemus photoreceptors, much less about their photopigments. Three visible-light-sensitive L. polyphemus opsins were characterized previously (LpOps1, 2 and 5). Here we characterize a UV opsin (LpUVOps1) that is expressed in all three types of L. polyphemus eyes. It is expressed in most photoreceptors in median ocelli, the only L. polyphemus eyes in which UV sensitivity was previously detected, and in the dendrite of eccentric cells in lateral compound eyes. Therefore, eccentric cells, previously thought to be non-photosensitive second-order neurons, may actually be UV-sensitive photoreceptors. LpUVOps1 is also expressed in small photoreceptors in L. polyphemus ventral larval eyes, and intracellular recordings from these photoreceptors confirm that LpUVOps1 is an active, UV-sensitive photopigment. These photoreceptors also express LpOps5, which we demonstrate is an active, long-wavelength-sensitive photopigment. Thus small photoreceptors in ventral larval eyes, and probably those of the other larval eyes, have dual sensitivity to UV and visible light. Interestingly, the spectral tuning of small ventral photoreceptors may change day to night, because the level of LpOps5 in their rhabdoms is lower during the day than during the night, whereas LpUVOps1 levels show no diurnal change. These and previous findings show that opsin co-expression and the differential regulation of co-expressed opsins in rhabdoms is a common feature of L. polyphemus photoreceptors. PMID:24948643

  8. The Microbial Opsin Homolog Sop1 is involved in Sclerotinia sclerotiorum Development and Environmental Stress Response

    PubMed Central

    Lyu, Xueliang; Shen, Cuicui; Fu, Yanping; Xie, Jiatao; Jiang, Daohong; Li, Guoqing; Cheng, Jiasen

    2016-01-01

    Microbial opsins play a crucial role in responses to various environmental signals. Here, we report that the microbial opsin homolog gene sop1 from the necrotrophic phytopathogenic fungus Sclerotinia sclerotiorum was dramatically up-regulated during infection and sclerotial development compared with the vegetative growth stage. Further, study showed that sop1 was essential for growth, sclerotial development and full virulence of S. sclerotiorum. Sop1-silenced transformants were more sensitive to high salt stress, fungicides and high osmotic stress. However, they were more tolerant to oxidative stress compared with the wild-type strain, suggesting that sop1 is involved in different stress responses and fungicide resistance, which plays a role in the environmental adaptability of S. sclerotiorum. Furthermore, a Delta blast search showed that microbial opsins are absent from the genomes of animals and most higher plants, indicating that sop1 is a potential drug target for disease control of S. sclerotiorum. PMID:26779159

  9. Atomistic design of microbial opsin-based blue-shifted optogenetics tools

    NASA Astrophysics Data System (ADS)

    Kato, Hideaki E.; Kamiya, Motoshi; Sugo, Seiya; Ito, Jumpei; Taniguchi, Reiya; Orito, Ayaka; Hirata, Kunio; Inutsuka, Ayumu; Yamanaka, Akihiro; Maturana, Andrs D.; Ishitani, Ryuichiro; Sudo, Yuki; Hayashi, Shigehiko; Nureki, Osamu

    2015-05-01

    Microbial opsins with a bound chromophore function as photosensitive ion transporters and have been employed in optogenetics for the optical control of neuronal activity. Molecular engineering has been utilized to create colour variants for the functional augmentation of optogenetics tools, but was limited by the complexity of the protein-chromophore interactions. Here we report the development of blue-shifted colour variants by rational design at atomic resolution, achieved through accurate hybrid molecular simulations, electrophysiology and X-ray crystallography. The molecular simulation models and the crystal structure reveal the precisely designed conformational changes of the chromophore induced by combinatory mutations that shrink its ?-conjugated system which, together with electrostatic tuning, produce large blue shifts of the absorption spectra by maximally 100 nm, while maintaining photosensitive ion transport activities. The design principle we elaborate is applicable to other microbial opsins, and clarifies the underlying molecular mechanism of the blue-shifted action spectra of microbial opsins recently isolated from natural sources.

  10. Contributions of rhodopsin, cone opsins, and melanopsin to postreceptoral pathways inferred from natural image statistics

    PubMed Central

    Barrionuevo, Pablo A.; Cao, Dingcai

    2014-01-01

    Visual neural representation is constrained by the statistical properties of the environment. Prior analysis of cone pigment excitations for natural images revealed three principal components corresponding to the major retinogeniculate pathways identified by anatomical and physiological studies in primates. Here, principal component analyses were conducted on the excitations of rhodopsin, cone opsins, and melanopsin for nine hyperspectral images under 21 natural illuminants. The results suggested that rhodopsin and melanopsin may contribute to the three major retinogeniculate pathways. Rhodopsin and melanopsin may provide additional constraints in natural scene statistics, leading to new components that cannot be revealed by analysis based on cone opsin excitations only. PMID:24695161

  11. Low-frequency vibrational modes in blue opsin: A computational study

    NASA Astrophysics Data System (ADS)

    Thirumuruganandham, Saravana Prakash; Urbassek, Herbert M.

    Vibrational excitations of low-frequency collective modes are essential for functionally important conformational transitions in proteins. We have carried out an analysis of the low-frequency modes in blue opsin based on both normal-mode analysis and molecular dynamics simulations. Power spectra obtained by molecular dynamics agree well with the normal modes. A representative set of low-frequency modes is discussed with the help of vector-field representation. We thus demonstrate that terahertz spectroscopy of low-frequency modes might be relevant for identifying those vibrational degrees of freedom that correlate to known conformational changes in opsins.

  12. Molecular evidence that only two opsin subfamilies, the blue light- (SWS2) and green light-sensitive (RH2), drive color vision in Atlantic cod (Gadus morhua).

    PubMed

    Valen, Ragnhild; Edvardsen, Rolf Brudvik; Sviknes, Anne Mette; Drivenes, yvind; Helvik, Jon Vidar

    2014-01-01

    Teleosts show a great variety in visual opsin complement, due to both gene duplication and gene loss. The repertoire ranges from one subfamily of visual opsins (scotopic vision) including rod opsin only retinas seen in many deep-sea species to multiple subfamilies of visual opsins in some pelagic species. We have investigated the opsin repertoire of Atlantic cod (Gadus morhua) using information in the recently sequenced cod genome and found that despite cod not being a deep sea species it lacks visual subfamilies sensitive towards the most extreme parts of the light spectra representing UV and red light. Furthermore, we find that Atlantic cod has duplicated paralogs of both blue-sensitive SWS2 and green-sensitive RH2 subfamilies, with members belonging to each subfamily linked in tandem within the genome (two SWS2-, and three RH2A genes, respectively). The presence of multiple cone opsin genes indicates that there have been duplication events in the cod ancestor SWS2 and RH2 opsins producing paralogs that have been retained in Atlantic. Our results are supported by expressional analysis of cone opsins, which further revealed an ontogenetic change in the array of cone opsins expressed. These findings suggest life stage specific programs for opsin regulation which could be linked to habitat changes and available light as the larvae is transformed into an early juvenile. Altogether we provide the first molecular evidence for color vision driven by only two families of cone opsins due to gene loss in a teleost. PMID:25551396

  13. Molecular Evidence that Only Two Opsin Subfamilies, the Blue Light- (SWS2) and Green Light-Sensitive (RH2), Drive Color Vision in Atlantic Cod (Gadus morhua)

    PubMed Central

    Søviknes, Anne Mette; Drivenes, Øyvind; Helvik, Jon Vidar

    2014-01-01

    Teleosts show a great variety in visual opsin complement, due to both gene duplication and gene loss. The repertoire ranges from one subfamily of visual opsins (scotopic vision) including rod opsin only retinas seen in many deep-sea species to multiple subfamilies of visual opsins in some pelagic species. We have investigated the opsin repertoire of Atlantic cod (Gadus morhua) using information in the recently sequenced cod genome and found that despite cod not being a deep sea species it lacks visual subfamilies sensitive towards the most extreme parts of the light spectra representing UV and red light. Furthermore, we find that Atlantic cod has duplicated paralogs of both blue-sensitive SWS2 and green-sensitive RH2 subfamilies, with members belonging to each subfamily linked in tandem within the genome (two SWS2-, and three RH2A genes, respectively). The presence of multiple cone opsin genes indicates that there have been duplication events in the cod ancestor SWS2 and RH2 opsins producing paralogs that have been retained in Atlantic. Our results are supported by expressional analysis of cone opsins, which further revealed an ontogenetic change in the array of cone opsins expressed. These findings suggest life stage specific programs for opsin regulation which could be linked to habitat changes and available light as the larvae is transformed into an early juvenile. Altogether we provide the first molecular evidence for color vision driven by only two families of cone opsins due to gene loss in a teleost. PMID:25551396

  14. Opsin transcripts of predatory diving beetles: a comparison of surface and subterranean photic niches.

    PubMed

    Tierney, Simon M; Cooper, Steven J B; Saint, Kathleen M; Bertozzi, Terry; Hyde, Josephine; Humphreys, William F; Austin, Andrew D

    2015-01-01

    The regressive evolution of eyes has long intrigued biologists yet the genetic underpinnings remain opaque. A system of discrete aquifers in arid Australia provides a powerful comparative means to explore trait regression at the genomic level. Multiple surface ancestors from two tribes of diving beetles (Dytiscidae) repeatedly invaded these calcrete aquifers and convergently evolved eye-less phenotypes. We use this system to assess transcription of opsin photoreceptor genes among the transcriptomes of two surface and three subterranean dytiscid species and test whether these genes have evolved under neutral predictions. Transcripts for UV, long-wavelength and ciliary-type opsins were identified from the surface beetle transcriptomes. Two subterranean beetles showed parallel loss of all opsin transcription, as expected under 'neutral' regressive evolution. The third species Limbodessus palmulaoides retained transcription of a long-wavelength opsin (lwop) orthologue, albeit in an aphotic environment. Tests of selection on lwop indicated no significant differences between transcripts derived from surface and subterranean habitats, with strong evidence for purifying selection acting on L. palmulaoides lwop. Retention of sequence integrity and the lack of evidence for neutral evolution raise the question of whether we have identified a novel pleiotropic role for lwop, or an incipient phase of pseudogene development. PMID:26064586

  15. Novel missense mutations in red/green opsin genes in congenital color-vision deficiencies.

    PubMed

    Ueyama, Hisao; Kuwayama, Shigeki; Imai, Hiroo; Tanabe, Shoko; Oda, Sanae; Nishida, Yasuhiro; Wada, Akimori; Shichida, Yoshinori; Yamade, Shinichi

    2002-06-01

    The DNAs from 217 Japanese males with congenital red/green color-vision deficiencies were analyzed. Twenty-three subjects had the normal genotype of a single red gene, followed by a green gene. Four of the 23 were from the 69 protan subject group and 19 of the 23 were from the 148 deutan subject group. Three of the 23 subjects had missense mutations. The mutation Asn94Lys (AAC-->AAA) occurred in the single green gene of a deutan subject (A155). The Arg330Gln (CGA-->CAA) mutation was detected in both green genes of another deutan subject (A164). The Gly338Glu (GGG-->GAG) mutation occurred in the single red gene of a protan subject (A89). Both normal and mutant opsins were expressed in cultured COS-7 cells and visual pigments were regenerated with 11-cis-retinal. The normal red and green opsins showed absorbance spectra with lambda(max) of 560 and 530 nm, respectively, but the three mutant opsins had altered spectra. The mutations in Asn94Lys and Gly338Glu resulted in no absorbance and the Arg330Gln mutation gave a low absorbance spectrum with a lambda(max) of 530 nm. Therefore these three mutant opsins are likely to be affected in the folding process, resulting in a loss of function as a visual pigment. PMID:12051694

  16. An opsin gene that is expressed only in the R7 photoreceptor cell of Drosophila.

    PubMed Central

    Fryxell, K J; Meyerowitz, E M

    1987-01-01

    We have used two techniques to isolate and characterize eye-specific genes from Drosophila melanogaster. First, we identified genes whose expression is limited to eyes, photoreceptor cells, or R7 photoreceptor cells by differential screening with [32P]cDNAs derived from the heads of mutant flies that have reduced amounts of these tissues and cells (Microcephalus, glass3, and sevenless, respectively). Secondly, we identified opsin genes by hybridization with synthetic [32P]oligonucleotides that encode domains that have been conserved between some opsin genes. We found seven clones that contain genes expressed only in the eye or optic lobes of Drosophila; three are expressed only in photoreceptor cells. One is expressed only in R7 photoreceptor cells and hybridizes to some of the previously mentioned oligonucleotides. The complete DNA sequence of the R7-specific opsin gene and its 5' and 3' flanking regions was determined. It is quite different from other known Drosophila opsin genes, in that it is not interrupted by introns and shares only 37-38% amino acid identity with the proteins encoded by these genes. The predicted protein structure contains many characteristics that are common to all rhodopsins, and the sequence differences help to identify four domains of the rhodopsin molecule that have been conserved in evolution. Images Fig. 1. Fig. 2. Fig. 5. PMID:2953598

  17. Opsin transcripts of predatory diving beetles: a comparison of surface and subterranean photic niches

    PubMed Central

    Tierney, Simon M.; Cooper, Steven J. B.; Saint, Kathleen M.; Bertozzi, Terry; Hyde, Josephine; Humphreys, William F.; Austin, Andrew D.

    2015-01-01

    The regressive evolution of eyes has long intrigued biologists yet the genetic underpinnings remain opaque. A system of discrete aquifers in arid Australia provides a powerful comparative means to explore trait regression at the genomic level. Multiple surface ancestors from two tribes of diving beetles (Dytiscidae) repeatedly invaded these calcrete aquifers and convergently evolved eye-less phenotypes. We use this system to assess transcription of opsin photoreceptor genes among the transcriptomes of two surface and three subterranean dytiscid species and test whether these genes have evolved under neutral predictions. Transcripts for UV, long-wavelength and ciliary-type opsins were identified from the surface beetle transcriptomes. Two subterranean beetles showed parallel loss of all opsin transcription, as expected under ‘neutral’ regressive evolution. The third species Limbodessus palmulaoides retained transcription of a long-wavelength opsin (lwop) orthologue, albeit in an aphotic environment. Tests of selection on lwop indicated no significant differences between transcripts derived from surface and subterranean habitats, with strong evidence for purifying selection acting on L. palmulaoides lwop. Retention of sequence integrity and the lack of evidence for neutral evolution raise the question of whether we have identified a novel pleiotropic role for lwop, or an incipient phase of pseudogene development. PMID:26064586

  18. Distinct functions for IFT140 and IFT20 in opsin transport.

    PubMed Central

    Crouse, Jacquelin A.; Lopes, Vanda S.; SanAgustin, Jovenal T.; Keady, Brian T.; Williams, David S.; Pazour, Gregory J.

    2014-01-01

    In the vertebrate retina, light is detected by the outer segments of photoreceptor rods and cones, which are highly modified cilia. Like other cilia, outer segments have no protein synthetic capacity and depend on proteins made in the cell body for their formation and maintenance. The mechanism of transport into the outer segment is not fully understood but intraflagellar transport (IFT) is thought to be a major mechanism for moving protein from the cell body into the cilium. In the case of photoreceptor cells, the high density of receptors and the disk turnover that occurs daily necessitates much higher rates of transport than would be required in other cilia. In this work, we show that the IFT complex A protein IFT140 is required for development and maintenance of outer segments. In earlier work we found that acute deletion of Ift20 caused opsin to accumulate at the Golgi complex. In this work we find that acute deletion of Ift140 does not cause opsin to accumulate at the Golgi complex but rather it accumulates in the plasma membrane of the inner segments. This work is strong support of a model of opsin transport where IFT20 is involved in the movement from the Golgi complex to the base of the cilium. Then, once at the base, the opsin is carried through the connecting cilium by an IFT complex that includes IFT140. PMID:24619649

  19. The lycaenid butterfly Polyommatus icarus uses a duplicated blue opsin to see green.

    PubMed

    Sison-Mangus, Marilou P; Briscoe, Adriana D; Zaccardi, Guillermo; Knüttel, Helge; Kelber, Almut

    2008-02-01

    The functional significance of gene duplication is rarely addressed at the level of animal behavior. Butterflies are excellent models in this regard because they can be trained and the use of their opsin-based visual pigments in color vision can be assessed. In the present study, we demonstrate that the lycaenid Polyommatus icarus uses its duplicate blue (B2) opsin, BRh2, in conjunction with its long-wavelength (LW) opsin, LWRh, to see color in the green part of the light spectrum extending up to 560 nm. This is in contrast to butterflies in the genus Papilio, which use duplicate LW opsins to discriminate colors in the long-wavelength range. We also found that P. icarus has a heterogeneously expressed red filtering pigment and red-reflecting ommatidia in the ventral eye region. In behavioural tests, the butterflies could not discriminate colors in the red range (570-640 nm). This finding is significant because we have previously found that the nymphalid butterfly Heliconius erato has filter-pigment mediated color vision in the long wavelength range. Our results suggest that lateral filtering pigments may not always influence color vision in insects. PMID:18203991

  20. The complete far infrared spectroscopic survey of Herbig AeBe stars obtained by ISO-LWS

    NASA Astrophysics Data System (ADS)

    Lorenzetti, D.; Giannini, T.; Nisini, B.; Benedettini, M.; Elia, D.; Campeggio, L.; Strafella, F.

    2002-11-01

    The ISO-LWS archive has been systematically searched in order to obtain a complete far IR spectrophotometric survey of Herbig AeBe (HAEBE) stars. The investigated sample is constituted by 15 objects which, together with the 11 HAEBE we have published in two previous papers, represents about 25% of all the known HAEBE. This catalogue constitues an essential data-base in view of far IR forthcoming space missions (e.g. Herschel Space Observatory), whose scientific programs are now in the planning phase. The new sources are analysed following the same approach as in our previous papers and both differences and similarities are discussed in a coherent framework. The [OI] 63 mu m and the [CII] 158 mu m lines are observed in many of the investigated sources, while the [OI] 145 mu m remains often undetected, due to its relative faintness. Molecular lines, in form of CO high-J rotational transitions are detected in only three cases and appear associated to local density peaks. A new class of ISO-LWS spectra of HAEBE emerges, constituted by objects without any detected gas feature either in emission or in absorption. Not unexpectedly, these HAEBE are isolated from molecular clouds and, as such, lack of the cold circumstellar material probed by far IR ionic and molecular transitions. By comparing line intensity ratios with model predictions we find that photodissociation caused by the stellar photons and active in a clumpy medium is likely the prevalent excitation mechanism for the far IR lines. Finally, an evolutionary trend is found according to which the contribution of the far IR line emission to the total emitted energy is less and less important with time.

  1. Genomic and gene regulatory signatures of cryptozoic adaptation: Loss of blue sensitive photoreceptors through expansion of long wavelength-opsin expression in the red flour beetle Tribolium castaneum

    PubMed Central

    Jackowska, Magdalena; Bao, Riyue; Liu, Zhenyi; McDonald, Elizabeth C; Cook, Tiffany A; Friedrich, Markus

    2007-01-01

    Background Recent genome sequence analysis in the red flour beetle Tribolium castaneum indicated that this highly crepuscular animal encodes only two single opsin paralogs: a UV-opsin and a long wavelength (LW)-opsin; however, these animals do not encode a blue (B)-opsin as most other insects. Here, we studied the spatial regulation of the Tribolium single LW- and UV-opsin gene paralogs in comparison to that of the five opsin paralogs in the retina of Drosophila melanogaster. Results In situ hybridization analysis reveals that the Tribolium retina, in contrast with other insect retinas, constitutes a homogenous field of ommatidia that have seven LW-opsin expressing photoreceptors and one UV-/LW-opsin co-expressing photoreceptor per eye unit. This pattern is consistent with the loss of photoreceptors sensitive to blue wavelengths. It also identifies Tribolium as the first example of a species in insects that co-expresses two different opsins across the entire retina in violation of the widely observed "one receptor rule" of sensory cells. Conclusion Broader studies of opsin evolution in darkling beetles and other coleopteran groups have the potential to pinpoint the permissive and adaptive forces that played a role in the evolution of vision in Tribolium castaneum. PMID:18154648

  2. Opsins in Limulus eyes: characterization of three visible light-sensitive opsins unique to and co-expressed in median eye photoreceptors and a peropsin/RGR that is expressed in all eyes

    PubMed Central

    Battelle, Barbara-Anne; Kempler, Karen E.; Saraf, Spencer R.; Marten, Catherine E.; Dugger, Donald R.; Speiser, Daniel I.; Oakley, Todd H.

    2015-01-01

    The eyes of the horseshoe crab Limulus polyphemus have long been used for studies of basic mechanisms of vision, and the structure and physiology of Limulus photoreceptors have been examined in detail. Less is known about the opsins Limulus photoreceptors express. We previously characterized a UV opsin (LpUVOps1) that is expressed in all three types of Limulus eyes (lateral compound eyes, median ocelli and larval eyes) and three visible light-sensitive rhabdomeric opsins (LpOps1, -2 and -5) that are expressed in Limulus lateral compound and larval eyes. Physiological studies showed that visible light-sensitive photoreceptors are also present in median ocelli, but the visible light-sensitive opsins they express were unknown. In the current study we characterize three newly identified, visible light-sensitive rhabdomeric opsins (LpOps6, -7 and -8) that are expressed in median ocelli. We show that they are ocellar specific and that all three are co-expressed in photoreceptors distinct from those expressing LpUVOps1. Our current findings show that the pattern of opsin expression in Limulus eyes is much more complex than previously thought and extend our previous observations of opsin co-expression in visible light-sensitive Limulus photoreceptors. We also characterize a Limulus peropsin/RGR (LpPerOps1). We examine the phylogenetic relationship of LpPerOps1 with other peropsins and RGRs, demonstrate that LpPerOps1 transcripts are expressed in each of the three types of Limulus eyes and show that the encoded protein is expressed in membranes of cells closely associated with photoreceptors in each eye type. These finding suggest that peropsin was in the opsin repertoire of euchelicerates. PMID:25524988

  3. Transcriptome analysis and RNA interference of cockroach phototransduction indicate three opsins and suggest a major role for TRPL channels

    PubMed Central

    French, Andrew S.; Meisner, Shannon; Liu, Hongxia; Weckstrm, Matti; Torkkeli, Pivi H.

    2015-01-01

    Our current understanding of insect phototransduction is based on a small number of species, but insects occupy many different visual environments. We created the retinal transcriptome of a nocturnal insect, the cockroach, Periplaneta americana to identify proteins involved in the earliest stages of compound eye phototransduction, and test the hypothesis that different visual environments are reflected in different molecular contributions to function. We assembled five novel mRNAs: two green opsins, one UV opsin, and one each TRP and TRPL ion channel homologs. One green opsin mRNA (pGO1) was 1001000 times more abundant than the other opsins (pGO2 and pUVO), while pTRPL mRNA was 10 times more abundant than pTRP, estimated by transcriptome analysis or quantitative PCR (qPCR). Electroretinograms were used to record photoreceptor responses. Gene-specific in vivo RNA interference (RNAi) was achieved by injecting long (596708 bp) double-stranded RNA into head hemolymph, and verified by qPCR. RNAi of the most abundant green opsin reduced both green opsins by more than 97% without affecting UV opsin, and gave a maximal reduction of 75% in ERG amplitude 7 days after injection that persisted for at least 19 days. RNAi of pTRP and pTRPL genes each specifically reduced the corresponding mRNA by 90%. Electroretinogram (ERG) reduction by pTRPL RNAi was slower than for opsin, reaching 75% attenuation by 21 days, without recovery at 29 days. pTRP RNAi attenuated ERG much less; only 30% after 21 days. Combined pTRP plus pTRPL RNAi gave only weak evidence of any cooperative interactions. We conclude that silencing retinal genes by in vivo RNAi using long dsRNA is effective, that visible light transduction in Periplaneta is dominated by pGO1, and that pTRPL plays a major role in cockroach phototransduction. PMID:26257659

  4. Imaging neural spiking in brain tissue using FRET-opsin protein voltage sensors

    PubMed Central

    Gong, Yiyang; Wagner, Mark J.; Li, Jin Zhong; Schnitzer, Mark J.

    2014-01-01

    Genetically encoded fluorescence voltage sensors offer the possibility of directly visualizing neural spiking dynamics in cells targeted by their genetic class or connectivity. Sensors of this class have generally suffered performance-limiting tradeoffs between modest brightness, sluggish kinetics, and limited signaling dynamic range in response to action potentials. Here we describe sensors that use fluorescence resonance energy transfer (FRET) to combine the rapid kinetics and substantial voltage-dependence of rhodopsin family voltage-sensing domains with the brightness of genetically engineered protein fluorophores. These FRET-opsin sensors significantly improve upon the spike detection fidelity offered by the genetically encoded voltage sensor, Arclight, while offering faster kinetics and higher brightness. Using FRET-opsin sensors we imaged neural spiking and sub-threshold membrane voltage dynamics in cultured neurons and in pyramidal cells within neocortical tissue slices. In live mice, rates and optical waveforms of cerebellar Purkinje neurons’ dendritic voltage transients matched expectations for these cells’ dendritic spikes. PMID:24755708

  5. Phenotypic plasticity in opsin expression in a butterfly compound eye complements sex role reversal

    PubMed Central

    2012-01-01

    Background Animals often display phenotypic plasticity in morphologies and behaviors that result in distinct adaptations to fluctuating seasonal environments. The butterfly Bicyclus anynana has two seasonal forms, wet and dry, that vary in wing ornament brightness and in the identity of the sex that performs the most courting and choosing. Rearing temperature is the cue for producing these alternative seasonal forms. We hypothesized that, barring any developmental constraints, vision should be enhanced in the choosy individuals but diminished in the non-choosy individuals due to physiological costs. As a proxy of visual performance we measured eye size, facet lens size, and sensitivity to light, e.g., the expression levels of all opsins, in males and females of both seasonal forms. Results We found that B. anynana eyes displayed significant sexual dimorphism and phenotypic plasticity for both morphology and opsin expression levels, but not all results conformed to our prediction. Males had larger eyes than females across rearing temperatures, and increases in temperature produced larger eyes in both sexes, mostly via increases in facet number. Ommatidia were larger in the choosy dry season (DS) males and transcript levels for all three opsins were significantly lower in the less choosy DS females. Conclusions Opsin level plasticity in females, and ommatidia size plasticity in males supported our visual plasticity hypothesis but males appear to maintain high visual function across both seasons. We discuss our results in the context of distinct sexual and natural selection pressures that may be facing each sex in the wild in each season. PMID:23194112

  6. Ancestral duplications and highly dynamic opsin gene evolution in percomorph fishes.

    PubMed

    Cortesi, Fabio; Musilová, Zuzana; Stieb, Sara M; Hart, Nathan S; Siebeck, Ulrike E; Malmstrøm, Martin; Tørresen, Ole K; Jentoft, Sissel; Cheney, Karen L; Marshall, N Justin; Carleton, Karen L; Salzburger, Walter

    2015-02-01

    Single-gene and whole-genome duplications are important evolutionary mechanisms that contribute to biological diversification by launching new genetic raw material. For example, the evolution of animal vision is tightly linked to the expansion of the opsin gene family encoding light-absorbing visual pigments. In teleost fishes, the most species-rich vertebrate group, opsins are particularly diverse and key to the successful colonization of habitats ranging from the bioluminescence-biased but basically dark deep sea to clear mountain streams. In this study, we report a previously unnoticed duplication of the violet-blue short wavelength-sensitive 2 (SWS2) opsin, which coincides with the radiation of highly diverse percomorph fishes, permitting us to reinterpret the evolution of this gene family. The inspection of close to 100 fish genomes revealed that, triggered by frequent gene conversion between duplicates, the evolutionary history of SWS2 is rather complex and difficult to predict. Coincidentally, we also report potential cases of gene resurrection in vertebrate opsins, whereby pseudogenized genes were found to convert with their functional paralogs. We then identify multiple novel amino acid substitutions that are likely to have contributed to the adaptive differentiation between SWS2 copies. Finally, using the dusky dottyback Pseudochromis fuscus, we show that the newly discovered SWS2A duplicates can contribute to visual adaptation in two ways: by gaining sensitivities to different wavelengths of light and by being differentially expressed between ontogenetic stages. Thus, our study highlights the importance of comparative approaches in gaining a comprehensive view of the dynamics underlying gene family evolution and ultimately, animal diversification. PMID:25548152

  7. Ancestral duplications and highly dynamic opsin gene evolution in percomorph fishes

    PubMed Central

    Cortesi, Fabio; Musilová, Zuzana; Stieb, Sara M.; Hart, Nathan S.; Siebeck, Ulrike E.; Malmstrøm, Martin; Tørresen, Ole K.; Jentoft, Sissel; Cheney, Karen L.; Marshall, N. Justin; Carleton, Karen L.; Salzburger, Walter

    2015-01-01

    Single-gene and whole-genome duplications are important evolutionary mechanisms that contribute to biological diversification by launching new genetic raw material. For example, the evolution of animal vision is tightly linked to the expansion of the opsin gene family encoding light-absorbing visual pigments. In teleost fishes, the most species-rich vertebrate group, opsins are particularly diverse and key to the successful colonization of habitats ranging from the bioluminescence-biased but basically dark deep sea to clear mountain streams. In this study, we report a previously unnoticed duplication of the violet-blue short wavelength-sensitive 2 (SWS2) opsin, which coincides with the radiation of highly diverse percomorph fishes, permitting us to reinterpret the evolution of this gene family. The inspection of close to 100 fish genomes revealed that, triggered by frequent gene conversion between duplicates, the evolutionary history of SWS2 is rather complex and difficult to predict. Coincidentally, we also report potential cases of gene resurrection in vertebrate opsins, whereby pseudogenized genes were found to convert with their functional paralogs. We then identify multiple novel amino acid substitutions that are likely to have contributed to the adaptive differentiation between SWS2 copies. Finally, using the dusky dottyback Pseudochromis fuscus, we show that the newly discovered SWS2A duplicates can contribute to visual adaptation in two ways: by gaining sensitivities to different wavelengths of light and by being differentially expressed between ontogenetic stages. Thus, our study highlights the importance of comparative approaches in gaining a comprehensive view of the dynamics underlying gene family evolution and ultimately, animal diversification. PMID:25548152

  8. Atomistic design of microbial opsin-based blue-shifted optogenetics tools

    PubMed Central

    Kato, Hideaki E.; Kamiya, Motoshi; Sugo, Seiya; Ito, Jumpei; Taniguchi, Reiya; Orito, Ayaka; Hirata, Kunio; Inutsuka, Ayumu; Yamanaka, Akihiro; Maturana, Andrés D.; Ishitani, Ryuichiro; Sudo, Yuki; Hayashi, Shigehiko; Nureki, Osamu

    2015-01-01

    Microbial opsins with a bound chromophore function as photosensitive ion transporters and have been employed in optogenetics for the optical control of neuronal activity. Molecular engineering has been utilized to create colour variants for the functional augmentation of optogenetics tools, but was limited by the complexity of the protein–chromophore interactions. Here we report the development of blue-shifted colour variants by rational design at atomic resolution, achieved through accurate hybrid molecular simulations, electrophysiology and X-ray crystallography. The molecular simulation models and the crystal structure reveal the precisely designed conformational changes of the chromophore induced by combinatory mutations that shrink its π-conjugated system which, together with electrostatic tuning, produce large blue shifts of the absorption spectra by maximally 100 nm, while maintaining photosensitive ion transport activities. The design principle we elaborate is applicable to other microbial opsins, and clarifies the underlying molecular mechanism of the blue-shifted action spectra of microbial opsins recently isolated from natural sources. PMID:25975962

  9. Luminopsins integrate opto- and chemogenetics by using physical and biological light sources for opsin activation.

    PubMed

    Berglund, Ken; Clissold, Kara; Li, Haofang E; Wen, Lei; Park, Sung Young; Gleixner, Jan; Klein, Marguerita E; Lu, Dongye; Barter, Joseph W; Rossi, Mark A; Augustine, George J; Yin, Henry H; Hochgeschwender, Ute

    2016-01-19

    Luminopsins are fusion proteins of luciferase and opsin that allow interrogation of neuronal circuits at different temporal and spatial resolutions by choosing either extrinsic physical or intrinsic biological light for its activation. Building on previous development of fusions of wild-type Gaussia luciferase with channelrhodopsin, here we expanded the utility of luminopsins by fusing bright Gaussia luciferase variants with either channelrhodopsin to excite neurons (luminescent opsin, LMO) or a proton pump to inhibit neurons (inhibitory LMO, iLMO). These improved LMOs could reliably activate or silence neurons in vitro and in vivo. Expression of the improved LMO in hippocampal circuits not only enabled mapping of synaptic activation of CA1 neurons with fine spatiotemporal resolution but also could drive rhythmic circuit excitation over a large spatiotemporal scale. Furthermore, virus-mediated expression of either LMO or iLMO in the substantia nigra in vivo produced not only the expected bidirectional control of single unit activity but also opposing effects on circling behavior in response to systemic injection of a luciferase substrate. Thus, although preserving the ability to be activated by external light sources, LMOs expand the use of optogenetics by making the same opsins accessible to noninvasive, chemogenetic control, thereby allowing the same probe to manipulate neuronal activity over a range of spatial and temporal scales. PMID:26733686

  10. Differentially-expressed opsin genes identified in Sinocyclocheilus cavefish endemic to China

    PubMed Central

    Meng, Fanwei; Zhao, Yahui; Postlethwait, John H.; Zhang, Chunguang

    2013-01-01

    Eye degeneration is a common troglomorphic character of cave-dwelling organisms. Comparing the morphology and molecular biology of cave species and their close surface relatives is a powerful tool for studying regressive eye evolution and other adaptive phenotypes. We compared two co-occurring and closely-related species of the fish genus Sinocyclocheilus, which is endemic to China and includes both surface- and cave-dwelling species. Sinocyclocheilus tileihornes, a cave species, had smaller eyes than Sinocyclocheilus angustiporus, a surface species. Histological and immunohistochemical analyses revealed that the cavefish had shorter cones and more disorderly rods than did the surface-dwelling species. Using quantitative PCR and in situ hybridization, we found that rhodopsin and a long-wavelength sensitive opsin had significantly lower expression levels in the cavefish. Furthermore, one of two short-wavelength-sensitive opsins was expressed at significantly higher levels in the cavefish. Changes in the expression of opsin genes may have played a role in the degeneration of cavefish eyes PMID:24363664

  11. Luminopsins integrate opto- and chemogenetics by using physical and biological light sources for opsin activation

    PubMed Central

    Berglund, Ken; Clissold, Kara; Li, Haofang E.; Wen, Lei; Park, Sung Young; Gleixner, Jan; Klein, Marguerita E.; Lu, Dongye; Barter, Joseph W.; Rossi, Mark A.; Augustine, George J.; Yin, Henry H.; Hochgeschwender, Ute

    2016-01-01

    Luminopsins are fusion proteins of luciferase and opsin that allow interrogation of neuronal circuits at different temporal and spatial resolutions by choosing either extrinsic physical or intrinsic biological light for its activation. Building on previous development of fusions of wild-type Gaussia luciferase with channelrhodopsin, here we expanded the utility of luminopsins by fusing bright Gaussia luciferase variants with either channelrhodopsin to excite neurons (luminescent opsin, LMO) or a proton pump to inhibit neurons (inhibitory LMO, iLMO). These improved LMOs could reliably activate or silence neurons in vitro and in vivo. Expression of the improved LMO in hippocampal circuits not only enabled mapping of synaptic activation of CA1 neurons with fine spatiotemporal resolution but also could drive rhythmic circuit excitation over a large spatiotemporal scale. Furthermore, virus-mediated expression of either LMO or iLMO in the substantia nigra in vivo produced not only the expected bidirectional control of single unit activity but also opposing effects on circling behavior in response to systemic injection of a luciferase substrate. Thus, although preserving the ability to be activated by external light sources, LMOs expand the use of optogenetics by making the same opsins accessible to noninvasive, chemogenetic control, thereby allowing the same probe to manipulate neuronal activity over a range of spatial and temporal scales. PMID:26733686

  12. Evolving visual pigments: hints from the opsin-based proteins in a phylogenetically old "eyeless" invertebrate.

    PubMed

    Santillo, Silvia; Orlando, Pierangelo; De Petrocellis, Luciano; Cristino, Luigia; Guglielmotti, Vittorio; Musio, Carlo

    2006-01-01

    Visual pigments are photosensitive receptor proteins that trigger the transduction process producing the visual excitation once they have absorbed photons. In spite of the molecular and morpho-functional complexity that has characterized the development of animal eyes and eyeless photoreceptive systems, opsin-based protein family appears ubiquous along metazoan visual systems. Moreover, in addition to classic rhodopsin photoreceptors, all Metazoa have supplementary non-visual photosensitive structures, mainly located in the central nervous system, that sense light without forming an image and that rather regulate the organism's temporal physiology. The investigation of novel non-visual photopigments exerting extraretinal photoreception is a challenging field in vision research. Here we propose the cnidarian Hydra as a useful tool of investigation for molecular and functional differences between these pigment families. Hydra is the first metazoan owning a nervous system and it is an eyeless invertebrate showing only an extraocular photoreception, as it has no recognized visual or photosensitive structures. In this paper we provide an overview of the molecular and functional features of the opsin-based protein subfamilies and preliminary evidences in a phylogenetically old species of both image-forming and non-visual opsins. Then we give new insights on the molecular biology of Hydra photoreception and on the evolutionary pathways of visual pigments. PMID:16843587

  13. Mutational changes in S-cone opsin genes common to both nocturnal and cathemeral Aotus monkeys.

    PubMed

    Levenson, David H; Fernandez-Duque, Eduardo; Evans, Sian; Jacobs, Gerald H

    2007-07-01

    Aotus is a platyrrhine primate that has been classically considered to be nocturnal. Earlier research revealed that this animal lacks a color vision capacity because, unlike all other platyrrhine monkeys, Aotus has a defect in the opsin gene that is required to produce short-wavelength sensitive (S) cone photopigment. Consequently, Aotus retains only a single type of cone photopigment. Other mammals have since been found to show similar losses and it has often been speculated that such change is in some fashion tied to nocturnality. Although most species of Aotus are indeed nocturnal, recent observations show that Aotus azarai, an owl monkey species native to portions of Argentina and Paraguay, displays a cathemeral activity pattern being active during daylight hours as frequently as during nighttime hours. We have sequenced portions of the S-cone opsin gene in A. azarai and Aotus nancymaae, the latter a typically nocturnal species. The S-cone opsin genes in both species contain the same fatal defects earlier detected for Aotus trivirgatus. On the basis of the phylogenetic relationships of these three species these results imply that Aotus must have lost a capacity for color vision early in its history and they also suggest that the absence of color vision is not compulsively linked to a nocturnal lifestyle. PMID:17253622

  14. NASA's Living With a Star (LWS) Sentinels mission to understand the origin of Solar Energetic Particles (SEPs)

    NASA Astrophysics Data System (ADS)

    Lin, R. P.; Sentinels Team

    One of the primary goals of NASA s Sentinels mission the heliospheric element of the integrated LWS program is to provide the observations necessary for an understanding of the physics of the Sun inner heliosphere processes that produce SEP events so the requirements for eventual predictive capability can be defined We present the results of the study by the Sentinels Science and Technology Definition Team STDT that recommends a combination of the Inner Heliosphere Sentinels IHS consisting of four identical spacecraft that utilize Venus gravity assists to achieve 0 25-0 75 AU orbits primarily for in situ particles and fields measurements a Near-Earth Sentinel NES with a spectroscopic coronagraph to provide the physical conditions in the SEP acceleration region and a wide field sim 0 3 AU coronagraph to connect to the IHS measurements and a Farside Sentinel FS with a magnetograph to provide near global photospheric magnetic field measurements for modeling the structure of the inner heliosphere We show how the combined measurements are designed to lead to an understanding of SEP origin and to improve our predictive capability for large SEP events

  15. Genetic deletion of S-opsin prevents rapid cone degeneration in a mouse model of Leber congenital amaurosis.

    PubMed

    Zhang, Tao; Enemchukwu, Nduka O; Jones, Alex; Wang, Shixian; Dennis, Emily; Watt, Carl B; Pugh, Edward N; Fu, Yingbin

    2015-03-15

    Mutations in RPE65 or lecithin-retinol acyltransferase (LRAT) disrupt 11-cis-retinal synthesis and cause Leber congenital amaurosis (LCA), a severe hereditary blindness occurring in early childhood. The pathology is attributed to a combination of 11-cis-retinal deficiency and photoreceptor degeneration. The mistrafficking of cone membrane-associated proteins including cone opsins (M- and S-opsins), cone transducin (G?t2), G-protein-coupled receptor kinase 1 (GRK1) and guanylate cyclase 1 (GC1) has been suggested to play a role in cone degeneration. However, their precise role in cone degeneration is unclear. Here we investigated the role of S-opsin (Opn1sw) in cone degeneration in Lrat(-) (/-), a murine model for LCA, by genetic ablation of S-opsin. We show that deletion of just one allele of S-opsin from Lrat(-) (/-) mice is sufficient to prevent the rapid cone degeneration for at least 1 month. Deletion of both alleles of S-opsin prevents cone degeneration for an extended period (at least 12 months). This genetic prevention is accompanied by a reduction of endoplasmic reticulum (ER) stress in Lrat(-) (/-) photoreceptors. Despite cone survival in Opn1sw(-/-)Lrat(-) (/-) mice, cone membrane-associated proteins (e.g. G?t2, GRK1 and GC1) continue to have trafficking problems. Our results suggest that cone opsins are the 'culprit' linking 11-cis-retinal deficiency to cone degeneration in LCA. This result has important implications for the current gene therapy strategy that emphasizes the need for a combinatorial therapy to both improve vision and slow photoreceptor degeneration. PMID:25416279

  16. P23H opsin knock-in mice reveal a novel step in retinal rod disc morphogenesis.

    PubMed

    Sakami, Sanae; Kolesnikov, Alexander V; Kefalov, Vladimir J; Palczewski, Krzysztof

    2014-04-01

    Retinal rod photoreceptor cells have double membrane discs located in their outer segments (ROS) that are continuously formed proximally from connecting cilia (CC) and phagocytized distally by the retinal pigmented epithelium. The major component of these rod discs, the light-sensitive visual pigment rhodopsin (Rho), consists of an opsin protein linked to 11-cis-retinal. The P23H mutation of rod opsin (P23H opsin) is the most common cause of human blinding autosomal dominant retinitis pigmentosa (adRP). A mouse model of adRP with this mutation (Rho(P23H/+)) shows low levels of P23H opsin protein, partial misalignment of discs and progressive retinal degeneration. However, the impact of mutant P23H opsin on the formation of abnormal discs is unclear and it is still unknown whether this mutant pigment can mediate phototransduction. Using transretinal ERG recordings, we demonstrate that P23H mutant Rho can trigger phototransduction but Rho(P23H/P23H) rods are ?17 000-fold less sensitive to light than Rho(+/+) rods and produce abnormally fast photo-responses. By analyzing homozygous Rho(P23H/P23H) knock-in mice, we show that P23H opsin is transported to ciliary protrusions where it forms sagittally elongated discs. Transmission electron microscopy of postnatal day (PND) 14 Rho(P23H/+) mouse retina revealed disordered sagittally oriented discs before the onset of retinal degeneration. Surprisingly, we also observed smaller, immature sagittally oriented discs in PND14 Rho(+/)(-) and Rho(+/+) mice that were not seen in older animals. These findings provide fundamental insights into the pathogenesis of the P23H mutant opsin and reveal a novel early sagittally aligned disc formation step in normal ROS disc expansion. PMID:24214395

  17. Evolutionary renovation of L/M opsin polymorphism confers a fruit discrimination advantage to ateline New World monkeys

    PubMed Central

    Matsumoto, Yoshifumi; Hiramatsu, Chihiro; Matsushita, Yuka; Ozawa, Norihiro; Ashino, Ryuichi; Nakata, Makiko; Kasagi, Satoshi; Di Fiore, Anthony; Schaffner, Colleen M; Aureli, Filippo; Melin, Amanda D; Kawamura, Shoji

    2014-01-01

    New World monkeys exhibit prominent colour vision variation due to allelic polymorphism of the long-to-middle wavelength (L/M) opsin gene. The known spectral variation of L/M opsins in primates is broadly determined by amino acid composition at three sites: 180, 277 and 285 (the ‘three-sites’ rule). However, two L/M opsin alleles found in the black-handed spider monkeys (Ateles geoffroyi) are known exceptions, presumably due to novel mutations. The spectral separation of the two L/M photopigments is 1.5 times greater than expected based on the ‘three-sites’ rule. Yet the consequence of this for the visual ecology of the species is unknown, as is the evolutionary mechanism by which spectral shift was achieved. In this study, we first examine L/M opsins of two other Atelinae species, the long-haired spider monkeys (A. belzebuth) and the common woolly monkeys (Lagothrix lagotricha). By a series of site-directed mutagenesis, we show that a mutation Y213D (tyrosine to aspartic acid at site 213) in the ancestral opsin of the two alleles enabled N294K, which occurred in one allele of the ateline ancestor and increased the spectral separation between the two alleles. Second, by modelling the chromaticity of dietary fruits and background leaves in a natural habitat of spider monkeys, we demonstrate that chromatic discrimination of fruit from leaves is significantly enhanced by these mutations. This evolutionary renovation of L/M opsin polymorphism in atelines illustrates a previously unappreciated dynamism of opsin genes in shaping primate colour vision. PMID:24612406

  18. Deletion of the X-linked Opsin Gene Array Locus Control Region (LCR) Results in Disruption of the Cone Mosaic

    PubMed Central

    Carroll, Joseph; Rossi, Ethan A.; Porter, Jason; Neitz, Jay; Roorda, Austin; Williams, David; Neitz, Maureen

    2010-01-01

    Blue-cone monochromacy (BCM) is an X-linked condition in which long- (L?) and middle- (M?) wavelength-sensitive cone function is absent. Due to the X-linked nature of the condition, female carriers are spared from a full manifestation of the associated defects but can show visual symptoms, including abnormal cone electroretinograms. Here we imaged the cone mosaic in four females carrying an L/M array with deletion of the locus control region, resulting in an absence of L/M opsin gene expression (effectively acting as a cone opsin knockout). On average, they had cone mosaics with reduced density and disrupted organization compared to normal trichromats. This suggests that the absence of opsin in a subset of cones results in their early degeneration, with X-inactivation the likely mechanism underlying phenotypic variability in BCM carriers. PMID:20638402

  19. Opsins in onychophora (velvet worms) suggest a single origin and subsequent diversification of visual pigments in arthropods.

    PubMed

    Hering, Lars; Henze, Miriam J; Kohler, Martin; Kelber, Almut; Bleidorn, Christoph; Leschke, Maren; Nickel, Birgit; Meyer, Matthias; Kircher, Martin; Sunnucks, Paul; Mayer, Georg

    2012-11-01

    Multiple visual pigments, prerequisites for color vision, are found in arthropods, but the evolutionary origin of their diversity remains obscure. In this study, we explore the opsin genes in five distantly related species of Onychophora, using deep transcriptome sequencing and screening approaches. Surprisingly, our data reveal the presence of only one opsin gene (onychopsin) in each onychophoran species, and our behavioral experiments indicate a maximum sensitivity of onychopsin to blue-green light. In our phylogenetic analyses, the onychopsins represent the sister group to the monophyletic clade of visual r-opsins of arthropods. These results concur with phylogenomic support for the sister-group status of the Onychophora and Arthropoda and provide evidence for monochromatic vision in velvet worms and in the last common ancestor of Onychophora and Arthropoda. We conclude that the diversification of visual pigments and color vision evolved in arthropods, along with the evolution of compound eyes-one of the most sophisticated visual systems known. PMID:22683812

  20. Co-Expression of VAL- and TMT-Opsins Uncovers Ancient Photosensory Interneurons and Motorneurons in the Vertebrate Brain

    PubMed Central

    Fischer, Ruth M.; Fontinha, Bruno M.; Kirchmaier, Stephan; Steger, Julia; Bloch, Susanne; Inoue, Daigo; Panda, Satchidananda; Rumpel, Simon; Tessmar-Raible, Kristin

    2013-01-01

    The functional principle of the vertebrate brain is often paralleled to a computer: information collected by dedicated devices is processed and integrated by interneuron circuits and leads to output. However, inter- and motorneurons present in today's vertebrate brains are thought to derive from neurons that combined sensory, integration, and motor function. Consistently, sensory intermotorneurons have been found in the simple nerve nets of cnidarians, animals at the base of the evolutionary lineage. We show that light-sensory motorneurons and light-sensory interneurons are also present in the brains of vertebrates, challenging the paradigm that information processing and output circuitry in the central brain is shielded from direct environmental influences. We investigated two groups of nonvisual photopigments, VAL- and TMT-Opsins, in zebrafish and medaka fish; two teleost species from distinct habitats separated by over 300 million years of evolution. TMT-Opsin subclasses are specifically expressed not only in hypothalamic and thalamic deep brain photoreceptors, but also in interneurons and motorneurons with no known photoreceptive function, such as the typeXIV interneurons of the fish optic tectum. We further show that TMT-Opsins and Encephalopsin render neuronal cells light-sensitive. TMT-Opsins preferentially respond to blue light relative to rhodopsin, with subclass-specific response kinetics. We discovered that tmt-opsins co-express with val-opsins, known green light receptors, in distinct inter- and motorneurons. Finally, we show by electrophysiological recordings on isolated adult tectal slices that interneurons in the position of typeXIV neurons respond to light. Our work supports sensory-inter-motorneurons as ancient units for brain evolution. It also reveals that vertebrate inter- and motorneurons are endowed with an evolutionarily ancient, complex light-sensory ability that could be used to detect changes in ambient light spectra, possibly providing the endogenous equivalent to an optogenetic machinery. PMID:23776409

  1. NinaB is essential for Drosophila vision but induces retinal degeneration in opsin-deficient photoreceptors.

    PubMed

    Voolstra, Olaf; Oberhauser, Vitus; Sumser, Emerich; Meyer, Nina E; Maguire, Michael E; Huber, Armin; von Lintig, Johannes

    2010-01-15

    In animals, visual pigments are essential for photoreceptor function and survival. These G-protein-coupled receptors consist of a protein moiety (opsin) and a covalently bound 11-cis-retinylidene chromophore. The chromophore is derived from dietary carotenoids by oxidative cleavage and trans-to-cis isomerization of double bonds. In vertebrates, the necessary chemical transformations are catalyzed by two distinct but structurally related enzymes, the carotenoid oxygenase beta-carotenoid-15,15'-monooxygenase and the retinoid isomerase RPE65 (retinal pigment epithelium protein of 65 kDa). Recently, we provided biochemical evidence that these reactions in insects are catalyzed by a single enzyme family member named NinaB. Here we show that in the fly pathway, carotenoids are mandatory precursors of the chromophore. After chromophore formation, the retinoid-binding protein Pinta acts downstream of NinaB and is required to supply photoreceptors with chromophore. Like ninaE encoding the opsin, ninaB expression is eye-dependent and is activated as a downstream target of the eyeless/pax6 and sine oculis master control genes for eye development. The requirement for coordinated synthesis of chromophore and opsin is evidenced by analysis of ninaE mutants. Retinal degeneration in opsin-deficient photoreceptors is caused by the chromophore and can be prevented by restricting its supply as seen in an opsin and chromophore-deficient double mutant. Thus, our study identifies NinaB as a key component for visual pigment production and provides evidence that chromophore in opsin-deficient photoreceptors can elicit retinal degeneration. PMID:19889630

  2. Nonvisual Opsins and the Regulation of Peripheral Clocks by Light and Hormones.

    PubMed

    Poletini, Maristela O; Ramos, Bruno C; Moraes, Maria Nathalia; Castrucci, Ana Maria L

    2015-01-01

    The molecular clock machinery is conserved throughout evolution. However, how environmental cues are perceived has evolved in such a way that peripheral clocks in mammals require a variety of signals, including hormones. On the other hand, in nonmammalian cells able to directly detect light, light seems to play a major role in the synchronization of the clock. The interaction between perception of circadian light by nonvisual opsins and hormones will be discussed under the perspective of clock synchronization at the molecular level. PMID:26174318

  3. Autosomal recessive retinitis pigmentosa E150K opsin mice exhibit photoreceptor disorganization

    PubMed Central

    Zhang, Ning; Kolesnikov, Alexander V.; Jastrzebska, Beata; Mustafi, Debarshi; Sawada, Osamu; Maeda, Tadao; Genoud, Christel; Engel, Andreas; Kefalov, Vladimir J.; Palczewski, Krzysztof

    2012-01-01

    The pathophysiology of the E150K mutation in the rod opsin gene associated with autosomal recessive retinitis pigmentosa (arRP) has yet to be determined. We generated knock-in mice carrying a single nucleotide change in exon 2 of the rod opsin gene resulting in the E150K mutation. This novel mouse model displayed severe retinal degeneration affecting rhodopsins stabilization of rod outer segments (ROS). Homozygous E150K (KK) mice exhibited early-onset retinal degeneration, with disorganized ROS structures, autofluorescent deposits in the subretinal space, and aberrant photoreceptor phagocytosis. Heterozygous (EK) mice displayed a delayed-onset milder retinal degeneration. Further, mutant receptors were mislocalized to the inner segments and perinuclear region. Though KK mouse rods displayed markedly decreased phototransduction, biochemical studies of the mutant rhodopsin revealed only minimally affected chromophore binding and G protein activation. Ablation of the chromophore by crossing KK mice with mice lacking the critical visual cycle protein LRAT slowed retinal degeneration, whereas blocking phototransduction by crossing KK mice with GNAT1-deficient mice slightly accelerated this process. This study highlights the importance of proper higher-order organization of rhodopsin in the native tissue and provides information about the signaling properties of this mutant rhodopsin. Additionally, these results suggest that patients heterozygous for the E150K mutation should be periodically reevaluated for delayed-onset retinal degeneration. PMID:23221340

  4. A human opsin-related gene that encodes a retinaldehyde-binding protein.

    PubMed

    Shen, D; Jiang, M; Hao, W; Tao, L; Salazar, M; Fong, H K

    1994-11-01

    The ligand-binding property of a cytoplasmic membrane-bound protein from bovine retinal pigment epithelium (RPE) has been demonstrated. The putative RPE-retinal G protein coupled receptor (RGR) covalently binds both all-trans- and 11-cis-retinal after reduction by sodium borohydride. The 32-kDa receptor binds all-trans-retinal preferentially, rather than the 11-cis isomer. The amino acid sequence of the opsin-related protein in humans is 86% identical to that of bovine RGR, and a lysine residue, analogous to the retinaldehyde attachment site of rhodopsin, is conserved in the seventh transmembrane domain of RGR in both species. The human gene that encodes the novel retinaldehyde receptor spans 14.8 kb and is split into seven exons. The structure of the gene is distinct from that of the visual pigment genes. These findings support the notion that the rgr gene represents the earliest independent branch of the vertebrate opsin gene family. A second form of human RGR in retina is predicted by alternative splicing of its precursor mRNA. This RGR variant results from the alternative use of an internal acceptor splice site in the second intron of the human gene, and it contains an insertion of four amino acids in the connecting loop between the second and thrid transmembrane domains. Since RGR binds all-trans-retinal preferentially, one of its functions may be to catalyze isomerization of the chromophore by a retinochrome-like mechanism. PMID:7947717

  5. The evolution of irradiance detection: melanopsin and the non-visual opsins

    PubMed Central

    Peirson, Stuart N.; Halford, Stephanie; Foster, Russell G.

    2009-01-01

    Circadian rhythms are endogenous 24 h cycles that persist in the absence of external time cues. These rhythms provide an internal representation of day length and optimize physiology and behaviour to the varying demands of the solar cycle. These clocks require daily adjustment to local time and the primary time cue (zeitgeber) used by most vertebrates is the daily change in the amount of environmental light (irradiance) at dawn and dusk, a process termed photoentrainment. Attempts to understand the photoreceptor mechanisms mediating non-image-forming responses to light, such as photoentrainment, have resulted in the discovery of a remarkable array of different photoreceptors and photopigment families, all of which appear to use a basic opsin/vitamin A-based photopigment biochemistry. In non-mammalian vertebrates, specialized photoreceptors are located within the pineal complex, deep brain and dermal melanophores. There is also strong evidence in fish and amphibians for the direct photic regulation of circadian clocks in multiple tissues. By contrast, mammals possess only ocular photoreceptors. However, in addition to the image-forming rods and cones of the retina, there exists a third photoreceptor system based on a subset of melanopsin-expressing photosensitive retinal ganglion cells (pRGCs). In this review, we discuss the range of vertebrate photoreceptors and their opsin photopigments, describe the melanopsin/pRGC system in some detail and then finally consider the molecular evolution and sensory ecology of these non-image-forming photoreceptor systems. PMID:19720649

  6. Jellyfish vision starts with cAMP signaling mediated by opsin-G(s) cascade.

    PubMed

    Koyanagi, Mitsumasa; Takano, Kosuke; Tsukamoto, Hisao; Ohtsu, Kohzoh; Tokunaga, Fumio; Terakita, Akihisa

    2008-10-01

    Light sensing starts with phototransduction in photoreceptor cells. The phototransduction cascade has diverged in different species, such as those mediated by transducin in vertebrate rods and cones, by G(q)-type G protein in insect and molluscan rhabdomeric-type visual cells and vertebrate photosensitive retinal ganglion cells, and by G(o)-type G protein in scallop ciliary-type visual cells. Here, we investigated the phototransduction cascade of a prebilaterian box jellyfish, the most basal animal having eyes containing lens and ciliary-type visual cells similar to vertebrate eyes, to examine the similarity at the molecular level and to obtain an implication of the origin of the vertebrate phototransduction cascade. We showed that the opsin-based pigment functions as a green-sensitive visual pigment and triggers the G(s)-type G protein-mediated phototransduction cascade in the ciliary-type visual cells of the box jellyfish lens eyes. We also demonstrated the light-dependent cAMP increase in the jellyfish visual cells and HEK293S cells expressing the jellyfish opsin. The first identified prebilaterian cascade was distinct from known phototransduction cascades but exhibited significant partial similarity with those in vertebrate and molluscan ciliary-type visual cells, because all involved cyclic nucleotide signaling. These similarities imply a monophyletic origin of ciliary phototransduction cascades distributed from prebilaterian to vertebrate. PMID:18832159

  7. Structure and function in rhodopsin: high level expression of a synthetic bovine opsin gene and its mutants in stable mammalian cell lines.

    PubMed Central

    Reeves, P J; Thurmond, R L; Khorana, H G

    1996-01-01

    Stable mammalian cell lines harboring a synthetic bovine opsin gene have been derived from the suspension-adapted HEK293 cell line. The opsin gene is under the control of the immediate-early cytomegalovirus promoter/enhancer in an expression vector that also contains a selectable marker (Neo) governed by a relatively weak promoter. The cell lines expressing the opsin gene at high levels are selected by growth in the presence of high concentrations of the antibiotic geneticin. Under the conditions used for cell growth in suspension, opsin is produced at saturated culture levels of more than 2 mg/liter. After reconstitution with 11-cis-retinal, rhodopsin is purified to homogeneity in a single step by immunoaffinity column chromatography. Rhodopsin thus prepared (> 90% recovery at concentrations of up to 15 microM) is indistinguishable from rhodopsin purified from bovine rod outer segments by the following criteria: (i) UV/Vis absorption spectra in the dark and after photobleaching and the rate of metarhodopsin II decay, (ii) initial rates of transducin activation, and (iii) the rate of phosphorylation by rhodopsin kinase. Although mammalian cell opsin migrates slower than rod outer segment opsin on SDS/polyacrylamide gels, presumably due to a different N-glycosylation pattern, their mobilities after deglycosylation are identical. This method has enabled the preparation of several site-specific mutants of bovine opsin in comparable amounts. Images Fig. 2 Fig. 6 PMID:8876162

  8. Evolution of color vision in pierid butterflies: blue opsin duplication, ommatidial heterogeneity and eye regionalization in Colias erate.

    PubMed

    Awata, Hiroko; Wakakuwa, Motohiro; Arikawa, Kentaro

    2009-04-01

    This paper documents the molecular organization of the eye of the Eastern Pale Clouded Yellow butterfly, Colias erate (Pieridae). We cloned four cDNAs encoding visual pigment opsins, corresponding to one ultraviolet, two blue and one long wavelength-absorbing visual pigments. Duplication of the blue visual pigment class occurs also in another pierid species, Pieris rapae, suggesting that blue duplication is a general feature in the family Pieridae. We localized the opsin mRNAs in the Colias retina by in situ hybridization. Among the nine photoreceptor cells in an ommatidium, R1-9, we found that R3-8 expressed the long wavelength class mRNA in all ommatidia. R1 and R2 expressed mRNAs of the short wavelength opsins in three fixed combinations, corresponding to three types of ommatidia. While the duplicated blue opsins in Pieris are separately expressed in two subsets of R1-2 photoreceptors, one blue sensitive and another violet sensitive, those of Colias appear to be always coexpressed. PMID:19224222

  9. Strategies for identification of mutations causing hereditary retinal diseases in dogs: evaluation of opsin as a candidate gene.

    PubMed

    Ray, K; Wang, W; Czarnecki, J; Zhang, Q; Acland, G M; Aguirre, G D

    1999-01-01

    Progressive retinal atrophy (PRA), like retinitis pigmentosa (RP) in man, represents a clinical classification grouping together a variety of hereditary diseases of the visual cells which have broadly similar clinical characteristics. At least six distinct autosomal recessive and one X-linked retinal disease locus have been identified. As one of the strategies to look for the gene defect causing the different forms of PRA, we are examining first the most promising candidate genes. These include those coding for photoreceptor-specific structural proteins and enzymes of the phototransduction pathway, especially those reported to cause RP. Preeminent among these candidates is the gene for rod opsin, in which multiple causative mutations have been identified in both dominant and recessive forms of RP. In addition, mutations in this gene are also causally associated with congenital stationary night blindness (CSNB) in man. We have used two strategies to examine the rod opsin gene for association with inherited retinal disease in dogs: (1) linkage to determine cosegregation of the disease locus with an intragenic polymorphic marker in the opsin gene in those breeds where suitable informative pedigrees were available; and (2) scanning the coding sequence of the gene in cases where only a limited number of affected or obligate heterozygous samples were available for a breed. We conclude that mutations in the rod opsin gene are not associated with PRA or CSNB in the 11 different dog breeds tested. PMID:9987920

  10. Metal Mesh Fabrication and Testing for Infrared Astronomy and ISO Science Programs; ISO GO Data Analysis and LWS Instrument Team Activities

    NASA Technical Reports Server (NTRS)

    Smith, Howard A.; Oliversen, Ronald J. (Technical Monitor)

    2001-01-01

    This research program addresses astrophysics research with the Infrared Space Observatory's Long Wavelength Spectrometer (ISO-LWS), including efforts to supply ISO-LWS with superior metal mesh filters. This grant has, over the years, enabled Dr. Smith in his role as a Co-Investigator on the satellite, the PI (Principal Investigator) on the Extragalactic Science Team, and a member of the Calibration and performance working groups. The emphasis of the budget in this proposal is in support of Dr. Smith's Infrared Space Observatory research. This program began (under a different grant number) while Dr. Smith was at the Smithsonian's National Air and Space Museum, and was transferred to SAO with a change in number. While Dr. Smith was a visiting Discipline Scientist at NASA HQ the program was in abeyance, but it has resumed in full since his return to SAO. The Infrared Space Observatory mission was launched in November, 1996, and since then has successfully completed its planned lifetime mission. Data are currently being calibrated to the 2% level.

  11. Genomic organization, evolution, and expression of photoprotein and opsin genes in Mnemiopsis leidyi: a new view of ctenophore photocytes

    PubMed Central

    2012-01-01

    Background Calcium-activated photoproteins are luciferase variants found in photocyte cells of bioluminescent jellyfish (Phylum Cnidaria) and comb jellies (Phylum Ctenophora). The complete genomic sequence from the ctenophore Mnemiopsis leidyi, a representative of the earliest branch of animals that emit light, provided an opportunity to examine the genome of an organism that uses this class of luciferase for bioluminescence and to look for genes involved in light reception. To determine when photoprotein genes first arose, we examined the genomic sequence from other early-branching taxa. We combined our genomic survey with gene trees, developmental expression patterns, and functional protein assays of photoproteins and opsins to provide a comprehensive view of light production and light reception in Mnemiopsis. Results The Mnemiopsis genome has 10 full-length photoprotein genes situated within two genomic clusters with high sequence conservation that are maintained due to strong purifying selection and concerted evolution. Photoprotein-like genes were also identified in the genomes of the non-luminescent sponge Amphimedon queenslandica and the non-luminescent cnidarian Nematostella vectensis, and phylogenomic analysis demonstrated that photoprotein genes arose at the base of all animals. Photoprotein gene expression in Mnemiopsis embryos begins during gastrulation in migrating precursors to photocytes and persists throughout development in the canals where photocytes reside. We identified three putative opsin genes in the Mnemiopsis genome and show that they do not group with well-known bilaterian opsin subfamilies. Interestingly, photoprotein transcripts are co-expressed with two of the putative opsins in developing photocytes. Opsin expression is also seen in the apical sensory organ. We present evidence that one opsin functions as a photopigment in vitro, absorbing light at wavelengths that overlap with peak photoprotein light emission, raising the hypothesis that light production and light reception may be functionally connected in ctenophore photocytes. We also present genomic evidence of a complete ciliary phototransduction cascade in Mnemiopsis. Conclusions This study elucidates the genomic organization, evolutionary history, and developmental expression of photoprotein and opsin genes in the ctenophore Mnemiopsis leidyi, introduces a novel dual role for ctenophore photocytes in both bioluminescence and phototransduction, and raises the possibility that light production and light reception are linked in this early-branching non-bilaterian animal. PMID:23259493

  12. Complex patterns of divergence among green-sensitive (RH2a) African cichlid opsins revealed by Clade model analyses

    PubMed Central

    2012-01-01

    Background Gene duplications play an important role in the evolution of functional protein diversity. Some models of duplicate gene evolution predict complex forms of paralog divergence; orthologous proteins may diverge as well, further complicating patterns of divergence among and within gene families. Consequently, studying the link between protein sequence evolution and duplication requires the use of flexible substitution models that can accommodate multiple shifts in selection across a phylogeny. Here, we employed a variety of codon substitution models, primarily Clade models, to explore how selective constraint evolved following the duplication of a green-sensitive (RH2a) visual pigment protein (opsin) in African cichlids. Past studies have linked opsin divergence to ecological and sexual divergence within the African cichlid adaptive radiation. Furthermore, biochemical and regulatory differences between the RH2a? and RH2a? paralogs have been documented. It thus seems likely that selection varies in complex ways throughout this gene family. Results Clade model analysis of African cichlid RH2a opsins revealed a large increase in the nonsynonymous-to-synonymous substitution rate ratio (?) following the duplication, as well as an even larger increase, one consistent with positive selection, for Lake Tanganyikan cichlid RH2a? opsins. Analysis using the popular Branch-site models, by contrast, revealed no such alteration of constraint. Several amino acid sites known to influence spectral and non-spectral aspects of opsin biochemistry were found to be evolving divergently, suggesting that orthologous RH2a opsins may vary in terms of spectral sensitivity and response kinetics. Divergence appears to be occurring despite intronic gene conversion among the tandemly-arranged duplicates. Conclusions Our findings indicate that variation in selective constraint is associated with both gene duplication and divergence among orthologs in African cichlid RH2a opsins. At least some of this variation may reflect an adaptive response to differences in light environment. Interestingly, these patterns only became apparent through the use of Clade models, not through the use of the more widely employed Branch-site models; we suggest that this difference stems from the increased flexibility associated with Clade models. Our results thus bear both on studies of cichlid visual system evolution and on studies of gene family evolution in general. PMID:23078361

  13. Spatial distribution of opsin-encoding mRNAs in the tiered larval retinas of the sunburst diving beetle Thermonectus marmoratus (Coleoptera: Dytiscidae).

    PubMed

    Maksimovic, Srdjan; Cook, Tiffany A; Buschbeck, Elke K

    2009-12-01

    Larvae of the sunburst diving beetle, Thermonectus marmoratus, have a cluster of six stemmata (E1-6) and one eye patch on each side of the head. Each eye has two retinas: a distal retina that is closer to the lens, and a proximal retina that lies directly underneath. The distal retinas of E1 and E2 are made of a dorsal and a ventral stack of at least twelve photoreceptor layers. Could this arrangement be used to compensate for lens chromatic aberration, with shorter wavelengths detected by the distal layers and longer wavelengths by the proximal layers? To answer this question we molecularly identified opsins and their expression patterns in these eyes. We found three opsin-encoding genes. The distal retinas of all six eyes express long-wavelength opsin (TmLW) mRNA, whereas the proximal retinas express ultraviolet opsin (TmUV I) mRNA. In the proximal retinas of E1 and E2, the TmUV I mRNA is expressed only in the dorsal stack. A second ultraviolet opsin mRNA (TmUV II), is expressed in the proximal retinas of E1 and E2 (both stacks). The finding that longer-wavelength opsins are expressed distally to shorter-wavelength opsins makes it unlikely that this retinal arrangement is used to compensate for lens chromatic aberration. In addition, we also described opsin expression patterns in the medial retina of E1 and in the non-tiered retina of the lensless eye patch. To our knowledge, this is also the first report of multiple UV opsins being expressed in the same stemma. PMID:19915119

  14. Parallel reduction in expression, but no loss of functional constraint, in two opsin paralogs within cave populations of Gammarus minus (Crustacea: Amphipoda)

    PubMed Central

    2013-01-01

    Background Gammarus minus, a freshwater amphipod living in the cave and surface streams in the eastern USA, is a premier candidate for studying the evolution of troglomorphic traits such as pigmentation loss, elongated appendages, and reduced eyes. In G. minus, multiple pairs of genetically related, physically proximate cave and surface populations exist which exhibit a high degree of intraspecific morphological divergence. The morphology, ecology, and genetic structure of these sister populations are well characterized, yet the genetic basis of their morphological divergence remains unknown. Results We used degenerate PCR primers designed to amplify opsin genes within the subphylum Crustacea and discovered two distinct opsin paralogs (average inter-paralog protein divergence???20%) in the genome of three independently derived pairs of G. minus cave and surface populations. Both opsin paralogs were found to be related to other crustacean middle wavelength sensitive opsins. Low levels of nucleotide sequence variation (< 1% within populations) were detected in both opsin genes, regardless of habitat, and dN/dS ratios did not indicate a relaxation of functional constraint in the cave populations with reduced or absent eyes. Maximum likelihood analyses using codon-based models also did not detect a relaxation of functional constraint in the cave lineages. We quantified expression level of both opsin genes and found that the expression of both paralogs was significantly reduced in all three cave populations relative to their sister surface populations. Conclusions The concordantly lowered expression level of both opsin genes in cave populations of G. minus compared to sister surface populations, combined with evidence for persistent purifying selection in the cave populations, is consistent with an unspecified pleiotropic function of opsin proteins. Our results indicate that phototransduction proteins such as opsins may have retained their function in cave-adapted organisms because they may play a pleiotropic role in other important processes that are unrelated to vision. PMID:23617561

  15. Mislocalized Opsin and cAMP Signaling: A Mechanism for Sprouting by Rod Cells in Retinal Degeneration

    PubMed Central

    Wang, Jianfeng; Zhang, Nan; Beuve, Annie; Townes-Anderson, Ellen

    2012-01-01

    Purpose. In human retinal degeneration, rod photoreceptors reactively sprout neurites. The mechanism is unknown in part because of the paucity of animal models displaying this feature of human pathology. We tested the role of cAMP and opsin in sprouting by tiger salamander rod cells, photoreceptors that can produce reactive growth. Methods. In vitro systems of isolated photoreceptor cells and intact neural retina were used. cAMP signaling was manipulated with nucleotide analogues, enzyme stimulators, agonists for adenosine and dopamine receptors, and the opsin agonist, ?-ionone. Levels of cAMP were determined by radioimmunoassay, and protein levels by Western blot and quantitative immunocytochemistry. Neuritic growth was assayed by image analysis and conventional and confocal microscopy. Results. cAMP analogues and stimulation of adenylyl cyclase (AC) directly or through G-proteincoupled receptors resulted in significant increases in neuritic growth of isolated rod, but not cone, cells. The signaling pathway included protein kinase A (PKA) and phosphorylation of the transcription factor cAMP response element-binding protein (pCREB). Opsin, a G-linked receptor, is present throughout the plasmalemma of isolated cells; its activation also induced sprouting. In neural retina, rod sprouting was significantly increased by ?-ionone with concomitant increases in cAMP, pCREB, and synaptic proteins. Notably, opsin stimulated sprouting only when mislocalized to the plasmalemma of the rod cell body. Conclusions. cAMP causes neuritic sprouting in rod, but not cone, cells through the AC-PKA-CREB pathway known to be associated with synaptic plasticity. We propose that in retinal disease, mislocalized rod opsin gains access to cAMP signaling, which leads to neuritic sprouting. PMID:22899763

  16. A Non-Mammalian Type Opsin 5 Functions Dually in the Photoreceptive and Non-Photoreceptive Organs of Birds

    PubMed Central

    Ohuchi, Hideyo; Yamashita, Takahiro; Tomonari, Sayuri; Fujita-Yanagibayashi, Sari; Sakai, Kazumi; Noji, Sumihare; Shichida, Yoshinori

    2012-01-01

    A mammalian type opsin 5 (neuropsin) is a recently identified ultraviolet (UV)-sensitive pigment of the retina and other photosensitive organs in birds. Two other opsin 5-related molecules have been found in the genomes of non-mammalian vertebrates. However, their functions have not been examined as yet. Here, we identify the molecular properties of a second avian opsin 5, cOpn5L2 (chicken opsin 5-like 2), and its localization in the post-hatch chicken. Spectrophotometric analysis and radionucleotide-binding assay have revealed that cOpn5L2 is a UV-sensitive bistable pigment that couples with the Gi subtype of guanine nucleotide-binding protein (G protein). As a bistable pigment, it also shows the direct binding ability to agonist all-trans-retinal to activate G protein. The absorption maxima of UV-light-absorbing and visible light-absorbing forms were 350 and 521 nm, respectively. Expression analysis showed relatively high expression of cOpn5L2 mRNA in the adrenal gland, which is not photoreceptive but an endocrine organ, while lower expression was found in the brain and retina. At the protein level, cOpn5L2 immunoreactive cells were present in the chromaffin cells of the adrenal gland. In the brain, cOpn5L2 immunoreactive cells were found in the paraventricular and supraoptic nuclei of the anterior hypothalamus, known for photoreceptive deep brain areas. In the retina, cOpn5L2 protein was localized to subsets of cells in the ganglion cell layer and the inner nuclear layer. These results suggest that the non-mammalian type opsin 5 (Opn5L2) functions as a second UV sensor in the photoreceptive organs, while it might function as chemosensor using its direct binding ability to agonist all-trans-retinal in non-photoreceptive organs such as the adrenal gland of birds. PMID:22348098

  17. Mapping the Moho with seismic surface waves: Sensitivity, resolution, and recommended inversion strategies

    NASA Astrophysics Data System (ADS)

    Lebedev, Sergei; Adam, Joanne; Meier, Thomas

    2013-04-01

    Seismic surface waves have been used to study the Earth's crust since the early days of modern seismology. In the last decade, surface-wave crustal imaging has been rejuvenated by the emergence of new, array techniques (ambient-noise and teleseismic interferometry). The strong sensitivity of both Rayleigh and Love waves to the Moho is evident from a mere visual inspection of their dispersion curves or waveforms. Yet, strong trade-offs between the Moho depth and crustal and mantle structure in surface-wave inversions have prompted doubts regarding their capacity to resolve the Moho. Although the Moho depth has been an inversion parameter in numerous surface-wave studies, the resolution of Moho properties yielded by a surface-wave inversion is still somewhat uncertain and controversial. We use model-space mapping in order to elucidate surface waves' sensitivity to the Moho depth and the resolution of their inversion for it. If seismic wavespeeds within the crust and upper mantle are known, then Moho-depth variations of a few kilometres produce large (over 1 per cent) perturbations in phase velocities. However, in inversions of surface-wave data with no a priori information (wavespeeds not known), strong Moho-depth/shear-speed trade-offs will mask about 90 per cent of the Moho-depth signal, with remaining phase-velocity perturbations 0.1-0.2 per cent only. In order to resolve the Moho with surface waves alone, errors in the data must thus be small (up to 0.2 per cent for resolving continental Moho). If the errors are larger, Moho-depth resolution is not warranted and depends on error distribution with period, with errors that persist over broad period ranges particularly damaging. An effective strategy for the inversion of surface-wave data alone for the Moho depth is to, first, constrain the crustal and upper-mantle structure by inversion in a broad period range and then determine the Moho depth in inversion in a narrow period range most sensitive to it, with the first-step results used as reference. We illustrate this strategy with an application to data from the Kaapvaal Craton. Prior information on crustal and mantle structure reduces the trade-offs and thus enables resolving the Moho depth with noisier data; such information should be sought and used whenever available (as has been done, explicitly or implicitly, in many previous studies). Joint analysis or inversion of surface-wave and other data (receiver functions, topography, gravity) can reduce uncertainties further and facilitate Moho mapping. Alone or as a part of multi-disciplinary datasets, surface-wave data offer unique sensitivity to the crustal and upper-mantle structure and are becoming increasingly important in the seismic imaging of the crust and the Moho. Reference Lebedev, S., J. Adam, T. Meier. Mapping the Moho with seismic surface waves: A review, resolution analysis, and recommended inversion strategies. Tectonophysics, "Moho" special issue, 10.1016/j.tecto.2012.12.030, 2013.

  18. Extraordinarily low evolutionary rates of short wavelength-sensitive opsin pseudogenes

    PubMed Central

    Yokoyama, Shozo; Starmer, William T.; Liu, Yang; Tada, Takashi; Britt, Lyle

    2013-01-01

    Aquatic organisms such as cichlids, coelacanths, seals, and cetaceans are active in UV-blue color environments, but many of them mysteriously lost their abilities to detect these colors. The loss of these functions is a consequence of the pseudogenization of their short wavelength-sensitive (SWS1) opsin genes without gene duplication. We show that the SWS1 gene (BdenS1?) of the deep-sea fish, pearleye (Benthalbella dentata), became a pseudogene in a similar fashion about 130 million years ago (Mya) yet it is still transcribed. The rates of nucleotide substitution (~1.4 10?9 /site/year) of the pseudogenes of these aquatic species as well as some prosimian and bat species are much smaller than the previous estimates for the globin and immunoglobulin pseudogenes. PMID:24125953

  19. Principles for applying optogenetic tools derived from direct comparative analysis of microbial opsins

    PubMed Central

    Mattis, Joanna; Tye, Kay M; Ferenczi, Emily A; Ramakrishnan, Charu; OShea, Daniel J; Prakash, Rohit; Gunaydin, Lisa A; Hyun, Minsuk; Fenno, Lief E; Gradinaru, Viviana; Yizhar, Ofer; Deisseroth, Karl

    2014-01-01

    Diverse optogenetic tools have allowed versatile control over neural activity. Many depolarizing and hyperpolarizing tools have now been developed in multiple laboratories and tested across different preparations, presenting opportunities but also making it difficult to draw direct comparisons. This challenge has been compounded by the dependence of performance on parameters such as vector, promoter, expression time, illumination, cell type and many other variables. As a result, it has become increasingly complicated for end users to select the optimal reagents for their experimental needs. For a rapidly growing field, critical figures of merit should be formalized both to establish a framework for further development and so that end users can readily understand how these standardized parameters translate into performance. Here we systematically compared microbial opsins under matched experimental conditions to extract essential principles and identify key parameters for the conduct, design and interpretation of experiments involving optogenetic techniques. PMID:22179551

  20. Optical control of neuronal excitation and inhibition using a single opsin protein, ChR2

    NASA Astrophysics Data System (ADS)

    Liske, Holly; Qian, Xiang; Anikeeva, Polina; Deisseroth, Karl; Delp, Scott

    2013-10-01

    The effect of electrical stimulation on neuronal membrane potential is frequency dependent. Low frequency electrical stimulation can evoke action potentials, whereas high frequency stimulation can inhibit action potential transmission. Optical stimulation of channelrhodopsin-2 (ChR2) expressed in neuronal membranes can also excite action potentials. However, it is unknown whether optical stimulation of ChR2-expressing neurons produces a transition from excitation to inhibition with increasing light pulse frequencies. Here we report optical inhibition of motor neuron and muscle activity in vivo in the cooled sciatic nerves of Thy1-ChR2-EYFP mice. We also demonstrate all-optical single-wavelength control of neuronal excitation and inhibition without co-expression of inhibitory and excitatory opsins. This all-optical system is free from stimulation-induced electrical artifacts and thus provides a new approach to investigate mechanisms of high frequency inhibition in neuronal circuits in vivo and in vitro.

  1. Optical control of neuronal excitation and inhibition using a single opsin protein, ChR2

    PubMed Central

    Liske, Holly; Qian, Xiang; Anikeeva, Polina; Deisseroth, Karl; Delp, Scott

    2013-01-01

    The effect of electrical stimulation on neuronal membrane potential is frequency dependent. Low frequency electrical stimulation can evoke action potentials, whereas high frequency stimulation can inhibit action potential transmission. Optical stimulation of channelrhodopsin-2 (ChR2) expressed in neuronal membranes can also excite action potentials. However, it is unknown whether optical stimulation of ChR2-expressing neurons produces a transition from excitation to inhibition with increasing light pulse frequencies. Here we report optical inhibition of motor neuron and muscle activity in vivo in the cooled sciatic nerves of Thy1-ChR2-EYFP mice. We also demonstrate all-optical single-wavelength control of neuronal excitation and inhibition without co-expression of inhibitory and excitatory opsins. This all-optical system is free from stimulation-induced electrical artifacts and thus provides a new approach to investigate mechanisms of high frequency inhibition in neuronal circuits in vivo and in vitro. PMID:24173561

  2. The Expression of Three Opsin Genes from the Compound Eye of Helicoverpa armigera (Lepidoptera: Noctuidae) Is Regulated by a Circadian Clock, Light Conditions and Nutritional Status

    PubMed Central

    Yan, Shuo; Zhu, Jialin; Zhu, Weilong; Zhang, Xinfang; Li, Zhen; Liu, Xiaoxia; Zhang, Qingwen

    2014-01-01

    Visual genes may become inactive in species that inhabit poor light environments, and the function and regulation of opsin components in nocturnal moths are interesting topics. In this study, we cloned the ultraviolet (UV), blue (BL) and long-wavelength-sensitive (LW) opsin genes from the compound eye of the cotton bollworm and then measured their mRNA levels using quantitative real-time PCR. The mRNA levels fluctuated over a daily cycle, which might be an adaptation of a nocturnal lifestyle, and were dependent on a circadian clock. Cycling of opsin mRNA levels was disturbed by constant light or constant darkness, and the UV opsin gene was up-regulated after light exposure. Furthermore, the opsin genes tended to be down-regulated upon starvation. Thus, this study illustrates that opsin gene expression is determined by multiple endogenous and exogenous factors and is adapted to the need for nocturnal vision, suggesting that color vision may play an important role in the sensory ecology of nocturnal moths. PMID:25353953

  3. Identification of cis-acting elements repressing blue opsin expression in zebrafish UV cones and pineal cells.

    PubMed

    Takechi, Masaki; Seno, Sadayoshi; Kawamura, Shoji

    2008-11-14

    Opsin genes are expressed in a cell type-specific manner in the retina and the pineal organ for visual and nonvisual photoreceptive purposes, but the regulatory mechanism behind the tissue and cell selectivity is not well understood. In this study, we focus on the expression regulation of the blue-sensitive opsin gene SWS2 of zebrafish by taking a transgenic approach using the green fluorescence protein as an expression reporter. The zebrafish SWS2 is a single-copy gene and is expressed specifically in the "long single cones" in the retina. We found the following. 1) A 0.3-kb region between 0.6 and 0.3 kb 5' of the SWS2 initiation codon, encompassing four cone-rod homeobox-binding sites (OTX sequences), contains the region necessary and sufficient to drive gene expression in long single cones. 2) A 15-bp portion (-341 to -327) in the 0.3-kb region represses the gene expression in the "short single cones," which are dedicated to the UV-sensitive opsin gene SWS1. 3) An 11-bp sequence TAACTGCCAGT (-441 to -431) in the 0.3-kb region, with its adjacent OTX element, also works as a repressor for gene expression in the pineal cells. 4) Finally, this OTX site is necessary for expression repression in the bipolar cells in the retina. These findings open a way for understanding the complex interaction of positive and negative regulatory factors that govern the cell type specificity of the opsin gene expression in the photoreceptive cells in the retina and the pineal organ. We termed the novel 11-bp sequence as the pineal negative regulatory element, PINE. PMID:18796431

  4. Localization and characterization of val-opsin isoform-expressing cells in the brain of adult zebrafish.

    PubMed

    Hang, Chong Yee; Kitahashi, Takashi; Parhar, Ishwar S

    2014-12-01

    In addition to vision, light information is used to regulate a range of animal physiology. Such nonimage-forming functions of light are mediated by nonvisual photoreceptors expressed in distinct neurons in the retina and the brain in most vertebrates. A nonvisual photoreceptor vertebrate ancient long opsin (VAL-opsin) possesses two functional isoforms in the zebrafish, encoded by valopa and valopb, which has received little attention. To delineate the neurochemical identities of valop cells and to test for colocalization of the valop isoforms, we used in situ hybridization to characterize the expression of the valop genes along with that of neurotransmitters and a neuropeptide known to be present at the sites of valop expression. Double labeling showed that the thalamic valop population coexpresses valopa and valopb. All the thalamic valop cells overlapped with a GABAergic cell mass that continues from the anterior nucleus to the intercalated thalamic nucleus. A novel valopa cell population found in the superior raphe was serotonergic in nature. A valopb cell population in the Edinger-Westphal nucleus was identified as containing thyrotropin-releasing hormone. Valopb cells localized in the hindbrain intermediate reticular formation were noncholinergic in nature (nonmotorneurons). Thus, the presence of valop cell populations in different brain regions with coexpression of neurotransmitters and neuropeptides and the colocalization of valop isoforms in the thalamic cell population indicate regulatory and functional complexity of VAL-opsin in the brain of the zebrafish. PMID:25043553

  5. Coexpression of opsin- and VIP-like-immunoreactivity in CSF-contacting neurons of the avian brain.

    PubMed

    Silver, R; Witkovsky, P; Horvath, P; Alones, V; Barnstable, C J; Lehman, M N

    1988-07-01

    Cerebrospinal fluid-contacting (CSF) cells in both the septal and the tuberal areas in the brain of the ring dove are labeled by RET-P1, a monoclonal antibody to opsin that reacts with inner and outer segment membranes of rod photoreceptors in a variety of vertebrates. Immunoblot analysis of proteins from diverse brain regions, however, revealed bands of anti-RET-P1 immunoreactivity that did not correspond to opsin. Binding of RET-P1 to opsin-containing membranes, was not inhibited by membranes rich in muscarinic and beta-adrenergic receptor proteins (red blood cells, heart, lung) taken from doves. RET-P1-immunoreactive CSF-contacting cells emit a dendritic process that penetrates the ependyma and ends in a knob-like terminal suspended in the ventricle. These cells also possess other processes that penetrate more or less deeply into the neuropil. Additionally, a band of labeled fibers occurs in the external layer of the median eminence. A double-label technique demonstrated that RET-P1-positive cells coexpress VIP-like immunoreactivity. VIP-positive cells in other brain areas are not RET-P1-positive. PMID:2970894

  6. Evolutionary dynamics of Rh2 opsins in birds demonstrate an episode of accelerated evolution in the New World warblers (Setophaga).

    PubMed

    Bloch, Natasha I; Price, Trevor D; Chang, Belinda S W

    2015-05-01

    Low rates of sequence evolution associated with purifying selection can be interrupted by episodic changes in selective regimes. Visual pigments are a unique system in which we can investigate the functional consequences of genetic changes, therefore connecting genotype to phenotype in the context of natural and sexual selection pressures. We study the RH2 and RH1 visual pigments (opsins) across 22 bird species belonging to two ecologically convergent clades, the New World warblers (Parulidae) and Old World warblers (Phylloscopidae) and evaluate rates of evolution in these clades along with data from 21 additional species. We demonstrate generally slow evolution of these opsins: both Rh1 and Rh2 are highly conserved across Old World and New World warblers. However, Rh2 underwent a burst of evolution within the New World genus Setophaga, where it accumulated substitutions at 6 amino acid sites across the species we studied. Evolutionary analyses revealed a significant increase in dN /dS in Setophaga, implying relatively strong selective pressures to overcome long-standing purifying selection. We studied the effects of each substitution on spectral tuning and found they do not cause large spectral shifts. Thus, substitutions may reflect other aspects of opsin function, such as those affecting photosensitivity and/or dark-light adaptation. Although it is unclear what these alterations mean for colour perception, we suggest that rapid evolution is linked to sexual selection, given the exceptional plumage colour diversification in Setophaga. PMID:25827331

  7. Informational Lesions: Optical Perturbation of Spike Timing and Neural Synchrony Via Microbial Opsin Gene Fusions

    PubMed Central

    Han, Xue; Qian, Xiaofeng; Stern, Patrick; Chuong, Amy S.; Boyden, Edward S.

    2009-01-01

    Synchronous neural activity occurs throughout the brain in association with normal and pathological brain functions. Despite theoretical work exploring how such neural coordination might facilitate neural computation and be corrupted in disease states, it has proven difficult to test experimentally the causal role of synchrony in such phenomena. Attempts to manipulate neural synchrony often alter other features of neural activity such as firing rate. Here we evaluate a single gene which encodes for the blue-light gated cation channel channelrhodopsin-2 and the yellow-light driven chloride pump halorhodopsin from Natronobacterium pharaonis, linked by a self-cleaving 2A peptide. This fusion enables proportional expression of both opsins, sensitizing neurons to being bi-directionally controlled with blue and yellow light, facilitating proportional optical spike insertion and deletion upon delivery of trains of precisely-timed blue and yellow light pulses. Such approaches may enable more detailed explorations of the causal role of specific features of the neural code. PMID:19753326

  8. Inhibitory luminopsins: genetically-encoded bioluminescent opsins for versatile, scalable, and hardware-independent optogenetic inhibition

    PubMed Central

    Tung, Jack K.; Gutekunst, Claire-Anne; Gross, Robert E.

    2015-01-01

    Optogenetic techniques provide an unprecedented ability to precisely manipulate neural activity in the context of complex neural circuitry. Although the toolbox of optogenetic probes continues to expand at a rapid pace with more efficient and responsive reagents, hardware-based light delivery is still a major hurdle that limits its practical use in vivo. We have bypassed the challenges of external light delivery by directly coupling a bioluminescent light source (a genetically encoded luciferase) to an inhibitory opsin, which we term an inhibitory luminopsin (iLMO). iLMO was shown to suppress action potential firing and synchronous bursting activity in vitro in response to both external light and luciferase substrate. iLMO was further shown to suppress single-unit firing rate and local field potentials in the hippocampus of anesthetized rats. Finally, expression of iLMO was scaled up to multiple structures of the basal ganglia to modulate rotational behavior of freely moving animals in a hardware-independent fashion. This novel class of optogenetic probes demonstrates how non-invasive inhibition of neural activity can be achieved, which adds to the versatility, scalability, and practicality of optogenetic applications in freely behaving animals. PMID:26399324

  9. Diversity of opsin immunoreactivities in the extraretinal tissues of four anuran amphibians.

    PubMed

    Okano, K; Okano, T; Yoshikawa, T; Masuda, A; Fukada, Y; Oishi, T

    2000-02-01

    The pineal complex, deep brain, and skin have been known to function as extraretinal photoreceptors in non-mammalian vertebrates. To see the diversity of localization of extraretinal photoreceptors in lower vertebrates having different habitats, we analyzed the opsin-like immunoreactivities in anuran amphibians, Xenopus laevis, Rana catesbeiana, Rana nigromaculata, and Bufo japonicus. An antiserum (toad Rh-AS) was raised against rhodopsin purified from the retinas of Japanese toad, B. japonicus. In the retina of all the anurans examined, the outer segments of rods were immunopositive to toad Rh-AS. The outer segments of most pinealocytes were immunopositive in R. catesbeiana, R. nigromaculata, and B. japonicus. The outer segments of photoreceptor-like cells within the frontal organ of R. nigromaculata were immunostained. Interestingly, toad Rh-AS immunostained many secretory cells of mucous glands in the head skin of B. japonicus, implying the presence of a novel photoreceptive molecule. Within the hypothalamus, toad Rh-AS immunostained many cells in the magnocellular preoptic nucleus of R. catesbeiana and B. japonicus. Toad Rh-AS also labeled cerebrospinal fluid (CSF)-contacting cells in the anterior preoptic nucleus of R. nigromaculata and those adjacent to the lateral ventricle within the septum of R. catesbeiana. Thus the distribution patterns of the rhodopsin-like immunoreactivities among the anurans were highly diverged, and there was no relationship between the distribution patterns and their habitats. J. Exp. Zool. 286:136-142, 2000. PMID:10617855

  10. Light perception in the vertebrate brain: an ultrastructural analysis of opsin- and vasoactive intestinal polypeptide-immunoreactive neurons in iguanid lizards.

    PubMed

    Grace, M S; Alones, V; Menaker, M; Foster, R G

    1996-04-15

    Recent biochemical and immunocytochemical evidence indicates that a population of circadian and reproductive rhythm-entraining photoreceptors lies in the basal diencephalon of iguanid lizards. Here, we report the results of correlated light and electron microscopy of opsin-immunoreactive cells in the basal brain, and we discuss their ultrastructural relationship to known photoreceptors. Cerebrospinal fluid (CSF)-contacting bipolar neurons in the lizards Anolis carolinensis and Iguana iguana were immunolabeled with antisera generated against vertebrate retinal opsins and vasoactive intestinal polypeptide (VIP). Within the brain, opsin-immunoreactive cells were found exclusively in the ependyma of the basal region of the lateral ventricles (adjacent to nucleus paraolfactorius/nucleus ventromedialis and neostriatum/paleostriatum). Cells in the same anatomical location and with the same morphology were labeled with anti-VIP antisera. These cells possessed a dendritic process that extended toward the lateral ventricle, ending in a bulbous terminal that protruded into the ventricle. Axonal processes travelled ventrally and caudally. The entire cell, including the axonal process, exhibited opsin-like and VIP-like immunoreactivity. By light microscopy, opsin-like immunostaining appeared punctate, with immunoreactivity greatest in the bulbous terminal. Opsin- and VIP-immunostained thick sections were resectioned, and individual cells observed by light microscopy were then characterized using electron microscopy. We found that all immunostained cells were morphologically similar and that they were morphologically distinct from neighboring nonimmunoreactive cells. CSF-contacting opsin- and VIP-immunoreactive cells lacked the membranous stacks characteristic of retinal photoreceptors but were ciliated and contained numerous large electron-dense vesicles. Multiple synaptic contacts were made on the soma and putative dendritic processes of opsin- and VIP-immunoreactive CSF-contacting neurons. Our results provide the first ultrastructural characterization of opsin-immunostained encephalic CSF-contacting neurons in a vertebrate animal, and they indicate that these putative photoreceptors share structural features with pineal photoreceptors and with certain invertebrate extraretinal photoreceptors, but they are morphologically and biochemically distinct from visual photoreceptors of the retina. PMID:8731227

  11. Opsin Effect on the Electronic Structure of the Retinylidene Chromophore in Rhodopsin.

    PubMed

    Sproviero, Eduardo M

    2015-03-10

    Direct examination of experimental NMR parameters combined with electronic structure analysis was used to provide a first-principle interpretation of NMR experiments and give a precise evaluation of how the electronic perturbation of the protein environment affects the electronic properties of the retinylidene chromophere in rhodopsin. To this end, we pursued a theoretical analysis using a combination of tools including quantum mechanics/molecular mechanics (QM/MM) at the Density Functional Theory (DFT) level, in conjunction with gauge independent atomic orbital (GIAO) calculations of (13)C NMR chemical shieldings and (1)JCC spin-spin coupling constants obtained with the Coupled Perturbed DFT (CPDFT) method. The opsin effect on the retinylidene chromophere is interpreted as an inductive effect of Glu-113 which readjusts the weighting factors of resonance substructures of the conjugated chain of the chromophere. These changes give a rationalization to the alternating effect of the (13)C chemical shifts magnitudes when comparing the retinylidene chromophere in the presence and absence of the protein environment. Conversely, perturbation of ? orbitals has little to no effect over (1)J (13)C-(13)C spin-spin coupling constants, as they are mainly dominated by the Fermi contact term, and hence the counteraion effect is restricted to the vicinity of the perturbation. Thus, the apparent contradiction between experimental findings based on chemical shifts (deep penetration) and one-bond J-couplings (localized effects of the protonated Schiff base at the chain terminus) is in fact a consequence of different properties responding differently to the same external perturbation. PMID:26579769

  12. The halo-opsin gene. II. Sequence, primary structure of halorhodopsin and comparison with bacteriorhodopsin

    PubMed Central

    Blanck, A.; Oesterhelt, D.

    1987-01-01

    The gene for the protein moiety of the light-driven chloride pump halorhodopsin (HR), hop gene, was sequenced and the primary structure of the protein derived thereof. The gene has a GC content of 67% and codes for 274 amino acids. A promoter structure, resembling that of the halobacterial 16S rRNA genes, is present and both a terminating stem and a loop sequence is found downstream of the TGA stop codon. A ribosomal binding site is located within the translated region. The HR protein moiety is processed at the amino terminus, as well as the carboxy terminus, yielding a dominant species of calculated Mr 26 961. Seven transmembrane helical parts of the protein are defined by hydropathy and acrophilicity calculations. Comparision with the bacteriorhodopsin (BR) structure reveals a conservation of 36% of amino acid residues in the transmembrane part and 19% in the connecting loops at both surfaces. The most conspicuous conserved amino acids are the retinal-binding Lys residue, four Trp residues (eventually interacting with retinal), two Asp residues (providing possibly the negative charge environment of retinal) and three Pro residues of unknown function. No significant homology with the opsins of eucaryotes was found. Helical wheel analysis shows that HR is an inside-out protein with the majority of conserved amino acid residues inside the circle of the seven transmembrane helices. It is postulated that the intrahelical spaces, which could be gated by the retinal moiety, are the physical entities for translocation of protons in BR and chloride ions in HR. Retinal, by its cis−trans isomerization, serves as a switch connecting the ion-specific binding sites in both proteins. PMID:15981336

  13. Adaptations to an extreme environment: retinal organisation and spectral properties of photoreceptors in Antarctic notothenioid fish.

    PubMed

    Pointer, Marie A; Cheng, Chi-Hing Christina; Bowmaker, James K; Parry, Juliet W L; Soto, Nelyn; Jeffery, Glen; Cowing, Jill A; Hunt, David M

    2005-06-01

    The Notothenioid suborder of teleosts comprises a number of species that live below the sea ice of the Antarctic. The presence of 'antifreeze' glycoproteins in these fish as an adaptation to freezing temperature has been well documented but little is known about the adaptations of the visual system of these fish to a light environment in which both the quantity and spectral composition of downwelling sunlight has been reduced by passage through ice and snow. In this study, we show that the red/long-wave sensitive (LWS) opsin gene is not present in these fish but a UV-sensitive short-wave sensitive (SWS1) pigment is expressed along with blue-sensitive (SWS2) and green/middle-wave sensitive (Rh2) pigments. The identity and spectral location of maximal absorbance of the SWS1 and Rh2 pigments was confirmed by in vitro expression of the recombinant opsins followed by regeneration with 11-cis retinal. Only the SWS2 pigment showed interspecific variations in peak absorbance. Expression of the Rh2 opsin is localised to double cone receptors in both the central and peripheral retina, whereas SWS2 opsin expression is present only in the peripheral retina. SWS1 cones could not be identified by either microspectrophotometry or in situ hybridisation, presumably reflecting their low number and/or uneven distribution across the retina. A study of photoreceptor organisation in the retina of two species, the shallower dwelling Trematomus hansoni and the deeper dwelling Dissostichus mawsoni, identified a square mosaic in the former, and a row mosaic in the latter species; the row mosaic in Dissostichus mawsoni with less tightly packed cone photoreceptors allows for a higher rod photoreceptor density. PMID:15939776

  14. Possible Involvement of Cone Opsins in Distinct Photoresponses of Intrinsically Photosensitive Dermal Chromatophores in Tilapia Oreochromis niloticus

    PubMed Central

    Chen, Shyh-Chi; Robertson, R. Meldrum; Hawryshyn, Craig W.

    2013-01-01

    Dermal specialized pigment cells (chromatophores) are thought to be one type of extraretinal photoreceptors responsible for a wide variety of sensory tasks, including adjusting body coloration. Unlike the well-studied image-forming function in retinal photoreceptors, direct evidence characterizing the mechanism of chromatophore photoresponses is less understood, particularly at the molecular and cellular levels. In the present study, cone opsin expression was detected in tilapia caudal fin where photosensitive chromatophores exist. Single-cell RT-PCR revealed co-existence of different cone opsins within melanophores and erythrophores. By stimulating cells with six wavelengths ranging from 380 to 580 nm, we found melanophores and erythrophores showed distinct photoresponses. After exposed to light, regardless of wavelength presentation, melanophores dispersed and maintained cell shape in an expansion stage by shuttling pigment granules. Conversely, erythrophores aggregated or dispersed pigment granules when exposed to short- or middle/long-wavelength light, respectively. These results suggest that diverse molecular mechanisms and light-detecting strategies may be employed by different types of tilapia chromatophores, which are instrumental in pigment pattern formation. PMID:23940562

  15. Identification of G protein coupled receptors for opsines and neurohormones in Rhodnius prolixus. Genomic and transcriptomic analysis.

    PubMed

    Ons, Sheila; Lavore, Andrs; Sterkel, Marcos; Wulff, Juan Pedro; Sierra, Ivana; Martnez-Barnetche, Jess; Rodriguez, Mario Henry; Rivera-Pomar, Rolando

    2016-02-01

    The importance of Chagas disease motivated the scientific effort to obtain the complete genomic sequence of the vector species Rhodnius prolixus, this information is also relevant to the understanding of triatomine biology in general. The central nervous system is the key regulator of insect physiology and behavior. Neurohormones (neuropeptides and biogenic amines) are the chemical messengers involved in the regulation and integration of neuroendocrine signals. In insects, this signaling is mainly mediated by the interaction of neurohormone ligands with G protein coupled receptors (GPCRs). The recently sequenced R.prolixus genome provides us with the opportunity to analyze this important family of genes in triatomines, supplying relevant information for further functional studies. Next-generation sequencing methods offer an excellent opportunity for transcriptomic exploration in key organs and tissues in the presence of a reference genome as well as when a reference genome is not available. We undertook a genomic analysis to obtain a genome-wide inventory of opsines and the GPCRs for neurohormones in R.prolixus. Furthermore, we performed a transcriptomic analysis of R.prolixus central nervous system, focusing on neuropeptide precursor genes and neurohormone and opsines GPCRs. In addition, we mined the whole transcriptomes of Triatoma dimidiata, Triatoma infestans and Triatoma pallidipennis - three sanitary relevant triatomine species - to identify neuropeptide precursors and GPCRs genes. Our study reveals a high degree of sequence conservation in the molecular components of the neuroendocrine system of triatomines. PMID:25976540

  16. Nocturnal light environments influence color vision and signatures of selection on the OPN1SW opsin gene in nocturnal lemurs.

    PubMed

    Veilleux, Carrie C; Louis, Edward E; Bolnick, Deborah A

    2013-06-01

    Although loss of short-wavelength-sensitive (SWS) cones and dichromatic color vision in mammals has traditionally been linked to a nocturnal lifestyle, recent studies have identified variation in selective pressure for the maintenance of the OPN1SW opsin gene (and thus, potentially dichromacy) among nocturnal mammalian lineages. These studies hypothesize that purifying selection to retain SWS cones may be associated with a selective advantage for nocturnal color vision under certain ecological conditions. In this study, we explore the effect of nocturnal light environment on OPN1SW opsin gene evolution in a diverse sample of nocturnal lemurs (106 individuals, 19 species, and 5 genera). Using both phylogenetic and population genetic approaches, we test whether species from closed canopy rainforests, which are impoverished in short-wavelength light, have experienced relaxed selection compared with species from open canopy forests. We identify clear signatures of differential selection on OPN1SW by habitat type. Our results suggest that open canopy species generally experience strong purifying selection to maintain SWS cones. In contrast, closed canopy species experience weaker purifying selection or a relaxation of selection on OPN1SW. We also found evidence of nonfunctional OPN1SW genes in all Phaner species and in Cheirogaleus medius, implying at least three independent losses of SWS cones in cheirogaleids. Our results suggest that the evolution of color vision in nocturnal lemurs has been influenced by nocturnal light environment. PMID:23519316

  17. X-linked cone dystrophy and colour vision deficiency arising from a missense mutation in a hybrid L/M cone opsin gene

    PubMed Central

    McClements, Michelle; Davies, Wayne I L; Michaelides, Michel; Carroll, Joseph; Rha, Jungate; Mollon, John D; Neitz, Maureen; MacLaren, Robert E; Moore, Anthony T; Hunt, David M

    2013-01-01

    In this report, we describe a male subject who presents with a complex phenotype of myopia associated with cone dysfunction and a protan vision deficiency. Retinal imaging demonstrates extensive cone disruption, including the presence of non-waveguiding cones, an overall thinning of the retina, and an irregular mottled appearance of the hyper reflective band associated with the inner segment ellipsoid portion of the photoreceptor. Mutation screening revealed a novel p.Glu41Lys missense mutation in a hybrid L/M opsin gene. Spectral analysis shows that the mutant opsin fails to form a pigment in vitro and fails to be trafficked to the cell membrane in transfected Neuro2a cells. Extensive sequence and quantitative PCR analysis identifies this mutant gene as the only gene present in the affected subject’s L/M opsin gene array, yet the presence of protanopia indicates that the mutant opsin must retain some activity in vivo. To account for this apparent contradiction, we propose that a limited amount of functional pigment is formed within the normal cellular environment of the intact photoreceptor, and that this requires the presence of chaperone proteins that promote stability and normal folding of the mutant protein. PMID:23337435

  18. Photoreceptors for a light biotransducer: a comparative study of the electrical responses of two (type-1) opsins

    NASA Astrophysics Data System (ADS)

    Alfinito, E.; Pousset, J.; Reggiani, L.; Lee, K.

    2013-10-01

    The increasing interest in photoactivated proteins as natural replacements for standard inorganic materials in photocells leads to the comparison analysis of bacteriorhodopsin and proteorhodopsin, two widely diffused proteins belonging to the family of type-1 opsins. These proteins share similar behaviors but exhibit relevant differences in the sequential chain of the amino acids constituting their tertiary structure. The use of an impedance network analog to model the protein main features provides a microscopic interpretation of a set of experiments on their photo-conductance properties. In particular, this model links the protein electrical responses to the tertiary structure and to the interactions between neighboring amino acids. The same model is also used to predict the small-signal response in terms of the Nyquist plot. Interestingly, these rhodopsins are found to behave like a wide-gap semiconductor with intrinsic conductivities of the order of 10-7 S cm-1.

  19. Retrograde intraciliary trafficking of opsin during the maintenance of cone shaped photoreceptor outer segments of Xenopus laevis

    PubMed Central

    Lee, Richard; Imanishi, Yoshikazu

    2014-01-01

    Photoreceptor outer segments (OSs) are essential for our visual perception, and take either rod or cone forms. The cell biological basis for the formation of rods is well established, however, the mechanism of cone formation is ill characterized. While Xenopus rods are called rods, they exhibit cone shaped OSs during the early process of development. To visualize the dynamic reorganization of disk membranes, opsin and peripherin/rds were fused to a fluorescent protein Dendra2 and expressed in early developing rod photoreceptors, in which OSs are still cone shaped. Dendra2 is a fluorescent protein which can be converted from green to red irreversibly, and thus allows spatiotemporal labeling of proteins. Using a photoconversion technique, we found that disk membranes are assembled at the base of cone shaped OSs. After incorporation into disks, however, Opsin-Dendra2 was also trafficked from old to new disk membranes, consistent with the hypothesis that retrograde trafficking of membrane components contributes to the larger disk membrane observed toward the base of the cone shaped OS. Such retrograde trafficking is cargo specific and was not observed for peripherin/rds-Dendra2. The trafficking is unlikely mediated by diffusion, since the disk membranes have a closed configuration, as evidenced by CNGA1 labeling of the plasma membrane. Consistent with retrograde trafficking, the axoneme, which potentially mediates retrograde intraflagellar trafficking, runs through the entire axis of OSs. This study provides an insight into the role of membrane reorganization in developing photoreceptor OSs, and proves that retrograde trafficking of membrane cargoes can occur there. PMID:24855015

  20. Opsin gene sequence variation across phylogenetic and population histories in Mysis (Crustacea: Mysida) does not match current light environments or visual-pigment absorbance spectra.

    PubMed

    Audzijonyte, Asta; Pahlberg, Johan; Viljanen, Martta; Donner, Kristian; Vinl, Risto

    2012-05-01

    The hypothesis that selection on the opsin gene is efficient in tuning vision to the ambient light environment of an organism was assessed in 49 populations of 12 Mysis crustacean species, inhabiting arctic marine waters, coastal littoral habitats, freshwater lakes ('glacial relicts') and the deep Caspian Sea. Extensive sequence variation was found within and among taxa, but its patterns did not match expectations based on light environments, spectral sensitivity of the visual pigment measured by microspectrophotometry or the history of species and populations. The main split in the opsin gene tree was between lineages I and II, differing in six amino acids. Lineage I was present in marine and Caspian Sea species and in the North American freshwater Mysis diluviana, whereas lineage II was found in the European and circumarctic fresh- and brackish-water Mysis relicta, Mysis salemaai and Mysis segerstralei. Both lineages were present in some populations of M. salemaai and M. segerstralei. Absorbance spectra of the visual pigment in nine populations of the latter three species showed a dichotomy between lake (?(max) =554-562 nm) and brackish-water (Baltic Sea) populations (?(max) = 521-535 nm). Judged by the shape of spectra, this difference was not because of different chromophores (A2 vs. A1), but neither did it coincide with the split in the opsin tree (lineages I/II), species identity or current light environments. In all, adaptive evolution of the opsin gene in Mysis could not be demonstrated, but its sequence variation did not conform to a neutral expectation either, suggesting evolutionary constraints and/or unidentified mechanisms of spectral tuning. PMID:22429275

  1. The influence of L-opsin gene polymorphisms and neural ageing on spatio-chromatic contrast sensitivity in 20-71 year olds.

    PubMed

    Dees, Elise W; Gilson, Stuart J; Neitz, Maureen; Baraas, Rigmor C

    2015-11-01

    Chromatic contrast sensitivity may be a more sensitive measure of an individual's visual function than achromatic contrast sensitivity. Here, the first aim was to quantify individual- and age-related variations in chromatic contrast sensitivity to a range of spatial frequencies for stimuli along two complementary directions in color space. The second aim was to examine whether polymorphisms at specific amino acid residues of the L- and M-opsin genes (OPN1LW and OPN1MW) known to affect spectral tuning of the photoreceptors could influence spatio-chromatic contrast sensitivity. Chromatic contrast sensitivity functions were measured in 50 healthy individuals (20-71 years) employing a novel pseudo-isochromatic grating stimulus. The spatio-chromatic contrast sensitivity functions were found to be low pass for all subjects, independent of age and color vision. The results revealed a senescent decline in spatio-chromatic contrast sensitivity. There were considerable between-individual differences in sensitivity within each age decade for individuals 49 years old or younger, and age did not predict sensitivity for these age decades alone. Forty-six subjects (including a color deficient male and eight female carriers) were genotyped for L- and M-opsin genes. The Ser180Ala polymorphisms on the L-opsin gene were found to influence the subject's color discrimination and their sensitivity to spatio-chromatic patterns. The results expose the significant role of neural and genetic factors in the deterioration of visual function with increasing age. PMID:26368273

  2. Development of Lead Hammerhead Ribozyme Candidates against Human Rod Opsin mRNA for Retinal Degeneration Therapy

    PubMed Central

    Abdelmaksoud, Heba E.; Yau, Edwin H.; Zuker, Michael; Sullivan, Jack M.

    2011-01-01

    To identify lead candidate allele-independent hammerhead ribozymes (hhRz) for the treatment of autosomal dominant mutations in the human rod opsin (RHO) gene, we tested a series of hhRzs for potential to significantly knockdown human RHO gene expression in a human cell expression system. Multiple computational criteria were used to select target mRNA regions likely to be single stranded and accessible to hhRz annealing and cleavage. Target regions are tested for accessibility in a human cell culture expression system where the hhRz RNA and target mRNA and protein are coexpressed. The hhRz RNA is embedded in an adenoviral VAI RNA chimeric RNA of established structure and properties which are critical to the experimental paradigm. The chimeric hhRz-VAI RNA is abundantly transcribed so that the hhRzs are expected to be in great excess over substrate mRNA. HhRz-VAI traffics predominantly to the cytoplasm to colocalize with the RHO mRNA target. Colocalization is essential for second-order annealing reactions. The VAI chimera protects the hhRz RNA from degradation and provides for a long half life. With cell lines chosen for high transfection efficiency and a molar excess of hhRz plasmid over target plasmid, the conditions of this experimental paradigm are specifically designed to evaluate for regions of accessibility of the target mRNA in cellulo. Western analysis was used to measure the impact of hhRz expression on RHO protein expression. Three lead candidate hhRz designs were identified that significantly knockdown target protein expression relative to control (p < 0.05). Successful lead candidates (hhRz CUC? 266, hhRz CUC? 1411, hhRz AUA? 1414) targeted regions of human RHO mRNA that were predicted to be accessible by a bioinformatics approach, whereas regions predicted to be inaccessible supported no knockdown. The maximum opsin protein level knockdown is approximately 30% over a 48 hr paradigm of testing. These results validate a rigorous computational bioinformatics approach to detect accessible regions of target mRNAs in cellulo. The opsin knockdown effect could prove to be clinically significant when integrated over longer periods in photoreceptors. Further optimization and animal testing is the next step in this stratified RNA drug discovery program. A recently developed novel and efficient screening assay based upon expression of a dicistronic mRNA (RHO-IRES-SEAP) containing both RHO and reporter (SEAP) cDNAs was used to compare the hhRz 266 lead candidate to another agent (Rz525/hhRz485) already known to partially rescue retinal degeneration in a rodent model. Lead hhRz 266 CUC? proved more efficacious than Rz525/hhRz485 which infers viability for rescue of retinal degeneration in appropriate preclinical models of disease. PMID:19094986

  3. Opsin1-2, Gq? and arrestin levels at Limulus rhabdoms are controlled by diurnal light and a circadian clock

    PubMed Central

    Battelle, Barbara-Anne; Kempler, Karen E.; Parker, Alexander K.; Gaddie, Cristina D.

    2013-01-01

    SUMMARY Dark and light adaptation in photoreceptors involve multiple processes including those that change protein concentrations at photosensitive membranes. Light- and dark-adaptive changes in protein levels at rhabdoms have been described in detail in white-eyed Drosophila maintained under artificial light. Here we tested whether protein levels at rhabdoms change significantly in the highly pigmented lateral eyes of wild-caught Limulus polyphemus maintained in natural diurnal illumination and whether these changes are under circadian control. We found that rhabdomeral levels of opsins (Ops1-2), the G protein activated by rhodopsin (Gq?) and arrestin change significantly from day to night and that nighttime levels of each protein at rhabdoms are significantly influenced by signals from the animal's central circadian clock. Clock input at night increases Ops1-2 and Gq? and decreases arrestin levels at rhabdoms. Clock input is also required for a rapid decrease in rhabdomeral Ops1-2 beginning at sunrise. We found further that dark adaptation during the day and the night are not equivalent. During daytime dark adaptation, when clock input is silent, the increase of Ops1-2 at rhabdoms is small and Gq? levels do not increase. However, increases in Ops1-2 and Gq? at rhabdoms are enhanced during daytime dark adaptation by treatments that elevate cAMP in photoreceptors, suggesting that the clock influences dark-adaptive increases in Ops1-2 and Gq? at Limulus rhabdoms by activating cAMP-dependent processes. The circadian regulation of Ops1-2 and Gq? levels at rhabdoms probably has a dual role: to increase retinal sensitivity at night and to protect photoreceptors from light damage during the day. PMID:23393287

  4. Temporal Resolution of ChR2 and Chronos in an Optogenetic-based Auditory Brainstem Implant Model: Implications for the Development and Application of Auditory Opsins

    PubMed Central

    Hight, A. E.; Kozin, Elliott D.; Darrow, Keith; Lehmann, Ashton; Boyden, Edward; Brown, M. Christian; Lee, Daniel J.

    2015-01-01

    The contemporary auditory brainstem implant (ABI) performance is limited by reliance on electrical stimulation with its accompanying channel cross talk and current spread to non-auditory neurons. A new generation ABI based on optogenetic-technology may ameliorate limitations fundamental to electrical neurostimulation. The most widely studied opsin is channelrhodopsin-2 (ChR2); however, its relatively slow kinetic properties may prevent the encoding of auditory information at high stimulation rates. In the present study, we compare the temporal resolution of light-evoked responses of a recently developed fast opsin, Chronos, to ChR2 in a murine ABI model. Viral mediated gene transfer via a posterolateral craniotomy was used to express Chronos or ChR2 in the mouse nucleus (CN). Following a four to six week incubation period, blue light (473 nm) was delivered via an optical fiber placed directly on the surface of the infected CN, and neural activity was recorded in the contralateral inferior colliculus (IC). Both ChR2 and Chronos evoked sustained responses to all stimuli, even at high driven rates. In addition, optical stimulation evoked excitatory responses throughout the tonotopic axis of the IC. Synchrony of the light-evoked response to stimulus rates of 14448 pulses/s was higher in Chronos compared to ChR2 mice (p<0.05 at 56, 168, and 224 pulses/s). Our results demonstrate that Chronos has the ability to drive the auditory system at higher stimulation rates than ChR2 and may be a more ideal opsin for manipulation of auditory pathways in future optogenetic-based neuroprostheses. PMID:25598479

  5. A comparison of the ultrastructure and opsin immunocytochemistry of the pineal organ and retina of the deep-sea fish Chimaera monstrosa.

    PubMed

    Vigh-Teichmann, I; Szl, A; Rhlich, P; Vigh, B

    1990-01-01

    The pineal organ and retina of the rat-fish Chimaera monstrosa were compared by electron microscopy and immunocytochemistry using antisera against colour-specific opsins and paying special attention to pineal CSF-contacting neurons and retinal Landolt's clubs. In the retina, a large number of Landolt's clubs and two types of rod-like photoreceptors were found. The outer segments of the numerous electron-dense "tall rods" displayed strong immunoreactivity with the monoclonal OS-2 antibodies--first of all detecting green- and blue-sensitive pigments. These results point out the presence of a chrysopsin-like photopigment. A weak cross-reactivity with the COS-1 and rhodopsin antisera indicates that the photopigment in question has certain amino acid sequence homologies with red and green photopigments. The outer segments of the few electron-lucent "broad rods" reacted with the OS-2 antiserum intensely but weakly with the COS-1 antiserum, a result suggesting the presence of a (blue?) photopigment differing from that of the tall rods. Since in the pineal organ the outer segments of the photoreceptor cells were opsin-immunonegative with all four antisera used, it is suggested that they contain an essentially different (UV-blue?) pigment. The pineal CSF-contacting neurons and retinal Landolt's bipolars were found to be principally similar in cytology. Their ciliated (receptor) dendrite terminals protruding into the photoreceptor space lacked photoreceptor membranes and were opsin-immunonegative. They are supposed to perceive information (on ionic properties?) from the fluid of the pineal lumen and retinal photoreceptor space. On the other hand, by their synaptic connections the CSF-contacting neurons and Landolt's bipolars are considered to be secondary neurons of the light-perceiving pathway of both organs. PMID:2142101

  6. Co-translational targeting and translocation of the amino terminus of opsin across the endoplasmic membrane requires GTP but not ATP.

    PubMed

    Kanner, Elliott M; Friedlander, Martin; Simon, Sanford M

    2003-03-01

    The tight coupling between ongoing translation and translocation across the mammalian endoplasmic reticulum has made it difficult to determine the requirements that are specific for translocation. We have developed an in vitro assay that faithfully mimics the co-translational targeting and translocation of the amino terminus of opsin without ongoing translation. Using this system we demonstrate that this post-translational targeting and translocation requires nucleotide triphosphates but not cytosolic proteins. The addition of GTP alone was sufficient to fully restore targeting. The addition of ATP was not specifically required, and non-hydrolyzable analogs of ATP that blocked 90% of the ATPase activity also had no inhibitory effect on translocation. PMID:12486130

  7. The Living With a Star (LWS) Sentinels

    NASA Astrophysics Data System (ADS)

    Szabo, Adam

    This paper gives a short account of the development of the living with a star Sentinels element. The Sentinels element is the heliospheric portion of the NASA program focused on improving our understanding of geo-effective events in the Sun-Earth connected system. The primary objectives of Sentinels are the investigation of the initiation and evolution of solar transients in the inner heliosphere, the acceleration and propagation of solar energetic particles, and the long term climatic change and structure of the inner heliosphere into which all of these geo-effective structures erupt. Due to the large volume of space to be covered, Sentinels will have to rely on, besides a dedicated mission, the observations of spacecraft from other programs of NASA and international partners along with a robust theoretical and modeling effort. The upcoming Sentinels Science and Technology Definition Team will develop specific details of this element.

  8. Opsin1-2, G(q)? and arrestin levels at Limulus rhabdoms are controlled by diurnal light and a circadian clock.

    PubMed

    Battelle, Barbara-Anne; Kempler, Karen E; Parker, Alexander K; Gaddie, Cristina D

    2013-05-15

    Dark and light adaptation in photoreceptors involve multiple processes including those that change protein concentrations at photosensitive membranes. Light- and dark-adaptive changes in protein levels at rhabdoms have been described in detail in white-eyed Drosophila maintained under artificial light. Here we tested whether protein levels at rhabdoms change significantly in the highly pigmented lateral eyes of wild-caught Limulus polyphemus maintained in natural diurnal illumination and whether these changes are under circadian control. We found that rhabdomeral levels of opsins (Ops1-2), the G protein activated by rhodopsin (G(q)?) and arrestin change significantly from day to night and that nighttime levels of each protein at rhabdoms are significantly influenced by signals from the animal's central circadian clock. Clock input at night increases Ops1-2 and G(q)? and decreases arrestin levels at rhabdoms. Clock input is also required for a rapid decrease in rhabdomeral Ops1-2 beginning at sunrise. We found further that dark adaptation during the day and the night are not equivalent. During daytime dark adaptation, when clock input is silent, the increase of Ops1-2 at rhabdoms is small and G(q)? levels do not increase. However, increases in Ops1-2 and G(q)? at rhabdoms are enhanced during daytime dark adaptation by treatments that elevate cAMP in photoreceptors, suggesting that the clock influences dark-adaptive increases in Ops1-2 and G(q)? at Limulus rhabdoms by activating cAMP-dependent processes. The circadian regulation of Ops1-2 and G(q)? levels at rhabdoms probably has a dual role: to increase retinal sensitivity at night and to protect photoreceptors from light damage during the day. PMID:23393287

  9. Targeting the cyclophilin domain of Ran-binding protein 2 (Ranbp2) with novel small molecules to control the proteostasis of STAT3, hnRNPA2B1 and M-opsin.

    PubMed

    Cho, Kyoung-In; Orry, Andrew; Park, Se Eun; Ferreira, Paulo A

    2015-08-19

    Cyclophilins are peptidyl cis-trans prolyl isomerases (PPIases), whose activity is typically inhibited by cyclosporine A (CsA), a potent immunosuppressor. Cyclophilins are also chaperones. Emerging evidence supports that cyclophilins present nonoverlapping PPIase and chaperone activities. The proteostasis of the disease-relevant substrates, signal transducer and activator of transcription 3 and 5 (STAT3/STAT5), heterogeneous nuclear ribonucleoprotein A2B1 (hnRNPA2B1), and M-opsin, is regulated by nonoverlapping chaperone and PPIase activities of the cyclophilin domain (CY) of Ranbp2, a multifunctional and modular scaffold that controls nucleocytoplasmic shuttling and proteostasis of selective substrates. Although highly homologous, CY and the archetypal cyclophilin A (CyPA) present distinct catalytic and CsA-binding activities owing to unique structural features between these cylophilins. We explored structural idiosyncrasies between CY and CyPA to screen in silico nearly 9 million small molecules (SM) against the CY PPIase pocket and identify SMs with selective bioactivity toward STAT3, hnRNPA2B1, or M-opsin proteostasis. We found three classes of SMs that enhance the cytokine-stimulated transcriptional activity of STAT3 without changing latent and activated STAT3 levels, down-regulate hnRNPA2B1 or M-opsin proteostasis, or a combination of these. Further, a SM that suppresses hnRNPA2B1 proteostasis also inhibits strongly and selectively the PPIase activity of CY. This study unravels chemical probes for multimodal regulation of CY of Ranbp2 and its substrates, and this regulation likely results in the allosterism stemming from the interconversion of conformational substates of cyclophilins. The results also demonstrate the feasibility of CY in drug discovery against disease-relevant substrates controlled by Ranbp2, and they open new opportunities for therapeutic interventions. PMID:26030368

  10. Targeting of exon VI-skipping human RGR-opsin to the plasma membrane of pigment epithelium and co-localization with terminal complement complex C5b-9

    PubMed Central

    Kochounian, Harold; Zhang, Zhaoxia; Spee, Christine; Hinton, David R.

    2016-01-01

    Purpose Rare mutations in the human RGR gene lead to autosomal recessive retinitis pigmentosa or dominantly inherited peripapillary choroidal atrophy. Here, we analyze a common exon-skipping isoform of the human retinal G protein-coupled receptor opsin (RGR-d) to determine differences in subcellular targeting between RGR-d and normal RGR and possible association with abnormal traits in the human eye. Methods The terminal complement complex (C5b-9), vitronectin, CD46, syntaxin-4, and RGR-d were analyzed in human eye tissue from young and old donors or in cultured fetal RPE cells by means of immunofluorescent labeling and high-resolution confocal microscopy or immunohistochemical staining. Results We observed that RGR-d is targeted to the basolateral plasma membrane of the RPE. RGR-d, but not normal RGR, is expressed in cultured human fetal RPE cells in which the protein also trafficks to the plasma membrane. In young donors, the amount of RGR-d protein in the basolateral plasma membrane was much higher than that in the RPE cells of older subjects. In older donor eyes, the level of immunoreactive RGR-d within RPE cells was often low or undetectable, and immunostaining of RGR-d was consistently strongest in extracellular deposits in Bruch’s membrane. Double immunofluorescent labeling in the basal deposits revealed significant aggregate and small punctate co-localization of RGR-d with C5b-9 and vitronectin. Conclusions RGR-d may escape endoplasmic reticulum-associated degradation and in contrast to full-length RGR, traffick to the basolateral plasma membrane, particularly in younger subjects. RGR-d in the plasma membrane indicates that the protein is properly folded, as misfolded membrane proteins cannot otherwise sort to the plasma membrane. The close association of extracellular RGR-d with both vitronectin and C5b-9 suggests a potential role of RGR-d-containing deposits in complement activation. PMID:27011730

  11. ISO Guest Observer Data Analysis and LWS Instrument Team Activities

    NASA Technical Reports Server (NTRS)

    Smith, Howard

    2001-01-01

    The following is an interim annual report. Dr. Smith is currently on an extended TDY to the Istituto di Fisica dello Spazio Interplanetario (IFSI) at the Consilio Nazionale delle Richerche (CNR) in Rome, Italy, where he has been working on a related NASA grant in support of analysis of Infrared Space Observatory (ISO) data on star formation in Ultra Luminous Infrared Galaxies and our galaxy. Work emphasizes development of metal mesh grids for use in spacecraft, and the design and fabrication of test elements by the Naval Research Laboratory, Washington D.C. Work has progressed well, but slowly, on that program due to the departure of a key engineer. NASA has been advised of the delay, and granted a no-cost extension, whereby SAO has authorized a delay in the final report from NRL. Nevertheless NRL has continued to make progress. Two papers have been submitted to refereed journals related to this program, and a new design for mesh operating in the 20-40 micron region has been developed. Meetings continue through the summer on these items. A new technical scientist has been made a job offer and hopefully will be on board NRL shortly, although most of the present grant work is already completed. A more complete report, with copies of the submitted papers, designs, and other measures of progress, will be submitted to NASA in September when Dr. Smith returns from his current TDY.

  12. ISO Guest Observer Data Analysis and LWS Instrument Team Activities

    NASA Technical Reports Server (NTRS)

    Smith, Howard

    2002-01-01

    This project was granted a no-cost extension prompted by the request of the major subcontractor, the Naval Research Laboratory, which had not yet completed its tasks. As of July 2002, they had made substantial progress. They have successfully fabricated a metal mesh grid on polyimide, and also successfully fabricated a 2-layer metal mesh infrared filter using stacks of these metal mesh grids on polyimide; the actual layering was done at SAO. Both warm and cold spectroscopic tests were done on these fabricated devices. The measurements were in good agreement with the theory, and also reasonable performance in absolute terms. NRL is now working on fabricating a 3-layer metal mesh infrared filter, and a prototype is expected in the next month. Testing should occur before the end of the fiscal year. Finally, NRL has preliminarily agreed to hire a new postdoctoral person to refine the modeling of the filters based on the new measurements. The person should arrive this fall. NRL has a new Fourier Transform Spectrometer which will be delivered in the next month, and which will be used to facilitate the testing which has up to now been done in collaboration with NASA Goddard Space Flight Space Center.

  13. Extending the LWS Data Environment: Distributed Data Processing and Analysis

    NASA Technical Reports Server (NTRS)

    Narock, Thomas

    2005-01-01

    The final stages of this work saw changes to the original framework, as well as the completion and integration of several data processing services. Initially, it was thought that a peer-to-peer architecture was necessary to make this work possible. The peer-to-peer architecture provided many benefits including the dynamic discovery of new services that would be continually added. A prototype example was built and while it showed promise, a major disadvantage was seen in that it was not easily integrated into the existing data environment. While the peer-to-peer system worked well for finding and accessing distributed data processing services, it was found that its use was limited by the difficulty in calling it from existing tools and services. After collaborations with members of the data community, it was determined that our data processing system was of high value and that a new interface should be pursued in order for the community to take full advantage of it. As such; the framework was modified from a peer-to-peer architecture to a more traditional web service approach. Following this change multiple data processing services were added. These services include such things as coordinate transformations and sub setting of data. Observatory (VHO), assisted with integrating the new architecture into the VHO. This allows anyone using the VHO to search for data, to then pass that data through our processing services prior to downloading it. As a second attempt at demonstrating the new system, a collaboration was established with the Collaborative Sun Earth Connector (CoSEC) group at Lockheed Martin. This group is working on a graphical user interface to the Virtual Observatories and data processing software. The intent is to provide a high-level easy-to-use graphical interface that will allow access to the existing Virtual Observatories and data processing services from one convenient application. Working with the CoSEC group we provided access to our data processing tools from within their software. This now allows the CoSEC community to take advantage of our services and also demonstrates another means of accessing our system.

  14. LWS design replacement study: Optimum design and tradeoff analysis

    NASA Technical Reports Server (NTRS)

    1973-01-01

    A design for two long-wavelength (LW) focal-plane and cooler assemblies, including associated preamplifiers and post-amplifiers is presented. The focal-planes and associated electronic assemblies are intended as direct replacement hardware to be installed into the existing 24-channel multispectral scanner used with the NASA Earth Observations Aircraft Program. An organization skilled in the art of LWIR systems can fabricate and deliver the two long-wavelength focal-plane assemblies described in this report when provided with the data and drawings developed during the performance of this contract. The concepts developed during the study including the alternative approaches and selection of components are discussed. Modifications to the preliminary design as reported in a preliminary design review meeting have also been included.

  15. ISO Guest Observer Data Analysis and LWS Instrument Team Activities

    NASA Technical Reports Server (NTRS)

    Oliversen, Ronald J. (Technical Monitor); Smith, Howard A.

    2003-01-01

    We have designed and fabricated infrared filters for use at wavelengths greater than or equal to 15 microns. Unlike conventional dielectric filters used at the short wavelengths, ours are made from stacked metal grids, spaced at a very small fraction of the performance wavelengths. The individual lattice layers are gold, the spacers are polyimide, and they are assembled using integrated circuit processing techniques; they resemble some metallic photonic band-gap structures. We simulate the filter performance accurately, including the coupling of the propagating, near-field electromagnetic modes, using computer aided design codes. We find no anomalous absorption. The geometrical parameters of the grids are easily altered in practice, allowing for the production of tuned filters with predictable useful transmission characteristics. Although developed for astronomical instrumentation, the filters are broadly applicable in systems across infrared and terahertz bands.

  16. The visual pigments of the West Indian manatee (Trichechus manatus).

    PubMed

    Newman, Lucy A; Robinson, Phyllis R

    2006-10-01

    Manatees are unique among the fully aquatic marine mammals in that they are herbivorous creatures, with hunting strategies restricted to grazing on sea-grasses. Since the other groups of (carnivorous) marine mammals have been found to possess various visual system adaptations to their unique visual environments, it was of interest to investigate the visual capability of the manatee. Previous work, both behavioral (Griebel & Schmid, 1996), and ultrastructural (Cohen, Tucker, & Odell, 1982; unpublished work cited by Griebel & Peichl, 2003), has suggested that manatees have the dichromatic color vision typical of diurnal mammals. This study uses molecular techniques to investigate the cone visual pigments of the manatee. The aim was to clone and sequence cone opsins from the retina, and, if possible, express and reconstitute functional visual pigments to perform spectral analysis. Both LWS and SWS cone opsins were cloned and sequenced from manatee retinae, which, upon expression and spectral analysis, had lambda(max) values of 555 and 410 nm, respectively. The expression of both the LWS and SWS cone opsin in the manatee retina is unique as both pinnipeds and cetaceans only express a cone LWS opsin. PMID:16650454

  17. Multiple Genetic Mechanisms Contribute to Visual Sensitivity Variation in the Labridae.

    PubMed

    Phillips, Genevieve A C; Carleton, Karen L; Marshall, N Justin

    2016-01-01

    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. PMID:26464127

  18. Functional characterization, tuning, and regulation of visual pigment gene expression in an anadromous lamprey.

    PubMed

    Davies, Wayne L; Cowing, Jill A; Carvalho, Livia S; Potter, Ian C; Trezise, Ann E O; Hunt, David M; Collin, Shaun P

    2007-09-01

    Lampreys are one of the two surviving groups of jawless vertebrates, whose ancestors arose more than 540 million years ago. Some species, such as Geotria australis, are anadromous, commencing life as ammocoetes in rivers, migrating downstream to the sea, and migrating back into rivers to spawn. Five photoreceptor types and five retinal cone opsin genes (LWS, SWS1, SWS2, RhA, and RhB) have previously been identified in G. australis. This implies that the ancestral vertebrates possessed photopic or cone-based vision with the potential for pentachromacy. Changes in the morphology of photoreceptors and their spectral sensitivity are encountered during differing aquatic phases of the lamprey lifecycle. To understand the molecular basis for these changes, we characterized the visual pigments and measured the relative levels of opsin expression over two lifecycle phases that are accompanied by contrasting ambient light environments. By expressing recombinant opsins in vitro, we show that SWS1, SWS2, RhA, and RhB visual pigments possess lambda(max) values of 359, 439, 497, and 492 nm respectively. For the LWS visual pigment, we predict a lambda(max) value of 560 nm based on key spectral tuning sites in other vertebrate LWS opsins. Quantitative reverse transcriptase-polymerase chain reaction reveals that the retinal opsin genes of G. australis are differentially regulated such that the visual system switches from a broad sensitivity across a wide spectral range to a much narrower sensitivity centered around 490-500 nm on transition from marine to riverine conditions. These quantitative changes in visual pigment expression throughout the lifecycle may directly result from changes in the lighting conditions of the surrounding milieu. PMID:17463225

  19. Cone visual pigments of monotremes: filling the phylogenetic gap.

    PubMed

    Wakefield, Matthew J; Anderson, Mark; Chang, Ellen; Wei, Ke-Jun; Kaul, Rajinder; Graves, Jennifer A Marshall; Grtzner, Frank; Deeb, Samir S

    2008-01-01

    We have determined the sequence and genomic organization of the genes encoding the cone visual pigment of the platypus (Ornithorhynchus anatinus) and the echidna (Tachyglossus aculeatus), and inferred their spectral properties and evolutionary pathways. We prepared platypus and echidna retinal RNA and used primers of the middle-wave-sensitive (MWS), long-wave-sensitive (LWS), and short-wave sensitive (SWS1) pigments corresponding to coding sequences that are highly conserved among mammals; to PCR amplify the corresponding pigment sequences. Amplification from the retinal RNA revealed the expression of LWS pigment mRNA that is homologous in sequence and spectral properties to the primate LWS visual pigments. However, we were unable to amplify the mammalian SWS1 pigment from these two species, indicating this gene was lost prior to the echidna-platypus divergence (21 MYA). Subsequently, when the platypus genome sequence became available, we found an LWS pigment gene in a conserved genomic arrangement that resembles the primate pigment, but, surprisingly we found an adjacent (20 kb) SWS2 pigment gene within this conserved genomic arrangement. We obtained the same result after sequencing the echidna genes. The encoded SWS2 pigment is predicted to have a wavelength of maximal absorption of about 440 nm, and is paralogous to SWS pigments typically found in reptiles, birds, and fish but not in mammals. This study suggests the locus control region (LCR) has played an important role in the conservation of photo receptor gene arrays and the control of their spatial and temporal expression in the retina in all mammals. In conclusion, a duplication event of an ancestral cone visual pigment gene, followed by sequence divergence and selection gave rise to the LWS and SWS2 visual pigments. So far, the echidna and platypus are the only mammals that share the gene structure of the LWS-SWS2 pigment gene complex with reptiles, birds and fishes. PMID:18598396

  20. Beauty in the eyes of the beholders: colour vision is tuned to mate preference in the Trinidadian guppy (Poecilia reticulata).

    PubMed

    Sandkam, Benjamin; Young, C Megan; Breden, Felix

    2015-02-01

    A broad range of animals use visual signals to assess potential mates, and the theory of sensory exploitation suggests variation in visual systems drives mate preference variation due to sensory bias. Trinidadian guppies (Poecilia reticulata), a classic system for studies of the evolution of female mate choice, provide a unique opportunity to test this theory by looking for covariation in visual tuning, light environment and mate preferences. Female preference co-evolves with male coloration, such that guppy females from 'low-predation' environments have stronger preferences for males with more orange/red coloration than do females from 'high-predation' environments. Here, we show that colour vision also varies across populations, with 'low'-predation guppies investing more of their colour vision to detect red/orange coloration. In independently colonized watersheds, guppies expressed higher levels of both LWS-1 and LWS-3 (the most abundant LWS opsins) in 'low-predation' populations than 'high-predation' populations at a time that corresponds to differences in cone cell abundance. We also observed that the frequency of a coding polymorphism differed between high- and low-predation populations. Together, this shows that the variation underlying preference could be explained by simple changes in expression and coding of opsins, providing important candidate genes to investigate the genetic basis of female preference variation in this model system. PMID:25556876

  1. Cone visual pigments of aquatic mammals.

    PubMed

    Newman, Lucy A; Robinson, Phyllis R

    2005-01-01

    It has long been hypothesized that the visual systems of animals are evolutionarily adapted to their visual environment. The entrance many millions of years ago of mammals into the sea gave these new aquatic mammals completely novel visual surroundings with respect to light availability and predominant wavelengths. This study examines the cone opsins of marine mammals, hypothesizing, based on previous studies [Fasick et al. (1998) and Levenson & Dizon (2003)], that the deep-dwelling marine mammals would not have color vision because the pressure to maintain color vision in the dark monochromatic ocean environment has been relaxed. Short-wavelength-sensitive (SWS) and long-wavelength-sensitive (LWS) cone opsin genes from two orders (Cetacea and Sirenia) and an additional suborder (Pinnipedia) of aquatic mammals were amplified from genomic DNA (for SWS) and cDNA (for LWS) by PCR, cloned, and sequenced. All animals studied from the order Cetacea have SWS pseudogenes, whereas a representative from the order Sirenia has an intact SWS gene, for which the corresponding mRNA was found in the retina. One of the pinnipeds studied (harp seal) has an SWS pseudogene, while another species (harbor seal) appeared to have an intact SWS gene. However, no SWS cone opsin mRNA was found in the harbor seal retina, suggesting a promoter or splice site mutation preventing transcription of the gene. The LWS opsins from the different species were expressed in mammalian cells and reconstituted with the 11-cis-retinal chromophore in order to determine maximal absorption wavelengths (lambda(max)) for each. The deeper dwelling Cetacean species had blue shifted lambda(max) values compared to shallower-dwelling aquatic species. Taken together, these findings support the hypothesis that in the monochromatic oceanic habitat, the pressure to maintain color vision has been relaxed and mutations are retained in the SWS genes, resulting in pseudogenes. Additionally, LWS opsins are retained in the retina and, in deeper-dwelling animals, are blue shifted in lambda(max). PMID:16469194

  2. Demonstration of a genotype-phenotype correlation in the polymorphic color vision of a non-callitrichine New World monkey, capuchin (Cebus apella).

    PubMed

    Saito, Atsuko; Kawamura, Shoji; Mikami, Akichika; Ueno, Yoshikazu; Hiramatsu, Chihiro; Koida, Kowa; Fujita, Kazuo; Kuroshima, Hika; Hasegawa, Toshikazu

    2005-12-01

    Color-vision polymorphism in New World monkeys occurs because of an allelic polymorphism of the single-copy red-green middle-to-long-wavelength-sensitive (M/LWS) opsin gene on the X chromosome. Because color-vision types can readily be estimated from allelic types of the M/LWS opsin gene, this polymorphic system offers researchers an excellent opportunity to study the association between vision and behavior. As a prerequisite for such studies, genetically determined color-vision types must be concordant with phenotypes determined directly by behavioral criteria (e.g., by a color discrimination test). However, such correlations between genotypes and phenotypes have been studied only for callitrichine species. Using genetic, electrophysiological, and behavioral approaches, we evaluated the color vision of brown capuchin monkeys (Cebus apella), a representative non-callitrichine model animal for physiology and behavior. Two allelic M/LWS opsins-P545 and P530-were identified in the studied captive population. Females had one or both of the alleles, and males had either one. The retinal sensitivity in P530 dichromats was short-wave shifted relative to that in P545 dichromats, whereas that in P530/P545 trichromats was between the two groups. In a discrimination task using Ishihara pseudo-isochromatic plates, P530/P545 trichromats were successful in discriminating stimuli that P530 and P545 dichromats were unable to discriminate. In a food-search task, P530/P545 trichromats were able to locate red targets among green distracters as quickly as among white distracters, whereas both types of dichromats took longer. These results demonstrate the mutual consistency between genotypes and phenotypes of color vision, and provide a solid genetic basis on which the ecology and evolution of color vision can be investigated. PMID:16342070

  3. Cone photoreceptors and potential UV vision in a subterranean insectivore, the European mole.

    PubMed

    Glösmann, Martin; Steiner, Marianne; Peichl, Leo; Ahnelt, Peter K

    2008-01-01

    We have examined the presence, the distribution, and the opsin identity of photoreceptor types in the retina of the European mole, Talpa europaea, a subterranean insectivore with regressed morphology of the visual system. Cones and rods were identified using opsin antisera, and their topographies determined from flat-mounted retinas. The retina (total area 0.75 mm(2)) contains about 100,000 photoreceptors, 10-12% of which are cones. Rod density is low (theoretical maximum 127,000 mm(-2)). Cone density peaks in central retina (17,750 mm(-2)). Similar to most mammals, two cone opsins, shortwave-sensitive (S) and middle-to-long-wave-sensitive (M), are present. Cone distribution shows a dorsoventral gradient with higher S cone numbers in ventral retina. Coexpression of S and M opsin occurs in more than 30% of the cones. Partial sequencing of the S opsin gene strongly supports UV sensitivity of the mole S cone photopigment. Amino acids that spectrally tune the S opsin are identical in T. europaea and in mammals with known UV cone photosensitivity. The lens transmits light down to 300 nm. Together, our data suggest that photopic vision and UV sensitivity of a cone pigment play a functional role in the European mole. PMID:18484862

  4. 2006 LWS TR & T Solar Wind Focused Science Topic Team: The Beginnings

    NASA Astrophysics Data System (ADS)

    Miralles, M. P.; Bhattacharjee, A.; Landi, E.; Markovskii, S.; Cranmer, S. R.; Doschek, G. A.; Forbes, T. G.; Isenberg, P. A.; Kohl, J. L.; Ng, C.; Raymond, J. C.; Vasquez, B. J.

    2006-12-01

    The Solar Wind Focused Science Topic (FST) team was created to apply a combination of theoretical studies, numerical simulations, and observations to the understanding of how the fast and slow solar wind are heated and accelerated. Four proposals were selected for this FST team. They will investigate the role of energy sources and kinetic mechanisms responsible for the heating and acceleration of the solar wind. In particular, the FST team will examine magnetic reconnection and turbulence as possible heating mechanisms. Plasma properties and their evolution over the solar cycle, determined from the analysis of remote and in situ measurements, will be used to put firm constraints on the models. The work of the Solar Wind FST team is in its initial stages. The organization, planning, and findings resulting from the first FST team meeting will be reported.

  5. The LWS Geospace Storm Investigations Exploring the Extremes of Space Weather

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Geospace mission of the Living With a Star program is a family of investigations focusing on the compelling science questions that advance our ability to specify, understand, and predict the societal impact of solar variance. Two key areas have been identified as combining both importance to society and potential for scientific progress: 1) characterization and understanding of the acceleration, global distribution, and variability of energetic electrons and ions in the inner magnetosphere, and 2) characterization and understanding of the ionosphere and irregularities that affect communications, navigation and radar systems. Under these broad categories specific science questions have emerged as the priority science objectives for the first Geospace Investigations: How and why do relativistic electrons in the outer zone and slot region vary during geomagnetic storms? How does the long- and short-term variability of the Sun affect the global-scale behavior of the ionospheric electron density and irregularities, especially during magnetic storms and at mid-latitudes? The first Geospace mission will attempt to answer these questions.

  6. LWS Proposal to Provide Scientific Guidance and Modeling Support for the Ionospheric Mapping Mission. Part 1

    NASA Technical Reports Server (NTRS)

    Richmond, Arthur D.

    2005-01-01

    A data assimilation system for specifying the thermospheric density has been developed over the last several years. This system ingests GRACE/CHAMP-type in situ as well as SSULI/SSUSI remote sensing observations while making use of a physical model, the Coupled Thermosphere-Ionosphere Model (CTIM) (Fuller-Rowel1 et al., 1996). The Kalman filter was implemented as the backbone to the data assimilation system, which provides a statistically 'best' estimate as well as an estimate of the error in its state. The system was tested using a simulated thermosphere and observations. CHAMP data were then used to provide the system with a real data source. The results of this study are herein.

  7. Flight Experiments for Living With a Star Space Environment Testbed (LWS-SET): Relationship to Technology

    NASA Technical Reports Server (NTRS)

    LaBel, Kenneth A.; Barth, Janet L.; Brewer, Dana A.

    2003-01-01

    This viewgraph presentation provides information on flight validation experiments for technologies to determine solar effects. The experiments are intended to demonstrate tolerance to a solar variant environment. The technologies tested are microelectronics, photonics, materials, and sensors.

  8. The Ionospheric-Thermospheric Component of the LWS-Geospace Program

    NASA Astrophysics Data System (ADS)

    Kintner, P. M.

    2005-05-01

    The Geospace Mission Definition Team report made a persuasive case for investigating the ionosphere-thermosphere system with both LEO in situ instruments and GEO ionospheric imaging. The GMDT science objectives were derived from the Living With a Star Science Architecture Team's consideration of space weather effects that concern society. The two highest priority ionospheric objectives are "Determine the effects of the long and short term variability of the Sun on the global-scale behavior of the ionospheric electron density" and "Determine the solar and geospace causes of small scale density irregularities in the 100-1000 km altitude range". These general objectives were then focused on specific science questions such as "How does the ionosphere-thermosphere system vary in response to changing fluxes of solar extreme ultraviolet radiation?", How does the mid- and low-latitude ionosphere-thermosphere system respond to geomagnetic storms?", and "What are the sources and characteristics of ionospheric irregularities at mid-latitudes?". Since the submission of the GMDT report to NASA, the case for investigating the disturbed mid-latitude ionosphere has become even more compelling. Society has become more vulnerable to ionospheric storms through augmented GPS systems for aviation. The ionospheric response to geomagnetic storms has been shown to extend from the equator through mid-latitudes and across the polar caps and from the F region to the equatorial plane. The total electron content from the peak of the positive-phase to the minima of the negative phase varies by up to one order of magnitude. Simulations have demonstrated that thermospheric transport can carry disturbed O/N2 ratios from the auroral zone to the equator. Density irregularities have been discovered with scale lengths of 100 km to the GPS signal Fresnel length (~ 400m). The GMDT developed a strategy to characterize and understand these phenomena. At low altitudes, within the thermosphere, two Ionospheric-Thermospheric Storm Probes were proposed with in situ instruments. The two ITSP will enable the separation of temporal from spatial phenomena and the investigation of temporal phenomena with time scales less than the orbital period. At high altitude a GEO ionospheric imager will yield context by providing global picture of the ionospheric-thermospheric response and evolution during solar disturbances and geomagnetic storms.

  9. Cone monochromacy and visual pigment spectral tuning in wobbegong sharks

    PubMed Central

    Theiss, Susan M.; Davies, Wayne I. L.; Collin, Shaun P.; Hunt, David M.; Hart, Nathan S.

    2012-01-01

    Much is known regarding the evolution of colour vision in nearly every vertebrate class, with the notable exception of the elasmobranchs. While multiple spectrally distinct cone types are found in some rays, sharks appear to possess only a single class of cone and, therefore, may be colour blind. In this study, the visual opsin genes of two wobbegong species, Orectolobus maculatus and Orectolobus ornatus, were isolated to verify the molecular basis of their monochromacy. In both species, only two opsin genes are present, RH1 (rod) and LWS (cone), which provide further evidence to support the concept that sharks possess only a single cone type. Examination of the coding sequences revealed substitutions that account for interspecific variation in the photopigment absorbance spectra, which may reflect the difference in visual ecology between these species. PMID:22993239

  10. Cone monochromacy and visual pigment spectral tuning in wobbegong sharks.

    PubMed

    Theiss, Susan M; Davies, Wayne I L; Collin, Shaun P; Hunt, David M; Hart, Nathan S

    2012-12-23

    Much is known regarding the evolution of colour vision in nearly every vertebrate class, with the notable exception of the elasmobranchs. While multiple spectrally distinct cone types are found in some rays, sharks appear to possess only a single class of cone and, therefore, may be colour blind. In this study, the visual opsin genes of two wobbegong species, Orectolobus maculatus and Orectolobus ornatus, were isolated to verify the molecular basis of their monochromacy. In both species, only two opsin genes are present, RH1 (rod) and LWS (cone), which provide further evidence to support the concept that sharks possess only a single cone type. Examination of the coding sequences revealed substitutions that account for interspecific variation in the photopigment absorbance spectra, which may reflect the difference in visual ecology between these species. PMID:22993239

  11. Effects of exogenous thyroid hormones on visual pigment composition in coho salmon (Oncorhynchus kisutch).

    PubMed

    Temple, Shelby E; Ramsden, Samuel D; Haimberger, Theodore J; Veldhoen, Kathy M; Veldhoen, Nik J; Carter, Nicolette L; Roth, Wolff-Michael; Hawryshyn, Craig W

    2008-07-01

    The role of exogenous thyroid hormone on visual pigment content of rod and cone photoreceptors was investigated in coho salmon (Oncorhynchus kisutch). Coho vary the ratio of vitamin A1- and A2-based visual pigments in their eyes. This variability potentially alters spectral sensitivity and thermal stability of the visual pigments. We tested whether the direction of shift in the vitamin A1/A2 ratio, resulting from application of exogenous thyroid hormone, varied in fish of different ages and held under different environmental conditions. Changes in the vitamin A1/A2 visual pigment ratio were estimated by measuring the change in maximum absorbance (lambda max) of rods using microspectrophotometry (MSP). Exogenous thyroid hormone resulted in a long-wavelength shift in rod, middle-wavelength-sensitive (MWS) and long-wavelength-sensitive (LWS) cone photoreceptors. Rod and LWS cone lambda max values increased, consistent with an increase in vitamin A2. MWS cone lambda max values increased more than predicted for a change in the vitamin A1/A2 ratio. To account for this shift, we tested for the expression of multiple RH2 opsin subtypes. We isolated and sequenced a novel RH2 opsin subtype, which had 48 amino acid differences from the previously sequenced coho RH2 opsin. A substitution of glutamate for glutamine at position 122 could partially account for the greater than predicted shift in MWS cone lambda max values. Our findings fit the hypothesis that a variable vitamin A1/A2 ratio provides seasonality in spectral tuning and/or improved thermal stability of visual pigments in the face of seasonal environmental changes, and that multiple RH2 opsin subtypes can provide flexibility in spectral tuning associated with migration-metamorphic events. PMID:18552303

  12. The Transcription Factor GTF2IRD1 Regulates the Topology and Function of Photoreceptors by Modulating Photoreceptor Gene Expression across the Retina

    PubMed Central

    Masuda, Tomohiro; Zhang, Xiaodong; Berlinicke, Cindy; Wan, Jun; Yerrabelli, Anitha; Conner, Elizabeth A.; Kjellstrom, Sten; Bush, Ronald; Thorgeirsson, Snorri S.; Swaroop, Anand; Chen, Shiming

    2014-01-01

    The mechanisms that specify photoreceptor cell-fate determination, especially as regards to short-wave-sensitive (S) versus medium-wave-sensitive (M) cone identity, and maintain their nature and function, are not fully understood. Here we report the importance of general transcription factor II-I repeat domain-containing protein 1 (GTF2IRD1) in maintaining M cone cell identity and function as well as rod function. In the mouse, GTF2IRD1 is expressed in cell-fate determined photoreceptors at postnatal day 10. GTF2IRD1 binds to enhancer and promoter regions in the mouse rhodopsin, M- and S-opsin genes, but regulates their expression differentially. Through interaction with the transcription factors CRX and thyroid hormone receptor β 2, it enhances M-opsin expression, whereas it suppresses S-opsin expression; and with CRX and NRL, it enhances rhodopsin expression. In an apparent paradox, although GTF2IRD1 is widely expressed in multiple cell types across the retina, knock-out of GTF2IRD1 alters the retinal expression of only a limited number of annotated genes. Interestingly, however, the null mutation leads to altered topology of cone opsin expression in the retina, with aberrant S-opsin overexpression and M-opsin underexpression in M cones. Gtf2ird1-null mice also demonstrate abnormal M cone and rod electrophysiological responses. These findings suggest an important role for GTF2IRD1 in regulating the level and topology of rod and cone gene expression, and in maintaining normal retinal function. PMID:25392503

  13. Long-wave sensitivity in the masked greenling (Hexagrammos octogrammus), a shallow-water marine fish.

    PubMed

    Kondrashev, Sergei L

    2008-09-01

    Microspectrophotometry (MSP) revealed that surprisingly for a "fully marine" species, in summer, photoreceptors of the nearshore scorpaeniform fish known as the masked greenling, Hexagrammos octogrammus, contained exclusively, or presumably, porphyropsin with a small admixture of rhodopsin. As a result of this, the lambda(max) of the spectral sensitivity of the photoreceptors were significantly shifted to longer wavelengths as compared to the lambda(max) typical of marine shallow-water fishes, showing about 530 nm for rods and single cones, and 570/625 nm for double-cone members. These unique spectral shifts would permit a cone-driven wavelength discrimination in spite of high-density orange corneal filters which block light at lower wavelengths. PMID:18675840

  14. Light-sensitive motile iridophores and visual pigments in the neon tetra, Paracheirodon innesi.

    PubMed

    Kasai, Akiko; Oshima, Noriko

    2006-09-01

    Although motile iridophores in the longitudinal stripes of neon tetra skin are under control of the sympathetic nervous system, they also respond to light directly and show circadian color changes. Using neon tetra skin, we found that the photoresponse of iridophores depends on light intensity, and that light near 500 nm is most effective. RT-PCR demonstrated the expression of mRNAs encoding rhodopsin and two kinds of cone opsins (Pi-green1 and Pi-green2) in neon tetra skin where the light-sensitive iridophores exist. These mRNAs are also expressed in the lateral eyes. The cone opsin genes, Pi-green1 and Pi-green2, show high similarity with the g101 and g103 genes of unique green cone opsins (belonging to the MWS/LWS group) of the blind Mexican cavefish. These results show that Pi-green1, Pi-green2, and/or rhodopsin may play important roles in the photoresponse of neon tetra iridophores, which are most sensitive to light near 500 nm. PMID:17043404

  15. Developmental plasticity in vision and behavior may help guppies overcome increased turbidity.

    PubMed

    Ehlman, Sean M; Sandkam, Benjamin A; Breden, Felix; Sih, Andrew

    2015-12-01

    Increasing turbidity in streams and rivers near human activity is cause for environmental concern, as the ability of aquatic organisms to use visual information declines. To investigate how some organisms might be able to developmentally compensate for increasing turbidity, we reared guppies (Poecilia reticulata) in either clear or turbid water. We assessed the effects of developmental treatments on adult behavior and aspects of the visual system by testing fish from both developmental treatments in turbid and clear water. We found a strong interactive effect of rearing and assay conditions: fish reared in clear water tended to decrease activity in turbid water, whereas fish reared in turbid water tended to increase activity in turbid water. Guppies from all treatments decreased activity when exposed to a predator. To measure plasticity in the visual system, we quantified treatment differences in opsin gene expression of individuals. We detected a shift from mid-wave-sensitive opsins to long wave-sensitive opsins for guppies reared in turbid water. Since long-wavelength sensitivity is important in motion detection, this shift likely allows guppies to salvage motion-detecting abilities when visual information is obscured in turbid water. Our results demonstrate the importance of developmental plasticity in responses of organisms to rapidly changing environments. PMID:26427995

  16. The activation of directional stem cell motility by green light-emitting diode irradiation.

    PubMed

    Ong, Wei-Kee; Chen, How-Foo; Tsai, Cheng-Ting; Fu, Yun-Ju; Wong, Yi-Shan; Yen, Da-Jen; Chang, Tzu-Hao; Huang, Hsien-Da; Lee, Oscar Kuang-Sheng; Chien, Shu; Ho, Jennifer Hui-Chun

    2013-03-01

    Light-emitting diode (LED) irradiation is potentially a photostimulator to manipulate cell behavior by opsin-triggered phototransduction and thermal energy supply in living cells. Directional stem cell motility is critical for the efficiency and specificity of stem cells in tissue repair. We explored that green LED (530 nm) irradiation directed the human orbital fat stem cells (OFSCs) to migrate away from the LED light source through activation of extracellular signal-regulated kinases (ERK)/MAP kinase/p38 signaling pathway. ERK inhibitor selectively abrogated light-driven OFSC migration. Phosphorylation of these kinases as well as green LED irradiation-induced cell migration was facilitated by increasing adenosine triphosphate (ATP) production in OFSCs after green LED exposure, and which was thermal stress-independent mechanism. OFSCs, which are multi-potent mesenchymal stem cells isolated from human orbital fat tissue, constitutionally express three opsins, i.e. retinal pigment epithelium-derived rhodopsin homolog (RRH), encephalopsin (OPN3) and short-wave-sensitive opsin 1 (OPN1SW). However, only two non-visual opsins, i.e. RRH and OPN3, served as photoreceptors response to green LED irradiation-induced OFSC migration. In conclusion, stem cells are sensitive to green LED irradiation-induced directional cell migration through activation of ERK signaling pathway via a wavelength-dependent phototransduction. PMID:23261211

  17. S cones: Evolution, retinal distribution, development, and spectral sensitivity.

    PubMed

    Hunt, David M; Peichl, Leo

    2014-03-01

    S 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. PMID:23895771

  18. Finite-frequency Sn-wave sensitivity kernels for the M6.0 Wells, Nevada earthquake and USArray stations

    NASA Astrophysics Data System (ADS)

    Lodewyk, J. A.; Zhao, L.; Van der Lee, S.

    2011-12-01

    Head waves contain important information about lithospheric structure. Studies have shown that sensitivity kernels of head waves can be incorporated into tomography studies to improve resolution of vertical velocity gradients. However Sn waves have not yet been used in a finite frequency approach. We aim to incorporate finite-frequency Sn sensitivity kernels into a tomographic inversion for North American upper mantle structure, in order to better resolve lithospheric mantle structure. In this study, sensitivity kernels of head waves were calculated using the strain Green tensor (SGT) approach of Zhao et al, 2006 which improves computational efficiency. This study utilized the M6.0 Wells,Nevada earthquake that occurred at 14:16:10 on February 21, 2008 in the midst of a Transportable Array deployment. The seismogram signals were filtered to isolate the Sn wave using a two-pole Butterworth filter with corner frequencies at .02 and .25 Hz. The SGTs were calculated for Transportable Array stations using both a 1D model, MC35, and the 3D S-velocity and Moho-depth model NA04 crustal model(Van der Lee and Frederiksen, 2005). The sensitivity kernels for Sn waves show that, similar to those for Pn waves, Sn waves are influenced by the velocity structure surrounding the ray path but are also weakly influenced by the structure along the ray path. We present finite-frequency Sn sensitivity kernels for 1D and 3D reference models and examine the effect of 3D heterogeneity on finite-frequency kernels. We also estimate traveltime perturbations using these kernels and compare them with observed Sn arrival times.

  19. Opsin switch reveals function of the ultraviolet cone in fish foraging

    PubMed Central

    Novales Flamarique, Iigo

    2013-01-01

    Although several studies have shown that ultraviolet (UV) wavelengths are important in naturally occurring, visually guided behaviours of vertebrates, the function of the UV cone in such behaviours is unknown. Here, I used thyroid hormone to transform the UV cones of young rainbow trout into blue cones, a phenomenon that occurs naturally as the animal grows, to test whether the resulting loss of UV sensitivity affected the animal's foraging performance on Daphnia magna, a prey zooplankton. The distances and angles at which prey were located (variables that are known indicators of foraging performance) were significantly reduced for UV knock-out fish compared with controls. Optical measurements and photon-catch calculations revealed that the contrast of Daphnia was greater when perceived by the visual system of control versus that of thyroid-hormone-treated fish, demonstrating that the UV cone enhanced the foraging performance of young rainbow trout. Because most juvenile fishes have UV cones and feed on zooplankton, this finding has wide implications for understanding the visual ecology of fishes. The enhanced target contrast provided by UV cones could be used by other vertebrates in various behaviours, including foraging, mate selection and communication. PMID:23222448

  20. Of Mice, Men, and Microbial Opsins: How Optogenetics Can Help Hone Mouse Models of Mental Illness.

    PubMed

    Marton, Tobias F; Sohal, Vikaas S

    2016-01-01

    Genetic, pharmacologic, and behavioral manipulations have long been powerful tools for generating rodent models to study the neural substrates underlying psychiatric disease. Recent advances in the use of optogenetics in awake behaving rodents has added an additional valuable methodology to this experimental toolkit. Here, we review several recent studies that leverage optogenetic technologies to elucidate neural mechanisms possibly related to depression, anxiety, and obsessive-compulsive disorder. We use a few illustrative examples to highlight key emergent principles about how optogenetics, in conjunction with more established modalities, can help to organize our understanding of how disease-related states, specific neuronal circuits, and various behavioral assays fit into hierarchical frameworks such as the National Institute of Mental Health Research Domain Criteria matrix. PMID:25981174

  1. Short-wavelength sensitive opsin (SWS1) as a new marker for vertebrate phylogenetics

    PubMed Central

    van Hazel, Ilke; Santini, Francesco; Mller, Johannes; Chang, Belinda SW

    2006-01-01

    Background Vertebrate SWS1 visual pigments mediate visual transduction in response to light at short wavelengths. Due to their importance in vision, SWS1 genes have been isolated from a surprisingly wide range of vertebrates, including lampreys, teleosts, amphibians, reptiles, birds, and mammals. The SWS1 genes exhibit many of the characteristics of genes typically targeted for phylogenetic analyses. This study investigates both the utility of SWS1 as a marker for inferring vertebrate phylogenetic relationships, and the characteristics of the gene that contribute to its phylogenetic utility. Results Phylogenetic analyses of vertebrate SWS1 genes produced topologies that were remarkably congruent with generally accepted hypotheses of vertebrate evolution at both higher and lower taxonomic levels. The few exceptions were generally associated with areas of poor taxonomic sampling, or relationships that have been difficult to resolve using other molecular markers. The SWS1 data set was characterized by a substantial amount of among-site rate variation, and a relatively unskewed substitution rate matrix, even when the data were partitioned into different codon sites and individual taxonomic groups. Although there were nucleotide biases in some groups at third positions, these biases were not convergent across different taxonomic groups. Conclusion Our results suggest that SWS1 may be a good marker for vertebrate phylogenetics due to the variable yet consistent patterns of sequence evolution exhibited across fairly wide taxonomic groups. This may result from constraints imposed by the functional role of SWS1 pigments in visual transduction. PMID:17107620

  2. Gene conversion between red and defective green opsin gene in blue cone monochromacy

    SciTech Connect

    Reyniers, E.; Van Thienen, M.N.; De Boulle, K.; Willems, P.J.

    1995-09-20

    Blue cone monochromacy is an X-linked condition in which the function of both the red pigment gene (RCP) and the green pigment gene (GCP) is impaired. Blue cone monochromacy can be due to a red/green gene array rearrangement existing of a single red/green hybrid gene and an inactivating C203R point mutation in both RCP and GCP. The flanking sequences of the C230R mutation in exon 4 of RCP were characteristic for GCP, indicating that this mutation was transferred from GCP into RCP by gene conversion. 23 refs., 3 figs., 1 tab.

  3. Evolution of the vertebrate eye: opsins, photoreceptors, retina and eye cup

    PubMed Central

    Lamb, Trevor D.; Collin, Shaun P.; Pugh, Edward N.

    2011-01-01

    Charles Darwin appreciated the conceptual difficulty in accepting that an organ as wonderful as the vertebrate eye could have evolved through natural selection. He reasoned that if appropriate gradations could be found that were useful to the animal and were inherited, then the apparent difficulty would be overcome. Here, we review a wide range of findings that capture glimpses of the gradations that appear to have occurred during eye evolution, and provide a scenario for the unseen steps that have led to the emergence of the vertebrate eye. PMID:18026166

  4. Temperature profile analysis for Amargosa Valley wells LWS-A, ASH-B, and MSH-C. DOE UGTA RI/FS geothermal gradient study results FY 1995

    SciTech Connect

    Gillespie, D.

    1995-09-01

    The purpose of this investigation is to estimate vertical fluid flux rates in saturated units penetrated by selected wells at the Nevada Test Site (NTS) using geothermal gradient data. Estimates of vertical fluid flux rates are critical in developing models for contaminate flow within, recharge potential to, and discharge from the groundwater system at the NTS. If temperature in the well is in equilibrium with the surrounding rocks, it is possible to detect the vertical flow of groundwater from the well`s thermal profile. Heat in the subsurface is transported by conduction through the rock and by advection caused by subsurface water movement. Units in which vertical flow is occurring will produce a curve in the thermal profile within the well. Prior to the implementation of the Underground Test Area Remedial Investigation/Feasibility Study (UGTA RI/FS), investigation of thermal data from wells at the NTS was hindered by the completion of wells as open holes or without casing cemented in place. The open-hole type of completion allows cross-flow within the wellbore which can yield information about relative pressures between connected aquifers, but which renders thermal gradient data essentially useless, or at best highly suspect for interpreting in situ groundwater movement. Wells recently completed in the Department of Energy (DOE) Environmental Restoration (ER) Program have been completed with casing cemented to the surface (to prohibit cross-flow between units in the annular space between the casing and the wellbore) and with completion zones open to a single hydrologic horizon. This type of completion results in temperature gradient profiles more representative of actual thermal conditions in the units penetrated by the well. Results are presented of temperature profiles of 3 wells located in the Death Valley Groundwater Basin, outside the southern border of the NTS.

  5. MODELING LARGE WOOD STRUCTURES IN SAND BED STREAMS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In-stream large wood structures (LWS) are becoming increasingly popular throughout the world. The LWS improve aquatic habitat quality and protect banks from erosion. While most reports describe the LWS in the Northwest as successful, LWS in one Mississippi sand-bed stream had an unacceptable failure...

  6. Eye spectral sensitivity in fresh- and brackish-water populations of three glacial-relict Mysis species (Crustacea): physiology and genetics of differential tuning.

    PubMed

    Donner, Kristian; Zak, Pavel; Viljanen, Martta; Lindström, Magnus; Feldman, Tatiana; Ostrovsky, Mikhail

    2016-04-01

    Absorbance spectra of single rhabdoms were studied by microspectrophotometry (MSP) and spectral sensitivities of whole eyes by electroretinography (ERG) in three glacial-relict species of opossum shrimps (Mysis). Among eight populations from Fennoscandian fresh-water lakes (L) and seven populations from the brackish-water Baltic Sea (S), L spectra were systematically red-shifted by 20-30 nm compared with S spectra, save for one L and one S population. The difference holds across species and bears no consistent adaptive relation to the current light environments. In the most extensively studied L-S pair, two populations of M. relicta (L p and S p) separated for less than 10,000 years, no differences translating into amino acid substitutions have been found in the opsin genes, and the chromophore of the visual pigments as analyzed by HPLC is pure A1. However, MSP experiments with spectrally selective bleaching show the presence of two rhodopsins (λ max ≈ 525-530 nm, MWS, and 565-570 nm, LWS) expressed in different proportions. ERG recordings of responses to "red" and "blue" light linearly polarized at orthogonal angles indicate segregation of the pigments into different cells differing in polarization sensitivity. We propose that the pattern of development of LWS and MWS photoreceptors is governed by an ontogenetic switch responsive to some environmental signal(s) other than light that generally differ(s) between lakes and sea, and that this reaction norm is conserved from a common ancestor of all three species. PMID:26984686

  7. RELAX: Detecting Relaxed Selection in a Phylogenetic Framework

    PubMed Central

    Wertheim, Joel O.; Murrell, Ben; Smith, Martin D.; Kosakovsky Pond, Sergei L.; Scheffler, Konrad

    2015-01-01

    Relaxation of selective strength, manifested as a reduction in the efficiency or intensity of natural selection, can drive evolutionary innovation and presage lineage extinction or loss of function. Mechanisms through which selection can be relaxed range from the removal of an existing selective constraint to a reduction in effective population size. Standard methods for estimating the strength and extent of purifying or positive selection from molecular sequence data are not suitable for detecting relaxed selection, because they lack power and can mistake an increase in the intensity of positive selection for relaxation of both purifying and positive selection. Here, we present a general hypothesis testing framework (RELAX) for detecting relaxed selection in a codon-based phylogenetic framework. Given two subsets of branches in a phylogeny, RELAX can determine whether selective strength was relaxed or intensified in one of these subsets relative to the other. We establish the validity of our test via simulations and show that it can distinguish between increased positive selection and a relaxation of selective strength. We also demonstrate the power of RELAX in a variety of biological scenarios where relaxation of selection has been hypothesized or demonstrated previously. We find that obligate and facultative γ-proteobacteria endosymbionts of insects are under relaxed selection compared with their free-living relatives and obligate endosymbionts are under relaxed selection compared with facultative endosymbionts. Selective strength is also relaxed in asexual Daphnia pulex lineages, compared with sexual lineages. Endogenous, nonfunctional, bornavirus-like elements are found to be under relaxed selection compared with exogenous Borna viruses. Finally, selection on the short-wavelength sensitive, SWS1, opsin genes in echolocating and nonecholocating bats is relaxed only in lineages in which this gene underwent pseudogenization; however, selection on the functional medium/long-wavelength sensitive opsin, M/LWS1, is found to be relaxed in all echolocating bats compared with nonecholocating bats. PMID:25540451

  8. RELAX: detecting relaxed selection in a phylogenetic framework.

    PubMed

    Wertheim, Joel O; Murrell, Ben; Smith, Martin D; Kosakovsky Pond, Sergei L; Scheffler, Konrad

    2015-03-01

    Relaxation of selective strength, manifested as a reduction in the efficiency or intensity of natural selection, can drive evolutionary innovation and presage lineage extinction or loss of function. Mechanisms through which selection can be relaxed range from the removal of an existing selective constraint to a reduction in effective population size. Standard methods for estimating the strength and extent of purifying or positive selection from molecular sequence data are not suitable for detecting relaxed selection, because they lack power and can mistake an increase in the intensity of positive selection for relaxation of both purifying and positive selection. Here, we present a general hypothesis testing framework (RELAX) for detecting relaxed selection in a codon-based phylogenetic framework. Given two subsets of branches in a phylogeny, RELAX can determine whether selective strength was relaxed or intensified in one of these subsets relative to the other. We establish the validity of our test via simulations and show that it can distinguish between increased positive selection and a relaxation of selective strength. We also demonstrate the power of RELAX in a variety of biological scenarios where relaxation of selection has been hypothesized or demonstrated previously. We find that obligate and facultative ?-proteobacteria endosymbionts of insects are under relaxed selection compared with their free-living relatives and obligate endosymbionts are under relaxed selection compared with facultative endosymbionts. Selective strength is also relaxed in asexual Daphnia pulex lineages, compared with sexual lineages. Endogenous, nonfunctional, bornavirus-like elements are found to be under relaxed selection compared with exogenous Borna viruses. Finally, selection on the short-wavelength sensitive, SWS1, opsin genes in echolocating and nonecholocating bats is relaxed only in lineages in which this gene underwent pseudogenization; however, selection on the functional medium/long-wavelength sensitive opsin, M/LWS1, is found to be relaxed in all echolocating bats compared with nonecholocating bats. PMID:25540451

  9. From the ultrasonic to the infrared: molecular evolution and the sensory biology of bats

    PubMed Central

    Jones, Gareth; Teeling, Emma C.; Rossiter, Stephen J.

    2013-01-01

    Great advances have been made recently in understanding the genetic basis of the sensory biology of bats. Research has focused on the molecular evolution of candidate sensory genes, genes with known functions [e.g., olfactory receptor (OR) genes] and genes identified from mutations associated with sensory deficits (e.g., blindness and deafness). For example, the FoxP2 gene, underpinning vocal behavior and sensorimotor coordination, has undergone diversification in bats, while several genes associated with audition show parallel amino acid substitutions in unrelated lineages of echolocating bats and, in some cases, in echolocating dolphins, representing a classic case of convergent molecular evolution. Vision genes encoding the photopigments rhodopsin and the long-wave sensitive opsin are functional in bats, while that encoding the short-wave sensitive opsin has lost functionality in rhinolophoid bats using high-duty cycle laryngeal echolocation, suggesting a sensory trade-off between investment in vision and echolocation. In terms of olfaction, bats appear to have a distinctive OR repertoire compared with other mammals, and a gene involved in signal transduction in the vomeronasal system has become non-functional in most bat species. Bitter taste receptors appear to have undergone a “birth-and death” evolution involving extensive gene duplication and loss, unlike genes coding for sweet and umami tastes that show conservation across most lineages but loss in vampire bats. Common vampire bats have also undergone adaptations for thermoperception, via alternative splicing resulting in the evolution of a novel heat-sensitive channel. The future for understanding the molecular basis of sensory biology is promising, with great potential for comparative genomic analyses, studies on gene regulation and expression, exploration of the role of alternative splicing in the generation of proteomic diversity, and linking genetic mechanisms to behavioral consequences. PMID:23755015

  10. From the ultrasonic to the infrared: molecular evolution and the sensory biology of bats.

    PubMed

    Jones, Gareth; Teeling, Emma C; Rossiter, Stephen J

    2013-01-01

    Great advances have been made recently in understanding the genetic basis of the sensory biology of bats. Research has focused on the molecular evolution of candidate sensory genes, genes with known functions [e.g., olfactory receptor (OR) genes] and genes identified from mutations associated with sensory deficits (e.g., blindness and deafness). For example, the FoxP2 gene, underpinning vocal behavior and sensorimotor coordination, has undergone diversification in bats, while several genes associated with audition show parallel amino acid substitutions in unrelated lineages of echolocating bats and, in some cases, in echolocating dolphins, representing a classic case of convergent molecular evolution. Vision genes encoding the photopigments rhodopsin and the long-wave sensitive opsin are functional in bats, while that encoding the short-wave sensitive opsin has lost functionality in rhinolophoid bats using high-duty cycle laryngeal echolocation, suggesting a sensory trade-off between investment in vision and echolocation. In terms of olfaction, bats appear to have a distinctive OR repertoire compared with other mammals, and a gene involved in signal transduction in the vomeronasal system has become non-functional in most bat species. Bitter taste receptors appear to have undergone a "birth-and death" evolution involving extensive gene duplication and loss, unlike genes coding for sweet and umami tastes that show conservation across most lineages but loss in vampire bats. Common vampire bats have also undergone adaptations for thermoperception, via alternative splicing resulting in the evolution of a novel heat-sensitive channel. The future for understanding the molecular basis of sensory biology is promising, with great potential for comparative genomic analyses, studies on gene regulation and expression, exploration of the role of alternative splicing in the generation of proteomic diversity, and linking genetic mechanisms to behavioral consequences. PMID:23755015

  11. Advantage of dichromats over trichromats in discrimination of color-camouflaged stimuli in nonhuman primates.

    PubMed

    Saito, Atsuko; Mikami, Akichika; Kawamura, Shoji; Ueno, Yoshikazu; Hiramatsu, Chihiro; Widayati, Kanthi A; Suryobroto, Bambang; Teramoto, Migaku; Mori, Yusuke; Nagano, Kunitoshi; Fujita, Kazuo; Kuroshima, Hika; Hasegawa, Toshikazu

    2005-12-01

    Due to a middle- to long-wavelength-sensitive (M/LWS) cone opsin polymorphism, there is considerable phenotypic variation in the color vision of New World monkeys. Many females have trichromatic vision, whereas some females and all males have dichromatic vision. The selective pressures that maintain this polymorphism are unclear. In the present study we compared the performance of dichromats and trichromats in a discrimination task. We examined tri- and dichromatic individuals of two species: brown capuchin monkeys (Cebus apella) and long-tailed macaques (Macaca fascicularis). We also examined one protanomalous chimpanzee (Pan troglodytes). The subjects' task was to discriminate a circular pattern from other patterns in which textural elements differed in orientation and thickness from the background. After they were trained with stimuli of a single color, the subjects were presented with color-camouflaged stimuli with a green/red mosaic overlaid onto the pattern. The dichromatic monkeys and the protanomalous chimpanzee selected the correct stimulus under camouflaged conditions at rates significantly above chance levels, while the trichromats did not. These findings demonstrate that dichromatic nonhuman primates possess a superior visual ability to discriminate color-camouflaged stimuli, and that such an ability may confer selective advantages with respect to the detection of cryptic foods and/or predators. PMID:16342068

  12. How parrots see their colours: novelty in the visual pigments of Platycercus elegans.

    PubMed

    Knott, Ben; Davies, Wayne I L; Carvalho, Livia S; Berg, Mathew L; Buchanan, Katherine L; Bowmaker, James K; Bennett, Andrew T D; Hunt, David M

    2013-12-01

    Intraspecific differences in retinal physiology have been demonstrated in several vertebrate taxa and are often subject to adaptive evolution. Nonetheless, such differences are currently unknown in birds, despite variations in habitat, behaviour and visual stimuli that might influence spectral sensitivity. The parrot Platycercus elegans is a species complex with extreme plumage colour differences between (and sometimes within) subspecies, making it an ideal candidate for intraspecific differences in spectral sensitivity. Here, the visual pigments of P. elegans were fully characterised through molecular sequencing of five visual opsin genes and measurement of their absorbance spectra using microspectrophotometry. Three of the genes, LWS, SW1 and SWS2, encode for proteins similar to those found in other birds; however, both the RH1 and RH2 pigments had polypeptides with carboxyl termini of different lengths and unusual properties that are unknown previously for any vertebrate visual pigment. Specifically, multiple RH2 transcripts and protein variants (short, medium and long) were identified for the first time that are generated by alternative splicing of downstream coding and non-coding exons. Our work provides the first complete characterisation of the visual pigments of a parrot, perhaps the most colourful order of birds, and moreover suggests more variability in avian eyes than hitherto considered. PMID:24259259

  13. Cone photoreceptor diversity in the retinas of fruit bats (megachiroptera).

    PubMed

    Mller, Brigitte; Goodman, Steven M; Peichl, Leo

    2007-01-01

    Older studies have claimed that bats including the Megachiroptera (fruit bats or flying foxes) have pure-rod retinas and possess no cone photoreceptors. We have determined the presence and the population densities of spectral cone types in six megachiropteran species belonging to four genera: Pteropus rufus, P. niger, P. rodricensis, Rousettus madagascariensis, Eidolon dupreanum, and Epomophorus gambianus. Spectral cone types and rods were assessed immunocytochemically with opsin-specific antibodies. All six species have rod-dominated retinas but possess significant cone populations. The high rod densities (range 350,000-800,000/mm(2), depending on species and retinal location) provide good scotopic sensitivity in these predominantly nocturnal animals. With the cones (density range 1,300-11,000/mm(2), corresponding to 0.25-0.6% of the photoreceptors, depending on species and retinal location) the retinas also possess the prerequisite for vision at photopic light levels. The three Pteropus species have two spectral cone types, a majority of middle-to-long-wave sensitive (L-) cones, and a minority of short-wave sensitive (S-) cones, indicating the potential for dichromatic color vision. This conforms to the pattern found in most mammals. In contrast, Rousettus, Eidolon and Epomophorus have L-cones but completely lack S-cones, indicating cone monochromacy and color blindness. The discussion relates these findings to the visual behavior of fruit bats. PMID:17522478

  14. Optogenetic manipulation of cGMP in cells and animals by the tightly light-regulated guanylyl-cyclase opsin CyclOp

    PubMed Central

    Gao, Shiqiang; Nagpal, Jatin; Schneider, Martin W.; Kozjak-Pavlovic, Vera; Nagel, Georg; Gottschalk, Alexander

    2015-01-01

    Cyclic GMP (cGMP) signalling regulates multiple biological functions through activation of protein kinase G and cyclic nucleotide-gated (CNG) channels. In sensory neurons, cGMP permits signal modulation, amplification and encoding, before depolarization. Here we implement a guanylyl cyclase rhodopsin from Blastocladiella emersonii as a new optogenetic tool (BeCyclOp), enabling rapid light-triggered cGMP increase in heterologous cells (Xenopus oocytes, HEK293T cells) and in Caenorhabditis elegans. Among five different fungal CyclOps, exhibiting unusual eight transmembrane topologies and cytosolic N-termini, BeCyclOp is the superior optogenetic tool (light/dark activity ratio: 5,000; no cAMP production; turnover (20 °C) ∼17 cGMP s−1). Via co-expressed CNG channels (OLF in oocytes, TAX-2/4 in C. elegans muscle), BeCyclOp photoactivation induces a rapid conductance increase and depolarization at very low light intensities. In O2/CO2 sensory neurons of C. elegans, BeCyclOp activation evokes behavioural responses consistent with their normal sensory function. BeCyclOp therefore enables precise and rapid optogenetic manipulation of cGMP levels in cells and animals. PMID:26345128

  15. Optogenetic manipulation of cGMP in cells and animals by the tightly light-regulated guanylyl-cyclase opsin CyclOp.

    PubMed

    Gao, Shiqiang; Nagpal, Jatin; Schneider, Martin W; Kozjak-Pavlovic, Vera; Nagel, Georg; Gottschalk, Alexander

    2015-01-01

    Cyclic GMP (cGMP) signalling regulates multiple biological functions through activation of protein kinase G and cyclic nucleotide-gated (CNG) channels. In sensory neurons, cGMP permits signal modulation, amplification and encoding, before depolarization. Here we implement a guanylyl cyclase rhodopsin from Blastocladiella emersonii as a new optogenetic tool (BeCyclOp), enabling rapid light-triggered cGMP increase in heterologous cells (Xenopus oocytes, HEK293T cells) and in Caenorhabditis elegans. Among five different fungal CyclOps, exhibiting unusual eight transmembrane topologies and cytosolic N-termini, BeCyclOp is the superior optogenetic tool (light/dark activity ratio: 5,000; no cAMP production; turnover (20 °C) ∼17 cGMP s(-1)). Via co-expressed CNG channels (OLF in oocytes, TAX-2/4 in C. elegans muscle), BeCyclOp photoactivation induces a rapid conductance increase and depolarization at very low light intensities. In O2/CO2 sensory neurons of C. elegans, BeCyclOp activation evokes behavioural responses consistent with their normal sensory function. BeCyclOp therefore enables precise and rapid optogenetic manipulation of cGMP levels in cells and animals. PMID:26345128

  16. Age-related deterioration of rod vision in mice.

    PubMed

    Kolesnikov, Alexander V; Fan, Jie; Crouch, Rosalie K; Kefalov, Vladimir J

    2010-08-18

    Even in healthy individuals, aging leads to deterioration in visual acuity, contrast sensitivity, visual field, and dark adaptation. Little is known about the neural mechanisms that drive the age-related changes of the retina and, more specifically, photoreceptors. According to one hypothesis, the age-related deterioration in rod function is due to the limited availability of 11-cis-retinal for rod pigment formation. To determine how aging affects rod photoreceptors and to test the retinoid-deficiency hypothesis, we compared the morphological and functional properties of rods of adult and aged B6D2F1/J mice. We found that the number of rods and the length of their outer segments were significantly reduced in 2.5-year-old mice compared with 4-month-old animals. Aging also resulted in a twofold reduction in the total level of opsin in the retina. Behavioral tests revealed that scotopic visual acuity and contrast sensitivity were decreased by twofold in aged mice, and rod ERG recordings demonstrated reduced amplitudes of both a- and b-waves. Sensitivity of aged rods determined from single-cell recordings was also decreased by 1.5-fold, corresponding to not more than 1% free opsin in these photoreceptors, and kinetic parameters of dim flash response were not altered. Notably, the rate of rod dark adaptation was unaffected by age. Thus, our results argue against age-related deficiency of 11-cis-retinal in the B6D2F1/J mouse rod visual cycle. Surprisingly, the level of cellular dark noise was increased in aged rods, providing an alternative mechanism for their desensitization. PMID:20720130

  17. Evolutionary changes of multiple visual pigment genes in the complete genome of Pacific bluefin tuna

    PubMed Central

    Nakamura, Yoji; Mori, Kazuki; Saitoh, Kenji; Oshima, Kenshiro; Mekuchi, Miyuki; Sugaya, Takuma; Shigenobu, Yuya; Ojima, Nobuhiko; Muta, Shigeru; Fujiwara, Atushi; Yasuike, Motoshige; Oohara, Ichiro; Hirakawa, Hideki; Chowdhury, Vishwajit Sur; Kobayashi, Takanori; Nakajima, Kazuhiro; Sano, Motohiko; Wada, Tokio; Tashiro, Kosuke; Ikeo, Kazuho; Hattori, Masahira; Kuhara, Satoru; Gojobori, Takashi; Inouye, Kiyoshi

    2013-01-01

    Tunas are migratory fishes in offshore habitats and top predators with unique features. Despite their ecological importance and high market values, the open-ocean lifestyle of tuna, in which effective sensing systems such as color vision are required for capture of prey, has been poorly understood. To elucidate the genetic and evolutionary basis of optic adaptation of tuna, we determined the genome sequence of the Pacific bluefin tuna (Thunnus orientalis), using next-generation sequencing technology. A total of 26,433 protein-coding genes were predicted from 16,802 assembled scaffolds. From these, we identified five common fish visual pigment genes: red-sensitive (middle/long-wavelength sensitive; M/LWS), UV-sensitive (short-wavelength sensitive 1; SWS1), blue-sensitive (SWS2), rhodopsin (RH1), and green-sensitive (RH2) opsin genes. Sequence comparison revealed that tuna's RH1 gene has an amino acid substitution that causes a short-wave shift in the absorption spectrum (i.e., blue shift). Pacific bluefin tuna has at least five RH2 paralogs, the most among studied fishes; four of the proteins encoded may be tuned to blue light at the amino acid level. Moreover, phylogenetic analysis suggested that gene conversions have occurred in each of the SWS2 and RH2 loci in a short period. Thus, Pacific bluefin tuna has undergone evolutionary changes in three genes (RH1, RH2, and SWS2), which may have contributed to detecting blue-green contrast and measuring the distance to prey in the blue-pelagic ocean. These findings provide basic information on behavioral traits of predatory fish and, thereby, could help to improve the technology to culture such fish in captivity for resource management. PMID:23781100

  18. The Living with a Star Program Mission Plan

    NASA Technical Reports Server (NTRS)

    Barth, Janet; Day, John (Technical Monitor)

    2001-01-01

    LWS (Living With a Star) is research science focused to facilitate enabling science for spacecraft design (specifically environment specification models) and spacecraft operations (specifically Space Weather research). The following topics are discussed: LWS goals and program, program architecture, the solar dynamic observer, the geospace plan, the space environment testbed concept, and the heliosphere missions.

  19. Design of Large Wood Structures in Sand-Bed Streams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Large woody structures (LWS) are potentially an efficient and cost effective way to protect streambanks from erosion while enhancing aquatic habitat. While LWS have been successful in some cases in the Pacific Northwest when ballasted with rock, the failure rate in sand-bed streams typical of the mi...

  20. Developmental dynamics of cone photoreceptors in the eel

    PubMed Central

    2009-01-01

    Background Many fish alter their expressed visual pigments during development. The number of retinal opsins expressed and their type is normally related to the environment in which they live. Eels are known to change the expression of their rod opsins as they mature, but might they also change the expression of their cone opsins? Results The Rh2 and Sws2 opsin sequences from the European Eel were isolated, sequenced and expressed in vitro for an accurate measurement of their λmax values. In situ hybridisation revealed that glass eels express only rh2 opsin in their cone photoreceptors, while larger yellow eels continue to express rh2 opsin in the majority of their cones, but also have <5% of cones which express sws2 opsin. Silver eels showed the same expression pattern as the larger yellow eels. This observation was confirmed by qPCR (quantitative polymerase chain reaction). Conclusions Larger yellow and silver European eels express two different cone opsins, rh2 and sws2. This work demonstrates that only the Rh2 cone opsin is present in younger fish (smaller yellow and glass), the sws2 opsin being expressed additionally only by older fish and only in <5% of cone cells. PMID:20025774

  1. Differential gene expression in mouse retina related to regional differences in vulnerability to hyperoxia

    PubMed Central

    Natoli, Riccardo; Valter, Krisztina; Stone, Jonathan

    2010-01-01

    Purpose In the C57BL/6J mouse retina, hyperoxia-induced degeneration of photoreceptors shows strong regional variation, beginning at a locus ~0.5 mm inferior to the optic disc. To identify gene expression differences that might underlie this variability in vulnerability, we have used microarray techniques to describe regional (superior-inferior) variations in gene expression in the retina. Methods Young adult C57BL/6J mice raised in dim cyclic illumination (12 h at 5 lx and 12 h in darkness) were exposed to hyperoxia (75% oxygen for two weeks). Retinas were collected from hyperoxia-exposed and control animals without fixation and divided into superior and inferior halves. RNA was extracted from each sample, purified, and hybridized to Mouse Gene 1.0 ST arrays (Affymetrix). The consistency of the microarray results was assessed using quantitative PCR for selected genes. Expression data were analyzed to identify genes and ncRNAs whose differential expression between the superior and inferior retina could be associated with relative vulnerability to hyperoxia. Results In control retinas, only two genes showed a fold difference in expression >2 between the superior and inferior retina; another 25 showed a fold difference of 1.5–2.0. Of these 27, the functions of six genes, including ventral anterior homeobox containing gene 2 (Vax2) and T-box 5 (Tbox5), are related to parameters of anatomic development and the functions of five are related to sensory perception. Among the latter, short-wave-sensitive cone opsin (Opn1sw) was more strongly expressed in the inferior retina and medium-wave-sensitive cone opsin (Opn1mw) in the superior retina. This is consistent with known differences in S- and M-cone distribution, confirming our separation of retinal regions. The highest fold difference was reported for membrane metalloendopeptidase (Mme), a member from the metallothionein group of cytoprotective proteins. To identify genes whose regulation by hyperoxia was significantly different between the inferior and superior retina, we calculated the “fold margin” (FM, the difference between hyperoxia-induced regulation in the inferior and superior retina) for each gene, and identified genes for which abs(FM) > 0.5. Genes thus identified numbered 112, and included many immune-, cell defense-, and inflammation- related genes. Conclusions Gene expression analysis revealed relatively subtle differences between inferior and superior regions of control C57BL/6J retinas, with only 27 genes showing an expression difference >1.5 fold. Among these, genes related to cytoprotection and apoptosis were included, along with genes related to central projections and cone-type differences. After hyperoxia-induced photoreceptor degeneration had begun, the number of genes that showed significant expression differences between the inferior and superior retina more than quadrupled, with genes related to immune processes, defense processes, and inflammation being numerically dominant. PMID:20454693

  2. Evolving the Living With a Star Data System Definition

    NASA Astrophysics Data System (ADS)

    Otranto, J.; Dijoseph, M.; Worrall, W.

    2003-04-01

    NASAs Living With a Star (LWS) Program is a space weather-focused and applications-driven research program. The LWS Program is soliciting input from the solar, space physics, space weather, and climate science communities to develop a system that enables access to science data associated with these disciplines, and advances the development of discipline and interdisciplinary findings. The LWS Program will implement a data system that builds upon the existing and planned data capture, processing, and storage components put in place by individual spacecraft missions and also inter-project data management systems, such as active archives, deep archives, and multi-mission repositories. It is technically feasible for the LWS Program to integrate data from a broad set of resources, assuming they are either publicly accessible or access is permitted by the systems administrators. The LWS Program data system will work in coordination with spacecraft mission data systems and science data repositories, integrating them into a common data representation. This common representation relies on a robust metadata definition that provides journalistic and technical data descriptions, plus linkages to supporting data products and tools. The LWS Program intends to become an enabling resource to PIs, interdisciplinary scientists, researchers, and students facilitating both access to a broad collection of science data, as well as the necessary supporting components to understand and make productive use of the data. For the LWS Program to represent science data that is physically distributed across various ground system elements, information about the data products stored on each system is collected through a series of LWS-created active agents. These active agents are customized to interface or interact with each one of these data systems, collect information, and forward updates to a single LWS-developed metadata broker. This broker, in turn, updates a centralized repository of LWS-specific metadata. A populated LWS metadata database is a single point-of-contact that can serve all users (the science community) with a one-stop-shop for data access. While data may not be physically stored in an LWS-specific repository, the LWS system enables data access from wherever the data are stored. Moreover, LWS provides the user access to information for understanding the data source, format, and calibration, enables access to ancillary and correlative data products, provides links to processing tools and models associated with the data, and any corresponding findings. The LWS may also support an active archive for solar, space physics, space weather, and climate data when these data would otherwise be discarded or archived off-line. This archive could potentially serve as a backup facility for LWS missions. This plan is developed based upon input already received from the science community; the architecture is based on system developed to date that have worked well on a smaller scale. The LWS Program continues to seek constructive input from the science community, examples of both successes and failures in dealing with science data systems, and insights regarding the obstacles between the current state-of-the-practice and this vision for the LWS Program data system.

  3. Wavelets method for the time fractional diffusion-wave equation

    NASA Astrophysics Data System (ADS)

    Heydari, M. H.; Hooshmandasl, M. R.; Maalek Ghaini, F. M.; Cattani, C.

    2015-01-01

    In this paper, an efficient and accurate computational method based on the Legendre wavelets (LWs) is proposed for solving the time fractional diffusion-wave equation (FDWE). To this end, a new fractional operational matrix (FOM) of integration for the LWs is derived. The LWs and their FOM of integration are used to transform the problem under consideration into a linear system of algebraic equations, which can be simply solved to achieve the solution of the problem. The proposed method is very convenient for solving such problems, since the initial and boundary conditions are taken into account automatically.

  4. Targeted Research and Technology Within NASA's Living With a Star Program

    NASA Technical Reports Server (NTRS)

    Hesse, Michael

    2003-01-01

    NASA's Living With a Star (LWS) initiative is a systematic, goal-oriented research program targeting those aspects of the Sun-Earth system that affect society. The Targeted Research and Technology (TR&T) component of LWS provides the theory, modeling, and data analysis necessary to enable an integrated, system-wide picture of Sun-Earth connection science with societal relevance. Recognizing the central and essential role that TR&T would have for the success of the LWS initiative, the LWS Science Architecture Team (SAT) recommended that a Science Definition Team (SDT), with the same status as a flight mission definition team, be formed to design and coordinate a TR&T program having prioritized goals and objectives that focused on practical societal benefits. This report details the SDT recommendations for the TR&T program.

  5. Chickens from lines artificially selected for juvenile low and high body weight differ in glucose homeostasis and pancreas physiology.

    PubMed

    Sumners, L H; Zhang, W; Zhao, X; Honaker, C F; Zhang, S; Cline, M A; Siegel, P B; Gilbert, E R

    2014-06-01

    Artificial selection of White Plymouth Rock chickens for juvenile (day 56) body weight resulted in two divergent genetic lines: hypophagic low weight (LWS) chickens and hyperphagic obese high weight (HWS) chickens, with the latter more than 10-fold heavier than the former at selection age. A study was designed to investigate glucose regulation and pancreas physiology at selection age in LWS chickens and HWS chickens. Oral glucose tolerance and insulin sensitivity tests revealed differences in threshold sensitivity to insulin and glucose clearance rate between the lines. Results from real-time PCR showed greater pancreatic mRNA expression of four glucose regulatory genes (preproinsulin, PPI; preproglucagon, PPG; glucose transporter 2, GLUT2; and pancreatic duodenal homeobox 1, Pdx1) in LWS chickens, than HWS chickens. Histological analysis of the pancreas revealed that HWS chickens have larger pancreatic islets, less pancreatic islet mass, and more pancreatic inflammation than LWS chickens, all of which presumably contribute to impaired glucose metabolism. PMID:24614025

  6. Targeted Research and Technology Within NASA's Living With a Star Program

    NASA Technical Reports Server (NTRS)

    Antiochos, Spiro; Baker, Kile; Bellaire, Paul; Blake, Bern; Crowley, Geoff; Eddy, Jack; Goodrich, Charles; Gopalswamy, Nat; Gosling, Jack; Hesse, Michael

    2004-01-01

    Targeted Research & Technology (TR&T) NASA's Living With a Star (LWS) initiative is a systematic, goal-oriented research program targeting those aspects of the Sun-Earth system that affect society. The Targeted Research and Technology (TR&T) component of LWS provides the theory, modeling, and data analysis necessary to enable an integrated, system-wide picture of Sun-Earth connection science with societal relevance. Recognizing the central and essential role that TR&T would have for the success of the LWS initiative, the LWS Science Architecture Team (SAT) recommended that a Science Definition Team (SDT), with the same status as a flight mission definition team, be formed to design and coordinate a TR&T program having prioritized goals and objectives that focused on practical societal benefits. This report details the SDT recommendations for the TR&T program.

  7. TARGETED RESEARCH AND TECHNOLOGY WITHIN NASA'S LIVING WITH A STAR PROGRAM.

    SciTech Connect

    Gosling, J. T.; Antiochos, Spiro; Baker, Kile; Bellaire, Paul; Blake, Bern; Crowley, Geoff; Eddy, Jack; Goodrich, Charles; Gopalswamy, Nat; Hesse, Michael; Hurlburt, Neal; Jackman, Charles; Kozyra, Janet; Labonte, Barry; Lean, Judith; Linker, Jon; Mazur, Joe; Onsager, Terry; Sibeck, David

    2003-07-10

    NASA’s Living With a Star (LWS) initiative is a systematic, goal-oriented research program targeting those aspects of the Sun-Earth system that affect society. The Targeted Research and Technology (TR&T) component of LWS provides the theory, modeling, and data analysis necessary to enable an integrated, system-wide picture of Sun-Earth connection science with societal relevance. Recognizing the central and essential role that TR&T would have for the success of the LWS initiative, the LWS Science Architecture Team (SAT) recommended that a Science Definition Team (SDT), with the same status as a flight mission definition team, be formed to design and coordinate a TR&T program having prioritized goals and objectives that focused on practical societal benefits. This report details the SDT recommendations for the TR&T program.

  8. C II 158 ??bservations of a Sample of Late-type Galaxies from the Virgo Cluster

    NASA Technical Reports Server (NTRS)

    Leech, K.; Volk, H.; Heinrichsen, I.; Hippelein, H.; Metcalfe, L.; Pierini, D.; Popescu, C.; Tuffs, R.; Xu, C.

    1999-01-01

    We have observed 19 Virgo cluster spiral galaxies with the Long Wavelength Spectrometer (LWS) onboard ESAs Infrared Space Observatory (ISO) obtaining spectra around the [CII] 157.741 ??ine structure line.

  9. [C II] 158-micrometer Observations of a Sample of Late-type Galaxies from the Virgo Cluster

    NASA Technical Reports Server (NTRS)

    Leech, K. J.; Volk, H. J.; Heinrichsen, I.; Hippelein, H.; Metcalfe, L.; Pierini, D.; Popescu, C. C.; Tuffs, R. J.; Xu, C.

    1998-01-01

    We have observed 19 Virgo cluster spiral galaxies with the Long Wavelength Spectrometer (LWS) onboard ESAs Infrared Space Observatory (ISO) obtaining spectral around the (C II) 157.741-micrometer fine structure line.

  10. Evolving the Living With a Star Data System Definition

    NASA Astrophysics Data System (ADS)

    Otranto, J. F.; Dijoseph, M.

    2003-12-01

    NASA's Living With a Star (LWS) Program is a space weather-focused and applications-driven research program. The LWS Program is soliciting input from the solar, space physics, space weather, and climate science communities to develop a system that enables access to science data associated with these disciplines, and advances the development of discipline and interdisciplinary findings. The LWS Program will implement a data system that builds upon the existing and planned data capture, processing, and storage components put in place by individual spacecraft missions and also inter-project data management systems, including active and deep archives, and multi-mission data repositories. It is technically feasible for the LWS Program to integrate data from a broad set of resources, assuming they are either publicly accessible or allow access by permission. The LWS Program data system will work in coordination with spacecraft mission data systems and science data repositories, integrating their holdings using a common metadata representation. This common representation relies on a robust metadata definition that provides journalistic and technical data descriptions, plus linkages to supporting data products and tools. The LWS Program intends to become an enabling resource to PIs, interdisciplinary scientists, researchers, and students facilitating both access to a broad collection of science data, as well as the necessary supporting components to understand and make productive use of these data. For the LWS Program to represent science data that are physically distributed across various ground system elements, information will be collected about these distributed data products through a series of LWS Program-created agents. These agents will be customized to interface or interact with each one of these data systems, collect information, and forward any new metadata records to a LWS Program-developed metadata library. A populated LWS metadata library will function as a single point-of-contact that serves the entire science community as a first stop for data availability, whether or not science data are physically stored in an LWS-operated repository. Further, this metadata library will provide the user access to information for understanding these data including descriptions of the associated spacecraft and instrument, data format, calibration and operations issues, links to ancillary and correlative data products, links to processing tools and models associated with these data, and any corresponding findings produced using these data. The LWS may also support an active archive for solar, space physics, space weather, and climate data when these data would otherwise be discarded or archived off-line. This archive could potentially serve also as a data storage backup facility for LWS missions. The plan for the LWS Program metadata library is developed based upon input received from the solar and geospace science communities; the library's architecture is based on existing systems developed for serving science metadata. The LWS Program continues to seek constructive input from the science community, examples of both successes and failures in dealing with science data systems, and insights regarding the obstacles between the current state-of-the-practice and this vision for the LWS Program metadata library.

  11. Fluid-Rock Interaction at the Slab-Mantle Interface: Insights from the High Pressure Rocks of the Sivrihisar Massif, Turkey

    NASA Astrophysics Data System (ADS)

    Fornash, K.; Whitney, D. L.; Cosca, M. A.

    2013-12-01

    Water is transported into the deep parts of the subduction system via hydrous phases such as lawsonite (lws, 11 wt.% H2O), phengite (ph, 4%), amphibole (4%), epidote-group minerals (2-4%), talc (5%), and chlorite (12%). These hydrous phases are abundant in the metabasaltic (lws eclogite and blueschist) and metasedimentary (marble, quartzite) rocks of the Sivrihisar Massif (Turkey), where they can exceed 40% modal abundance. The hydrous nature of these rocks (~5-6 wt.% H2O) likely reflects the effects of prolonged fluid-rock interaction at or near the slab-mantle interface at depths up to ~80 km for at least ~10 Ma, as indicated by the difference in 40Ar/39Ar phengite ages for lws eclogite and lws blueschist that formed from eclogite during decompression. To document the conditions, scale, and mechanism of fluid-mineral interaction at 80-45 km depth in a Late Cretaceous subduction zone, we integrate geochemical (major and trace element compositions, zoning patterns), geochronologic (40Ar/39Ar phengite), and microstructural (EBSD, XRCT) data. These techniques are applied to minerals in different textural positions (grt inclusions, fabric-forming minerals in matrix, HP veins) to investigate changes as a function of P-T conditions and to minerals in different structural positions (proximity to fault contact with overlying ultramafic unit, serpentinite lenses, lithologic contacts) to evaluate the effects of deformation and identify fluid sources and pathways. Microprobe analysis and mapping shows that lawsonite is commonly zoned in Fe, Ti, and (less common) Cr. Cr zoning is typically oscillatory and occurs in lws+grt+ph veins at lws-ecl pod margins or in blueschist located along lithologic or structural contacts. Blueschist/eclogite lws zoned in Fe typically has a Fe-poor core and Fe-richer rim, but oscillatory Fe zoning is also observed in lws veins and coarse-grained lws at pod margins. Fe-poor cores are enriched in Ti. Hourglass Ti sector zoning is common in blueschist, and can be seen in prism sections of grains cut parallel to the c-axis. Grains cut perpendicular to the c-axis show less zoning, with the exception of oscillatory rim zoning. Highly deformed lws (displaying subgrains) and lws clusters have irregular, patchy zoning patterns. Lws in retrogressed (chl+ep+lws) rocks have higher Fe content; chl-lws rocks at the margins of serpentinite lenses in the HP unit have elevated trace element content. Together, these observations indicate crystallographic and environmental control on lws composition and zoning; systematic evaluation of these characteristics and trends for different generations of lws provides information about how the fluid-rock history evolved with the P-T-time-deformation path.

  12. Identification and characterization of a protostome homologue of peropsin from a jumping spider.

    PubMed

    Nagata, Takashi; Koyanagi, Mitsumasa; Tsukamoto, Hisao; Terakita, Akihisa

    2010-01-01

    Peropsin, a member of the opsin family, has characteristics of two functionally distinct opsin-groups, that is, amino acid residues conserved among opsins for light-sensing and a retinal-photoisomerase-like molecular property. Although such a bilateral feature of peropsin seems to be important for understanding the diversity of the opsin family, previous studies have been limited to higher deuterostome, vertebrate and amphioxus peropsins. Here, we report a protostome peropsin homologue from a jumping spider. We found a spider opsin that shares amino acid homology and conserved amino acid residues with known peropsins. The spider opsin-based pigment heterologously expressed in cultured cells exhibited photoisomerase-like isomerization characteristics and a bistable nature. Based on the characteristics of both the amino acid homology and its photochemical properties, we concluded that the spider opsin is the first protostome peropsin homologue. These results show that peropsin existed before the deuterostome-protostome split like other members of the opsin family. In addition, the spider peropsin was localized to non-visual cells in the retina, and fluorescence from reduced retinal chromophore was also observed in the region where peropsin was localized. These findings provide the first demonstration that the peropsin can form a photosensitive pigment in vivo and underlie non-visual function. PMID:19960196

  13. Into the blue: Gene duplication and loss underlie color vision adaptations in a deep-sea chimaera, the elephant shark Callorhinchus milii

    PubMed Central

    Davies, Wayne L.; Carvalho, Livia S.; Tay, Boon-Hui; Brenner, Sydney; Hunt, David M.; Venkatesh, Byrappa

    2009-01-01

    The cartilaginous fishes reside at the base of the gnathostome lineage as the oldest extant group of jawed vertebrates. Recently, the genome of the elephant shark, Callorhinchus milii, a chimaerid holocephalan, has been sequenced and therefore becomes the first cartilaginous fish to be analyzed in this way. The chimaeras have been largely neglected and very little is known about the visual systems of these fishes. By searching the elephant shark genome, we have identified gene fragments encoding a rod visual pigment, Rh1, and three cone visual pigments, the middle wavelength-sensitive or Rh2 pigment, and two isoforms of the long wavelength-sensitive or LWS pigment, LWS1 and LWS2, but no evidence for the two short wavelength-sensitive cone classes, SWS1 and SWS2. Expression of these genes in the retina was confirmed by RT-PCR. Full-length coding sequences were used for in vitro expression and gave the following peak absorbances: Rh1 496 nm, Rh2 442 nm, LWS1 499 nm, and LWS2 548 nm. Unusually, therefore, for a deep-sea fish, the elephant shark possesses cone pigments and the potential for trichromacy. Compared with other vertebrates, the elephant shark Rh2 and LWS1 pigments are the shortest wavelength-shifted pigments of their respective classes known to date. The mechanisms for this are discussed and we provide experimental evidence that the elephant shark LWS1 pigment uses a novel tuning mechanism to achieve the short wavelength shift to 499 nm, which inactivates the chloride-binding site. Our findings have important implications for the present knowledge of color vision evolution in early vertebrates. PMID:19196633

  14. Into the blue: gene duplication and loss underlie color vision adaptations in a deep-sea chimaera, the elephant shark Callorhinchus milii.

    PubMed

    Davies, Wayne L; Carvalho, Livia S; Tay, Boon-Hui; Brenner, Sydney; Hunt, David M; Venkatesh, Byrappa

    2009-03-01

    The cartilaginous fishes reside at the base of the gnathostome lineage as the oldest extant group of jawed vertebrates. Recently, the genome of the elephant shark, Callorhinchus milii, a chimaerid holocephalan, has been sequenced and therefore becomes the first cartilaginous fish to be analyzed in this way. The chimaeras have been largely neglected and very little is known about the visual systems of these fishes. By searching the elephant shark genome, we have identified gene fragments encoding a rod visual pigment, Rh1, and three cone visual pigments, the middle wavelength-sensitive or Rh2 pigment, and two isoforms of the long wavelength-sensitive or LWS pigment, LWS1 and LWS2, but no evidence for the two short wavelength-sensitive cone classes, SWS1 and SWS2. Expression of these genes in the retina was confirmed by RT-PCR. Full-length coding sequences were used for in vitro expression and gave the following peak absorbances: Rh1 496 nm, Rh2 442 nm, LWS1 499 nm, and LWS2 548 nm. Unusually, therefore, for a deep-sea fish, the elephant shark possesses cone pigments and the potential for trichromacy. Compared with other vertebrates, the elephant shark Rh2 and LWS1 pigments are the shortest wavelength-shifted pigments of their respective classes known to date. The mechanisms for this are discussed and we provide experimental evidence that the elephant shark LWS1 pigment uses a novel tuning mechanism to achieve the short wavelength shift to 499 nm, which inactivates the chloride-binding site. Our findings have important implications for the present knowledge of color vision evolution in early vertebrates. PMID:19196633

  15. Dichromatic vision in a fruit bat with diurnal proclivities: the Samoan flying fox (Pteropus samoensis).

    PubMed

    Melin, Amanda D; Danosi, Christina F; McCracken, Gary F; Dominy, Nathaniel J

    2014-12-01

    A nocturnal bottleneck during mammalian evolution left a majority of species with two cone opsins, or dichromatic color vision. Primate trichromatic vision arose from the duplication and divergence of an X-linked opsin gene, and is long attributed to tandem shifts from nocturnality to diurnality and from insectivory to frugivory. Opsin gene variation and at least one duplication event exist in the order Chiroptera, suggesting that trichromatic vision could evolve under favorable ecological conditions. The natural history of the Samoan flying fox (Pteropus samoensis) meets these conditions--it is a large bat that consumes nectar and fruit and demonstrates strong diurnal proclivities. It also possesses a visual system that is strikingly similar to that of primates. To explore the potential for opsin gene duplication and divergence in this species, we sequenced the opsin genes of 11 individuals (19 X-chromosomes) from three South Pacific islands. Our results indicate the uniform presence of two opsins with predicted peak sensitivities of ca. 360 and 553 nm. This result fails to support a causal link between diurnal frugivory and trichromatic vision, although it remains plausible that the diurnal activities of P. samoensis have insufficient antiquity to favor opsin gene renovation. PMID:25319538

  16. Evolution of cichlid vision via trans-regulatory divergence

    PubMed Central

    2012-01-01

    Background Phenotypic evolution may occur through mutations that affect either the structure or expression of protein-coding genes. Although the evolution of color vision has historically been attributed to structural mutations within the opsin genes, recent research has shown that opsin regulatory mutations can also tune photoreceptor sensitivity and color vision. Visual sensitivity in African cichlid fishes varies as a result of the differential expression of seven opsin genes. We crossed cichlid species that express different opsin gene sets and scanned their genome for expression Quantitative Trait Loci (eQTL) responsible for these differences. Our results shed light on the role that different structural, cis-, and trans-regulatory mutations play in the evolution of color vision. Results We identified 11 eQTL that contribute to the divergent expression of five opsin genes. On three linkage groups, several eQTL formed regulatory hotspots associated with the expression of multiple opsins. Importantly, however, the majority of the eQTL we identified (8/11 or 73%) occur on linkage groups located trans to the opsin genes, suggesting that cichlid color vision has evolved primarily via trans-regulatory divergence. By modeling the impact of just two of these trans-regulatory eQTL, we show that opsin regulatory mutations can alter cichlid photoreceptor sensitivity and color vision at least as much as opsin structural mutations can. Conclusions Combined with previous work, we demonstrate that the evolution of cichlid color vision results from the interplay of structural, cis-, and especially trans-regulatory loci. Although there are numerous examples of structural and cis-regulatory mutations that contribute to phenotypic evolution, our results suggest that trans-regulatory mutations could contribute to phenotypic divergence more commonly than previously expected, especially in systems like color vision, where compensatory changes in the expression of multiple genes are required in order to produce functional phenotypes. PMID:23267665

  17. Number and Distribution of Mouse Retinal Cone Photoreceptors: Differences between an Albino (Swiss) and a Pigmented (C57/BL6) Strain

    PubMed Central

    Jimnez-Lpez, Manuel; Alburquerque-Bjar, Juan J.; Nieto-Lpez, Leticia; Garca-Ayuso, Diego; Villegas-Prez, Maria P.; Vidal-Sanz, Manuel; Agudo-Barriuso, Marta

    2014-01-01

    We purpose here to analyze and compare the population and topography of cone photoreceptors in two mouse strains using automated routines, and to design a method of retinal sampling for their accurate manual quantification. In whole-mounted retinas from pigmented C57/BL6 and albino Swiss mice, the longwave-sensitive (L) and the shortwave-sensitive (S) opsins were immunodetected to analyze the population of each cone type. In another group of retinas both opsins were detected with the same fluorophore to quantify all cones. In a third set of retinas, L-opsin and Brn3a were immunodetected to determine whether L-opsin+cones and retinal ganglion cells (RGCs) have a parallel distribution. Cones and RGCs were automatically quantified and their topography illustrated with isodensity maps. Our results show that pigmented mice have a significantly higher number of total cones (all-cones) and of L-opsin+cones than albinos which, in turn, have a higher population of S-opsin+cones. In pigmented animals 40% of cones are dual (cones that express both opsins), 34% genuine-L (cones that only express the L-opsin), and 26% genuine-S (cones that only express the S-opsin). In albinos, 23% of cones are genuine-S and the proportion of dual cones increases to 76% at the expense of genuine-L cones. In both strains, L-opsin+cones are denser in the central than peripheral retina, and all-cones density increases dorso-ventrally. In pigmented animals S-opsin+cones are scarce in the dorsal retina and very numerous in the ventral retina, being densest in its nasal aspect. In albinos, S-opsin+cones are abundant in the dorsal retina, although their highest densities are also ventral. Based on the densities of each cone population, we propose a sampling method to manually quantify and infer their total population. In conclusion, these data provide the basis to study cone degeneration and its prevention in pathologic conditions. PMID:25029531

  18. Strategic Science to Address Current and Future Space Weather Needs

    NASA Astrophysics Data System (ADS)

    Mannucci, A. J.; Schwadron, N.; Antiochos, S. K.; Bhattacharjee, A.; Bisi, M. M.; Gopalswamy, N.; Kamalabadi, F.; Pulkkinen, A. A.; Tobiska, W. K.; Weimer, D. R.; Withers, P.

    2014-12-01

    NASA's Living With a Star (LWS) program has contributed a wealth of scientific knowledge that is relevant to space weather and user needs. A targeted approach to science questions has resulted in leveraging new scientific knowledge to improve not only our understanding of the Heliophysics domain, but also to develop predictive capabilities in key areas of LWS science. This fascinating interplay between science and applications promises to benefit both domains. Scientists providing feedback to the LWS program are now discussing an evolution of the targeted approach that explicitly considers how new science improves, or enables, predictive capability directly. Long-term program goals are termed "Strategic Science Areas" (SSAs) that address predictive capabilities in six specific areas: geomagnetically induced currents, satellite drag, solar energetic particles, ionospheric total electron content, radio frequency scintillation induced by the ionosphere, and the radiation environment. SSAs are organized around user needs and the impacts of space weather on society. Scientists involved in the LWS program identify targeted areas of research that reference (or bear upon) societal needs. Such targeted science leads to new discoveries and is one of the valid forms of exploration. In this talk we describe the benefits of targeted science, and how addressing societal impacts in an appropriate way maintains the strong science focus of LWS, while also leading to its broader impacts.

  19. Living With a Star, the Geospace Mission Definition Team and Aeronomy

    NASA Technical Reports Server (NTRS)

    Kintner, Paul M., Jr.; Meier, R. R.; Spann, Jim; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    To gain an understanding of the Sun-Earth system, including how and why the sun varies, how the earth responds, and the impacts on humanity, research is needed that has a integrated and systematic approach. The Living With a Star (LWS) program represents an important element in this regard both to continued progress in space science in general and in Aeronomy in particular. A fundamental question in Aeronomy is how the variable sun affects the ionosphere, thermosphere, and mesosphere. The LWS program focuses on those areas of scientific understanding that promote progress in areas that have human impact and can be investigated with space borne instruments. The Geospace Mission Definition Team is charged with investigating the science priorities identified by the LWS Science Architecture Team and developing an approach to making the necessary measurements in concert with other missions and programs. An important aspect of this approach is that all LWS measurement programs are operating simultaneously for several years. We will review some of the areas that the LWS SAT have emphasized in Aeronomy, including understanding the effects of solar variability on ionospheric density and irregularities, the effects of solar variability on the mass density of the atmosphere at LEO altitudes, and the effects of solar variability on near-surface temperatures and on ozone distribution.

  20. Definition Team of NASA's ``Living with a Star'' Geospace Mission Sets Science Priorities

    NASA Astrophysics Data System (ADS)

    Kintner, Paul M.; Guhathakurta, Madhulika; Spann, James; Giles, Barbara

    In a recently released report, a NASA appointed panel presented recommendations for the science goals and implementation approach for the Geospace Project of the Living with a Star (LWS) program, a crucial component of the National Space Weather Program. The primary goal of LWS is to develop the scientific understanding necessary to enable the U.S. to effectively address those aspects of the connected Sun-Earth system that directly affect life and society. As a component of the LWS program, the Geospace Project would address the near-Earth interplanetary medium, the Earth's magnetosphere, the ionosphere and the upper atmosphere, with a goal to understand and characterize the geospace phenomena that most affect life and society.

  1. Breaking the Covalent Bond—A Pigment Property that Contributes to Desensitization in Cones

    PubMed Central

    Kefalov, Vladimir J.; Estevez, Maureen E.; Kono, Massahiro; Goletz, Patrice W.; Crouch, Rosalie K.; Cornwall, M. Carter; Yau, King-Wai

    2010-01-01

    Summary Retinal rod and cone pigments consist of an apoprotein, opsin, covalently linked to a chromophore, 11-cis retinal. Here we demonstrate that the formation of the covalent bond between opsin and 11-cis retinal is reversible in darkness in amphibian red cones, but essentially irreversible in red rods. This dissociation, apparently a general property of cone pigments, results in a surprisingly large amount of free opsin—about 10% of total opsin—in dark-adapted red cones. We attribute this significant level of free opsin to the low concentration of intracellular free 11-cis retinal, estimated to be only a tiny fraction (~0.1 %) of the pigment content in red cones. With its constitutive transducin-stimulating activity, the free cone opsin produces an ~2-fold desensitization in red cones, equivalent to that produced by a steady light causing 500 photoisomerizations s−1. Cone pigment dissociation therefore contributes to the sensitivity difference between rods and cones. PMID:15953417

  2. Total land water storage change over 2003–2013 estimated from a global mass budget approach

    NASA Astrophysics Data System (ADS)

    Dieng, H. B.; Champollion, N.; Cazenave, A.; Wada, Y.; Schrama, E.; Meyssignac, B.

    2015-12-01

    We estimate the total land water storage (LWS) change between 2003 and 2013 using a global water mass budget approach. Hereby we compare the ocean mass change (estimated from GRACE space gravimetry on the one hand, and from the satellite altimetry-based global mean sea level corrected for steric effects on the other hand) to the sum of the main water mass components of the climate system: glaciers, Greenland and Antarctica ice sheets, atmospheric water and LWS (the latter being the unknown quantity to be estimated). For glaciers and ice sheets, we use published estimates of ice mass trends based on various types of observations covering different time spans between 2003 and 2013. From the mass budget equation, we derive a net LWS trend over the study period. The mean trend amounts to +0.30 ± 0.18 mm yr‑1 in sea level equivalent. This corresponds to a net decrease of ‑108 ± 64 km3 yr‑1 in LWS over the 2003–2013 decade. We also estimate the rate of change in LWS and find no significant acceleration over the study period. The computed mean global LWS trend over the study period is shown to be explained mainly by direct anthropogenic effects on land hydrology, i.e. the net effect of groundwater depletion and impoundment of water in man-made reservoirs, and to a lesser extent the effect of naturally-forced land hydrology variability. Our results compare well with independent estimates of human-induced changes in global land hydrology.

  3. Total Land Water Storage Change over 2003 - 2013 Estimated from a Global Mass Budget Approach

    NASA Technical Reports Server (NTRS)

    Dieng, H. B.; Champollion, N.; Cazenave, A.; Wada, Y.; Schrama, E.; Meyssignac, B.

    2015-01-01

    We estimate the total land water storage (LWS) change between 2003 and 2013 using a global water mass budget approach. Hereby we compare the ocean mass change (estimated from GRACE space gravimetry on the one hand, and from the satellite altimetry-based global mean sea level corrected for steric effects on the other hand) to the sum of the main water mass components of the climate system: glaciers, Greenland and Antarctica ice sheets, atmospheric water and LWS (the latter being the unknown quantity to be estimated). For glaciers and ice sheets, we use published estimates of ice mass trends based on various types of observations covering different time spans between 2003 and 2013. From the mass budget equation, we derive a net LWS trend over the study period. The mean trend amounts to +0.30 +/- 0.18 mm/yr in sea level equivalent. This corresponds to a net decrease of -108 +/- 64 cu km/yr in LWS over the 2003-2013 decade. We also estimate the rate of change in LWS and find no significant acceleration over the study period. The computed mean global LWS trend over the study period is shown to be explained mainly by direct anthropogenic effects on land hydrology, i.e. the net effect of groundwater depletion and impoundment of water in man-made reservoirs, and to a lesser extent the effect of naturally-forced land hydrology variability. Our results compare well with independent estimates of human-induced changes in global land hydrology.

  4. Activation of Transducin by Bistable Pigment Parapinopsin in the Pineal Organ of Lower Vertebrates

    PubMed Central

    Kawano-Yamashita, Emi; Koyanagi, Mitsumasa; Wada, Seiji; Tsukamoto, Hisao; Nagata, Takashi; Terakita, Akihisa

    2015-01-01

    Pineal organs of lower vertebrates contain several kinds of photosensitive molecules, opsins that are suggested to be involved in different light-regulated physiological functions. We previously reported that parapinopsin is an ultraviolet (UV)-sensitive opsin that underlies hyperpolarization of the pineal photoreceptor cells of lower vertebrates to achieve pineal wavelength discrimination. Although, parapinopsin is phylogenetically close to vertebrate visual opsins, it exhibits a property similar to invertebrate visual opsins and melanopsin: the photoproduct of parapinopsin is stable and reverts to the original dark states, demonstrating the nature of bistable pigments. Therefore, it is of evolutionary interest to identify a phototransduction cascade driven by parapinopsin and to compare it with that in vertebrate visual cells. Here, we showed that parapinopsin is coupled to vertebrate visual G protein transducin in the pufferfish, zebrafish, and lamprey pineal organs. Biochemical analyses demonstrated that parapinopsins activated transducin in vitro in a light-dependent manner, similar to vertebrate visual opsins. Interestingly, transducin activation by parapinopsin was provoked and terminated by UV- and subsequent orange-lights irradiations, respectively, due to the bistable nature of parapinopsin, which could contribute to a wavelength-dependent control of a second messenger level in the cell as a unique optogenetic tool. Immunohistochemical examination revealed that parapinopsin was colocalized with Gt2 in the teleost, which possesses rod and cone types of transducin, Gt1, and Gt2. On the other hand, in the lamprey, which does not possess the Gt2 gene, in situ hybridization suggested that parapinopsin-expressing photoreceptor cells contained Gt1 type transducin GtS, indicating that lamprey parapinopsin may use GtS in place of Gt2. Because it is widely accepted that vertebrate visual opsins having a bleaching nature have evolved from non-bleaching opsins similar to parapinopsin, these results implied that ancestral bistable opsins might acquire coupling to the transducin-mediated cascade and achieve light-dependent hyperpolarizing response of the photoreceptor cells. PMID:26492337

  5. Living with a Star Space Environment Testbed

    NASA Technical Reports Server (NTRS)

    Barth, Janet

    2003-01-01

    Summary of activities: (1) FYO1 NRA - Model development and data mining. (2) FY03 NRA - Flight investigations. (3) SET carrier development. (4) Study for accommodation of SET carrier to support advanced detectors. (5) Collaboration with other programs: LWS TR&T to maximize synergy between TR&T space environment research and SET space environment effects research. LWS Data System to optimize dissemination of SET data. NASA Electronic Parts and Packaging Program to leverage ground testing of technologies. Defense Threat Reduction Agency to leverage ground testing and common interests in advanced detectors. and Air Force Research Laboratory to leverage flight opportunities. (6) Education and Public Outreach.

  6. Seismic properties of subducting oceanic crust: Constraints from natural lawsonite-bearing blueschist and eclogite in Sivrihisar Massif, Turkey

    NASA Astrophysics Data System (ADS)

    Cao, Yi; Jung, Haemyeong

    2016-01-01

    Investigating the seismic properties of natural lawsonite (Lws)-bearing blueschist and eclogite is particularly important for constraining the seismic interpretation of subducting oceanic crust based on seismological observations. To achieve this end, we analyzed in detail the mineral fabrics and seismic properties of foliated Lws-blueschist and Lws-eclogites from Sivrihisar Massif in Turkey. In both blueschists and eclogites, the lawsonite fabric is characterized by three different patterns: [0 0 1] axes aligning sub-normal to foliation, and [0 1 0] axes aligning sub-parallel to lineation (normal type); [0 0 1] axes aligning sub-parallel to lineation, and [1 0 0] axes aligning sub-normal to foliation with a girdle sub-normal to lineation (abnormal type); and [0 0 1] axes aligning both sub-normal to foliation and sub-parallel to lineation, [0 1 0] axes aligning sub-parallel to lineation, and [1 0 0] axes aligning sub-normal to foliation (transitional pattern). In contrast, glaucophane and omphacite mostly present consistent axial fabrics with the [0 0 1] axes aligning to lineation. These mineral fabrics produce whole-rock seismic anisotropies with similar patterns. However, the variations in seismic anisotropies are mainly controlled by the rock type, to a lesser extent are determined by the lawsonite fabric type, and to only a small extent are affected by mineral fabric strength. Despite the constructive abnormal-type lawsonite fabric on whole-rock seismic anisotropies, because of their weaker mineral fabric strength (or deformation degree), the abnormal-type Lws-blueschist still exhibit comparatively lower seismic anisotropies than those normal-type Lws-blueschist from other localities. Based on the calculated seismic anisotropies and velocities, we estimated that when oceanic crust transforms from Lws-blueschist to Lws-eclogite with increasing subduction depth, (1) P-wave and max. S-wave polarization anisotropies reduce about 70% and 40%, respectively; and (2) variations of Vp and Vs contrasts relative to mantle peridotites are about -7% to -3% and -8% to -6%, respectively. These results corroborate the important roles of Lws-bearing blueschist and eclogite in interpreting the existence and gradual weakening of low-velocity layers in subducting oceanic crust, during the subduction process.

  7. The Living With a Star Program Space Environment Testbed

    NASA Technical Reports Server (NTRS)

    Barth, Janet; Day, John H. (Technical Monitor)

    2001-01-01

    This viewgraph presentation describes the objective, approach, and scope of the Living With a Star (LWS) program at the Marshall Space Flight Center. Scientists involved in the project seek to refine the understanding of space weather and the role of solar variability in terrestrial climate change. Research and the development of improved analytic methods have led to increased predictive capabilities and the improvement of environment specification models. Specifically, the Space Environment Testbed (SET) project of LWS is responsible for the implementation of improved engineering approaches to observing solar effects on climate change. This responsibility includes technology development, ground test protocol development, and the development of a technology application model/engineering tool.

  8. Evidence for distributed light sensing in the skin of cuttlefish, Sepia officinalis.

    PubMed

    Mthger, Lydia M; Roberts, Steven B; Hanlon, Roger T

    2010-10-23

    We report that the skin of cuttlefish, Sepia officinalis, contains opsin transcripts suggesting a possible role of distributed light sensing for dynamic camouflage and signalling. The mRNA coding for opsin from various body regions was amplified and sequenced, and gene expression was detected in fin and ventral skin samples. The amino acid sequence of the opsin polypeptide that these transcripts would produce was identical in retina and fin tissue samples, but the ventral skin opsin transcripts differed by a single amino acid. The diverse camouflage and signalling body patterns of cephalopods are visually controlled, and these findings suggest a possible additional mechanism of light sensing and subsequent skin patterning. Cuttlefish, along with a number of other cephalopod species, have been shown to be colour-blind. Since the opsin in the fin is identical to that of the retina (?max=492 nm), and the ventral transcripts are also unlikely to be spectrally different, colour discrimination by the skin opsins is unlikely. However, spectral discrimination could be provided by involving other skin structures (chromatophores and iridophores), which produce changeable colours and patterns. This 'distributed sensing' could supplement the otherwise visually driven dynamic camouflage system by assisting with colour or brightness matching to adjacent substrates. PMID:20392722

  9. Human Cone Visual Pigment Deletions Spare Sufficient Photoreceptors to Warrant Gene Therapy

    PubMed Central

    Cideciyan, Artur V.; Hufnagel, Robert B.; Carroll, Joseph; Sumaroka, Alexander; Luo, Xunda; Schwartz, Sharon B.; Dubra, Alfredo; Land, Megan; Michaelides, Michel; Gardner, Jessica C.; Hardcastle, Alison J.; Moore, Anthony T.; Sisk, Robert A.; Ahmed, Zubair M.; Kohl, Susanne

    2013-01-01

    Abstract Human X-linked blue-cone monochromacy (BCM), a disabling congenital visual disorder of cone photoreceptors, is a candidate disease for gene augmentation therapy. BCM is caused by either mutations in the red (OPN1LW) and green (OPN1MW) cone photoreceptor opsin gene array or large deletions encompassing portions of the gene array and upstream regulatory sequences that would predict a lack of red or green opsin expression. The fate of opsin-deficient cone cells is unknown. We know that rod opsin null mutant mice show rapid postnatal death of rod photoreceptors. Using in vivo histology with high-resolution retinal imaging, we studied a cohort of 20 BCM patients (age range 558) with large deletions in the red/green opsin gene array. Already in the first years of life, retinal structure was not normal: there was partial loss of photoreceptors across the central retina. Remaining cone cells had detectable outer segments that were abnormally shortened. Adaptive optics imaging confirmed the existence of inner segments at a spatial density greater than that expected for the residual blue cones. The evidence indicates that human cones in patients with deletions in the red/green opsin gene array can survive in reduced numbers with limited outer segment material, suggesting potential value of gene therapy for BCM. PMID:24067079

  10. An extended family of novel vertebrate photopigments is widely expressed and displays a diversity of function.

    PubMed

    Davies, Wayne I L; Tamai, T Katherine; Zheng, Lei; Fu, Josephine K; Rihel, Jason; Foster, Russell G; Whitmore, David; Hankins, Mark W

    2015-11-01

    Light affects animal physiology and behavior more than simply through classical visual, image-forming pathways. Nonvisual photoreception regulates numerous biological systems, including circadian entrainment, DNA repair, metabolism, and behavior. However, for the majority of these processes, the photoreceptive molecules involved are unknown. Given the diversity of photophysiological responses, the question arises whether a single photopigment or a greater diversity of proteins within the opsin superfamily detect photic stimuli. Here, a functional genomics approach identified the full complement of photopigments in a highly light-sensitive model vertebrate, the zebrafish (Danio rerio), and characterized their tissue distribution, expression levels, and biochemical properties. The results presented here reveal the presence of 42 distinct genes encoding 10 classical visual photopigments and 32 nonvisual opsins, including 10 novel opsin genes comprising four new pigment classes. Consistent with the presence of light-entrainable circadian oscillators in zebrafish, all adult tissues examined expressed two or more opsins, including several novel opsins. Spectral and electrophysiological analyses of the new opsins demonstrate that they form functional photopigments, each with unique chromophore-binding and wavelength specificities. This study has revealed a remarkable number and diversity of photopigments in zebrafish, the largest number so far discovered for any vertebrate. Found in amphibians, reptiles, birds, and all three mammalian clades, most of these genes are not restricted to teleosts. Therefore, nonvisual light detection is far more complex than initially appreciated, which has significant biological implications in understanding photoreception in vertebrates. PMID:26450929

  11. Encephalic photoreception and phototactic response in the troglobiont Somalian blind cavefish Phreatichthys andruzzii

    PubMed Central

    Tarttelin, Emma E.; Frigato, Elena; Bellingham, James; Di Rosa, Viviana; Berti, Roberto; Foulkes, Nicholas S.; Lucas, Robert J.; Bertolucci, Cristiano

    2012-01-01

    SUMMARY Many physiological and behavioural responses to changes in environmental lighting conditions are mediated by extraocular photoreceptors. Here we investigate encephalic photoreception in Phreatichthys andruzzii, a typical cave-dwelling fish showing an extreme phenotype with complete anophthalmy and a reduction in size of associated brain structures. We firstly identified two P. andruzzii photopigments, orthologues of rod opsin and exo-rod opsin. In vitro, both opsins serve as light-absorbing photopigments with ?max around 500 nm when reconstituted with an A1 chromophore. When corrected for the summed absorption from the skin and skull, the spectral sensitivity profiles shifted to longer wavelengths (rod opsin: 521 nm; exo-rod opsin: 520 nm). We next explored the involvement of both opsins in the negative phototaxis reported for this species. A comparison of the spectral sensitivity of the photophobic response with the putative A2 absorbance spectra corrected for skin/skull absorbance indicates that the A2 versions of either or both of these pigments could explain the observed behavioural spectral sensitivity. PMID:22837464

  12. A butterfly eye's view of birds.

    PubMed

    Frentiu, Francesca D; Briscoe, Adriana D

    2008-11-01

    The striking color patterns of butterflies and birds have long interested biologists. But how these animals see color is less well understood. Opsins are the protein components of the visual pigments of the eye. Color vision has evolved in butterflies through opsin gene duplications, through positive selection at individual opsin loci, and by the use of filtering pigments. By contrast, birds have retained the same opsin complement present in early-jawed vertebrates, and their visual system has diversified primarily through tuning of the short-wavelength-sensitive photoreceptors, rather than by opsin duplication or the use of filtering elements. Butterflies and birds have evolved photoreceptors that might use some of the same amino acid sites for generating similar spectral phenotypes across approximately 540 million years of evolution, when rhabdomeric and ciliary-type opsins radiated during the early Cambrian period. Considering the similarities between the two taxa, it is surprising that the eyes of birds are not more diverse. Additional taxonomic sampling of birds may help clarify this mystery. PMID:18937365

  13. Numerical analysis of effects of large wood structures on channel morphology and fish habitat suitability in Little Topashaw Creek

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A depth-averaged two dimensional (2D) model has been applied to simulate the effect of large wood structures (LWS) on flow, sediment transport, bed change, and fish habitat suitability in a deeply-incised sharp bend in the Little Topashaw Creek, North Central Mississippi. The hydrodynamic simulation...

  14. FIELD EVALUATION OF LOW-EMISSION COAL BURNER TECHNOLOGY ON UTILITY BURNERS VOLUME V. BURNER EVALUATION DATA APPENDICES

    EPA Science Inventory

    The report gives a detailed summary of data which were generated during the testing of experimental burners on EPA's Large Watertube Simulator (LWS) test facility. The test data are presented as a series of appendices. Appendix A describe the data quality assurance procedures whi...

  15. Numerical Analysis of Effects of Large Wood Structures on Channel Morphology and Fish Habitat Suitability in a Southern U.S. Sandy Creek

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A depth-averaged two-dimensional model was applied to simulate the effect of large wood structures (LWS) on flow, sediment transport, bed change, and fish habitat in a deeply-incised sharp bend in the Little Topashaw Creek, North Central Mississippi. The hydrodynamic simulation showed that the flow ...

  16. Internal P-T-t Structure of Subduction Complexes — Insights from Lu-Hf Geochronology on Garnet and Lawsonite (Halilbağı, Central Anatolia)

    NASA Astrophysics Data System (ADS)

    Pourteau, A.; Scherer, E. E.; Schmidt, A.; Bast, R.

    2014-12-01

    The subduction complex near Halilbağı (Central Anatolia) is among the best sites to investigate deep-seated tectonic, petrologic, and geochemical processes taking place in subduction zones. The Halilbağı Unit comprises slices of lawsonite- and/or epidote-bearing blueschist and eclogite, as well as meta-chert and marble. The unit is overlain by an ophiolitic slab and underlain by a HP/LT metamorphosed carbonate platform. Previous studies of the Halilbağı Unit suggested tectonic blocks were metamorphosed under diverse peak conditions, but shared a common exhumation P-T path marked by syn-decompression cooling (Davis and Whitney, 2006; Çetinkaplan et al., 2008). To better understand the internal structure and dynamics of this subduction complex, we carried out Lu-Hf geochronology on garnet (grt) and lawsonite (lws) from a variety of HP oceanic rocks, as well as the sub-ophiolitic metamorphic sole. Our results suggest that intra-oceanic subduction started at ~110 Ma (grt-amph isochron from a grt amphibolite). Less than 23 Myr later, the subduction interface was refrigerated enough to allow clockwise P-T loops (~87 Ma peak grt-matrix isochron for a lws+grt-bearing eclogitic blueschist) and syn-decompression cooling (~79 Ma retrograde lws-matrix isochron) of subducted oceanic rocks. We will present further results for several HP metamorphic sub-facies (e.g., epidote (ep) eclogite, lws+ep blueschist, lws blueschist, lws eclogite). Such data may allow unraveling whether the co-occurrence of "warm" (i.e., ep-bearing), and "cold" (i.e., lws-bearing) HP rocks in the same locality results from (a) sampling of distinct levels of the subduction slab, (b) thermal maturation of the juvenile subduction zone, or (c) inaccurate P-T estimates. Novel natural constraints are thus expected on the dynamics of the Halilbağı Unit and of subduction complexes in general. Çetinkaplan M., Candan O., Oberhänsli R. and Bousquet R., 2008. Pressure-Temperature Evolution of Lawsonite Eclogite in Sivrihisar, Tavşanlı Zone-Turkey. Lithos, 104(1-4): 12-32. Davis P. B. and Whitney D. L., 2006. Petrogenesis of Lawsonite and Epidote Eclogite and Blueschist, Sivrihisar Massif, Turkey. Journal of Metamorphic Geology, 24(9): 823-849.

  17. Fed and fasted chicks from lines divergently selected for low or high body weight have differential hypothalamic appetite-associated factor mRNA expression profiles.

    PubMed

    Yi, Jiaqing; Gilbert, Elizabeth R; Siegel, Paul B; Cline, Mark A

    2015-06-01

    We have demonstrated that chicken lines which have undergone intense divergent selection for either low (LWS) or high (HWS) body weight (anorexic and obese containing, respectively) have differential food intake threshold responses to a range of intracerebroventricular injected neurotransmitters. The study reported herein was designed to measure endogenous appetite-associated factor mRNA profiles between these lines in an effort to further understand the molecular mechanisms involved in their differential eating patterns. Whole hypothalamus was collected from 5 day-old chicks that had been fasted for 180 min or had free access to food. Total RNA was isolated, reverse transcribed, and real-time PCR performed. Although mRNAs encoding orexigenic neuropeptides including agouti-related peptide, neuropeptide Y (NPY), prolactin-releasing peptide, and visfatin did not differ in expression between the lines, NPY receptor 5 mRNA was greater in fed LWS than HWS chicks, but fasting decreased the magnitude of difference. Anorexigenic factors including amylin, corticotropin releasing factor (CRF) and ghrelin were not differentially expressed between lines, while mRNA abundance of calcitonin, CRF receptor 1, leptin receptor, neuropeptide S, melanocortin receptor 3, and oxytocin were greater in LWS than HWS chicks. Pro-opiomelanocortin mRNA was lower in LWS than HWS chicks, while fasting decreased its expression in both lines. These results suggest that there are differences in gene expression of appetite-associated factors between LWS and HWS lines that might be associated with their differential food intake and thus contribute to differences in severity of anorexia, body weight, adiposity, and development of obesity. PMID:25677648

  18. Optogenetics for retinal disorders.

    PubMed

    Henriksen, Bradley S; Marc, Robert E; Bernstein, Paul S

    2014-01-01

    Optogenetics is the use of genetic methods combined with optical technology to achieve gain or loss of function within neuronal circuits. The field of optogenetics has been rapidly expanding in efforts to restore visual function to blinding diseases such as retinitis pigmentosa (RP). Most work in the field includes a group of light-sensitive retinaldehyde-binding proteins known as opsins. Opsins couple photon absorption to molecular signaling chains that control cellular ion currents. Targeting of opsin genes to surviving retinal cells is fundamental to the success of optogenetic therapy. Viral delivery, primarily adeno-associated virus, using intravitreal injection for inner retinal cells and subretinal injection for outer retinal cells, has proven successful in many models. Challenges in bioengineering remain for optogenetics including relative insensitivity of opsins to physiologic light levels of stimulation and difficulty with viral delivery in primate models. However, targeting optogenetic therapy may present an even greater challenge. Neural and glial remodeling seen in advanced stages of RP result in reorganization of remaining neural retina, and optogenetic therapy may not yield functional results. Remodeling also poses a challenge to the selection of cellular targets, with bipolar, amacrine and ganglion cells all playing distinct physiologic roles, and affected by remodeling differently. Although optogenetics has drawn closer to clinical utility, advances in opsin engineering, therapeutic targeting and ultimately in molecular inhibition of remodeling will play critical roles in the continued clinical advancement of optogenetic therapy. PMID:25667740

  19. Thyroid Hormone Signaling and Cone Photoreceptor Viability.

    PubMed

    Ma, Hongwei; Ding, Xi-Qin

    2016-01-01

    Thyroid hormone (TH) signaling regulates cell proliferation, differentiation, and apoptosis. In the retina, TH signaling plays a central role in cone opsin expression. TH signaling inhibits S opsin expression, stimulates M opsin expression, and promotes dorsal-ventral opsin patterning. TH signaling has also been associated with cone photoreceptor viability. Treatment with thyroid hormone triiodothyronine (T3) or induction of high T3 by deleting the hormone-inactivating enzyme type 3 iodothyronine deiodinase (DIO3) causes cone death in mice. This effect is reversed by deletion of the TH receptor (TR) gene. Consistent with the T3 treatment effect, suppressing TH signaling preserves cones in mouse models of retinal degeneration. The regulation of cone survival by TH signaling appears to be independent of its regulatory role in cone opsin expression. The mechanism by which TH signaling regulates cone viability remains to be identified. The current understanding of TH signaling regulation in photoreceptor viability suggests that suppressing TH signaling locally in the retina may represent a novel strategy for retinal degeneration management. PMID:26427466

  20. Eye-independent, light-activated chromatophore expansion (LACE) and expression of phototransduction genes in the skin of Octopus bimaculoides.

    PubMed

    Ramirez, M Desmond; Oakley, Todd H

    2015-05-15

    Cephalopods are renowned for changing the color and pattern of their skin for both camouflage and communication. Yet, we do not fully understand how cephalopods control the pigmented chromatophore organs in their skin and change their body pattern. Although these changes primarily rely on eyesight, we found that light causes chromatophores to expand in excised pieces of Octopus bimaculoides skin. We call this behavior light-activated chromatophore expansion (or LACE). To uncover how octopus skin senses light, we used antibodies against r-opsin phototransduction proteins to identify sensory neurons that express r-opsin in the skin. We hypothesized that octopus LACE relies on the same r-opsin phototransduction cascade found in octopus eyes. By creating an action spectrum for the latency to LACE, we found that LACE occurred most quickly in response to blue light. We fit our action spectrum data to a standard opsin curve template and estimated the λmax of LACE to be 480 nm. Consistent with our hypothesis, the maximum sensitivity of the light sensors underlying LACE closely matches the known spectral sensitivity of opsin from octopus eyes. LACE in isolated preparations suggests that octopus skin is intrinsically light sensitive and that this dispersed light sense might contribute to their unique and novel patterning abilities. Finally, our data suggest that a common molecular mechanism for light detection in eyes may have been co-opted for light sensing in octopus skin and then used for LACE. PMID:25994633

  1. Optogenetics for Retinal Disorders

    PubMed Central

    Henriksen, Bradley S.; Marc, Robert E.; Bernstein, Paul S.

    2014-01-01

    Optogenetics is the use of genetic methods combined with optical technology to achieve gain or loss of function within neuronal circuits. The field of optogenetics has been rapidly expanding in efforts to restore visual function to blinding diseases such as retinitis pigmentosa (RP). Most work in the field includes a group of light-sensitive retinaldehyde-binding proteins known as opsins. Opsins couple photon absorption to molecular signaling chains that control cellular ion currents. Targeting of opsin genes to surviving retinal cells is fundamental to the success of optogenetic therapy. Viral delivery, primarily adeno-associated virus, using intravitreal injection for inner retinal cells and subretinal injection for outer retinal cells, has proven successful in many models. Challenges in bioengineering remain for optogenetics including relative insensitivity of opsins to physiologic light levels of stimulation and difficulty with viral delivery in primate models. However, targeting optogenetic therapy may present an even greater challenge. Neural and glial remodeling seen in advanced stages of RP result in reorganization of remaining neural retina, and optogenetic therapy may not yield functional results. Remodeling also poses a challenge to the selection of cellular targets, with bipolar, amacrine and ganglion cells all playing distinct physiologic roles, and affected by remodeling differently. Although optogenetics has drawn closer to clinical utility, advances in opsin engineering, therapeutic targeting and ultimately in molecular inhibition of remodeling will play critical roles in the continued clinical advancement of optogenetic therapy. PMID:25667740

  2. The eyes have it: regulatory and structural changes both underlie cichlid visual pigment diversity.

    PubMed

    Hofmann, Christopher M; O'Quin, Kelly E; Marshall, N Justin; Cronin, Thomas W; Seehausen, Ole; Carleton, Karen L

    2009-12-01

    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. PMID:20027211

  3. Spectral sensitivity of light-induced hatching and expression of genes mediating photoreception in eggs of the Asian tadpole shrimp Triops granarius.

    PubMed

    Kashiyama, Kazuyuki; Ito, Chihiro; Numata, Hideharu; Goto, Shin G

    2010-08-01

    Embryonic development of the Asian tadpole shrimp Triops granarius is arrested at an early stage of organogenesis under darkness, whereas exposure to light resumes its development and promotes hatching. To better understand the photoreception systems involved in the light-induced hatching of T. granarius eggs, we examined the spectral sensitivity of hatching and the expression of genes involved in photoreception (opsins) and phototransduction (arrestin 2). Hatching of eggs is induced by light of broad wavelengths, from ultraviolet (UV) (395 nm) to red (660 nm), suggesting that visual pigments are involved in photoreception. Next, we focused on opsins which are protein moieties of visual pigments and arrestin 2 which is involved in a phototransduction cascade. Transcripts of several opsin genes and the arrestin 2 gene were detected in T. granarius eggs. Thus, we present a possibility that T. granarius eggs use visual pigments for light perception in light-induced hatching. PMID:20347048

  4. Molecular evidence for color discrimination in the Atlantic sand fiddler crab, Uca pugilator.

    PubMed

    Rajkumar, Premraj; Rollmann, Stephanie M; Cook, Tiffany A; Layne, John E

    2010-12-15

    Fiddler crabs are intertidal brachyuran crabs that belong to the genus Uca. Approximately 97 different species have been identified, and several of these live sympatrically. Many have species-specific body color patterns that may act as signals for intra- and interspecific communication. To understand the behavioral and ecological role of this coloration we must know whether fiddler crabs have the physiological capacity to perceive color cues. Using a molecular approach, we identified the opsin-encoding genes and determined their expression patterns across the eye of the sand fiddler crab, Uca pugilator. We identified three different opsin-encoding genes (UpRh1, UpRh2 and UpRh3). UpRh1 and UpRh2 are highly related and have similarities in their amino acid sequences to other arthropod long- and medium-wavelength-sensitive opsins, whereas UpRh3 is similar to other arthropod UV-sensitive opsins. All three opsins are expressed in each ommatidium, in an opsin-specific pattern. UpRh3 is present only in the R8 photoreceptor cell, whereas UpRh1 and UpRh2 are present in the R1-7 cells, with UpRh1 expression restricted to five cells and UpRh2 expression present in three cells. Thus, one photoreceptor in every ommatidium expresses both UpRh1 and UpRh2, providing another example of sensory receptor coexpression. These results show that U. pugilator has the basic molecular machinery for color perception, perhaps even trichromatic vision. PMID:21113005

  5. Spectral and temporal sensitivity of cone-mediated responses in mouse retinal ganglion cells

    PubMed Central

    Wang, Yanbin V.; Weick, Michael; Demb, Jonathan B.

    2011-01-01

    The retina uses two photoreceptor types to encode the wide range of light intensities in the natural environment. Rods mediate vision in dim light, whereas cones mediate vision in bright light. Mouse photoreceptors include only 3% cones, and the majority of these co-express two opsins (S, M), with peak sensitivity to either ultraviolet (360 nm) or green light (508 nm). The M:S opsin ratio varies across the retina but has not been characterized functionally, preventing quantitative study of cone-mediated vision. Furthermore, physiological and behavioral measurements suggested that mouse retina supports relatively slow temporal processing (peak sensitivity, ~2–5 Hz), compared to primates; however, past studies used visible wavelengths that are inefficient at stimulating mouse S opsin. Here, we measured the M:S opsin expression ratio across the mouse retina, as reflected by ganglion cell responses, in vitro, and probed cone-mediated ganglion cell temporal properties using ultraviolet light stimulation and linear systems analysis. From recordings in mice lacking rod function (Gnat1−/−, Rho−/−), we estimate ~70% M-opsin expression in far dorsal retina, dropping to <5% M-opsin expression throughout ventral retina. In mice lacking cone function (Gnat2cpfl3), light-adapted rod-mediated responses peaked at ~5–7 Hz. In wild-type mice, cone-mediated responses peaked at ~10 Hz, with substantial responsiveness up to ~30 Hz. Therefore, despite the small percentage of cones, cone-mediated responses in mouse ganglion cells are fast and robust, similar to those in primates. These measurements enable quantitative analysis of cone-mediated responses at all levels of the visual system. PMID:21613480

  6. Molecular evidence for color discrimination in the Atlantic sand fiddler crab, Uca pugilator

    PubMed Central

    Rajkumar, Premraj; Rollmann, Stephanie M.; Cook, Tiffany A.; Layne, John E.

    2010-01-01

    SUMMARY Fiddler crabs are intertidal brachyuran crabs that belong to the genus Uca. Approximately 97 different species have been identified, and several of these live sympatrically. Many have species-specific body color patterns that may act as signals for intra- and interspecific communication. To understand the behavioral and ecological role of this coloration we must know whether fiddler crabs have the physiological capacity to perceive color cues. Using a molecular approach, we identified the opsin-encoding genes and determined their expression patterns across the eye of the sand fiddler crab, Uca pugilator. We identified three different opsin-encoding genes (UpRh1, UpRh2 and UpRh3). UpRh1 and UpRh2 are highly related and have similarities in their amino acid sequences to other arthropod long- and medium-wavelength-sensitive opsins, whereas UpRh3 is similar to other arthropod UV-sensitive opsins. All three opsins are expressed in each ommatidium, in an opsin-specific pattern. UpRh3 is present only in the R8 photoreceptor cell, whereas UpRh1 and UpRh2 are present in the R1-7 cells, with UpRh1 expression restricted to five cells and UpRh2 expression present in three cells. Thus, one photoreceptor in every ommatidium expresses both UpRh1 and UpRh2, providing another example of sensory receptor coexpression. These results show that U. pugilator has the basic molecular machinery for color perception, perhaps even trichromatic vision. PMID:21113005

  7. In Vivo Application of Optogenetics for Neural Circuit Analysis

    PubMed Central

    2012-01-01

    Optogenetics combines optical and genetic methods to rapidly and reversibly control neural activities or other cellular functions. Using genetic methods, specific cells or anatomical pathways can be sensitized to light through exogenous expression of microbial light activated opsin proteins. Using optical methods, opsin expressing cells can be rapidly and reversibly controlled by pulses of light of specific wavelength. With the high spatial temporal precision, optogenetic tools have enabled new ways to probe the causal role of specific cells in neural computation and behavior. Here, we overview the current state of the technology, and provide a brief introduction to the practical considerations in applying optogenetics in vivo to analyze neural circuit functions. PMID:22896801

  8. ANTENNA RADIATION NEAR THE LOCAL PLASMA FREQUENCY BY LANGMUIR WAVE EIGENMODES

    SciTech Connect

    Malaspina, David M.; Cairns, Iver H.; Ergun, Robert E. E-mail: cairns@physics.usyd.edu.au

    2012-08-10

    Langmuir waves (LWs) in the solar wind are generated by electron beams associated with solar flares, interplanetary shock fronts, planetary bow shocks, and magnetic holes. In principle, LWs localized as eigenmodes of density fluctuations can emit electromagnetic (EM) radiation by an antenna mechanism near the local plasma frequency f{sub p} and twice the local plasma frequency. In this work, analytic expressions are derived for the radiated electric and magnetic fields and power generated near f{sub p} by LW eigenmodes. The EM wave power emitted near f{sub p} is predicted as a function of the eigenmode length scale L, maximum electric field, driving electron beam speed, and the ambient plasma density and temperature. The escape to a distant observer of f{sub p} radiation from a localized Langmuir eigenmode is also briefly explored as a function of the plasma conditions.

  9. NASA's Living with a Star Program: The Geospace Mission Concept

    NASA Technical Reports Server (NTRS)

    Barth, Janet L.; Giles, Barbara; Zanetti, Lawrence; Spann, James; Day, John H. (Technical Monitor)

    2002-01-01

    NASA has initiated the Living with a Star Program (LWS) to develop the scientific understanding to address the aspects of the Connected Sun-Earth system that affect life and society. A goal of the program is to bridge the gap between science, engineering, and user application communities. This will enable future science, operational, and commercial objectives in space and atmospheric environments by improving engineering approaches to the accommodation and/or mitigation of the effects of solar variability on technological systems. Three program elements are the Science Missions; a Theory, Modeling, and Data Analysis program; and a Space Environment Testbeds program. Because many of the effects of solar variability on humanity are observed in Geospace regions of space, the science research for all three elements of the LWS Program have significant components in Geospace regions.

  10. Comprehensive analysis of escape-cone losses from luminescent waveguides.

    PubMed

    McDowall, Stephen; Butler, Tristan; Bain, Edward; Scharnhorst, Kelsey; Patrick, David

    2013-02-20

    Luminescent waveguides (LWs) occur in a wide range of applications, from solar concentrators to doped fiber amplifiers. Here we report a comprehensive analysis of escape-cone losses in LWs, which are losses associated with internal rays making an angle less than the critical angle with a waveguide surface. For applications such as luminescent solar concentrators, escape-cone losses often dominate all others. A statistical treatment of escape-cone losses is given accounting for photoselection, photon polarization, and the Fresnel relations, and the model is used to analyze light absorption and propagation in waveguides with isotropic and orientationally aligned luminophores. The results are then compared to experimental measurements performed on a fluorescent dye-doped poly(methyl methacrylate) waveguide. PMID:23434994

  11. Proviral integrations and expression of endogenous Avian leucosis virus during long term selection for high and low body weight in two chicken lines

    PubMed Central

    Ka, Sojeong; Kerje, Susanne; Bornold, Lina; Liljegren, Ulrika; Siegel, Paul B; Andersson, Leif; Hallbk, Finn

    2009-01-01

    Background Long-term selection (> 45 generations) for low or high juvenile body weight from a common founder population of White Plymouth Rock chickens has generated two extremely divergent lines, the LWS and HWS lines. In addition to a > 9-fold difference between lines for the selected trait, large behavioural and metabolic differences between the two lines evolved during the course of the selection. We recently compared gene expression in brain tissue from birds representing these lines using a global cDNA array analysis and the results showed multiple but small expression differences in protein coding genes. The main differentially expressed transcripts were endogenous retroviral sequences identified as avian leucosis virus subgroup-E (ALVE). Results In this work we confirm the differential ALVE expression and analysed expression and number of proviral integrations in the two parental lines as well as in F9 individuals from an advanced intercross of the lines. Correlation analysis between expression, proviral integrations and body weight showed that high ALVE levels in the LWS line were inherited and that more ALVE integrations were detected in LWS than HWS birds. Conclusion We conclude that only a few of the integrations contribute to the high expression levels seen in the LWS line and that high ALVE expression was significantly correlated with lower body weights for the females but not males. The conserved correlation between high expression and low body weight in females after 9 generations of intercrosses, indicated that ALVE loci conferring high expression directly affects growth or are very closely linked to loci regulating growth. PMID:19604406

  12. Implementing a Virtual Workshop for Interdiscplinary collaboration on Grand Challenge Issues: Lessons Learned

    NASA Astrophysics Data System (ADS)

    Barnes, R. J.; Kozyra, J.; Weiss, M.; Fox, N. J.; Morrison, D.; Paxton, L.

    2006-12-01

    During October of 2006 a Virtual Workshop (eWorkshop), sponsored by CAWSES, NASA/LWS, eGY, IHY, NSF, and ICESTAR was held to discuss the state of the Sun-Earth system during super substorms. This virtual workshop used the Internet to allow world-wide participants to discuss and exchange data using various web based tools. Presented here are the technical aspects of the implementation and the lessons learned from this preliminary workshop.

  13. Wetland treatment of oil and gas well wastewaters. Quarterly technical report, November 25, 1993--March 24, 1994

    SciTech Connect

    Kadlec, R.H.; Srinivasan, K.R.

    1994-04-15

    In the third quarterly report, adsorption of heavy metals ions such as Cu(II) and Cr(VI) onto soils drawn from the laboratory-type wetland (LW) was shown to be weak. On the other hand, it was shown that modified-clays did adsorb Cr(VI) ions strongly at pH 4.5. Further, studies on the pH dependence of the adsorption of {beta}-naphthoic acid, (NA), a well-documented contaminant in many oil and gas well waste waters (4), onto modified-clays were undertaken and it was shown that uptake of NA by modified-clays was of the high affinity type at pH 4.5 and 7.0, but weak at pH 9.0. Adsorption of heavy metal ions, Cu{sup 2+}, and CR(VI) onto algae, a proposed wetland amendment, was carried out and the results were presented and discussed in the fourth quarterly report. Studies on the dynamics of uptake of phenol and NA by laboratory-type wetlands (LWs) were initiated and preliminary results indicated that both phenol and NA were sorbed onto components of LWs. A mass balance model has been developed to quantify the fate of phenol in LWs. The model is based on the postulate that the fate of phenol in LWs can be attributed to a combination of (1) evaporation of solute and solvent, (2) adsorption of phenol onto various components of LW and (3) its biodegradation, both in solution and at solid-liquid interface. As an initial approximation, the latter two processes have been lumped together and incorporated into the model as an unit operation. Both zero order and first order kinetics for the disappearance of phenol have been considered. Evaporative losses of water and phenol have also been taken into account and this model is presented and discussed in this quarterly report.

  14. The Living With a Star CDAW on the Solar and Geospace Connections of Solar Energetic Particles

    NASA Technical Reports Server (NTRS)

    Thompson, Barbara J.; Gopalswamy, Nat; Colon, Gilberto (Technical Monitor)

    2002-01-01

    The Living With a Star Program is sponsoring its first CDAW (Coordinated Data Analysis Workshop) to be held July 23-26, 2002 at a conference support location near the NASA Goddard Space Flight Center. This CDAW's topic is Solar Energetic Particle events. The topic was chosen due to the breadth of the impact of SEP's on the space environment and terrestrial climate. General goals of the LWS CDAW are a) Stimulate LWS Science on the near term, b) Facilitate cross-disciplinary interaction between the LWS scientific and space environment communities, c) Produce science products for all potential users, and d) Assist in the development of the LWS data system. The workshop will proceed similar to a previous CDAW held in 1999 on Interplanetary Type 11 Shocks. A list of target events has been compiled, which can be found at the workshop home page. The page lists all of the SEP events from 1996 January to 2001 December with energy > 10 MeV particle intensities exceeding 10 PFU. Preparation for the workshop consists of identifying relevant data from a wide variety of sources (solar, interplanetary, magnetospheric and climatary), accumulating the data (frequently this consists of both raw data, processed data and plots to ease perusal during the workshop) and gathering the software tools. Participants in the workshop are expected to complete their contributions of data or models prior to arriving at the workshop. Most of the CDAW consists of joint analysis of this data; only a few introductory talks are given at the beginning of the workshop, with the rest of the time being devoted to producing scientific results. Additional symposia may be scheduled at a later date, which will allow a venue for scientific talks on the CDAW results and associated science. The poster will list the scientific goals of the workshop, as well as a scientific discussion of the data which has been accumulated thus far.

  15. Evaluation of mercury in liquid waste processing facilities - Phase I report

    SciTech Connect

    Jain, V.; Occhipinti, J. E.; Shah, H.; Wilmarth, W. R.; Edwards, R. E.

    2015-07-01

    This report provides a summary of Phase I activities conducted to support an Integrated Evaluation of Mercury in Liquid Waste System (LWS) Processing Facilities. Phase I activities included a review and assessment of the liquid waste inventory and chemical processing behavior of mercury using a system by system review methodology approach. Gaps in understanding mercury behavior as well as action items from the structured reviews are being tracked. 64% of the gaps and actions have been resolved.

  16. Evaluation of Mercury in Liquid Waste Processing Facilities - Phase I Report

    SciTech Connect

    Jain, V.; Occhipinti, J.; Shah, H.; Wilmarth, B.; Edwards, R.

    2015-07-01

    This report provides a summary of Phase I activities conducted to support an Integrated Evaluation of Mercury in Liquid Waste System (LWS) Processing Facilities. Phase I activities included a review and assessment of the liquid waste inventory and chemical processing behavior of mercury using a system by system review methodology approach. Gaps in understanding mercury behavior as well as action items from the structured reviews are being tracked. 64% of the gaps and actions have been resolved.

  17. Evaluation of mercury in the liquid waste processing facilities

    SciTech Connect

    Jain, Vijay; Shah, Hasmukh; Occhipinti, John E.; Wilmarth, William R.; Edwards, Richard E.

    2015-08-13

    This report provides a summary of Phase I activities conducted to support an Integrated Evaluation of Mercury in Liquid Waste System (LWS) Processing Facilities. Phase I activities included a review and assessment of the liquid waste inventory and chemical processing behavior of mercury using a system by system review methodology approach. Gaps in understanding mercury behavior as well as action items from the structured reviews are being tracked. 64% of the gaps and actions have been resolved.

  18. Solar Dynamics Observatory and Solar Sentinels Missions in Living With A Star Program

    NASA Astrophysics Data System (ADS)

    Guhathakurta, M.

    We live in the extended atmosphere of an active star. While sunlight enables and sustains life, the Sun's variability produces streams of high-energy particles and radiation that can affect life. In the year 2000 NASA established a new program called the Living With a Star (LWS). The objective of this program is to "develop the scientific understanding necessary to effectively address those aspects of the Connected SunEarth system that directly affect life and society." To address this objective NASA formulated two groups of mission scenarios in the LWS Space Weather Research Network: (a) solar dynamics elements (Solar Dynamics Observatory/Sentinels) that observe the Sun and track disturbances originating there and (b) geospace dynamics elements (Geospace Missions Network) consisting of constellations of small satellites located in key regions around the Earth to measure downstream effects. Science payload for the first mission of LWS, namely Solar Dynamics Observatory (SDO) to study the Sun as a magnetic variable star and quantify its input into the Earth's atmosphere has been selected with a launch date of 2007. Details of the scientific objectives of the mission and its payload will be discussed. Solar Sentinels, a set of notional missions to investigate the physics of interplanetary medium that link solar processes to Earth's environment are planned to be launched in the 2010-2013 time frame depending on budgetary and other factors. A small fleet of spacecraft (four in the nominal plan) will be used to track and understand the evolution of matter ejected from the Sun. Concepts which are presently under study for the future missions will be described in detail. Although originally a U.S. initiative, the problems that LWS addresses are global in nature. Thus under the auspices of IACG an International Living With a Star (ILWS) working group has been established and I will report on the joint activities between NASA and other space agencies.

  19. Delayed access of low body weight-selected chicks to food at hatch is associated with up-regulated pancreatic glucagon and glucose transporter gene expression.

    PubMed

    Parker, Grace A; Sumners, Lindsay H; Zhao, Xiaoling; Honaker, Christa F; Siegel, Paul B; Cline, Mark A; Gilbert, Elizabeth R

    2015-11-01

    Chickens selected for low (LWS) and high (HWS) juvenile body weight (BW) for 55 generations differ in BW by 10-fold at selection age. High (HWR) and low (LWR) body weight-relaxed lines have been random-bred since the 46th generation. Our objective was to evaluate the developmental and nutritional regulation of pancreatic mRNA abundance of pancreatic and duodenal homeobox 1 (PDX1), preproinsulin (PPI), preproglucagon (PPG), and glucose transporter 2 (GLUT2). At day of hatch (DOH) and days 1, 3, 7, and 15 (D1, 3, 7 and 15, respectively), pancreas was collected and real time PCR was performed in Experiment 1. In Experiment 2, HWS and LWS were fed or delayed access to food for 72 h post-hatch, and pancreas collected at D15. There was an interaction of line and age for GLUT2 (P=0.001), PPI (P<0.0001), PPG (P=0.034), and PDX1 (P<0.0001). Expression was greater in chicks from LWR and LWS than HWR and HWS. There was an interaction of line and nutrition on PPG (P<0.0001) and GLUT2 (P=0.001) mRNA, where expression was similar among chicks that were fed but greater in LWS than HWS when chicks were delayed access to food. Thus, the first two weeks is important for maturation of pancreatic endocrine function. Long-term selection for BW is associated with differences in pancreas development, and delaying access to food at hatch may have persisting effects on glucose regulatory function. PMID:26260898

  20. Solar Sentinels: Report of the Science and Technology Definition Team

    NASA Technical Reports Server (NTRS)

    2006-01-01

    The goal of NASA s Living With a Star (LWS) program is to develop the scientific understanding necessary to effectively address those aspects of the connected Sun Earth system that directly affect life and society. Along with the other elements of LWS, Solar Sentinels aims to discover, understand, and model the heliospheric initiation, propagation, and solar connection of those energetic phenomena that adversely affect space exploration and life and society here on Earth. The Solar Sentinels mission will address the following questions: (1) How, where, and under what circumstances are solar energetic particles (SEPs) accelerated to high energies and how do they propagate through the heliosphere? And (2) How are solar wind structures associated with these SEPs, like CMEs, shocks, and high-speed streams, initiated, propagate, evolve, and interact in the inner heliosphere? The Sentinels STDT recommends implementing this mission in two portions, one optimized for inner heliospheric in-situ measurements and the other for solar remote observations. Sentinels will greatly enhance the overall LWS science return.

  1. The distribution of the Intermediate and Deep Water Masses on 60N in the Atlantic Ocean in 2006-2011.

    NASA Astrophysics Data System (ADS)

    Kolokolova, Alexandra

    2014-05-01

    Subpolar water structure in Atlantic Ocean has been analyzed using the newest hydrochemical data as well as CTD data. Water mass properties are compared to measurement data obtained in 2006, 2009 and 2011. New data analysis made it possible to reveal, that gradual Labrador Sea Water (LWS) dense lower core destruction in Irminger Basin and Icelandic Basin has been going on within the period of 2006-2011. In 2009 and 2011 dual-mode LWS structure was already not observed. New, developed Labrador Sea waters have spread in the upper layer. In addition to that arctic waters' influence increased slightly, and the tendency of intermediate southern-origin waters' intense penetration to the north continued. The detected LWS and Icelandic-Scotlandic Overflow Water (ISOW) warming, salinization and depletion in dissolved oxygen in Irminger Basin and Icelandic Basin have been going on in 2006-2011, happening simultaneously. Such a mode of water mass interaction in years 2000 is a reflection of the fact that one of the meridional circulation pattern dynamic phase is being completed. The mode is establishing, when water exchange between North Atlantic and Arctic Ocean is going to be defined by a weak current in the intermediate layer, intense entrance of deep waters from the north as well as strong subtropical Atlantic water transfer to the north.

  2. Assessing Lvy walks as models of animal foraging

    PubMed Central

    James, Alex; Plank, Michael J.; Edwards, Andrew M.

    2011-01-01

    The hypothesis that the optimal search strategy is a Lvy walk (LW) or Lvy flight, originally suggested in 1995, has generated an explosion of interest and controversy. Long-standing empirical evidence supporting the LW hypothesis has been overturned, while new models and data are constantly being published. Statistical methods have been criticized and new methods put forward. In parallel with the empirical studies, theoretical search models have been developed. Some theories have been disproved while others remain. Here, we gather together the current state of the art on the role of LWs in optimal foraging theory. We examine the body of theory underpinning the subject. Then we present new results showing that deviations from the idealized one-dimensional search model greatly reduce or remove the advantage of LWs. The search strategy of an LW with exponent ? = 2 is therefore not as robust as is widely thought. We also review the available techniques, and their potential pitfalls, for analysing field data. It is becoming increasingly recognized that there is a wide range of mechanisms that can lead to the apparent observation of power-law patterns. The consequence of this is that the detection of such patterns in field data implies neither that the foragers in question are performing an LW, nor that they have evolved to do so. We conclude that LWs are neither a universal optimal search strategy, nor are they as widespread in nature as was once thought. PMID:21632609

  3. Lawsonite blueschist in Northern Qilian, NW China: P-T pseudosections and petrologic implications

    NASA Astrophysics Data System (ADS)

    Zhang, Lifei; Wang, Qianjie; Song, Shuguang

    2009-07-01

    The lawsonite-bearing blueschist from the Nine Spring area, Sunan, Northern Qilian Mountains, is a unique well-preserved lawsonite blueschist terrane in China. Based on the dominant Ca-Al hydrosilicate, the lawsonite-bearing blueschists were divided into lawsonite-bearing pumpellyite blueschist, lawsonite blueschist and epidote blueschist with mineral assemblages of Gln (>40%) + Pmp (30%) + Lws (3%) + Chl (10%) + Ab (8%) + Qtz (5%) + Cal (1%), Gln (35-40%) + Lws (35-40%) + Chl (10%) + Ab (10%) + Grt (1-2%) + Zo (<2%) + Qtz (<1%) and Gln (30-35%) + Zo/Czo/Ep (30%) + Chl (15%) + Ab (15-15%) + Grt (2%) + Qtz (<2%) and Mag (1%), respectively. P-T pseudosections using internally consistent mineral thermodynamic database and Domino/Theriak software yield P-T conditions of 320-350 C, 0.75-0.85 GPa for lawsonite-bearing pumpellyite blueschist, 335-355 C, 0.8-0.95 GPa for lawsonite blueschist and 345-375 C, 0.75-0.85 GPa for epidote blueschist, respectively. The transition from the lawsonite blueschist facies to epidote blueschist facies is defined by the reaction Lws + Gln = Chl + Czo + Ab + Qtz + H 2O. These high-P rocks of the Northern Qilian Mountains have undergone prograde metamorphic P-T path with no retrograde overprinting suggesting a fast subduction and exhumation which is consistent with channel flow model.

  4. Leptin effects on food and water intake in lines of chickens selected for high or low body weight.

    PubMed

    Kuo, Alice Y; Cline, Mark A; Werner, Elizabeth; Siegel, Paul B; Denbow, D Michael

    2005-03-16

    There is an association between autonomic nervous system output and obesity. The sympathetic nervous system stimulates lipid metabolism and regulates food intake and, hence, body weight. Leptin, produced by adipocytes in proportion to their size, has been shown to directly stimulate the satiety center. In the experiment reported here, food and water intake were compared after intracerebroventricular administration of human recombinant leptin to lines of chickens that had undergone divergent selection for over 45 generations from a common White Rock base population for high (HWS) or low (LWS) body weight at 8 weeks-of-age. Leptin caused a linear decrease in food intake in chickens from the LWS line whereas no effect was observed in those from the HWS line. The HWS chickens tended to have reduced water intake post leptin administration. Others reported that leptin decreased food intake in both broiler and Leghorn chickens. Leptin concentration in the central nervous system may not contribute directly to the difference of body weight between HWS and LWS chickens. PMID:15763584

  5. Differential expression of photoreceptor-specific genes in the retina of a zebrafish cadherin2 mutant glass onion and zebrafish cadherin4 morphants.

    PubMed

    Liu, Q; Frey, R A; Babb-Clendenon, S G; Liu, B; Francl, J; Wilson, A L; Marrs, J A; Stenkamp, D L

    2007-01-01

    Cadherins are Ca2+ -dependent transmembrane molecules that mediate cell-cell adhesion through homophilic interactions. Cadherin2 (also called N-cadherin) and cadherin4 (also called R-cadherin), members of the classic cadherin subfamily, have been shown to be involved in development of a variety of tissues and organs including the visual system. To gain insight into cadherin2 and cadherin4 function in differentiation of zebrafish photoreceptors, we have analyzed expression patterns of several photoreceptor-specific genes (crx, gnat1, gnat2, irbp, otx5, rod opsin, rx1, and uv opsin) and/or a cone photoreceptor marker (zpr-1) in the retina of a zebrafish cadherin2 mutant, glass onion (glo) and in zebrafish embryos injected with a cadherin4 specific antisense morpholino oligonucleotide (cdh4MO). We find that expression of all these genes, and of zpr-1, is greatly reduced in the retina of both the glo and cadherin4 morphants. Moreover, in these embryos, expression of some genes (e.g. gnat1, gnat2 and irbp) is more affected than others (e.g. rod opsin and uv opsin). In embryos with both cadherins functions blocked (glo embryos injected with the cdh4MO), the eye initially formed, but became severely and progressively disintegrated and expressed little or no crx and otx5 as development proceeded. Our results suggest that cadherin2 and cadherin4 play important roles in the differentiation of zebrafish retinal photoreceptors. PMID:17070801

  6. Molecular genetics of rhodopsin and phototrans duction in the visual system of Drosophila

    SciTech Connect

    Zuker, C.; Cowman, A.; Montell, C.; Rubin, G.

    1987-05-01

    The authors have isolated the genes encoding four Drosophila visual pigments. Each of these opsins is expressed in a set of functionally and anatomically distinct photoreceptor cells of the eye. One is expressed in the six outer photoreceptor cells (R1-R6), the second in the central R8 photoreceptor cell, and the other two in the UV sensitive R7 photoreceptor cells. They have determined the structure and nucleotide sequence of each of these genes. They have used P element-mediated gene transfer to introduce the cloned structural gene for the R1-R6 opsin in the Drosophila germline and restored the ninaE mutant phenotype to wild-type. In an attempt to study the contribution of the various opsins to the specific functional properties of the different photoreceptor cell types, they have genetically engineered Drosophila lines that express R8 opsin in the R1-R6 photoreceptor cells. In collaboration with Drs. Ozaki and Pak at Purdue University, they have used oligonucleotide site-directed mutagenesis to mutate selected amino acids and regions of the rhodopsin molecule and reintroduced the mutated genes into Drosophila to analyze structure-function relationships in the rhodopsin molecule.

  7. Spectral sensitivity of the principal eyes of sunburst diving beetle, Thermonectus marmoratus (Coleoptera: Dytiscidae), larvae.

    PubMed

    Maksimovic, Srdjan; Layne, John E; Buschbeck, Elke K

    2011-11-01

    The principal eyes of sunburst diving beetle, Thermonectus marmoratus, larvae are among the most unusual eyes in the animal kingdom. They are composed of long tubes connecting bifocal lenses with two retinas: a distal retina situated a few hundred micrometers behind the lens, and a proximal retina that is situated directly beneath. A recent molecular study on first instar larvae suggests that the distal retina expresses a long-wavelength-sensitive opsin (TmLW), whereas the proximal retina predominantly expresses an ultraviolet-sensitive opsin (TmUV II). Using cloning and in situ hybridization we here confirm that this opsin distribution is, for the most part, maintained in third instar larvae (with the exception of the TmUV I that is weakly expressed only in proximal retinas of first instar larvae). We furthermore use intracellular electrophysiological recordings and neurobiotin injections to determine the spectral sensitivity of individual photoreceptor cells. We find that photoreceptors of the proximal retina have a sensitivity curve that peaks at 374-375 nm. The shape of the curve is consistent with the predicted absorbance of a single-opsin template. The spectral response of photoreceptors from the distal retina confirms their maximum sensitivity to green light with the dominant ?-peak between 520 and 540 nm, and the secondary ?-peak between 340 and 360 nm. These physiological measurements support molecular predictions and represent important steps towards understanding the functional organization of the unusual stemmata of T. marmoratus larvae. PMID:21993780

  8. Visual responses in mice lacking critical components of all known retinal phototransduction cascades.

    PubMed

    Allen, Annette E; Cameron, Morven A; Brown, Timothy M; Vugler, Anthony A; Lucas, Robert J

    2010-01-01

    The mammalian visual system relies upon light detection by outer-retinal rod/cone photoreceptors and melanopsin-expressing retinal ganglion cells. Gnat1(-/-);Cnga3(-/-);Opn4(-/-) mice lack critical elements of each of these photoreceptive mechanisms via targeted disruption of genes encoding rod ? transducin (Gnat1); the cone-specific ?3 cyclic nucleotide gated channel subunit (Cnga3); and melanopsin (Opn4). Although assumed blind, we show here that these mice retain sufficiently widespread retinal photoreception to drive a reproducible flash electroretinogram (ERG). The threshold sensitivity of this ERG is similar to that of cone-based responses, however it is lost under light adapted conditions. Its spectral efficiency is consistent with that of rod opsin, but not cone opsins or melanopsin, indicating that it originates with light absorption by the rod pigment. The TKO light response survives intravitreal injection of U73122 (a phospholipase C antagonist), but is inhibited by a missense mutation of cone ? transducin (Gnat2(cpfl3)), suggesting Gnat2-dependence. Visual responses in TKO mice extend beyond the retina to encompass the lateral margins of the lateral geniculate nucleus and components of the visual cortex. Our data thus suggest that a Gnat1-independent phototransduction mechanism downstream of rod opsin can support relatively widespread responses in the mammalian visual system. This anomalous rod opsin-based vision should be considered in experiments relying upon Gnat1 knockout to silence rod phototransduction. PMID:21124780

  9. Positive selection of a duplicated UV-sensitive visual pigment coincides with wing pigment evolution in Heliconius butterflies.

    PubMed

    Briscoe, Adriana D; Bybee, Seth M; Bernard, Gary D; Yuan, Furong; Sison-Mangus, Marilou P; Reed, Robert D; Warren, Andrew D; Llorente-Bousquets, Jorge; Chiao, Chuan-Chin

    2010-02-23

    The butterfly Heliconius erato can see from the UV to the red part of the light spectrum with color vision proven from 440 to 640 nm. Its eye is known to contain three visual pigments, rhodopsins, produced by an 11-cis-3-hydroxyretinal chromophore together with long wavelength (LWRh), blue (BRh) and UV (UVRh1) opsins. We now find that H. erato has a second UV opsin mRNA (UVRh2)-a previously undescribed duplication of this gene among Lepidoptera. To investigate its evolutionary origin, we screened eye cDNAs from 14 butterfly species in the subfamily Heliconiinae and found both copies only among Heliconius. Phylogeny-based tests of selection indicate positive selection of UVRh2 following duplication, and some of the positively selected sites correspond to vertebrate visual pigment spectral tuning residues. Epi-microspectrophotometry reveals two UV-absorbing rhodopsins in the H. erato eye with lambda(max) = 355 nm and 398 nm. Along with the additional UV opsin, Heliconius have also evolved 3-hydroxy-DL-kynurenine (3-OHK)-based yellow wing pigments not found in close relatives. Visual models of how butterflies perceive wing color variation indicate this has resulted in an expansion of the number of distinguishable yellow colors on Heliconius wings. Functional diversification of the UV-sensitive visual pigments may help explain why the yellow wing pigments of Heliconius are so colorful in the UV range compared to the yellow pigments of close relatives lacking the UV opsin duplicate. PMID:20133601

  10. Regulation of photoreceptor gene expression by the retinal homeobox (Rx) gene product

    PubMed Central

    Pan, Yi; Martinez-De Luna, Reyna I.; Lou, Chih-Hong; Nekkalapudi, Srivamsi; Kelly, Lisa E.; Sater, Amy K.; El-Hodiri, Heithem M.

    2010-01-01

    The retinal homeobox (Rx) gene product is essential for eye development. However little is known about its molecular function. It has been demonstrated that Rx binds to photoreceptor conserved element (PCE-1), a highly conserved element found in the promoter region of photoreceptor-specific genes such as rhodopsin and red cone opsin. We verify that Rx is co-expressed with rhodopsin and red cone opsin in maturing photoreceptors and demonstrate that Rx binds to the rhodopsin and red cone opsin promoters in vivo. We also find that Rx can cooperate with the Xenopus analogs of Crx and Nrl, otx5b and XLMaf (respectively), to activate a Xenopus opsin promoter-dependent reporter. Finally, we demonstrate that reduction of Rx expression in tadpoles results in decreases in expression of several PCE-1 containing photoreceptor genes, abnormal photoreceptor morphology, and impaired vision. Our data suggests that Rx, in combination with other transcription factors, is necessary for normal photoreceptor gene expression, maintenance, and function. This establishes a direct role for Rx in regulation of genes expressed in a differentiated cell type. PMID:20060393

  11. Photoreceptor disc morphogenesis: The classical evagination model prevails.

    PubMed

    Pugh, Edward N

    2015-11-01

    Vision begins in photoreceptor outer segments with light captured by opsins in continually synthesized disc membranes. The process by which rod photoreceptor discs are formed has been controversial. In this issue, Ding et al. (2015. J. Cell Biol. http://dx.doi.org/10.1083/jcb.201508093) show conclusively that rod discs are formed by plasma membrane evagination. PMID:26527745

  12. A Simplified Mass-Transfer Model for Visual Pigments in Amphibian Retinal-Cone Outer Segments

    PubMed Central

    Weber, Paul W.; Howle, Laurens E.; Murray, Mark M.; Corless, Joseph M.

    2011-01-01

    When radiolabeled precursors and autoradiography are used to investigate turnover of protein components in photoreceptive cone outer segments (COSs), the labeled componentsprimarily visual pigment molecules (opsins)are diffusely distributed along the COS. To further assess this COS labeling pattern, we derive a simplified mass-transfer model for quantifying the contributions of advective and diffusive mechanisms to the distribution of opsins within COSs of the frog retina. Two opsin-containing regions of the COS are evaluated: the core axial array of disks and the plasmalemma. Numerical solutions of the mass-transfer model indicate three distinct stages of system evolution. In the first stage, plasmalemma diffusion is dominant. In the second stage, the plasmalemma density reaches a metastable state and transfer between the plasmalemma and disk region occurs, which is followed by an increase in density that is qualitatively similar for both regions. The final stage consists of both regions slowly evolving to the steady-state solution. Our results indicate that autoradiographic and cognate approaches for tracking labeled opsins in the COS cannot be effective methodologies for assessing new disk formation at the base of the COS. PMID:21281566

  13. Positive selection of a duplicated UV-sensitive visual pigment coincides with wing pigment evolution in Heliconius butterflies

    PubMed Central

    Briscoe, Adriana D.; Bybee, Seth M.; Bernard, Gary D.; Yuan, Furong; Sison-Mangus, Marilou P.; Reed, Robert D.; Warren, Andrew D.; Llorente-Bousquets, Jorge; Chiao, Chuan-Chin

    2010-01-01

    The butterfly Heliconius erato can see from the UV to the red part of the light spectrum with color vision proven from 440 to 640 nm. Its eye is known to contain three visual pigments, rhodopsins, produced by an 11-cis-3-hydroxyretinal chromophore together with long wavelength (LWRh), blue (BRh) and UV (UVRh1) opsins. We now find that H. erato has a second UV opsin mRNA (UVRh2)a previously undescribed duplication of this gene among Lepidoptera. To investigate its evolutionary origin, we screened eye cDNAs from 14 butterfly species in the subfamily Heliconiinae and found both copies only among Heliconius. Phylogeny-based tests of selection indicate positive selection of UVRh2 following duplication, and some of the positively selected sites correspond to vertebrate visual pigment spectral tuning residues. Epi-microspectrophotometry reveals two UV-absorbing rhodopsins in the H. erato eye with ?max = 355 nm and 398 nm. Along with the additional UV opsin, Heliconius have also evolved 3-hydroxy-DL-kynurenine (3-OHK)-based yellow wing pigments not found in close relatives. Visual models of how butterflies perceive wing color variation indicate this has resulted in an expansion of the number of distinguishable yellow colors on Heliconius wings. Functional diversification of the UV-sensitive visual pigments may help explain why the yellow wing pigments of Heliconius are so colorful in the UV range compared to the yellow pigments of close relatives lacking the UV opsin duplicate. PMID:20133601

  14. Constitutively active rhodopsin mutants causing night blindness are effectively phosphorylated by GRKs but differ in arrestin-1 binding.

    PubMed

    Vishnivetskiy, Sergey A; Ostermaier, Martin K; Singhal, Ankita; Panneels, Valerie; Homan, Kristoff T; Glukhova, Alisa; Sligar, Stephen G; Tesmer, John J G; Schertler, Gebhard F X; Standfuss, Joerg; Gurevich, Vsevolod V

    2013-11-01

    The effects of activating mutations associated with night blindness on the stoichiometry of rhodopsin interactions with G protein-coupled receptor kinase 1 (GRK1) and arrestin-1 have not been reported. Here we show that the monomeric form of WT rhodopsin and its constitutively active mutants M257Y, G90D, and T94I, reconstituted into HDL particles are effectively phosphorylated by GRK1, as well as two more ubiquitously expressed subtypes, GRK2 and GRK5. All versions of arrestin-1 tested (WT, pre-activated, and constitutively monomeric mutants) bind to monomeric rhodopsin and show the same selectivity for different functional forms of rhodopsin as in native disc membranes. Rhodopsin phosphorylation by GRK1 and GRK2 promotes arrestin-1 binding to a comparable extent, whereas similar phosphorylation by GRK5 is less effective, suggesting that not all phosphorylation sites on rhodopsin are equivalent in promoting arrestin-1 binding. The binding of WT arrestin-1 to phospho-opsin is comparable to the binding to its preferred target, P-Rh*, suggesting that in photoreceptors arrestin-1 only dissociates after opsin regeneration with 11-cis-retinal, which converts phospho-opsin into inactive phospho-rhodopsin that has lower affinity for arrestin-1. Reduced binding of arrestin-1 to the phospho-opsin form of G90D mutant likely contributes to night blindness caused by this mutation in humans. PMID:23872075

  15. Alouatta Trichromatic Color Vision: Cone Spectra and Physiological Responses Studied with Microspectrophotometry and Single Unit Retinal Electrophysiology

    PubMed Central

    Silveira, Luiz Carlos L.; Saito, Czar A.; da Silva Filho, Manoel; Kremers, Jan; Bowmaker, James K.; Lee, Barry B.

    2014-01-01

    The howler monkeys (Alouatta sp.) are the only New World primates to exhibit routine trichromacy. Both males and females have three cone photopigments. However, in contrast to Old World monkeys, Alouatta has a locus control region upstream of each opsin gene on the X-chromosome and this might influence the retinal organization underlying its color vision. Post-mortem microspectrophotometry (MSP) was performed on the retinae of two male Alouatta to obtain rod and cone spectral sensitivities. The MSP data were consistent with only a single opsin being expressed in each cone and electrophysiological data were consistent with this primate expressing full trichromacy. To study the physiological organization of the retina underlying Alouatta trichromacy, we recorded from retinal ganglion cells of the same animals used for MSP measurements with a variety of achromatic and chromatic stimulus protocols. We found MC cells and PC cells in the Alouatta retina with similar properties to those previously found in the retina of other trichromatic primates. MC cells showed strong phasic responses to luminance changes and little response to chromatic pulses. PC cells showed strong tonic response to chromatic changes and small tonic response to luminance changes. Responses to other stimulus protocols (flicker photometry; changing the relative phase of red and green modulated lights; temporal modulation transfer functions) were also similar to those recorded in other trichromatic primates. MC cells also showed a pronounced frequency double response to chromatic modulation, and with luminance modulation response saturation accompanied by a phase advance between 1020 Hz, characteristic of a contrast gain mechanism. This indicates a very similar retinal organization to Old-World monkeys. Cone-specific opsin expression in the presence of a locus control region for each opsin may call into question the hypothesis that this region exclusively controls opsin expression. PMID:25405863

  16. Alouatta trichromatic color vision: cone spectra and physiological responses studied with microspectrophotometry and single unit retinal electrophysiology.

    PubMed

    Silveira, Luiz Carlos L; Saito, Czar A; da Silva Filho, Manoel; Kremers, Jan; Bowmaker, James K; Lee, Barry B

    2014-01-01

    The howler monkeys (Alouatta sp.) are the only New World primates to exhibit routine trichromacy. Both males and females have three cone photopigments. However, in contrast to Old World monkeys, Alouatta has a locus control region upstream of each opsin gene on the X-chromosome and this might influence the retinal organization underlying its color vision. Post-mortem microspectrophotometry (MSP) was performed on the retinae of two male Alouatta to obtain rod and cone spectral sensitivities. The MSP data were consistent with only a single opsin being expressed in each cone and electrophysiological data were consistent with this primate expressing full trichromacy. To study the physiological organization of the retina underlying Alouatta trichromacy, we recorded from retinal ganglion cells of the same animals used for MSP measurements with a variety of achromatic and chromatic stimulus protocols. We found MC cells and PC cells in the Alouatta retina with similar properties to those previously found in the retina of other trichromatic primates. MC cells showed strong phasic responses to luminance changes and little response to chromatic pulses. PC cells showed strong tonic response to chromatic changes and small tonic response to luminance changes. Responses to other stimulus protocols (flicker photometry; changing the relative phase of red and green modulated lights; temporal modulation transfer functions) were also similar to those recorded in other trichromatic primates. MC cells also showed a pronounced frequency double response to chromatic modulation, and with luminance modulation response saturation accompanied by a phase advance between 10-20 Hz, characteristic of a contrast gain mechanism. This indicates a very similar retinal organization to Old-World monkeys. Cone-specific opsin expression in the presence of a locus control region for each opsin may call into question the hypothesis that this region exclusively controls opsin expression. PMID:25405863

  17. Gene Therapy Rescues Cone Structure and Function in the 3-Month-Old rd12 Mouse: A Model for Midcourse RPE65 Leber Congenital Amaurosis

    PubMed Central

    Li, Xia; Li, Wensheng; Dai, Xufeng; Kong, Fansheng; Zheng, Qinxiang; Zhou, Xiangtian; L, Fan; Chang, Bo; Rohrer, Brbel; Hauswirth, William. W.; Qu, Jia; Pang, Ji-jing

    2011-01-01

    Purpose. RPE65 function is necessary in the retinal pigment epithelium (RPE) to generate chromophore for all opsins. Its absence results in vision loss and rapid cone degeneration. Recent Leber congenital amaurosis type 2 (LCA with RPE65 mutations) phase I clinical trials demonstrated restoration of vision on RPE65 gene transfer into RPE cells overlying cones. In the rd12 mouse, a naturally occurring model of RPE65-LCA early cone degeneration was observed; however, some peripheral M-cones remained. A prior study showed that AAV-mediated RPE65 expression can prevent early cone degeneration. The present study was conducted to test whether the remaining cones in older rd12 mice can be rescued. Methods. Subretinal treatment with the scAAV5-smCBA-hRPE65 vector was initiated at postnatal day (P)14 and P90. After 2 months, electroretinograms were recorded, and cone morphology was analyzed by using cone-specific peanut agglutinin and cone opsinspecific antibodies. Results. Cone degeneration started centrally and spread ventrally, with cells losing cone-opsin staining before that for the PNA-lectinpositive cone sheath. Gene therapy starting at P14 resulted in almost wild-type M- and S-cone function and morphology. Delaying gene-replacement rescued the remaining M-cones, and most important, more M-cone opsinpositive cells were identified than were present at the onset of gene therapy, suggesting that opsin expression could be reinitiated in cells with cone sheaths. Conclusions. The results support and extend those of the previous study that gene therapy can stop early cone degeneration, and, more important, they provide proof that delayed treatment can restore the function and morphology of the remaining cones. These results have important implications for the ongoing LCA2 clinical trials. PMID:21169527

  18. G Protein-Coupled Receptor Rhodopsin: A Prospectus

    PubMed Central

    Filipek, S?awomir; Stenkamp, Ronald E.; Teller, David C.; Palczewski, Krzysztof

    2006-01-01

    Rhodopsin is a retinal photoreceptor protein of bipartite structure consisting of the transmembrane protein opsin and a light-sensitive chromophore 11-cis-retinal, linked to opsin via a protonated Schiff base. Studies on rhodopsin have unveiled many structural and functional features that are common to a large and pharmacologically important group of proteins from the G protein-coupled receptor (GPCR) superfamily, of which rhodopsin is the best-studied member. In this work, we focus on structural features of rhodopsin as revealed by many biochemical and structural investigations. In particular, the high-resolution structure of bovine rhodopsin provides a template for understanding how GPCRs work. We describe the sensitivity and complexity of rhodopsin that lead to its important role in vision. PMID:12471166

  19. WP1: transgenic opto-animals

    NASA Astrophysics Data System (ADS)

    UŻarowska, E.; Czajkowski, Rafał; Konopka, W.

    2014-11-01

    We aim to create a set of genetic tools where permanent opsin expression (ChR or NpHR) is precisely limited to the population of neurons that express immediate early gene c-fos during a specific temporal window of behavioral training. Since the c-fos gene is only expressed in neurons that form experience-dependent ensemble, this approach will result in specific labeling of a small subset of cells that create memory trace for the learned behavior. To this end we employ two alternative inducible gene expression systems: Tet Expression System and Cre/lox System. In both cases, the temporal window for opsin induction is controlled pharmacologically, by doxycycline or tamoxifen, respectively. Both systems will be used for creating lines of transgenic animals.

  20. Inhibiting the Activity of CA1 Hippocampal Neurons Prevents the Recall of Contextual Fear Memory in Inducible ArchT Transgenic Mice

    PubMed Central

    Sakaguchi, Masanori; Kim, Karam; Yu, Lily Mae Yee; Hashikawa, Yoshiko; Sekine, Yukiko; Okumura, Yuki; Kawano, Masako; Hayashi, Masanobu; Kumar, Deependra; Boyden, Edward S.; McHugh, Thomas J.; Hayashi, Yasunori

    2015-01-01

    The optogenetic manipulation of light-activated ion-channels/pumps (i.e., opsins) can reversibly activate or suppress neuronal activity with precise temporal control. Therefore, optogenetic techniques hold great potential to establish causal relationships between specific neuronal circuits and their function in freely moving animals. Due to the critical role of the hippocampal CA1 region in memory function, we explored the possibility of targeting an inhibitory opsin, ArchT, to CA1 pyramidal neurons in mice. We established a transgenic mouse line in which tetracycline trans-activator induces ArchT expression. By crossing this line with a CaMKII?-tTA transgenic line, the delivery of light via an implanted optrode inhibits the activity of excitatory CA1 neurons. We found that light delivery to the hippocampus inhibited the recall of a contextual fear memory. Our results demonstrate that this optogenetic mouse line can be used to investigate the neuronal circuits underlying behavior. PMID:26075894

  1. Neuropsin (OPN5)-mediated photoentrainment of local circadian oscillators in mammalian retina and cornea

    PubMed Central

    Buhr, Ethan D.; Yue, Wendy W. S.; Ren, Xiaozhi; Jiang, Zheng; Liao, Hsi-Wen Rock; Mei, Xue; Vemaraju, Shruti; Nguyen, Minh-Thanh; Reed, Randall R.; Lang, Richard A.; Yau, King-Wai; Van Gelder, Russell N.

    2015-01-01

    The molecular circadian clocks in the mammalian retina are locally synchronized by environmental light cycles independent of the suprachiasmatic nuclei (SCN) in the brain. Unexpectedly, this entrainment does not require rods, cones, or melanopsin (OPN4), possibly suggesting the involvement of another retinal photopigment. Here, we show that the ex vivo mouse retinal rhythm is most sensitive to short-wavelength light but that this photoentrainment requires neither the short-wavelengthsensitive cone pigment [S-pigment or cone opsin (OPN1SW)] nor encephalopsin (OPN3). However, retinas lacking neuropsin (OPN5) fail to photoentrain, even though other visual functions appear largely normal. Initial evidence suggests that OPN5 is expressed in select retinal ganglion cells. Remarkably, the mouse corneal circadian rhythm is also photoentrainable ex vivo, and this photoentrainment likewise requires OPN5. Our findings reveal a light-sensing function for mammalian OPN5, until now an orphan opsin. PMID:26392540

  2. UV wavelengths experienced during development affect larval newt visual sensitivity and predation efficiency.

    PubMed

    Martin, Mlissa; Thry, Marc; Rodgers, Gwendolen; Goven, Delphine; Sourice, Stphane; Mge, Pascal; Secondi, Jean

    2016-02-01

    We experimentally investigated the influence of developmental plasticity of ultraviolet (UV) visual sensitivity on predation efficiency of the larval smooth newt, Lissotriton vulgaris. We quantified expression of SWS1 opsin gene (UV-sensitive protein of photoreceptor cells) in the retinas of individuals who had developed in the presence (UV+) or absence (UV-) of UV light (developmental treatments), and tested their predation efficiency under UV+ and UV- light (testing treatments). We found that both SWS1 opsin expression and predation efficiency were significantly reduced in the UV- developmental group. Larvae in the UV- testing environment displayed consistently lower predation efficiency regardless of their developmental treatment. These results prove for the first time, we believe, functional UV vision and developmental plasticity of UV sensitivity in an amphibian at the larval stage. They also demonstrate that UV wavelengths enhance predation efficiency and suggest that the magnitude of the behavioural response depends on retinal properties induced by the developmental lighting environment. PMID:26843556

  3. Neuropsin (OPN5)-mediated photoentrainment of local circadian oscillators in mammalian retina and cornea.

    PubMed

    Buhr, Ethan D; Yue, Wendy W S; Ren, Xiaozhi; Jiang, Zheng; Liao, Hsi-Wen Rock; Mei, Xue; Vemaraju, Shruti; Nguyen, Minh-Thanh; Reed, Randall R; Lang, Richard A; Yau, King-Wai; Van Gelder, Russell N

    2015-10-20

    The molecular circadian clocks in the mammalian retina are locally synchronized by environmental light cycles independent of the suprachiasmatic nuclei (SCN) in the brain. Unexpectedly, this entrainment does not require rods, cones, or melanopsin (OPN4), possibly suggesting the involvement of another retinal photopigment. Here, we show that the ex vivo mouse retinal rhythm is most sensitive to short-wavelength light but that this photoentrainment requires neither the short-wavelength-sensitive cone pigment [S-pigment or cone opsin (OPN1SW)] nor encephalopsin (OPN3). However, retinas lacking neuropsin (OPN5) fail to photoentrain, even though other visual functions appear largely normal. Initial evidence suggests that OPN5 is expressed in select retinal ganglion cells. Remarkably, the mouse corneal circadian rhythm is also photoentrainable ex vivo, and this photoentrainment likewise requires OPN5. Our findings reveal a light-sensing function for mammalian OPN5, until now an orphan opsin. PMID:26392540

  4. Inhibiting the Activity of CA1 Hippocampal Neurons Prevents the Recall of Contextual Fear Memory in Inducible ArchT Transgenic Mice.

    PubMed

    Sakaguchi, Masanori; Kim, Karam; Yu, Lily Mae Yee; Hashikawa, Yoshiko; Sekine, Yukiko; Okumura, Yuki; Kawano, Masako; Hayashi, Masanobu; Kumar, Deependra; Boyden, Edward S; McHugh, Thomas J; Hayashi, Yasunori

    2015-01-01

    The optogenetic manipulation of light-activated ion-channels/pumps (i.e., opsins) can reversibly activate or suppress neuronal activity with precise temporal control. Therefore, optogenetic techniques hold great potential to establish causal relationships between specific neuronal circuits and their function in freely moving animals. Due to the critical role of the hippocampal CA1 region in memory function, we explored the possibility of targeting an inhibitory opsin, ArchT, to CA1 pyramidal neurons in mice. We established a transgenic mouse line in which tetracycline trans-activator induces ArchT expression. By crossing this line with a CaMKII?-tTA transgenic line, the delivery of light via an implanted optrode inhibits the activity of excitatory CA1 neurons. We found that light delivery to the hippocampus inhibited the recall of a contextual fear memory. Our results demonstrate that this optogenetic mouse line can be used to investigate the neuronal circuits underlying behavior. PMID:26075894

  5. Colour vision in marine organisms.

    PubMed

    Marshall, Justin; Carleton, Karen L; Cronin, Thomas

    2015-10-01

    Colour vision in the marine environment is on average simpler than in terrestrial environments with simple or no colour vision through monochromacy or dichromacy. Monochromacy is found in marine mammals and elasmobranchs, including whales and sharks, but not some rays. Conversely, there is also a greater diversity of colour vision in the ocean than on land, examples being the polyspectral stomatopods and the many colour vision solutions found among reef fish. Recent advances in sequencing reveal more opsin (visual pigment) types than functionally useful at any one time. This diversity arises through opsin duplication and conversion. Such mechanisms allow pick-and-mix adaptation that tunes colour vision on a variety of very short non-evolutionary timescales. At least some of the diversity in marine colour vision is best explained as unconventional colour vision or as neutral drift. PMID:25725325

  6. Phototransduction and the Evolution of Photoreceptors

    PubMed Central

    Fain, Gordon L.; Hardie, Roger; Laughlin, Simon B.

    2010-01-01

    Photoreceptors in metazoans can be grouped into two classes, with their photoreceptive membrane derived either from cilia or microvilli. Both classes use some form of the visual pigment protein opsin, which together with 11-cis retinaldehyde absorbs light and activates a G-protein cascade, resulting in the opening or closing of ion channels. Considerable attention has recently been given to the molecular evolution of the opsins and other photoreceptor proteins; much is also known about transduction in the various photoreceptor types. Here we combine this knowledge in an attempt to understand why certain photoreceptors might have conferred particular selective advantages during evolution. We suggest that microvillar photoreceptors became predominant in most invertebrate species because of their single-photon sensitivity, high temporal resolution, and large dynamic range, and that rods and a duplex retina provided primitive chordates and vertebrates with similar sensitivity and dynamic range, but with a smaller expenditure of ATP. PMID:20144772

  7. Evidence from Chlamydomonas on the photoactivation of rhodopsins without isomerization of their chromophore

    PubMed Central

    Foster, Kenneth W.; Saranak, Jureepan; Krane, Sonja; Johnson, Randy L.; Nakanishi, Koji

    2011-01-01

    SUMMARY Attachment of retinal to opsin forms the chromophore N-retinylidene which isomerizes during photoactivation of rhodopsins. To test whether isomerization is crucial, custom-tailored chromophores lacking the ?-ionone ring and any isomerizable bonds were incorporated in vivo into the opsin of a blind mutant of the eukaryote Chlamydomonas reinhardtii. The analogues restored phototaxis with the anticipated action spectra, ruling out the need for isomerization in photoactivation. To further elucidate photoactivation, responses to chromophores formed from naphthalene aldehydes were studied. The resulting action spectral shifts suggest that charge separation within the excited chromophore leads to electric field induced polarization of nearby amino-acid residues and altered hydrogen bonding. This redistribution of charge faciliates the reported multiple bond rotations and protein rearrangements of rhodopsin activation. These results provide new insight into the activation of rhodopsins and related GPCRs. PMID:21700209

  8. The Living with a Star Radiation Belt Storm Probes Mission and Related Missions of Opportunity

    NASA Technical Reports Server (NTRS)

    Sibeck, David G.; Mauk, Barry H.; Grebowsky, Joseph M.; Fox, Nicola J.

    2006-01-01

    This presentation provides an overview of the Living With a Star (LWS) Radiation Belt Storm Probes (RBSP) mission in the context of the broader Geospace program. Missions to Geospace offer an opportunity to observe in situ the fundamental processes that operate throughout the solar system and in particular those that generate hazardous space weather effects in the vicinity of Earth. The recently selected investigations on NASA's LWS program's RBSP will provide the measurements needed to characterize and quantify the processes that supply and remove energetic particles from the Earth's Van Allen radiation belts. Instruments on the RBSP spacecraft will observe charged particles that comprise the Earth's radiation belts over the full energy range from 1 eV to more than 10 MeV (including composition), the plasma waves which energize them, the electric fields which transport them, and the magnetic fields which guide their motion. The two-point measurements by the RBSP spacecraft will enable researchers to discriminate between spatial and temporal effects, and therefore between the various proposed mechanisms for particle acceleration and loss. The measurements taken by the RBSP spacecraft will be used in data modeling projects in order to improve the understanding of these fundamental processes and allow better predictions to be made. NASA's LWS program has also recently selected three teams to study concepts for Missions of Opportunity that will augment the RBSP program, by (1) providing an instrument for a Canadian spacecraft in the Earth's radiation belts, (2) quantifying the flux of particles precipitating into the Earth's atmosphere from the Earth's radiation belts, and (3) remotely sensing both spatial and temporal variations in the Earth's ionosphere and thermosphere.

  9. Blue cone monochromacy: Causative mutations and associated phenotypes

    PubMed Central

    Gardner, Jessica C.; Michaelides, Michel; Holder, Graham E.; Kanuga, Naheed; Webb, Tom R.; Mollon, John D.; Moore, Anthony T.

    2009-01-01

    Purpose To perform a phenotypic assessment of members of three British families with blue cone monochromatism (BCM), and to determine the underlying molecular genetic basis of disease. Methods Affected members of three British families with BCM were examined clinically and underwent detailed electrophysiological and psychophysical testing. Blood samples were taken for DNA extraction. Molecular analysis involved the amplification of the coding regions of the long (L) and medium (M) wave cone opsin genes and the upstream locus control region (LCR) by polymerase chain reaction (PCR). Gene products were directly sequenced and analyzed. Results In all three families, genetic analysis identified that the underlying cause of BCM involved an unequal crossover within the opsin gene array, with an inactivating mutation. Family 1 had a single 5?-LM-3? hybrid gene, with an inactivating Cys203Arg (C203R) mutation. Family 3 had an array composed of a C203R inactivated 5?-LM-3? hybrid gene followed by a second inactive gene. Families 1 and 3 had typical clinical, electrophysiological, and psychophysical findings consistent with stationary BCM. A novel mutation was detected in Family 2 that had a single hybrid gene lacking exon 2. This family presented clinical and psychophysical evidence of a slowly progressive phenotype. Conclusions Two of the BCM-causing family genotypes identified in this study comprised different hybrid genes, each of which contained the commonly described C203R inactivating mutation. The genotype in the family with evidence of a slowly progressive phenotype represents a novel BCM mutation. The deleted exon 2 in this family is not predicted to result in a shift in the reading frame, therefore we hypothesize that an abnormal opsin protein product may accumulate and lead to cone cell loss over time. This is the first report of slow progression associated with this class of mutation in the L or M opsin genes in BCM. PMID:19421413

  10. A High-Throughput Drug Screening Strategy for Detecting Rhodopsin P23H Mutant Rescue and Degradation

    PubMed Central

    Chen, Yuanyuan; Tang, Hong; Seibel, William; Papoian, Ruben; Li, Xiaoyu; Lambert, Nevin A.; Palczewski, Krzysztof

    2015-01-01

    Purpose. Inherent instability of the P23H mutant opsin accounts for approximately 10% of autosomal dominant retinitis pigmentosa cases. Our purpose was to develop an overall set of reliable screening strategies to assess if either stabilization or enhanced degradation of mutant rhodopsin could rescue rod photoreceptors expressing this mutant protein. These strategies promise to reveal active compounds and clarify molecular mechanisms of biologically important processes, such as inhibition of target degradation or enhanced target folding. Methods. Cell-based bioluminescence reporter assays were developed and validated for high-throughput screening (HTS) of compounds that promote either stabilization or degradation of P23H mutant opsin. Such assays were further complemented by immunoblotting and image-based analyses. Results. Two stabilization assays of P23H mutant opsin were developed and validated, one based on ?-galactosidase complementarity and a second assay involving bioluminescence resonance energy transfer (BRET) technology. Moreover, two additional assays evaluating mutant protein degradation also were employed, one based on the disappearance of luminescence and another employing the ALPHA immunoassay. Imaging of cells revealed the cellular localization of mutant rhodopsin, whereas immunoblots identified changes in the aggregation and glycosylation of P23H mutant opsin. Conclusions. Our findings indicate that these initial HTS and following assays can identify active therapeutic compounds, even for difficult targets such as mutant rhodopsin. The assays are readily scalable and their function has been proven with model compounds. High-throughput screening, supported by automated imaging and classic immunoassays, can further characterize multiple steps and pathways in the biosynthesis and degradation of this essential visual system protein. PMID:25783607

  11. The Giant Mottled Eel, Anguilla marmorata, Uses Blue-Shifted Rod Photoreceptors during Upstream Migration

    PubMed Central

    Wang, Feng-Yu; Fu, Wen-Chun; Wang, I-Li

    2014-01-01

    Catadromous fishes migrate between ocean and freshwater during particular phases of their life cycle. The dramatic environmental changes shape their physiological features, e.g. visual sensitivity, olfactory ability, and salinity tolerance. Anguilla marmorata, a catadromous eel, migrates upstream on dark nights, following the lunar cycle. Such behavior may be correlated with ontogenetic changes in sensory systems. Therefore, this study was designed to identify changes in spectral sensitivity and opsin gene expression of A. marmorata during upstream migration. Microspectrophotometry analysis revealed that the tropical eel possesses a duplex retina with rod and cone photoreceptors. The λmax of rod cells are 493, 489, and 489 nm in glass, yellow, and wild eels, while those of cone cells are 508, and 517 nm in yellow, and wild eels, respectively. Unlike European and American eels, Asian eels exhibited a blue-shifted pattern of rod photoreceptors during upstream migration. Quantitative gene expression analyses of four cloned opsin genes (Rh1f, Rh1d, Rh2, and SWS2) revealed that Rh1f expression is dominant at all three stages, while Rh1d is expressed only in older yellow eel. Furthermore, sequence comparison and protein modeling studies implied that a blue shift in Rh1d opsin may be induced by two known (N83, S292) and four putative (S124, V189, V286, I290) tuning sites adjacent to the retinal binding sites. Finally, expression of blue-shifted Rh1d opsin resulted in a spectral shift in rod photoreceptors. Our observations indicate that the giant mottled eel is color-blind, and its blue-shifted scotopic vision may influence its upstream migration behavior and habitat choice. PMID:25101636

  12. [Inherited colour vision deficiencies--from Dalton to molecular genetics].

    PubMed

    Cvetkovi?, Dragana; Cvetkovi?, Dobrosav

    2005-01-01

    In recent years, great advances have been made in our understanding of the molecular basis of colour vision defects, as well as of the patterns of genetic variation in individuals with normal colour vision. Molecular genetic analyses have explained the diversity of types and degrees of severity in colour vision anomalies, their frequencies, pronounced individual variations in test results, etc. New techniques have even enabled the determination of John Dalton's real colour vision defect, 150 years after his death. Inherited colour vision deficiencies most often result from the mutations of genes that encode cone opsins. Cone opsin genes are linked to chromosomes 7 (the S or "blue" gene) and X (the L or "red" gene and the M or "green" gene). The L and M genes are located on the q arm of the X chromosome in a head-to-tail array, composed of 2 to 6 (typically 3) genes--a single L is followed by one or more M genes. Only the first two genes of the array are expressed and contribute to the colour vision phenotype. The high degree of homology (96%) between the L and M genes predisposes them to unequal recombination, leading to gene deletion or the formation of hybrid genes (comprising portions of both the L and M genes), explaining the majority of the common red-green colour vision deficiencies. The severity of any deficiency is influenced by the difference in spectral sensitivity between the opsins encoded by the first two genes of the array. A rare defect, S monochromacy, is caused either by the deletion of the regulatory region of the array or by mutations that inactivate the L and M genes. Most recent research concerns the molecular basis of complete achromatopsia, a rare disorder that involves the complete loss of all cone function. This is not caused by mutations in opsin genes, but in other genes that encode cone-specific proteins, e.g. channel proteins and transducin. PMID:16758855

  13. Colour tuning mechanisms of visual pigments.

    PubMed

    Lin, S W; Sakmar, T P

    1999-01-01

    Spectral tuning by visual pigments involves modulation of physical properties of the 11-cis-retinylidene protonated Schiff base (PSB) chromophore by amino acid side chains in and around the chromophore-binding pocket. Specific molecular contacts between the chromophore and the amino acid side chains of the opsin chromophore-binding pocket have been determined recently using an interdisciplinary approach consisting of site-directed mutagenesis, optical and vibrational spectroscopy, and molecular graphics modelling. These studies provide insight into the mechanism of spectral tuning among visual pigments. In blue pigments a majority of the opsin shift is caused by polar amino acid side chains arrayed about the PSB to increase the energy gap between the ground (S0) and excited states (S1). In addition, a specific tyrosine near the chromophore ring causes a decrease in solvent polarizability. Other amino acid residues alter the binding pocket structure to strengthen electrostatic interaction between the PSB and its counterion and/or solvent dipoles. In the green and red pigments, the work of Kochendoerfer et al (1997; Biochemistry 26:6577-6587) demonstrates that local structural perturbations at the PSB or elsewhere are not responsible for spectral tuning. Instead, the green-to-red opsin shift is best explained by dipolar side chains near the chromophore ring that lower the transition energy that occurs upon electronic excitation by affecting the change in electric dipole moment. In summary, the absorption maximum of a visual pigment is primarily regulated by the interaction of the chromophore charge distribution with dipolar residues in its opsin chromophore-binding pocket. The work presented in this paper is reported in greater detail in Lin et al. PMID:10614049

  14. Common transcriptional mechanisms for visual photoreceptor cell differentiation among Pancrustaceans.

    PubMed

    Mahato, Simpla; Morita, Shinichi; Tucker, Abraham E; Liang, Xulong; Jackowska, Magdalena; Friedrich, Markus; Shiga, Yasuhiro; Zelhof, Andrew C

    2014-07-01

    A hallmark of visual rhabdomeric photoreceptors is the expression of a rhabdomeric opsin and uniquely associated phototransduction molecules, which are incorporated into a specialized expanded apical membrane, the rhabdomere. Given the extensive utilization of rhabdomeric photoreceptors in the eyes of protostomes, here we address whether a common transcriptional mechanism exists for the differentiation of rhabdomeric photoreceptors. In Drosophila, the transcription factors Pph13 and Orthodenticle (Otd) direct both aspects of differentiation: rhabdomeric opsin transcription and rhabdomere morphogenesis. We demonstrate that the orthologs of both proteins are expressed in the visual systems of the distantly related arthropod species Tribolium castaneum and Daphnia magna and that their functional roles are similar in these species. In particular, we establish that the Pph13 homologs have the ability to bind a subset of Rhodopsin core sequence I sites and that these sites are present in key phototransduction genes of both Tribolium and Daphnia. Furthermore, Pph13 and Otd orthologs are capable of executing deeply conserved functions of photoreceptor differentiation as evidenced by the ability to rescue their respective Drosophila mutant phenotypes. Pph13 homologs are equivalent in their ability to direct both rhabdomere morphogenesis and opsin expression within Drosophila, whereas Otd paralogs demonstrate differential abilities to regulate photoreceptor differentiation. Finally, loss-of-function analyses in Tribolium confirm the conserved requirement of Pph13 and Otd in regulating both rhabdomeric opsin transcription and rhabdomere morphogenesis. Taken together, our data identify components of a regulatory framework for rhabdomeric photoreceptor differentiation in Pancrustaceans, providing a foundation for defining ancestral regulatory modules of rhabdomeric photoreceptor differentiation. PMID:24991928

  15. Rhodopsin in the rod surface membrane regenerates more rapidly than bulk rhodopsin in the disc membranes in vivo

    PubMed Central

    Kessler, Christopher; Tillman, Megan; Burns, Marie E; Pugh, Edward N

    2014-01-01

    Sustained vertebrate vision requires that opsin chromophores isomerized by light to the all-trans form be replaced with 11-cis retinal to regenerate the visual pigment. We have characterized the early receptor potential (ERP), a component of the electroretinogram arising from photoisomerization-induced charge displacements in plasma membrane visual pigment, and used it to measure pigment bleaching and regeneration in living mice. The mouse ERP was characterized by an outward R2 charge displacement with a time constant of 215 ?s that discharged through a membrane with an apparent time constant of ?0.6 ms. After complete bleaching of rhodopsin, the ERP recovered in two phases. The initial, faster phase had a time constant of ?1 min, accounted for ?20% of the total, and was not dependent on the level of expression of the retinal pigment epithelium isomerase, Rpe65. The slower, complementary phase had a time constant of 23 min in wild-type (WT) mice (C57Bl/6) and was substantially slowed in Rpe65+/? mice. Comparison of the ERPs of a mouse line expressing 150% of the normal level of cone M-opsin with those of WT mice revealed that M-opsin contributed 26% of the total WT ERP in these experiments, with the remaining 74% arising from rhodopsin. Thus, the fast regenerating fraction (20%) corresponds approximately to the fraction of the total ERP independently estimated to arise from M-opsin. Because both phases of the ERP recover substantially faster than previous measurements of bulk rhodopsin regeneration in living mice, we conclude that delivery of the highly hydrophobic 11-cis retinal to the interior of rod photoreceptors appears to be retarded by transit across the cytoplasmic gap between plasma and disc membranes. PMID:24801306

  16. Gene duplication is an evolutionary mechanism for expanding spectral diversity in the long-wavelength photopigments of butterflies.

    PubMed

    Frentiu, Francesca D; Bernard, Gary D; Sison-Mangus, Marilou P; Brower, Andrew Van Zandt; Briscoe, Adriana D

    2007-09-01

    Butterfly long-wavelength (L) photopigments are interesting for comparative studies of adaptive evolution because of the tremendous phenotypic variation that exists in their wavelength of peak absorbance (lambda(max) value). Here we present a comprehensive survey of L photopigment variation by measuring lambda(max) in 12 nymphalid and 1 riodinid species using epi-microspectrophotometry. Together with previous data, we find that L photopigment lambda(max) varies from 510-565 nm in 22 nymphalids, with an even broader 505- to 600-nm range in riodinids. We then surveyed the L opsin genes for which lambda(max) values are available as well as from related taxa and found 2 instances of L opsin gene duplication within nymphalids, in Hermeuptychia hermes and Amathusia phidippus, and 1 instance within riodinids, in the metalmark butterfly Apodemia mormo. Using maximum parsimony and maximum likelihood ancestral state reconstructions to map the evolution of spectral shifts within the L photopigments of nymphalids, we estimate the ancestral pigment had a lambda(max) = 540 nm +/- 10 nm standard error and that blueshifts in wavelength have occurred at least 4 times within the family. We used ancestral state reconstructions to investigate the importance of several amino acid substitutions (Ile17Met, Ala64Ser, Asn70Ser, and Ser137Ala) previously shown to have evolved under positive selection that are correlated with blue spectral shifts. These reconstructions suggest that the Ala64Ser substitution has indeed occurred along the newly identified blueshifted L photopigment lineages. Substitutions at the other 3 sites may also be involved in the functional diversification of L photopigments. Our data strongly suggest that there are limits to the evolution of L photopigment spectral shifts among species with only one L opsin gene and that opsin gene duplication broadens the potential range of lambda(max) values. PMID:17609538

  17. The giant mottled eel, Anguilla marmorata, uses blue-shifted rod photoreceptors during upstream migration.

    PubMed

    Wang, Feng-Yu; Fu, Wen-Chun; Wang, I-Li; Yan, Hong Young; Wang, Tzi-Yuan

    2014-01-01

    Catadromous fishes migrate between ocean and freshwater during particular phases of their life cycle. The dramatic environmental changes shape their physiological features, e.g. visual sensitivity, olfactory ability, and salinity tolerance. Anguilla marmorata, a catadromous eel, migrates upstream on dark nights, following the lunar cycle. Such behavior may be correlated with ontogenetic changes in sensory systems. Therefore, this study was designed to identify changes in spectral sensitivity and opsin gene expression of A. marmorata during upstream migration. Microspectrophotometry analysis revealed that the tropical eel possesses a duplex retina with rod and cone photoreceptors. The ?max of rod cells are 493, 489, and 489 nm in glass, yellow, and wild eels, while those of cone cells are 508, and 517 nm in yellow, and wild eels, respectively. Unlike European and American eels, Asian eels exhibited a blue-shifted pattern of rod photoreceptors during upstream migration. Quantitative gene expression analyses of four cloned opsin genes (Rh1f, Rh1d, Rh2, and SWS2) revealed that Rh1f expression is dominant at all three stages, while Rh1d is expressed only in older yellow eel. Furthermore, sequence comparison and protein modeling studies implied that a blue shift in Rh1d opsin may be induced by two known (N83, S292) and four putative (S124, V189, V286, I290) tuning sites adjacent to the retinal binding sites. Finally, expression of blue-shifted Rh1d opsin resulted in a spectral shift in rod photoreceptors. Our observations indicate that the giant mottled eel is color-blind, and its blue-shifted scotopic vision may influence its upstream migration behavior and habitat choice. PMID:25101636

  18. Common Transcriptional Mechanisms for Visual Photoreceptor Cell Differentiation among Pancrustaceans

    PubMed Central

    Mahato, Simpla; Morita, Shinichi; Tucker, Abraham E.; Liang, Xulong; Jackowska, Magdalena; Friedrich, Markus; Shiga, Yasuhiro; Zelhof, Andrew C.

    2014-01-01

    A hallmark of visual rhabdomeric photoreceptors is the expression of a rhabdomeric opsin and uniquely associated phototransduction molecules, which are incorporated into a specialized expanded apical membrane, the rhabdomere. Given the extensive utilization of rhabdomeric photoreceptors in the eyes of protostomes, here we address whether a common transcriptional mechanism exists for the differentiation of rhabdomeric photoreceptors. In Drosophila, the transcription factors Pph13 and Orthodenticle (Otd) direct both aspects of differentiation: rhabdomeric opsin transcription and rhabdomere morphogenesis. We demonstrate that the orthologs of both proteins are expressed in the visual systems of the distantly related arthropod species Tribolium castaneum and Daphnia magna and that their functional roles are similar in these species. In particular, we establish that the Pph13 homologs have the ability to bind a subset of Rhodopsin core sequence I sites and that these sites are present in key phototransduction genes of both Tribolium and Daphnia. Furthermore, Pph13 and Otd orthologs are capable of executing deeply conserved functions of photoreceptor differentiation as evidenced by the ability to rescue their respective Drosophila mutant phenotypes. Pph13 homologs are equivalent in their ability to direct both rhabdomere morphogenesis and opsin expression within Drosophila, whereas Otd paralogs demonstrate differential abilities to regulate photoreceptor differentiation. Finally, loss-of-function analyses in Tribolium confirm the conserved requirement of Pph13 and Otd in regulating both rhabdomeric opsin transcription and rhabdomere morphogenesis. Taken together, our data identify components of a regulatory framework for rhabdomeric photoreceptor differentiation in Pancrustaceans, providing a foundation for defining ancestral regulatory modules of rhabdomeric photoreceptor differentiation. PMID:24991928

  19. Origin of the vertebrate visual cycle: III. Distinct distribution of RPE65 and beta-carotene 15,15'-monooxygenase homologues in Ciona intestinalis.

    PubMed

    Takimoto, Noriko; Kusakabe, Takehiro; Horie, Takeo; Miyamoto, Yuki; Tsuda, Motoyuki

    2006-01-01

    We previously identified three genes that encode putative visual cycle proteins that are homologues of retinal G-protein coupled receptor (Ci-opsin3), cellular retinaldehyde-binding protein (Ci-CRALBP) and beta-carotene 15,15'-monooxygenase (Ci-BCO) in the ascidian Ciona intestinalis. Ci-opsin3 and Ci-CRALBP are localized in both ocellus photoreceptor cells and surrounding non-photoreceptor cells in the brain vesicle of the larva. In the present study, we investigated the possible role and evolutionary origin of the BCO/RPE65 family in the visual cycle by analyzing Ci-BCO localization by immunohistochemistry and by identifying a novel gene that encodes a homologue of retinal pigment epithelium-specific 65 kDa protein (Ci-RPE65) in C. intestinalis. In situ hybridization and expressed sequence tag (EST) profiles consistently suggest that Ci-RPE65 is not significantly expressed in the ocellus and brain vesicle of the larva. Ci-RPE65 is expressed in the neural complex, a photoreceptor organ of the adult ascidian, at a level comparable to that of Ci-opsin3 and Ci-CRALBP. Ci-RPE65 is also expressed in various adult tissues, including the gill, body wall and intestine, suggesting that Ci-RPE65 plays a role in addition to that in the visual cycle. In contrast, Ci-BCO is predominantly localized in ocellus photoreceptor cells of the larva. The larval visual cycle seems to use Ci-opsin3 as a photo-isomerase. Our results also suggest that the RPE65-dependent visual cycle is used in the adult photoreceptors of a primitive chordate. PMID:16544957

  20. High Angular Resolution Mid-Infrared Imaging of Young Stars in Orion BN/KL

    NASA Technical Reports Server (NTRS)

    Greenhill, L. J.; Gezari, D. Y.; Danchi, W. C.; Najita, J.; Monnier, J. D.

    2004-01-01

    The authors present Keck LWS images of the Orion BN/KL star forming region obtained in the first multi-wavelength study to have 0.3--0.5 resolution from 4.7 (micro)m to 22 (micro)m. The young stellar objects designed infrared source n and radio source I are believed to dominate the BN/KL region. They have detected extended emission from a probable accretion disk around source n but infer a stellar luminosity on the order of only 2000 L(sub (center-dot)).

  1. ISO Spectroscopy of Ultracompact H II Regions: Element Abundance Gradient in the Galaxy

    NASA Astrophysics Data System (ADS)

    Martn-Hernndez, N. L.; Peeters, E.; Damour, F.; Cox, P.; Roelfsema, P. R.; Baluteau, J.-P.; Tielens, A. G. G. M.; Churchwell, E.; Jones, A. P.; Kessler, M. F.; Mathis, J. S.; Morisset, C.; Schaerer, D.

    2002-02-01

    In order to study the element abundance distribution in the Galaxy, infrared spectra between 2.3 and 196 mu m were taken towards a sample of ultracompact H II regions using the two spectrometers (SWS and LWS) on board ISO. The sample spans a large range in galactocentric distance (0 to 20 kpc). The fine structure lines of O, N, Ne, Ar, S, C and Si are detected in most of the sources with some species (O, N, S, Ne, and Ar) present in different stages of ionization. From the measured line fluxes, the properties of the ionized gas can be precisely constrained.

  2. WASTE CERTIFICATION PROGRAM PLAN - REVISION 7

    SciTech Connect

    MORGAN, LK

    2002-01-08

    The primary changes that have been made to this revision reflect the relocation of the Waste Certification Official (WCO) organizationally from the Quality Services Division (QSD) into the Laboratory Waste Services (LWS) Organization. Additionally, the responsibilities for program oversight have been differentiated between the QSD and LWS. The intent of this effort is to ensure that those oversight functions, which properly belonged to the WCO, moved with that function; but retain an independent oversight function outside of the LWS Organization ensuring the potential for introduction of organizational bias, regarding programmatic and technical issues, is minimized. The Waste Certification Program (WCP) itself has been modified to allow the waste certification function to be performed by any of the personnel within the LWS Waste Acceptance/Certification functional area. However, a single individual may not perform both the technical waste acceptance review and the final certification review on the same 2109 data package. Those reviews must be performed by separate individuals in a peer review process. There will continue to be a designated WCO who will have lead programmatic responsibility for the WCP and will exercise overall program operational oversite as well as determine the overall requirements of the certification program. The quality assurance organization will perform independent, outside oversight to ensure that any organizational bias does not degrade the integrity of the waste certification process. The core elements of the previous WCP have been retained, however, the terms and process structure have been modified.. There are now two ''control points,'' (1) the data package enters the waste certification process with the signature of the Generator Interface/Generator Interface Equivalent (GI/GIE), (2) the package is ''certified'', thus exiting the process. The WCP contains three steps, (1) the technical review for waste acceptance, (2) a review of the packaging and labeling (the old Control Point 3), and (3) programmatic review and certification. The signature of the individual performing the certification review resulting in certification of the package constitutes Control Point 2 in the revised process.

  3. Designing 2D arrays for SHM of planar structures: a review

    NASA Astrophysics Data System (ADS)

    Stepinski, Tadeusz; Ambrozinski, Lukasz; Uhl, Tadeusz

    2013-04-01

    Monitoring structural integrity of large planar structures that aims at detecting and localizing impact or damage at any point of the structure requires normally a relatively dense network of uniformly distributed ultrasonic sensors. 2-D ultrasonic phased arrays, due to their beam-steering capability and all azimuth angle coverage are a very promising tool for structural health monitoring (SHM) of plate-like structures using Lamb waves (LW). Linear phased arrays that have been proposed for that purpose, produce mirrored image characterized by azimuth dependent resolution, which prevents unequivocal damage localization. 2D arrays do not have this drawback and they are even capable of mode selectivity when generating and receiving LWs. Performance of 2D arrays depends on their topology as well as the number of elements (transducers) used and their spacing in terms of wavelength. In this paper we propose a consistent methodology for three-step: theoretical, numerical and experimental investigation of a diversity of 2D array topologies in SHM applications. In the first step, the theoretical evaluation is performed using frequency-dependent structure transfer function (STF). STF that defines linear propagation of different LWs modes through the dispersive medium enables theoretical investigation of the particular array performance for a predefined tone-burst excitation signal. A dedicated software tool has been developed for the numerical evaluation of 2D array directional characteristics (beampattern) in a specific structure. The simulations are performed using local interaction simulation approach (LISA), implemented using NVIDIA CUDA graphical computation unit (GPU), which enables time-efficient 3D simulations of LWs propagation. Beampatterns of a 2D array can be to some extend evaluated analytically and using numerical simulations; in most cases, however, they require experimental verification. Using scanning laser vibrometer is proposed for that purpose, in a setup where LWs, excited by PZT transmitters of the investigated array are sensed in multiple points corresponding to the locations of the 2D array receiving elements. A virtual receiving sub-array is created in this way and the performance of various array architectures in the reception mode can be evaluated experimentally without the need of physical prototype; a change of topology requires only straightforward modification of the measurement points distribution at the tested structure. For illustration, beampatterns of three symmetrical 2D topologies, i.e., circular, star-shaped and spiralshaped, will be examined in the paper and compared in terms of their beam-width and side-lobes level. The effect of apodization applied to the array elements will be also investigated.

  4. Thermal Evolution of Juvenile Subduction Zones ' New Constraints from Lu-Hf Geochronology on HP oceanic rocks (Halilbaǧi, Central Anatolia)

    NASA Astrophysics Data System (ADS)

    Pourteau, Amaury; Scherer, Erik; Schmidt, Alexander; Bast, Rebecca

    2015-04-01

    The thermal structure of subduction zones plays a key role on mechanical and chemical processes taking place along the slab-mantle interface. Until now, changes through time of this thermal structure have been explored mostly by the means of numerical simulations. However, both "warm" (i.e., epidote-bearing), and "cold" (i.e., lawsonite-bearing) HP oceanic rocks have been reported in some fossil subduction complexes exposed at the Earth's surface (e.g., Franciscan Complex, California; Rio San Juan Complex, Hispañola; Halilbağı Unit, Central Anatolia). These a-priori "incompatible" rocks witness different thermal stages of ancient subduction zones and their study might provide complementary constraints to numerical models. To decipher the meaning of these contrasting metamorphic rocks in the Halilbağı Unit, we are carrying out Lu-Hf geochronology on garnet (grt) and lws from a variety of HP oceanic rocks, as well as the metamorphic sole of the overlying ophiolite. We selected five samples that are representative of the variety of metamorphic evolutions (i.e. peak conditions and P-T paths) encountered in this area. Preliminary analyses yielded 110 Ma (grt-hbl isochron) for a sub-ophiolitic grt amphibolite; 92 Ma (grt-omp) for an eclogite with prograde and retrograde ep; 90 Ma (grt-omp) for an eclogitic metabasite with prograde ep and retrograde ep+lws; 87 Ma (grt-gln) for a lws eclogite with prograde ep; and 86 Ma (grt-gln) for a blueschist with prograde and retrograde lws. These ages are mainly two-point isochrons. Further-refined data will be presented at the EGU General Assembly 2015, in Vienna. The consistent younging trend from "warm" to "cold" metamorphic rocks revealed by these first-order results points to metamorphic-sole formation during the initiation of intra-oceanic subduction at ~110 Ma, and subsequent cooling of the slab-mantle interface between 92 and 86 Ma. Therefore, the contrasting metamorphic evolutions encountered in the Halilbağı Unit record the progressive thermal maturation of the juvenile Neotethyan subduction zone. This period of ~23 myr between subduction initiation and thermal "steady state" is significantly shorter than that obtained for the Rio San Juan Complex (~60 myr; Krebs et al. 2008, Lithos, 103, 106-137), but compares well with that for the Franciscan Complex (~22 myr; Anczkiewicz et al. 2004, EPSL, 225, 147-161) and falls in the range predicted in numerical simulations (e.g., Gerya et al. 2002, Tectonics, 21/6, 1056).

  5. The Living With a Star Space Environment Testbed Experiments

    NASA Technical Reports Server (NTRS)

    Xapsos, Michael A.

    2014-01-01

    The focus of the Living With a Star (LWS) Space Environment Testbed (SET) program is to improve the performance of hardware in the space radiation environment. The program has developed a payload for the Air Force Research Laboratory (AFRL) Demonstration and Science Experiments (DSX) spacecraft that is scheduled for launch in August 2015 on the SpaceX Falcon Heavy rocket. The primary structure of DSX is an Evolved Expendable Launch Vehicle (EELV) Secondary Payload Adapter (ESPA) ring. DSX will be in a Medium Earth Orbit (MEO). This oral presentation will describe the SET payload.

  6. Using Digital Globes to Explore the Deep Sea and Advance Public Literacy in Earth System Science

    NASA Astrophysics Data System (ADS)

    Beaulieu, S. E.; Brickley, A.; Emery, M.; Spargo, A.; Patterson, K.; Joyce, K.; Silva, T.; Madin, K.

    2014-12-01

    Digital globes are new technologies increasingly used in both informal and formal education to display global datasets. By creating a narrative using multiple datasets, linkages between Earth systems - lithosphere, hydrosphere, atmosphere, and biosphere - can be conveyed. But how effective are digital globes in advancing public literacy in Earth system science? We addressed this question in developing new content for digital globes that interweaves imagery obtained by deep-diving vehicles with global datasets, including a new dataset locating the world's known hydrothermal vents. Our two narratives, "Life Without Sunlight" (LWS) and "Smoke and Fire Underwater" (SFU), each focus on STEM (science, technology, engineering, and mathematics) principles related to geology, biology, and exploration. We are preparing a summative evaluation for our content delivered on NOAA's Science on a Sphere as interactive presentations and as movies. We tested knowledge gained with respect to the STEM principles and the level of excitement generated by the virtual deep-sea exploration. We conducted a Post-test Only Design with quantitative data based on self-reporting on a Likert scale. A total of 75 adults and 48 youths responded to our questionnaire, distributed into test groups that saw either one of the two narratives delivered either as a movie or as an interactive presentation. Here, we report preliminary results for the youths, the majority (81%) of which live in towns with lower income and lower levels of educational attainment as compared to other towns in Massachusetts. For both narratives, there was knowledge gained for all 6 STEM principles and "Quite a Bit" of excitement. The mode in responses for knowledge gained was "Quite a Bit" for both the movie and the interactive presentation for 4 of the STEM principles (LWS geology, LWS biology, SFU geology, and SFU exploration) and "Some" for SFU biology. Only for LWS exploration was there a difference in mode between the interactive presentation ("A Little") and the movie ("Quite a Bit"). We conclude that our content for digital globes is effective in teaching the STEM principles and exciting viewers about the deep ocean frontier. We attribute this success to the tight collaboration between scientists, educators, and graphic artists in developing the content for public audiences.

  7. The Living With a Star Space Environment Testbed Program

    NASA Technical Reports Server (NTRS)

    Barth, Janet; LaBel, Kenneth; Day, John H. (Technical Monitor)

    2001-01-01

    NASA has initiated the Living with a Star (LWS) Program to develop the scientific understanding to address the aspects of the Connected Sun-Earth system that affects life and society. The Program Architecture includes science missions, theory and modeling and Space Environment Testbeds (SET). This current paper discusses the Space Environment Testbeds. The goal of the SET program is to improve the engineering approach to accomodate and/or mitigate the effects of solar variability on spacecraft design and operations. The SET Program will infuse new technologies into the space programs through collection of data in space and subsequent design and validation of technologies. Examples of these technologies are cited and discussed.

  8. Space Weather Monitoring with DSCOVR and Beyond

    NASA Astrophysics Data System (ADS)

    Szabo, A.

    2013-05-01

    With the NOAA/NASA DSCOVR spacecraft launched around 2015, continued near-Earth solar wind monitoring will be assured. However, to provide more than the current 30-45 minutes warning time of incoming solar transients, newer platforms are required. Solar sail missions would orbit an artificial 1st Lagrange point nearly doubling the current warning time. Four or five LWS Solar Sentinels orbiting the Sun inside 0.5 AU would provide warning times close to 1 day. The required scientific understanding is already at hand to take full advantage of such new missions. DSCOVR and these new missions will be discussed in detail.

  9. Melanopsin mediates light-dependent relaxation in blood vessels

    PubMed Central

    Sikka, Gautam; Hussmann, G. Patrick; Pandey, Deepesh; Cao, Suyi; Hori, Daijiro; Park, Jong Taek; Steppan, Jochen; Kim, Jae Hyung; Barodka, Viachaslau; Myers, Allen C.; Santhanam, Lakshmi; Nyhan, Daniel; Halushka, Marc K.; Koehler, Raymond C.; Snyder, Solomon H.; Shimoda, Larissa A.; Berkowitz, Dan E.

    2014-01-01

    Melanopsin (opsin4; Opn4), a non-image-forming opsin, has been linked to a number of behavioral responses to light, including circadian photo-entrainment, light suppression of activity in nocturnal animals, and alertness in diurnal animals. We report a physiological role for Opn4 in regulating blood vessel function, particularly in the context of photorelaxation. Using PCR, we demonstrate that Opn4 (a classic G protein-coupled receptor) is expressed in blood vessels. Force-tension myography demonstrates that vessels from Opn4?/? mice fail to display photorelaxation, which is also inhibited by an Opn4-specific small-molecule inhibitor. The vasorelaxation is wavelength-specific, with a maximal response at ?430460 nm. Photorelaxation does not involve endothelial-, nitric oxide-, carbon monoxide-, or cytochrome p450-derived vasoactive prostanoid signaling but is associated with vascular hyperpolarization, as shown by intracellular membrane potential measurements. Signaling is both soluble guanylyl cyclase- and phosphodiesterase 6-dependent but protein kinase G-independent. ?-Adrenergic receptor kinase 1 (?ARK 1 or GRK2) mediates desensitization of photorelaxation, which is greatly reduced by GRK2 inhibitors. Blue light (455 nM) regulates tail artery vasoreactivity ex vivo and tail blood blood flow in vivo, supporting a potential physiological role for this signaling system. This endogenous opsin-mediated, light-activated molecular switch for vasorelaxation might be harnessed for therapy in diseases in which altered vasoreactivity is a significant pathophysiologic contributor. PMID:25404319

  10. Ablation of Chop Transiently Enhances Photoreceptor Survival but Does Not Prevent Retinal Degeneration in Transgenic Mice Expressing Human P23H Rhodopsin

    PubMed Central

    Chiang, Wei-Chieh; Joseph, Victory; Matthes, Michael T.; Lewin, Alfred S.; Gorbatyuk, Marina S.; Ahern, Kelly; LaVail, Matthew M.

    2016-01-01

    RHO (Rod opsin) encodes a G-protein coupled receptor that is expressed exclusively by rod photoreceptors of the retina and forms the essential photopigment, rhodopsin, when coupled with 11-cis-retinal. Many rod opsin disease mutations cause rod opsin protein misfolding and trigger endoplasmic reticulum (ER) stress, leading to activation of the Unfolded Protein Response (UPR) signal transduction network. Chop is a transcriptional activator that is induced by ER stress and promotes cell death in response to chronic ER stress. Here, we examined the role of Chop in transgenic mice expressing human P23H rhodopsin (hP23H Rho Tg) that undergo retinal degeneration. With the exception of one time point, we found no significant induction of Chop in these animals and no significant change in retinal degeneration by histology and electrophysiology when hP23H Rho Tg animals were bred into a Chop?/? background. Our results indicate that Chop does not play a significant causal role during retinal degeneration in these animals. We suggest that other modules of the ER stress-induced UPR signaling network may be involved photoreceptor disease induced by P23H rhodopsin. PMID:26427410

  11. Beyond spectral tuning: human cone visual pigments adopt different transient conformations for chromophore regeneration.

    PubMed

    Srinivasan, Sundaramoorthy; Cordom, Arnau; Ramon, Eva; Garriga, Pere

    2016-03-01

    Human red and green visual pigments are seven transmembrane receptors of cone photoreceptor cells of the retina that mediate color vision. These pigments share a very high degree of homology and have been assumed to feature analogous structural and functional properties. We report on a different regeneration mechanism among red and green cone opsins with retinal analogs using UV-Vis/fluorescence spectroscopic analyses, molecular modeling and site-directed mutagenesis. We find that photoactivated green cone opsin adopts a transient conformation which regenerates via an unprotonated Schiff base linkage with its natural chromophore, whereas red cone opsin forms a typical protonated Schiff base. The chromophore regeneration kinetics is consistent with a secondary retinal uptake by the cone pigments. Overall, our findings reveal, for the first time, structural differences in the photoactivated conformation between red and green cone pigments that may be linked to their molecular evolution, and support the proposal of secondary retinal binding to visual pigments, in addition to binding to the canonical primary site, which may serve as a regulatory mechanism of dark adaptation in the phototransduction process. PMID:26387074

  12. Why aye-ayes see blue.

    PubMed

    Melin, Amanda D; Moritz, Gillian L; Fosbury, Robert A E; Kawamura, Shoji; Dominy, Nathaniel J

    2012-03-01

    The capacity for cone-mediated color vision varies among nocturnal primates. Some species are colorblind, having lost the functionality of their short-wavelength-sensitive-1 (SWS1) opsin pigment gene. In other species, such as the aye-aye (Daubentonia madagascariensis), the SWS1 gene remains intact. Recent studies focused on aye-ayes indicate that this gene has been maintained by natural selection and that the pigment has a peak sensitivity (lambda(max)) of 406 nm, which is -20 nm closer to the ultraviolet region of the spectrum than in most primates. The functional significance behind the retention and unusual lambda(max) of this opsin pigment is unknown, and it is perplexing given that all mammals are presumed to be colorblind in the dark. Here we comment on this puzzle and discuss recent findings on the color vision intensity thresholds of terrestrial vertebrates with comparable optics to aye-ayes. We draw attention to the twilight activities of aye-ayes and report that twilight is enriched in short-wavelength (bluish) light. We also show that the intensity of twilight and full moonlight is probably sufficient to support cone-mediated color vision. We speculate that the intact SWS1 opsin pigment gene of aye-ayes is a crepuscular adaptation and we report on the blueness of potential visual targets, such as scent marks and the brilliant blue arils of Ravenala madagascariensis. PMID:24006536

  13. Rhodopsin Photoactivation Dynamics Revealed by Quasi-Elastic Neutron Scattering

    NASA Astrophysics Data System (ADS)

    Bhowmik, Debsindhu; Shrestha, Utsab; Perera, Suchhithranga M. C. D.; Chawla, Udeep; Mamontov, Eugene; Brown, Michael; Chu, Xiang-Qiang

    2015-03-01

    Rhodopsin is a G-protein-coupled receptor (GPCR) responsible for vision. During photoactivation, the chromophore retinal dissociates from protein yielding the opsin apoprotein. What are the changes in protein dynamics that occur during the photoactivation process? Here, we studied the microscopic dynamics of dark-state rhodopsin and the ligand-free opsin using quasielastic neutron scattering (QENS). The QENS technique tracks individual hydrogen atom motion because of the much higher neutron scattering cross-section of hydrogen than other atoms. We used protein with CHAPS detergent hydrated with heavy water. The activation of proteins is confirmed at low temperatures up to 300 K by mean-square displacement (MSD) analysis. The QENS experiments at temperatures ranging from 220 K to 300 K clearly indicate an increase in protein dynamic behavior with temperature. The relaxation time for the ligand-bound protein rhodopsin is faster compared to opsin, which can be correlated with the photoactivation. Moreover, the protein dynamics are orders of magnitude slower than the accompanying CHAPS detergent, which unlike protein, manifests localized motions.

  14. Ablation of Chop Transiently Enhances Photoreceptor Survival but Does Not Prevent Retinal Degeneration in Transgenic Mice Expressing Human P23H Rhodopsin.

    PubMed

    Chiang, Wei-Chieh; Joseph, Victory; Yasumura, Douglas; Matthes, Michael T; Lewin, Alfred S; Gorbatyuk, Marina S; Ahern, Kelly; LaVail, Matthew M; Lin, Jonathan H

    2016-01-01

    RHO (Rod opsin) encodes a G-protein coupled receptor that is expressed exclusively by rod photoreceptors of the retina and forms the essential photopigment, rhodopsin, when coupled with 11-cis-retinal. Many rod opsin disease -mutations cause rod opsin protein misfolding and trigger endoplasmic reticulum (ER) stress, leading to activation of the Unfolded Protein Response (UPR) signal transduction network. Chop is a transcriptional activator that is induced by ER stress and promotes cell death in response to chronic ER stress. Here, we examined the role of Chop in transgenic mice expressing human P23H rhodopsin (hP23H Rho Tg) that undergo retinal degeneration. With the exception of one time point, we found no significant induction of Chop in these animals and no significant change in retinal degeneration by histology and electrophysiology when hP23H Rho Tg animals were bred into a Chop (-/-) background. Our results indicate that Chop does not play a significant causal role during retinal degeneration in these animals. We suggest that other modules of the ER stress-induced UPR signaling network may be involved photoreceptor disease induced by P23H rhodopsin. PMID:26427410

  15. Volvoxrhodopsin, a light-regulated sensory photoreceptor of the spheroidal green alga Volvox carteri.

    PubMed Central

    Ebnet, E; Fischer, M; Deininger, W; Hegemann, P

    1999-01-01

    Somatic cells of the multicellular alga Volvox carteri contain a visual rhodopsin that controls the organism's phototactic behavior via two independent photoreceptor currents. Here, we report the identification of an opsinlike gene, designated as volvoxopsin (vop). The encoded protein exhibits homologies to the opsin of the unicellular alga Chlamydomonas reinhardtii (chlamyopsin) and to the entire animal opsin family, thus providing new perspectives on opsin evolution. Volvoxopsin accumulates within the eyes of somatic cells. However, the vop transcript is detectable only in the reproductive eyeless gonidia and embryos. vop mRNA levels increase 400-fold during embryogenesis, when embryos develop in darkness, whereas the vop transcript does not accumulate when embryos develop in the light. An antisense transformant, T3, was generated. This transformant produces 10 times less volvoxopsin than does the wild type. In T3, the vop transcript is virtually absent, whereas the antisense transcript is predominant and light regulated. It follows that vop expression is under light-dependent transcriptional control but that volvoxopsin itself is not the regulatory photoreceptor. Transformant T3 is phototactic, but its phototactic sensitivity is reduced 10-fold relative to the parental wild-type strain HK10. Thus, we offer definitive genetic evidence that a rhodopsin serves as the photoreceptor for phototaxis in a green alga. PMID:10449581

  16. Cone-Specific Promoters for Gene Therapy of Achromatopsia and Other Retinal Diseases.

    PubMed

    Ye, Guo-Jie; Budzynski, Ewa; Sonnentag, Peter; Nork, T Michael; Sheibani, Nader; Gurel, Zafer; Boye, Sanford L; Peterson, James J; Boye, Shannon E; Hauswirth, William W; Chulay, Jeffrey D

    2016-01-01

    Adeno-associated viral (AAV) vectors containing cone-specific promoters have rescued cone photoreceptor function in mouse and dog models of achromatopsia, but cone-specific promoters have not been optimized for use in primates. Using AAV vectors administered by subretinal injection, we evaluated a series of promoters based on the human L-opsin promoter, or a chimeric human cone transducin promoter, for their ability to drive gene expression of green fluorescent protein (GFP) in mice and nonhuman primates. Each of these promoters directed high-level GFP expression in mouse photoreceptors. In primates, subretinal injection of an AAV-GFP vector containing a 1.7-kb L-opsin promoter (PR1.7) achieved strong and specific GFP expression in all cone photoreceptors and was more efficient than a vector containing the 2.1-kb L-opsin promoter that was used in AAV vectors that rescued cone function in mouse and dog models of achromatopsia. A chimeric cone transducin promoter that directed strong GFP expression in mouse and dog cone photoreceptors was unable to drive GFP expression in primate cones. An AAV vector expressing a human CNGB3 gene driven by the PR1.7 promoter rescued cone function in the mouse model of achromatopsia. These results have informed the design of an AAV vector for treatment of patients with achromatopsia. PMID:26603570

  17. Retinal Pathology of a Patient with Goldmann-Favre Syndrome

    PubMed Central

    Bonilha, Vera L.; Fishman, Gerald A.; Rayborn, Mary E.; Hollyfield, Joe G.

    2013-01-01

    Purpose To define the retinal pathology in an 88 year-old male affected with Goldmann-Favre syndrome with a 2bp 5 A>C splice site mutation in the NR2E3 gene. Methods Retinal tissue from the macula and periphery was processed for immunohistochemistry. Perimacular retina was processed for transmission electron microscopy. Cryosections were studied by indirect immunofluorescence, using well-characterized antibodies to rhodopsin, cone cytoplasm, and cone opsins. The affected donor eye was compared to a postmortem matched normal eye. Results The retina was highly disorganized without laminar organization. The RPE was discontinuous in some perimacular regions. Large (>1mm) spherical electrondense melanosomes were observed in the RPE and choroid by TEM. Rods were virtually absent in the affected retina. Cones were present in the macula, but were mostly absent from the retinal periphery. In addition, cone rosettes were observed in the perimacular area. Both red/green and blue cone opsins were distributed along the entire cellular expanse of the cone photoreceptors in the affected eye, but were restricted to the cone outer segments in the control retina. Conclusions The histological data obtained from the retina of an elderly male patient with Goldmann-Favre syndrome showed an absence of rods and abnormal distribution of red/green and blue cone opsins. PMID:19852574

  18. Transcriptome profiling of developing photoreceptor subtypes reveals candidate genes involved in avian photoreceptor diversification.

    PubMed

    Enright, Jennifer M; Lawrence, Karen A; Hadzic, Tarik; Corbo, Joseph C

    2015-03-01

    Avian photoreceptors are a diverse class of neurons, comprised of four single cones, the two members of the double cone, and rods. The signaling events and transcriptional regulators driving the differentiation of these diverse photoreceptors are largely unknown. In addition, many distinctive features of photoreceptor subtypes, including spectral tuning, oil droplet size and pigmentation, synaptic targets, and spatial patterning, have been well characterized, but the molecular mechanisms underlying these attributes have not been explored. To identify genes specifically expressed in distinct chicken (Gallus gallus) photoreceptor subtypes, we developed fluorescent reporters that label photoreceptor subpopulations, isolated these subpopulations by using fluorescence-activated cell sorting, and subjected them to next-generation sequencing. By comparing the expression profiles of photoreceptors labeled with rhodopsin, red opsin, green opsin, and violet opsin reporters, we have identified hundreds of differentially expressed genes that may underlie the distinctive features of these photoreceptor subtypes. These genes are involved in a variety of processes, including phototransduction, transcriptional regulation, cell adhesion, maintenance of intra- and extracellular structure, and metabolism. Of particular note are a variety of differentially expressed transcription factors, which may drive and maintain photoreceptor diversity, and cell adhesion molecules, which may mediate spatial patterning of photoreceptors and act to establish retinal circuitry. These analyses provide a framework for future studies that will dissect the role of these various factors in the differentiation of avian photoreceptor subtypes. PMID:25349106

  19. Making Sense of Optogenetics

    PubMed Central

    Guru, Akash; Post, Ryan J; Ho, Yi-Yun

    2015-01-01

    This review, one of a series of articles, tries to make sense of optogenetics, a recently developed technology that can be used to control the activity of genetically-defined neurons with light. Cells are first genetically engineered to express a light-sensitive opsin, which is typically an ion channel, pump, or G proteincoupled receptor. When engineered cells are then illuminated with light of the correct frequency, opsin-bound retinal undergoes a conformational change that leads to channel opening or pump activation, cell depolarization or hyperpolarization, and neural activation or silencing. Since the advent of optogenetics, many different opsin variants have been discovered or engineered, and it is now possible to stimulate or inhibit neuronal activity or intracellular signaling pathways on fast or slow timescales with a variety of different wavelengths of light. Optogenetics has been successfully employed to enhance our understanding of the neural circuit dysfunction underlying mood disorders, addiction, and Parkinsons disease, and has enabled us to achieve a better understanding of the neural circuits mediating normal behavior. It has revolutionized the field of neuroscience, and has enabled a new generation of experiments that probe the causal roles of specific neural circuit components. PMID:26209858

  20. Self-organized criticality and color vision: A guide to water-protein landscape evolution

    NASA Astrophysics Data System (ADS)

    Phillips, J. C.

    2013-02-01

    We focus here on the scaling properties of small interspecies differences between red cone opsin transmembrane proteins, using a hydropathic elastic roughening tool previously applied to the rhodopsin rod transmembrane proteins. This tool is based on a non-Euclidean hydropathic metric realistically rooted in the atomic coordinates of 5526 protein segments, which thereby encapsulates universal non-Euclidean long-range differential geometrical features of water films enveloping globular proteins in the Protein Data Bank. Whereas the rhodopsin blue rod water films are smoothest in humans, the red cone opsins water films are optimized for smoothness in cats and elephants, consistent with protein species landscapes that evolve differently in different contexts. We also analyze red cone opsins in the chromatophore-containing family of chameleons, snakes, zebrafish and goldfish, where short- and long-range (BLAST and hydropathic) amino acid (aa) correlations are found with values as large as 97%-99%. We use hydropathic aa optimization to estimate the maximum number Nmax of color shades that the human eye can discriminate, and obtain 106

  1. Differential Light-induced Responses in Sectorial Inherited Retinal Degeneration*

    PubMed Central

    Ramon, Eva; Cordom, Arnau; Aguil, Mnica; Srinivasan, Sundaramoorthy; Dong, Xiaoyun; Moore, Anthony T.; Webster, Andrew R.; Cheetham, Michael E.; Garriga, Pere

    2014-01-01

    Retinitis pigmentosa (RP) is a group of genetically and clinically heterogeneous inherited degenerative retinopathies caused by abnormalities of photoreceptors or retinal pigment epithelium in the retina leading to progressive sight loss. Rhodopsin is the prototypical G-protein-coupled receptor located in the vertebrate retina and is responsible for dim light vision. Here, novel M39R and N55K variants were identified as causing an intriguing sector phenotype of RP in affected patients, with selective degeneration in the inferior retina. To gain insights into the molecular aspects associated with this sector RP phenotype, whose molecular mechanism remains elusive, the mutations were constructed by site-directed mutagenesis, expressed in heterologous systems, and studied by biochemical, spectroscopic, and functional assays. M39R and N55K opsins had variable degrees of chromophore regeneration when compared with WT opsin but showed no gross structural misfolding or altered trafficking. M39R showed a faster rate for transducin activation than WT rhodopsin with a faster metarhodopsinII decay, whereas N55K presented a reduced activation rate and an altered photobleaching pattern. N55K also showed an altered retinal release from the opsin binding pocket upon light exposure, affecting its optimal functional response. Our data suggest that these sector RP mutations cause different protein phenotypes that may be related to their different clinical progression. Overall, these findings illuminate the molecular mechanisms of sector RP associated with rhodopsin mutations. PMID:25359768

  2. Spectral sensitivity of the ctenid spider Cupiennius salei.

    PubMed

    Zopf, Lydia M; Schmid, Axel; Fredman, David; Eriksson, Bo Joakim

    2013-11-01

    The spectral sensitivity of adult male Cupiennius salei Keys, a nocturnal hunting spider, was studied in a behavioural test. As known from earlier behavioural tests, C. salei will walk towards a black target presented in front of a white background. In this study, a black target (size 4270 cm) was presented in a white arena illuminated by monochromatic light in the range 365-695 nm using 19 monochromatic filters (half-width in the range 6-10 nm). In the first trial, the transmission of the optical filters was between 40% and 80%. In the second trial, the transmission was reduced to 5% using a neutral density filter. At the high intensity, the spiders showed a spectral sensitivity in the range 380-670 nm. In the second trial, the animals only showed directed walks if the illumination was in the range 449-599 nm, indicating a lower sensitivity at the margins of the spectral sensitivity. In previous intracellular recordings, the measured spectral sensitivity was between 320 and 620 nm. Interestingly, these results do not completely match the behaviourally tested spectral sensitivity of the photoreceptors, where the sensitivity range is shifted to longer wavelengths. In order to investigate the molecular background of spectral sensitivity, we searched for opsin genes in C. salei. We found three visual opsins that correspond to UV and middle to long wavelength sensitive opsins as described for jumping spiders. PMID:23948480

  3. Spectral Sensitivity of the ctenid spider Cupiennius salei Keys

    PubMed Central

    Zopf, Lydia M.; Schmid, Axel; Fredman, David; Eriksson, Bo Joakim

    2014-01-01

    Summary The spectral sensitivity of adult male Cupiennius salei Keys, a nocturnal hunting spider, was studied in a behavioural test. As known from earlier behavioural tests, C. salei walks towards a black target presented in front of a white background. In this study a black target (size 42 70 cm) was presented in a white arena illuminated by monochromatic light in the range of 365 to 695 nm using 19 monochromatic filters (HW in the range of 6 10 nm). In the first trial, the transmission of the optical filters was between 40 % and 80%. In a second trial the transmission was reduced to 5%, using a neutral density filter. At the high intensity the spiders showed a spectral sensivity in the range from 380 to 670 nm. In the second trial the animals only showed directed walks if the illumination was in the range of 449 to 599 nm, indicating a lower sensitivity at the margins of the spectral sensitivity. In previous intracellular recordings, the measured spectral sensitivity was between 320 and 620 nm. Interestingly, these results do not completely match the behaviourally tested spectral sensitivity of the photoreceptors, where the sensitivity range is shifted to longer wavelengths. In order to investigate the molecular background of spectral sensitivity, we searched for opsin genes in C. salei. We found three visual opsins that correspond to UV and middle to long wavelength sensitive opsins as described for jumping spiders. PMID:23948480

  4. Signatures of Selection and Gene Conversion Associated with Human Color Vision Variation

    PubMed Central

    Verrelli, Brian C.; Tishkoff, Sarah A.

    2004-01-01

    Trichromatic color vision in humans results from the combination of red, green, and blue photopigment opsins. Although color vision genes have been the targets of active molecular and psychophysical research on color vision abnormalities, little is known about patterns of normal genetic variation in these genes among global human populations. The current study presents nucleotide sequence analyses and tests of neutrality for a 5.5-kb region of the X-linked long-wave “red” opsin gene (OPN1LW) in 236 individuals from ethnically diverse human populations. Our analysis of the recombination landscape across OPN1LW reveals an unusual haplotype structure associated with amino acid replacement variation in exon 3 that is consistent with gene conversion. Compared with the absence of OPN1LW amino acid replacement fixation since divergence from chimpanzee, the human population exhibits a significant excess of high-frequency OPN1LW replacements. Our results suggest that subtle changes in L-cone opsin wavelength absorption may have been adaptive during human evolution. PMID:15252758

  5. Non-invasive activation of optogenetic actuators

    NASA Astrophysics Data System (ADS)

    Birkner, Elisabeth; Berglund, Ken; Klein, Marguerita E.; Augustine, George J.; Hochgeschwender, Ute

    2014-03-01

    The manipulation of genetically targeted neurons with light (optogenetics) continues to provide unprecedented avenues into studying the function of the mammalian brain. However, potential translation into the clinical arena faces a number of significant hurdles, foremost among them the need for insertion of optical fibers into the brain to deliver light to opsins expressed on neuronal membranes. In order to overcome these hardware-related problems, we have developed an alternative strategy for delivering light to opsins which does not involve fiber implants. Rather, the light is produced by a protein, luciferase, which oxidizes intravenously applied substrate, thereby emitting bioluminescence. In proof-ofprinciple studies employing a fusion protein of a light-generating luciferase to a light-sensing opsin (luminopsin), we showed that light emitted by Gaussia luciferase is indeed able to activate channelrhodopsin, allowing modulation of neuronal activity when expressed in cultured neurons. Here we assessed applicability of the concept in vivo in mice expressing luminopsins from viral vectors and from genetically engineered transgenes. The experiments demonstrate that intravenously applied substrate reaches neurons in the brain, causing the luciferase to produce bioluminescence which can be imaged in vivo, and that activation of channelrhodopsin by bioluminescence is sufficient to affect behavior. Further developments of such technology based on combining optogenetics with bioluminescence - i.e. combining lightsensing molecules with biologically produced light through luciferases - should bring optogenetics closer to clinical applications.

  6. [Phototransduction mediated by melanopsin in intrinsically photosensitive retinal ganglion cells].

    PubMed

    Domnguez-Sols, Carlos Augusto; Prez-Len, Jorge Alberto

    2015-01-01

    Melanopsin is the most recent photopigment described. As all the other opsins, it attaches in the retina as chromophore. Its amino acid sequence resembles more invertebrate opsins than those of vertebrates. The signal transduction pathway of opsins in vertebrates is based on the coupling to the G protein transducin, triggering a signaling cascade that results in the hyperpolarization of the plasma membrane. On the contrary, the photoreceptors of invertebrates activate the Gq protein pathway, which leads to depolarizing responses. Phototransduction mediated by melanopsin leads to the depolarization of those cells where it is expressed, the intrinsically photosensitive retinal ganglion cells; the cellular messengers and the ion channel type(s) responsible for the cells response is still unclear. Studies to elucidate the signaling cascade of melanopsin in heterologous expression systems, in retina and isolated/cultured intrinsically photosensitive retinal ganglion cells, have provided evidence for the involvement of protein Gq and phospholipase C together with the likely participation of an ion channel member of the transient receptor potential-canonical family, a transduction pathway similar to invertebrate photopigments, particularly Drosophila melanogaster. The intrinsically photosensitive retinal ganglion cells are the sole source of retinal inferences to the suprachiasmatic nucleus; thus, clarifying completely the melanopsin signaling pathway will impact the chronobiology field, including the clinical aspects. PMID:26581535

  7. Tracking the primary photoconversion events in rhodopsins by ultrafast optical spectroscopy.

    PubMed

    Polli, D; Rivalta, I; Nenov, A; Weingart, O; Garavelli, M; Cerullo, G

    2015-02-01

    Opsins are a broad class of photoactive proteins, found in all classes of living beings from bacteria to higher animals, which work either as light-driven ion pumps or as visual pigments. The photoactive function in opsins is triggered by the ultrafast isomerization of the retinal chromophore around a specific carbon double bond, leading to a highly distorted, spectrally red-shifted photoproduct. Understanding, by either experimental or computational methods, the time course of this photoisomerization process is of utmost importance, both for its biological significance and because opsin proteins are the blueprint for molecular photoswitches. This paper focuses on the ultrafast 11-cis to all-trans isomerization in visual rhodopsins, and has a twofold goal: (i) to review the most recent experimental and computational efforts aimed at exposing the very early phases of photoconversion; and (ii) discuss future advanced experiments and calculations that will allow an even deeper understanding of the process. We present high time resolution pump-probe data, enabling us to follow the wavepacket motion through the conical intersection connecting excited and ground states, as well as femtosecond stimulated Raman scattering data allowing us to track the subsequent structural evolution until the first stable all-trans photoproduct is reached. We conclude by introducing computational results for two-dimensional electronic spectroscopy, which has the potential to provide even greater detail on the evolution of the electronic structure of retinal during the photoisomerization process. PMID:25429920

  8. Virally mediated optogenetic excitation and inhibition of pain in freely moving non-transgenic mice

    PubMed Central

    Iyer, Shrivats Mohan; Montgomery, Kate L.; Towne, Chris; Lee, Soo Yeun; Ramakrishnan, Charu; Deisseroth, Karl; Delp, Scott L.

    2014-01-01

    Primary nociceptors are the first neurons involved in the complex processing system that regulates normal and pathological pain1. Our ability to excite and inhibit these neurons has been limited by pharmacological and electrical stimulation constraints; non-invasive excitation and inhibition of these neurons in freely moving non-transgenic animals has not been possible. Here we use an optogenetic2 strategy to bidirectionally control nociceptors of non-transgenic mice. Intra-sciatic nerve injection of adeno-associated viruses encoding an excitatory opsin enabled light-inducible stimulation of acute pain, place aversion, and optogenetically mediated reductions in withdrawal thresholds to mechanical and thermal stimuli. In contrast, viral delivery of an inhibitory opsin enabled light-inducible inhibition of acute pain perception, and reversed mechanical allodynia and thermal hyperalgesia in a model of neuropathic pain. Light was delivered transdermally enabling these behaviors to be induced in freely moving animals. This approach may have utility in basic and translational pain research, and enable rapid drug screening and testing of newly engineered opsins. PMID:24531797

  9. Photoreceptor Cell Death, Proliferation and Formation of Hybrid Rod/S-Cone Photoreceptors in the Degenerating STK38L Mutant Retina

    PubMed Central

    Berta, gnes I.; Boesze-Battaglia, Kathleen; Genini, Sem; Goldstein, Orly; O'Brien, Paul J.; Szl, goston; Acland, Gregory M.; Beltran, William A.; Aguirre, Gustavo D.

    2011-01-01

    A homozygous mutation in STK38L in dogs impairs the late phase of photoreceptor development, and is followed by photoreceptor cell death (TUNEL) and proliferation (PCNA, PHH3) events that occur independently in different cells between 714 weeks of age. During this period, the outer nuclear layer (ONL) cell number is unchanged. The dividing cells are of photoreceptor origin, have rod opsin labeling, and do not label with markers specific for macrophages/microglia (CD18) or Mller cells (glutamine synthetase, PAX6). Nestin labeling is absent from the ONL although it labels the peripheral retina and ciliary marginal zone equally in normals and mutants. Cell proliferation is associated with increased cyclin A1 and LATS1 mRNA expression, but CRX protein expression is unchanged. Coincident with photoreceptor proliferation is a change in the photoreceptor population. Prior to cell death the photoreceptor mosaic is composed of L/M- and S-cones, and rods. After proliferation, both cone types remain, but the majority of rods are now hybrid photoreceptors that express rod opsin and, to a lesser extent, cone S-opsin, and lack NR2E3 expression. The hybrid photoreceptors renew their outer segments diffusely, a characteristic of cones. The results indicate the capacity for terminally differentiated, albeit mutant, photoreceptors to divide with mutations in this novel retinal degeneration gene. PMID:21980341

  10. Identification and characterization of visual pigments in caecilians (Amphibia: Gymnophiona), an order of limbless vertebrates with rudimentary eyes.

    PubMed

    Mohun, S M; Davies, W L; Bowmaker, J K; Pisani, D; Himstedt, W; Gower, D J; Hunt, D M; Wilkinson, M

    2010-10-15

    In comparison with the other amphibian orders, the Anura (frogs) and Urodela (salamanders), knowledge of the visual system of the snake-like Gymnophiona (caecilians) is relatively sparse. Most caecilians are fossorial with, as far as is known any surface activity occurring mainly at night. They have relatively small, poorly developed eyes and might be expected to possess detectable changes in the spectral sensitivity of their visual pigments. Microspectrophotometry was used to determine the spectral sensitivities of the photoreceptors in three species of caecilian, Rhinatrema bivittatum, Geotrypetes seraphini and Typhlonectes natans. Only rod opsin visual pigment, which may be associated with scotopic (dim light) vision when accompanied by other 'rod-specific' components of the phototransduction cascade, was found to be present. Opsin sequences were obtained from the eyes of two species of caecilian, Ichthyophis cf. kohtaoensis and T. natans. These rod opsins were regenerated in vitro with 11-cis retinal to give pigments with spectral sensitivity peaks close to 500 nm. No evidence for cone photoreception, associated with diurnal and colour vision, was detected using molecular and physiological methods. Additionally, visual pigments are short-wavelength shifted in terms of the maximum absorption of light when compared with other amphibian lineages. PMID:20889838

  11. Optogenetics in Mice Performing a Visual Discrimination Task: Measurement and Suppression of Retinal Activation and the Resulting Behavioral Artifact

    PubMed Central

    Danskin, Bethanny; Denman, Daniel; Valley, Matthew; Ollerenshaw, Douglas; Williams, Derric; Groblewski, Peter; Reid, Clay; Olsen, Shawn; Waters, Jack

    2015-01-01

    Optogenetic techniques are used widely to perturb and interrogate neural circuits in behaving animals, but illumination can have additional effects, such as the activation of endogenous opsins in the retina. We found that illumination, delivered deep into the brain via an optical fiber, evoked a behavioral artifact in mice performing a visually guided discrimination task. Compared with blue (473 nm) and yellow (589 nm) illumination, red (640 nm) illumination evoked a greater behavioral artifact and more activity in the retina, the latter measured with electrical recordings. In the mouse, the sensitivity of retinal opsins declines steeply with wavelength across the visible spectrum, but propagation of light through brain tissue increases with wavelength. Our results suggest that poor retinal sensitivity to red light was overcome by relatively robust propagation of red light through brain tissue and stronger illumination of the retina by red than by blue or yellow light. Light adaptation of the retina, via an external source of illumination, suppressed retinal activation and the behavioral artifact without otherwise impacting behavioral performance. In summary, long wavelength optogenetic stimuli are particularly prone to evoke behavioral artifacts via activation of retinal opsins in the mouse, but light adaptation of the retina can provide a simple and effective mitigation of the artifact. PMID:26657323

  12. Beta-ionone activates and bleaches visual pigment in salamander photoreceptors.

    PubMed

    Isayama, Tomoki; McCabe England, S L; Crouch, R K; Zimmerman, A L; Makino, C L

    2009-01-01

    Vision begins with photoisomerization of 11-cis retinal to the all-trans conformation within the chromophore-binding pocket of opsin, leading to activation of a biochemical cascade. Release of all-trans retinal from the binding pocket curtails but does not fully quench the ability of opsin to activate transducin. All-trans retinal and some other analogs, such as beta-ionone, enhance opsin's activity, presumably on binding the empty chromophore-binding pocket. By recording from isolated salamander photoreceptors and from patches of rod outer segment membrane, we now show that high concentrations of beta-ionone suppressed circulating current in dark-adapted green-sensitive rods by inhibiting the cyclic nucleotide-gated channels. There were also decreases in circulating current and flash sensitivity, and accelerated flash response kinetics in dark-adapted blue-sensitive (BS) rods and cones, and in ultraviolet-sensitive cones, at concentrations too low to inhibit the channels. These effects persisted in BS rods even after incubation with 9-cis retinal to ensure complete regeneration of their visual pigment. After long exposures to high concentrations of beta-ionone, recovery was incomplete unless 9-cis retinal was given, indicating that visual pigment had been bleached. Therefore, we propose that beta-ionone activates and bleaches some types of visual pigments, mimicking the effects of light. PMID:19500430

  13. Evolution of Vision

    NASA Astrophysics Data System (ADS)

    Ostrovsky, Mikhail

    The evolution of photoreception, giving rise to eye, offers a kaleidoscopic view on selection acting at both the organ and molecular levels. The molecular level is mainly considered in the lecture. The greatest progress to date has been made in relation to the opsin visual pigments. Opsins appeared before eyes did. Two- and three-dimensional organization for rhodopsin in the rod outer segment disk membrane, as well as molecular mechanisms of visual pigments spectral tuning, photoisomerization and also opsin as a G-protein coupled receptor are considered. Molecular mechanisms of visual pigments spectral tuning, namely switching of chromophore (physiological time scale) and amino acid changes in the chromophore site of opsin (evolutionary time scale) is considered in the lecture. Photoisomerization of rhodopsin chromophore, 11-cis retinal is the only photochemical reaction in vision. The reaction is extemely fast (less that 200 fs) and high efficient (. is 0.65). The rhodopsin photolysis and kinetics of the earlier products appearance, photo- and bathorhodopsin, is considered. It is known that light is not only a carrier of information, but also a risk factor of damage to the eye. This photobiological paradox of vision is mainly due to the nature of rhodopsin chromophore. Photooxidation is the base of the paradox. All factors present in the phototrceptor cells to initiate free-radical photooxidation: photosensitizers, oxygen and substrates of oxidation: lipids and proteins (opsin). That is why photoprotective system of the eye structures appeared in the course of evolution. Three lines of protective system to prevent light damage to the retina and retina pigment epithelium is known: permanent renewal of rod and cone outer segment, powerful antioxidant system and optical media as cut-off filters where the lens is a key component. The molecular mechanisms of light damage to the eye and photoprotective system of the eye is considered in the lecture. The molecular mechanisms of phototransduction in vertebrates eye is also briefly considered in the lecture. Evolution of vision is an enormous subject for thought and investigation. In the postgenomic era evolutionary molecular physiology as a whole and evolutionary molecular physiology of vision can be considered as a key approach for understanding how genome is working.

  14. First Light Results from the SDO Extreme Ultraviolet Variability Experiment (EVE)

    NASA Astrophysics Data System (ADS)

    Woods, Thomas; Eparvier, Francis; Hock, Rachel; Jones, Andrew; Didkovsky, Leonid; Judge, Darrell; Chamberlin, Phillip

    The highly variable solar extreme ultraviolet (EUV) irradiance is a key measurement for the NASA Living With the Star (LWS) program as it is the major energy input into the Earth's upper atmosphere and thus impacts the geospace environment that affects satellite operations and communication and navigation systems. The Extreme ultraviolet Variability Experiment (EVE) aboard the NASA Solar Dynamics Observatory (SDO) is part of the first LWS mission and was launched on 11 February 2010. The EVE instruments measure the solar EUV irradiance from 0.1 to 105 nm with unprecedented spectral resolution (0.1 nm), temporal cadence (10 sec minimum), and accuracy (20% or better). The 0.1-nm spectral resolution is needed to resolve many of the brighter emission lines so that understanding of the solar EUV irradiance can be advanced, such as improving physics-based spectral models of the Sun. The high time cadence of 10 sec is required to study the detailed evolution of flare events that are an important interest for space weather research and operations. The 20% accuracy is needed to advance understanding of the geospace environment through detailed modeling of Earth's ionosphere and thermosphere and their response to solar variations. The first light results from EVE during the rise of solar cycle 24 will be presented.

  15. Comparison of force-related performance indicators between heavyweight and lightweight rowers.

    PubMed

    Doyle, Matthew M; Lyttle, Andrew; Elliott, Bruce

    2010-09-01

    The aim of this study was to examine biomechanical variables relating to the force production of men's Lightweight (LW) and Heavyweight (HW) rowing pairs. Seven HW and seven LW coxless pairs were studied under a range of stroke rates, from 20 spm to race rating (average of 33.7 spm for the HWs and 33.9 spm for the LWs). Each crew was equipped with biomechanical apparatus allowing the measurement of gate force, horizontal oar angle, and boat velocity. The HW crews exhibited significantly higher (p < 0.05) values for all variables examined, at all rates. Peak handle force was 26.2% to 30.2% higher in the HW group. Average handle force ranged from 18.7% to 22.1% higher than the LW group. Work per stroke was found to be 26% to 28% higher for the HW crews, and Power Per Kilogram was also greater for the HW crews, from 24.0% to 29.2%. The LWs were observed to be consistently, but not significantly, slower than the HWs (from 96.9% at the race situation, to 98.7% at 28 spm). These observations are important when considering biomechanical performance indicators in rowing, as significant changes in performance indicators may lead to only minimal alteration in boat velocity. PMID:21162363

  16. CD changes of 193-nm resists during SEM measurement

    NASA Astrophysics Data System (ADS)

    Kudo, Takanori; Bae, Jun-Bom; Dammel, Ralph R.; Kim, Woo-Kyu; McKenzie, Douglas S.; Rahman, M. D.; Padmanaban, Munirathna; Ng, Waiman

    2001-08-01

    CD linewidth change during SEM inspection has been one of the issues encountered in the introduction of 193 nm resists. As a general tendency, the methacrylate resists exhibit faster line width reduction than the cycloolefin- maleic anhydride (COMA) systems; however, other resist components as well as CD SEM settings paly an important role. Based on the exposure time vs. CD loss, the line width slimming (LSW) is found to proceed in three steps, which are assigned as: 1) chemical change of outer resist layer, 2) evaporation of volatiles and 3) bulk chain scission or deprotection. Countermeasures for CD degradation are proposed form both the formulation and process sides. A calculation of e-beam penetration depth suggests that deprotection, chain scission and other reactions occur in the first 20-40nm, and these reaction rates combined with thermal effects determine LWS. The CD SEM measurement method has been improved to minimize e-beam exposure and to spread out the thermal load over a larger period of time. An optimized formulation exhibits less than 0.2% LWS per measurement with the improved CD measurement program.

  17. The Objectives of NASA's Living with a Star Space Environment Testbed

    NASA Technical Reports Server (NTRS)

    Barth, Janet L.; LaBel, Kenneth A.; Brewer, Dana; Kauffman, Billy; Howard, Regan; Griffin, Geoff; Day, John H. (Technical Monitor)

    2001-01-01

    NASA is planning to fly a series of Space Environment Testbeds (SET) as part of the Living With A Star (LWS) Program. The goal of the testbeds is to improve and develop capabilities to mitigate and/or accommodate the affects of solar variability in spacecraft and avionics design and operation. This will be accomplished by performing technology validation in space to enable routine operations, characterize technology performance in space, and improve and develop models, guidelines and databases. The anticipated result of the LWS/SET program is improved spacecraft performance, design, and operation for survival of the radiation, spacecraft charging, meteoroid, orbital debris and thermosphere/ionosphere environments. The program calls for a series of NASA Research Announcements (NRAs) to be issued to solicit flight validation experiments, improvement in environment effects models and guidelines, and collateral environment measurements. The selected flight experiments may fly on the SET experiment carriers and flights of opportunity on other commercial and technology missions. This paper presents the status of the project so far, including a description of the types of experiments that are intended to fly on SET-1 and a description of the SET-1 carrier parameters.

  18. Dust processing in the Carina nebula region

    NASA Astrophysics Data System (ADS)

    Onaka, Takashi; Mori, Tamami I.; Okada, Yoko

    2015-10-01

    Dust processing in the Carina nebula is investigated based on mid- to far-infrared spectroscopy with Infrared Space Observatory (ISO). Mapping observations over a central 40? 20? area of the nebula with PHT-S, SWS, and LWS onboard ISO not only reveal spectroscopically that the mid-infrared unidentified infrared (UIR) bands at 6.2, 7.7, 8.6, and 11.3 ?m are absent in the ionized region, but also indicate that the 11.3 ?m may behave differently from the other three UIR bands near the edge of the ionized region, suggesting a variation either in the size distribution or in the ionization fraction of the band carriers. The correlation of [NII]122 ?m and [SiII]35 ?m line emissions observed with SWS and LWS is reinvestigated based on the recent atomic data as well as the latest cosmic abundance, suggesting that a large fraction (> 70%), if not all, of silicon returns to the gas phase in the Carina nebula, suggesting that silicates cannot survive under harsh conditions, such as massive star-forming regions. The present observations clearly show dust processing taking place in active regions in the Galaxy.

  19. Calibration of the AKARI Far-Infrared Imaging Fourier-Transform Spectrometer

    NASA Astrophysics Data System (ADS)

    Murakami, Noriko; Kawada, Mitsunobu; Ootsubo, Takafumi; Okada, Yoko; Takahashi, Hidenori; Yasuda, Akiko; Kaneda, Hidehiro; Matsuo, Hiroshi; Baluteau, Jean-Paul; Davis-Imhof, Peter; Gom, Brad G.; Naylor, David A.; Zavagno, Annie; Yamamura, Issei; Matsuura, Shuji; Shirahata, Mai; Doi, Yasuo; Nakagawa, Takao; Shibai, Hiroshi

    2010-10-01

    The Far-Infrared Surveyor (FIS) onboard the AKARI satellite has a spectroscopic capability provided by a Fourier transform spectrometer (FIS-FTS). FIS-FTS is the first space-borne imaging FTS dedicated to far-infrared astronomical observations. We describe the calibration process of the FIS-FTS, and discuss its accuracy and reliability. The calibration is based on observational data of bright astronomical sources as well as two instrumental sources. We have compared the FIS-FTS spectra with the spectra obtained from the Long Wavelength Spectrometer (LWS) of the Infrared Space Observatory (ISO), having a similar spectral coverage. The present calibration method accurately reproduces the spectra of several solar system objects having a reliable spectral model. Under this condition the relative uncertainty of the calibration of the continuum is estimated to be 15% for SW, 10% for 70-85 cm-1 of LW, and 20% for 60-70 cm-1 of LW; and the absolute uncertainty is estimated to be +35%/-55% for SW, +35%/-55% for 70-85 cm-1 of LW, and +40%/-60% for 60-70 cm-1 of LW. These values have been confirmed by comparisons with theoretical models and previous observations by the ISO / LWS.

  20. O-bearing Molecules in Carbon-rich Proto-Planetary Objects: Study of CRL 618

    NASA Astrophysics Data System (ADS)

    Herpin, F.; Cernicharo, J.

    2001-08-01

    We present ISO LWS observations of the proto-planetary nebula CRL 618, AFGL 618 a star evolving very fast to the planetary nebula stage. In addition to the lines of COd, COt, HCN and HNC, we report on the detection of water and OH emission together with the fine structure lines of [OI] at 63 and 145 microns. We suggest that O-bearing species other than CO are produced in the innermost region of the circumstellar envelope. The UV photons from the central star photodissociate most of the molecular species produced in the AGB phase and allow a chemistry dominated by standard ion-neutral reactions. Not only allow these reactions the formation of O-bearing species, but they also modify the abundances of C-rich molecules like HCN and HNC for which we found an abundance ratio of ? 1, much lower than in AGB stars. The molecular abundances in the different regions of the circumstellar envelope have been derived from radiative transfer models and our knowledge of its physical structure. Furthermore, we compare ISO LWS observations of three C-rich objects typical of each step of the fast transition of an AGB star to the Planetay Nebula stage: CRL 2688, AFGL 2688 a very young Proto-Planetary Nebula, CRL 618 a Proto-Planetary Nebula, and NGC 7027 a young Planetary Nebula.

  1. [Current views on vision of mammals].

    PubMed

    Khokhlova, T V

    2012-01-01

    In the review, research data are presented on mammals' vision including visual pigments, color and contrast vision, and visual behaviour in different species. It is shown that in course of evolution mammals were gradually losing the elements of daylight cone vision system that are typical of other vertebrates. In monotremes, visual pigments SWS2 (cone blue-sensitive 2) and MWS/LWS (green/red-sensitive) are still present, as well as rod RH1. Theria, except some primates, also have two cone visual pigments: SWS1 (ultraviolet/violet or blue-sensitive 1) and MWS/LWS along with rod RH1. Humans and some other higher primates evolved the new visual pigment, MWS, and acquired trichromatic vision. Marine mammals (cetaceans and pinnipeds) and some species of other orders have lost also the visual pigment SWS1, probably due to specificity of processing the information received by these cones. Current view on mammals' vision with two cone pigments and rods is presented. Data on maximum spectral sensitivity of visual pigments in different species and orders are given along with data on spatial contrast sensation. High visual acuity has been acquired by ungulates, artiodactyls, and primates, while the highest one--by humans with their specialized fovea. PMID:23330397

  2. The Living With A Star Program

    NASA Astrophysics Data System (ADS)

    St. Cyr, O. C.; Giles, B.; Poland, A.; Zanetti, L.; Mauk, B.

    2003-04-01

    The goal of NASA's Living With a Star (LWS) program is to develop the scientific understanding necessary to address effectively those aspects of the connected Sun-Earth system that affect life and society. LWS has solar, heliospheric, magnetospheric and ionospheric elements, and efforts are underway to forge a connection with the atmospheric and Earth science community. An understanding of the Suns dynamics, as well as the nature and sources of solar variations will be provided by the Solar Dynamics Observatory, currently in the early phase of development. The payload includes a helioseismology investigation and multi-spectral coronal imaging, as well as an extreme ultraviolet irradiance spectrometer that will provide measurements critical to characterization of the ionospheric-thermospheric response to variations in solar energy input. Recently the Geospace Mission Definition Team has released their report outlining a family of science investigations that address the near-Earth interplanetary medium, the magnetosphere, the ionosphere, and the upper atmosphere. The recommended elements are contained in two coupled investigations: a Radiation Belt Investigation whose flight components consist of two Radiation Belt Storm Probes (RBSP) and an energetic neutral atom imager. The RBSP will measure relativistic electrons, electric and magnetic fields, wave fields, ring current ions and radiation belt ions; the imager will provide information on the global distribution and dynamics of the ring current ion population. The Ionosphere-Thermosphere Investigation consists of two identical spacecraft in low-Earth orbit and a mid-latitude far-ultraviolet imager in geosynchronous orbit on a mission of opportunity. The Ionosphere-Thermosphere Storm Probes will make in-situ measurements of plasma density, drifts, irregularities, neutral densities and winds, as well as currents, wave fields, and precipitating particles. The mid latitude imager will map the oxygen to nitrogen ratio and the square of the electron density, providing global context for the in-situ measurements. An initial set of Space Environment Testbed proposals is under evaluation, with the goal of improving engineering approaches to accommodation or mitigation of the effects of solar variability on spacecraft design and operations. Much of the knowledge obtained by the LWS Program will be transferred to the space weather community in the form of scientific models, which will provide the basis for operational models, design tools, and decision aids to be used by those concerned with designing around or operating through hazardous space weather conditions. Definition and strategy panels have been formed to provide direction for the Targeted Research and Technology and the Solar Sentinels programs. LWS has adopted an open data policy for all missions. Since the program emphasizes cross-disciplinary and correlative studies, multiple studies of the data environment are also underway. This presentation will provide an update of the status of all elements in the LWS Program.

  3. Current Status on NASA's Living With a Star Program

    NASA Astrophysics Data System (ADS)

    Guhathakurta, M.; Stcyr, O. C.

    Living With a Star is a space weather-focused and application-driven research program. Its goal is to develop the scientific understanding necessary to effectively address those aspects of the connected Sun-Earth system that directly affect life and society. This program is part of the Sun-Earth Connection (SEC) theme within the office of Space Science. Living With a Star is a cross-cutting program whose goals and objectives have the following links to each of the four NASA Strategic Enterprises: Space Science: LWS quantifies the physics, dynamics, and behavior of the only stellar/planetary system we can see at a close distance. Earth Science: LWS improves understanding of the effects of solar variability and disturbances on terrestrial climate change. Human Space Flight: LWS provides data and scientific understanding required for advanced warning of energetic particle events that affect the safety of humans in space. Aeronautics and Space Transportation: LWS provides detailed characterization of radiation environments useful in the design of more reliable electronic components for air and space transportation system. LWS Program is implemented by a sequence of inter-related science missions, space environment test bed and targeted research and technology. 1) A space weather research network of spacecraft will provide continuous observations of the Sun-Earth system for interlocking, dual use, scientific and applications research. Flight of a Solar Dynamics Observatory (launch 2008) to: - Probe solar interior, especially region where the dynamo is located, vs time to unravel physics of ``engine'' driving solar variability. -Track, for first time, solar active regions/solar storm regions simultaneously above and below solar surface to understand development and triggering of explosive events (Flares, Coronal Mass Ejections). Flight of Solar Sentinels, launch before and around next solar max to provide global view of the heliosphere, track solar active regions over entire sun, including for the first time the backside of Sun and describe the evolution of eruptions and flares from the Sun to Earth to Mars and beyond. Flight of Magnetospheric and Ionospheric Storm Probes, launch around solar max, geospace ``buoys'' in critical regions of Earth's space environment to determine its global and local response to solar variability. 2) A special data analysis and modeling program (Targeted Research & Technology) targeted at (1) obtaining a Sun-Earth systems model, (2) improving knowledge of space environmental conditions and variations over the solar cycle, (3) developing techniques and models for predicting solar/geospace disturbances which affect human technology, and (4) assimilating data from networks of spacecraft. 3) Orbital Technology Testbeds (Space Environment Testbeds) for low cost validation of rad-hard and rad-tolerant systems in high radiation orbits. - Implemented as missions of opportunity via cost-sharing partnerships with various international and national partners 4) Establishing and expanding partnerships for interdisciplinary science and applications with other NASA programs (Earth Science, Human Space Flight, Life Sciences), with other federal agencies (via interagency for National Space Weather Program, NOAA, NSF, DOE), international partners, academic community, and industry to obtain synergism and address common needs.

  4. An immunocytochemical study of encephalic photoreceptors in three species of lamprey.

    PubMed

    Garca-Fernndez, J M; Jimnez, A J; Gonzlez, B; Pombal, M A; Foster, R G

    1997-05-01

    The extraretinal and extrapineal photoreceptors of three species of adult lamprey, sea lamprey (Petromyzon marinus), river lamprey (Lampetra fluviatilis) and silver lamprey (Ichthyomyzon unicuspis) were studied using antibodies raised against photoreceptor rod and cone opsins, alpha-transducin and arrestin. In all three species cells in the pineal organ (P), parapineal organ (PP), nucleus preopticus (T5), nucleus commissurae postopticae (D8), nucleus ventralis hypothalami (D10) and nucleus dorsalis hypothalami (D11) were labelled by one or more of the anti-opsin antibodies. In addition, anti-arrestin antibodies labelled cells within the D8 and anti-alpha-transducin antibodies labelled cells within the pineal complex and hypothalamus (primarily D8 and/or D10). A more variable and species dependent pattern of opsin, arrestin and alpha-transducin labelling was observed within the nucleus commissurae postinfundibularis (D12) in an area comprising the nucleus dorsalis thalami pars subhabenularis (D4sh) and nucleus dorsalis thalami pars caudalis/nucleus commissurae posterioris (D4c/M1), and in the proximity of the second Mller cells in the ventrocaudal diencephalon (2.MZ/M6). The majority of the neurons labelled within the pineal and parapineal organs and hypothalamus were periventricular with clear cerebrospinal fluid contacts (CSF-contacting neurons). Labelled neurons in the epithalamic (D4sh and D4c/M1) and caudal diencephalon (2.MZ/M6) had no obvious ventricular contacts. We speculate that the "primitive" vertebrate brain of lampreys represents an ancestral condition in which different populations of encephalic photoreceptors are associated with different behavioural and physiological responses. Image-forming vision needs an eye, but irradiance detection does not require a specialised organ. Rather the photoreceptors could be closely associated with their effector systems within the brain. PMID:9082962

  5. NIGHT BLINDNESS AND THE MECHANISM OF CONSTITUTIVE SIGNALING OF MUTANT G90D RHODOPSIN

    PubMed Central

    Dizhoor, Alexander M.; Woodruff, Michael L.; Olshevskaya, Elena V.; Cilluffo, Marianne C.; Cornwall, M. Carter; Sieving, Paul A.; Fain, Gordon L.

    2008-01-01

    The G90D rhodopsin mutation is known to produce congenital night blindness in humans. This mutation produces a similar condition in mice, since rods of animals heterozygous (D+) or homozygous (D+/+) for this mutation have decreased dark current and sensitivity, reduced Ca2+, and accelerated values of ?REC and ?D, similar to light-adapted WT rods. Our experiments indicate that G90D pigment activates the cascade, producing an equivalent background light of about 130 Rh* rod?1 for D+ and 890 Rh* rod?1 for D+/+. The active species of the G90D pigment could be unregenerated G90D opsin or G90D rhodopsin, either spontaneously activated (as Rh*) or in some other form. Addition of 11-cis retinal in lipid vesicles, which produces regeneration of both WT and G90D opsin in intact rods and ROS membranes, had no effect on the waveform or sensitivity of dark-adapted G90D responses, indicating that the active species is not G90D opsin. The noise spectrum of a dark-adapted G90D and WT rods are similar, and the G90D noise variance is much less than of a WT rod exposed to background light of about the same intensity as the G90D equivalent light, indicating that Rh* is not the active species. We hypothesize that G90D rhodopsin undergoes spontaneous changes in molecular conformation which activate the transduction cascade with low gain. Our experiments provide the first indication that a mutant form of the rhodopsin molecule bound to its 11-cis chromophore can stimulate the visual cascade spontaneously at a rate large enough to produce visual dysfunction. PMID:18987202

  6. Immuno-histochemical analysis of rod and cone reaction to RPE65 deficiency in the inferior and superior canine retina.

    PubMed

    Klein, Daniela; Mendes-Madeira, Alexandra; Schlegel, Patrice; Rolling, Fabienne; Lorenz, Birgit; Haverkamp, Silke; Stieger, Knut

    2014-01-01

    Mutations in the RPE65 gene are associated with autosomal recessive early onset severe retinal dystrophy. Morphological and functional studies indicate early and dramatic loss of rod photoreceptors and early loss of S-cone function, while L and M cones remain initially functional. The Swedish Briard dog is a naturally occurring animal model for this disease. Detailed information about rod and cone reaction to RPE65 deficiency in this model with regard to their location within the retina remains limited. The aim of this study was to analyze morphological parameters of cone and rod viability in young adult RPE65 deficient dogs in different parts of the retina in order to shed light on local disparities in this disease. In retinae of affected dogs, sprouting of rod bipolar cell dendrites and horizontal cell processes was dramatically increased in the inferior peripheral part of affected retinae, while central inferior and both superior parts did not display significantly increased sprouting. This observation was correlated with photoreceptor cell layer thickness. Interestingly, while L/M cone opsin expression was uniformly reduced both in the superior and inferior part of the retina, S-cone opsin expression loss was less severe in the inferior part of the retina. In summary, in retinae of young adult RPE65 deficient dogs, the degree of rod bipolar and horizontal cell sprouting as well as of S-cone opsin expression depends on the location. As the human retinal pigment epithelium (RPE) is pigmented similar to the RPE in the inferior part of the canine retina, and the kinetics of photoreceptor degeneration in humans seems to be similar to what has been observed in the inferior peripheral retina in dogs, this area should be studied in future gene therapy experiments in this model. PMID:24466015

  7. Retinal photoreceptors of two subterranean tuco-tuco species (Rodentia, Ctenomys): morphology, topography, and spectral sensitivity.

    PubMed

    Schleich, Cristian E; Vielma, Alex; Glsmann, Martin; Palacios, Adrian G; Peichl, Leo

    2010-10-01

    Traditionally, vision was thought to be useless for animals living in dark underground habitats, but recent studies in a range of subterranean rodent species have shown a large diversity of eye features, from small subcutaneous eyes to normal-sized functional eyes. We analyzed the retinal photoreceptors in the subterranean hystricomorph rodents Ctenomys talarum and Ctenomys magellanicus to elucidate whether adaptation was to their near-lightless burrows or rather to their occasional diurnal surface activity. Both species had normally developed eyes. Overall photoreceptor densities were comparatively low (95,000-150,000/mm(2) in C. magellanicus, 110,000-200,000/mm(2) in C. talarum), and cone proportions were rather high (10-31% and 14-31%, respectively). The majority of cones expressed the middle-to-longwave-sensitive (L) opsin, and a 6-16% minority expressed the shortwave-sensitive (S) opsin. In both species the densities of L and S cones were higher in ventral than in dorsal retina. In both species the tuning-relevant amino acids of the S opsin indicate sensitivity in the near UV rather than the blue/violet range. Photopic spectral electroretinograms were recorded. Unexpectedly, their sensitivity profiles were best fitted by the linear summation of three visual pigment templates with lambda(max) at 370 nm (S pigment, UV), at 510 nm (L pigment), and at 450 nm (an as-yet unexplained mechanism). Avoiding predators and selecting food during the brief aboveground excursions may have exerted pressure to retain robust cone-based vision in Ctenomys. UV tuning of the S cone pigment is shared with a number of other hystricomorphs. PMID:20737597

  8. Considering the Influence of Nonadaptive Evolution on Primate Color Vision

    PubMed Central

    Jacobs, Rachel L.; Bradley, Brenda J.

    2016-01-01

    Color vision in primates is variable across species, and it represents a rare trait in which the genetic mechanisms underlying phenotypic variation are fairly well-understood. Research on primate color vision has largely focused on adaptive explanations for observed variation, but it remains unclear why some species have trichromatic or polymorphic color vision while others are red-green color blind. Lemurs, in particular, are highly variable. While some species are polymorphic, many closely-related species are strictly dichromatic. We provide the first characterization of color vision in a wild population of red-bellied lemurs (Eulemur rubriventer, Ranomafana National Park, Madagascar) with a sample size (87 individuals; NX chromosomes = 134) large enough to detect even rare variants (0.95 probability of detection at ≥ 3% frequency). By sequencing exon 5 of the X-linked opsin gene we identified opsin spectral sensitivity based on known diagnostic sites and found this population to be dichromatic and monomorphic for a long wavelength allele. Apparent fixation of this long allele is in contrast to previously published accounts of Eulemur species, which exhibit either polymorphic color vision or only the medium wavelength opsin. This unexpected result may represent loss of color vision variation, which could occur through selective processes and/or genetic drift (e.g., genetic bottleneck). To indirectly assess the latter scenario, we genotyped 55 adult red-bellied lemurs at seven variable microsatellite loci and used heterozygosity excess and M-ratio tests to assess if this population may have experienced a recent genetic bottleneck. Results of heterozygosity excess but not M-ratio tests suggest a bottleneck might have occurred in this red-bellied lemur population. Therefore, while selection may also play a role, the unique color vision observed in this population might have been influenced by a recent genetic bottleneck. These results emphasize the need to consider adaptive and nonadaptive mechanisms of color vision evolution in primates. PMID:26959829

  9. The phylogenetic distribution of ultraviolet sensitivity in birds

    PubMed Central

    2013-01-01

    Background Colour vision in birds can be categorized into two classes, the ultraviolet (UVS) and violet sensitive (VS). Their phylogenetic distributions have traditionally been regarded as highly conserved. However, the complicated nature of acquiring spectral sensitivities from cone photoreceptors meant that until recently, only a few species had actually been studied. Whether birds are UVS or VS can nowadays be inferred from a wide range of species via genomic sequencing of the UV/violet SWS1 cone opsin gene. Results We present genomic sequencing results of the SWS1 gene from 21 avian orders. Amino acid residues signifying UV sensitivity are found in the two most important spectral tuning sites 86 and 90 of Pteroclidiformes and Coraciiformes, in addition to the major clades, Palaeognathae, Charadriiformes, Trogoniformes, Psittaciformes and Passeriformes, where they where previously known to occur. We confirm that the presumed UVS-conferring amino acid combination F86, C90 and M93 is common to Palaeognathae and unique to this clade, despite available spectrometric evidence showing the ostrich retina to be VS. Conclusions By mapping our results together with data from previous studies on a molecular phylogeny we show that avian colour vision shifted between VS and UVS at least 14 times. Single nucleotide substitutions can explain all these shifts. The common ancestor of birds most likely had a VS phenotype. However, the ancestral state of the avian SWS1 opsins spectral tuning sites cannot be resolved, since the Palaeognathae are F86, C90 while the Neognathae are ancestrally S86, S90. The phylogenetic distribution of UVS and VS colour vision in birds is so complex that inferences of spectral sensitivities from closely related taxa should be used with caution. PMID:23394614

  10. Immuno-Histochemical Analysis of Rod and Cone Reaction to RPE65 Deficiency in the Inferior and Superior Canine Retina

    PubMed Central

    Klein, Daniela; Mendes-Madeira, Alexandra; Schlegel, Patrice; Rolling, Fabienne; Lorenz, Birgit; Haverkamp, Silke; Stieger, Knut

    2014-01-01

    Mutations in the RPE65 gene are associated with autosomal recessive early onset severe retinal dystrophy. Morphological and functional studies indicate early and dramatic loss of rod photoreceptors and early loss of S-cone function, while L and M cones remain initially functional. The Swedish Briard dog is a naturally occurring animal model for this disease. Detailed information about rod and cone reaction to RPE65 deficiency in this model with regard to their location within the retina remains limited. The aim of this study was to analyze morphological parameters of cone and rod viability in young adult RPE65 deficient dogs in different parts of the retina in order to shed light on local disparities in this disease. In retinae of affected dogs, sprouting of rod bipolar cell dendrites and horizontal cell processes was dramatically increased in the inferior peripheral part of affected retinae, while central inferior and both superior parts did not display significantly increased sprouting. This observation was correlated with photoreceptor cell layer thickness. Interestingly, while L/M cone opsin expression was uniformly reduced both in the superior and inferior part of the retina, S-cone opsin expression loss was less severe in the inferior part of the retina. In summary, in retinae of young adult RPE65 deficient dogs, the degree of rod bipolar and horizontal cell sprouting as well as of S-cone opsin expression depends on the location. As the human retinal pigment epithelium (RPE) is pigmented similar to the RPE in the inferior part of the canine retina, and the kinetics of photoreceptor degeneration in humans seems to be similar to what has been observed in the inferior peripheral retina in dogs, this area should be studied in future gene therapy experiments in this model. PMID:24466015

  11. On the origins of arrestin and rhodopsin

    PubMed Central

    2008-01-01

    Background G protein coupled receptors (GPCRs) are the most numerous proteins in mammalian genomes, and the most common targets of clinical drugs. However, their evolution remains enigmatic. GPCRs are intimately associated with trimeric G proteins, G protein receptor kinases, and arrestins. We conducted phylogenetic studies to reconstruct the history of arrestins. Those findings, in turn, led us to investigate the origin of the photosensory GPCR rhodopsin. Results We found that the arrestin clan is comprised of the Spo0M protein family in archaea and bacteria, and the arrestin and Vps26 families in eukaryotes. The previously known animal arrestins are members of the visual/beta subfamily, which branched from the founding "alpha" arrestins relatively recently. Curiously, we identified both the oldest visual/beta arrestin and opsin genes in Cnidaria (but not in sponges). The arrestin clan has 14 human members: 6 alphas, 4 visual/betas, and 4 Vps26 genes. Others recently showed that the 3D structure of mammalian Vps26 and the biochemical function of the yeast alpha arrestin PalF are similar to those of beta arrestins. We note that only alpha arrestins have PY motifs (known to bind WW domains) in their C-terminal tails, and only visual/betas have helix I in the Arrestin N domain. Conclusion We identified ciliary opsins in Cnidaria and propose this subfamily is ancestral to all previously known animal opsins. That finding is consistent with Darwin's theory that eyes evolved once, and lends some support to Parker's hypothesis that vision triggered the Cambrian explosion of life forms. Our arrestin findings have implications on the evolution of GPCR signaling, and on the biological roles of human alpha arrestins. PMID:18664266

  12. Superior temporal resolution of Chronos versus channelrhodopsin-2 in an optogenetic model of the auditory brainstem implant.

    PubMed

    Hight, Ariel Edward; Kozin, Elliott D; Darrow, Keith; Lehmann, Ashton; Boyden, Edward; Brown, M Christian; Lee, Daniel J

    2015-04-01

    Contemporary auditory brainstem implant (ABI) performance is limited by reliance on electrical neurostimulation with its accompanying channel cross talk and current spread to non-auditory neurons. A new generation ABI based on optogenetic technology may ameliorate limitations fundamental to electrical stimulation. The most widely studied opsin is channelrhodopsin-2 (ChR2); however, its relatively slow kinetic properties may prevent the encoding of auditory information at high stimulation rates. In the present study, we compare the temporal resolution of light-evoked responses of ChR2 to a recently developed fast opsin, Chronos, to ChR2 in a murine ABI model. Viral mediated gene transfer via a posterolateral craniotomy was used to express Chronos or ChR2 in the cochlear nucleus (CN). Following a four to eight week incubation period, blue light (473nm) was delivered via an optical fiber placed directly on the surface of the infected CN, and neural activity was recorded in the contralateral inferior colliculus (IC). Both ChR2 and Chronos evoked sustained responses to all stimuli, even at high pulse rates. In addition, optical stimulation evoked excitatory responses throughout the tonotopic axis of the IC. Synchrony of the light-evoked response to stimulus rates of 14-448pulses/s was higher in Chronos compared to ChR2 mice (p<0.05 at 56, 168, and 224pulses/s). Our results demonstrate that Chronos has the ability to drive the auditory system at higher stimulation rates than ChR2 and may be a more ideal opsin for manipulation of auditory pathways in future optogenetic-based neuroprostheses. This article is part of a Special Issue entitled "Lasker Award". PMID:25598479

  13. Light Responses in Rods of Vitamin ADeprived Xenopus

    PubMed Central

    Solessio, Eduardo; Umino, Yumiko; Cameron, David A.; Loew, Ellis; Engbretson, Gustav A.; Knox, Barry E.; Barlow, Robert B.

    2009-01-01

    Purpose Accumulation of free opsin by mutations in rhodopsin or insufficiencies in the visual cycle can lead to retinal degeneration. Free opsin activates phototransduction; however, the link between constitutive activation and retinal degeneration is unclear. In this study, the photoresponses of Xenopus rods rendered constitutively active by vitamin A deprivation were examined. Unlike their mammalian counterparts, Xenopus rods do not degenerate. Contrasting phototransduction in vitamin Adeprived Xenopus rods with phototransduction in constitutively active mammalian rods may provide new understanding of the mechanisms that lead to retinal degeneration. Methods The photocurrents of Xenopus tadpole rods were measured with suction electrode recordings, and guanylate cyclase activity was measured with the IBMX (3-isobutyl-1-methylxanthine) jump technique. The amount of rhodopsin in rods was determined by microspectrophotometry. Results The vitamin Adeprived rod outer segments were 60% to 70% the length and diameter of the rods in age-matched animals. Approximately 90% of its opsin content was in the free or unbound form. Analogous to bleaching adaptation, the photoresponses were desensitized (10- to 20-fold) and faster. Unlike bleaching adaptation, the vitamin Adeprived rods maintained near normal saturating (dark) current densities by developing abnormally high rates of cGMP synthesis. Their rate of cGMP synthesis in the dark (15 seconds?1) was twofold greater than the maximum levels attainable by control rods (~7 seconds?1). Conclusions Preserving circulating current density and response range appears to be an important goal for rod homeostasis. However, the compensatory changes associated with vitamin A deprivation in Xenopus rods come at the high metabolic cost of a 15-fold increase in basal ATP consumption. PMID:19407019

  14. Considering the Influence of Nonadaptive Evolution on Primate Color Vision.

    PubMed

    Jacobs, Rachel L; Bradley, Brenda J

    2016-01-01

    Color vision in primates is variable across species, and it represents a rare trait in which the genetic mechanisms underlying phenotypic variation are fairly well-understood. Research on primate color vision has largely focused on adaptive explanations for observed variation, but it remains unclear why some species have trichromatic or polymorphic color vision while others are red-green color blind. Lemurs, in particular, are highly variable. While some species are polymorphic, many closely-related species are strictly dichromatic. We provide the first characterization of color vision in a wild population of red-bellied lemurs (Eulemur rubriventer, Ranomafana National Park, Madagascar) with a sample size (87 individuals; NX chromosomes = 134) large enough to detect even rare variants (0.95 probability of detection at ? 3% frequency). By sequencing exon 5 of the X-linked opsin gene we identified opsin spectral sensitivity based on known diagnostic sites and found this population to be dichromatic and monomorphic for a long wavelength allele. Apparent fixation of this long allele is in contrast to previously published accounts of Eulemur species, which exhibit either polymorphic color vision or only the medium wavelength opsin. This unexpected result may represent loss of color vision variation, which could occur through selective processes and/or genetic drift (e.g., genetic bottleneck). To indirectly assess the latter scenario, we genotyped 55 adult red-bellied lemurs at seven variable microsatellite loci and used heterozygosity excess and M-ratio tests to assess if this population may have experienced a recent genetic bottleneck. Results of heterozygosity excess but not M-ratio tests suggest a bottleneck might have occurred in this red-bellied lemur population. Therefore, while selection may also play a role, the unique color vision observed in this population might have been influenced by a recent genetic bottleneck. These results emphasize the need to consider adaptive and nonadaptive mechanisms of color vision evolution in primates. PMID:26959829

  15. From Blue Light to Clock Genes in Zebrafish ZEM-2S Cells

    PubMed Central

    Ramos, Bruno C. R.; Moraes, Maria Nathália C. M.; Poletini, Maristela O.; Lima, Leonardo H. R. G.; Castrucci, Ana Maria L.

    2014-01-01

    Melanopsin has been implicated in the mammalian photoentrainment by blue light. This photopigment, which maximally absorbs light at wavelengths between 470 and 480 nm depending on the species, is found in the retina of all classes of vertebrates so far studied. In mammals, melanopsin activation triggers a signaling pathway which resets the circadian clock in the suprachiasmatic nucleus (SCN). Unlike mammals, Drosophila melanogaster and Danio rerio do not rely only on their eyes to perceive light, in fact their whole body may be capable of detecting light and entraining their circadian clock. Melanopsin, teleost multiple tissue (tmt) opsin and others such as neuropsin and va-opsin, are found in the peripheral tissues of Danio rerio, however, there are limited data concerning the photopigment/s or the signaling pathway/s directly involved in light detection. Here, we demonstrate that melanopsin is a strong candidate to mediate synchronization of zebrafish cells. The deduced amino acid sequence of melanopsin, although being a vertebrate opsin, is more similar to invertebrate than vertebrate photopigments, and melanopsin photostimulation triggers the phosphoinositide pathway through activation of a Gq/11-type G protein. We stimulated cultured ZEM-2S cells with blue light at wavelengths consistent with melanopsin maximal absorption, and evaluated the time course expression of per1b, cry1b, per2 and cry1a. Using quantitative PCR, we showed that blue light is capable of slightly modulating per1b and cry1b genes, and drastically increasing per2 and cry1a expression. Pharmacological assays indicated that per2 and cry1a responses to blue light are evoked through the activation of the phosphoinositide pathway, which crosstalks with nitric oxide (NO) and mitogen activated protein MAP kinase (MAPK) to activate the clock genes. Our results suggest that melanopsin may be important in mediating the photoresponse in Danio rerio ZEM-2S cells, and provide new insights about the modulation of clock genes in peripheral clocks. PMID:25184495

  16. Stable transgenesis in the marine annelid Platynereis dumerilii sheds new light on photoreceptor evolution

    PubMed Central

    Backfisch, Benjamin; Veedin Rajan, Vinoth Babu; Fischer, Ruth M.; Lohs, Claudia; Arboleda, Enrique; Tessmar-Raible, Kristin; Raible, Florian

    2013-01-01

    Research in eye evolution has mostly focused on eyes residing in the head. In contrast, noncephalic light sensors are far less understood and rather regarded as evolutionary innovations. We established stable transgenesis in the annelid Platynereis, a reference species for evolutionary and developmental comparisons. EGFP controlled by cis-regulatory elements of r-opsin, a characteristic marker for rhabdomeric photoreceptors, faithfully recapitulates known r-opsin expression in the adult eyes, and marks a pair of pigment-associated frontolateral eyelets in the brain. Unexpectedly, transgenic animals revealed an additional series of photoreceptors in the ventral nerve cord as well as photoreceptors that are located in each pair of the segmental dorsal appendages (notopodia) and project into the ventral nerve cord. Consistent with a photosensory function of these noncephalic cells, decapitated animals display a clear photoavoidance response. Molecular analysis of the receptors suggests that they differentiate independent of pax6, a gene involved in early eye development of many metazoans, and that the ventral cells may share origins with the Hesse organs in the amphioxus neural tube. Finally, expression analysis of opn4×-2 and opn4m-2, two zebrafish orthologs of Platynereis r-opsin, reveals that these genes share expression in the neuromasts, known mechanoreceptors of the lateral line peripheral nervous system. Together, this establishes that noncephalic photoreceptors are more widespread than assumed, and may even reflect more ancient aspects of sensory systems. Our study marks significant advance for the understanding of photoreceptor cell (PRC) evolution and development and for Platynereis as a functional lophotrochozoan model system. PMID:23284166

  17. Power analysis of tests for loss of selective constraint in cave crayfish and nonphotosynthetic plant lineages.

    PubMed

    Leebens-Mack, Jim; DePamphilis, Claude

    2002-08-01

    Loss of selective constraint on a gene may be expected following changes in the environment or life history that render its function unnecessary. The long-term persistence of protein-coding genes after the loss of known functional necessity can occur by chance or because of selective maintenance of an unknown gene function. The selective maintenance of an alternative gene function is not demonstrated by the failure of statistical tests to reject the hypothesis that there has been no change in the degree of constraint on the evolution of coding genes. Maintenance may be inferred, however, when power analyses of such tests demonstrate that there has been a sufficient number of nucleotide substitutions to detect the loss of selective constraint. Here, we describe a power analysis for tests of loss of constraint on protein-coding genes. The power analysis was applied to loss-of-constraint tests for opsin gene evolution in cave-dwelling crayfish and rbcL evolution in nonphotosynthetic parasitic plants. The power of previously applied tests for loss of constraint on cave crayfish opsin genes was insufficient to distinguish between chance retention and selective maintenance of opsin genes. However, the power of codon-based likelihood ratio tests for change in d(N)/d(S) (=omega) (nonsynonymous to synonymous change) did have sufficient power to detect a loss of constraint on rbcL associated with a loss of photosynthesis in most examples but failed to detect such a change in three independent lineages. We conclude that rbcL has been selectively maintained in these holoparasitic plant lineages. This conclusion suggests that either these taxa are photosynthetic for at least a part of their life or rbcL may have an unknown function in these plants unrelated to photosynthesis. PMID:12140241

  18. Quantum mechanical/molecular mechanical structure, enantioselectivity, and spectroscopy of hydroxyretinals and insights into the evolution of color vision in small white butterflies.

    PubMed

    Sekharan, Sivakumar; Yokoyama, Shozo; Morokuma, Keiji

    2011-12-29

    Since Vogt's discovery of A(3)-retinal or 3-hydroxyretinal in insects in 1983 and Matsui's discovery of A(4)-retinal or 4-hydroxyretinal in firefly squid in 1988, hydroxyretinal-protein interactions mediating vision have remained largely unexplored. In the present study, A(3)- and A(4)-retinals are theoretically incorporated into squid and bovine visual pigments by use of the hybrid quantum mechanics/molecular mechanics [SORCI+Q//B3LYP/6-31G(d):Amber96] method, and insights into structure, enantioselectivity, and spectroscopy are gathered and presented for the first time. Contrary to general perception, our findings rule out the formation of a hydrogen bond between the hydroxyl-bearing β-ionone ring portion of retinal and opsin. Compared to A(1)-pigments, A(3)- and A(4)-pigments exhibit slightly blue-shifted absorption maxima due to increase in bond-length alternation of the hydroxyretinal. We suggest that (i) the binding site of firefly squid (Watasenia scintillans) opsin is very similar to that of the Japanese common squid (Todarodes pacificus) opsin; (ii) the molecular mechanism of spectral tuning in small white butterflies involve sites S116 and T185 and breaking of a hydrogen bond between sites E180 and T185; and finally (iii) A(3)-retinal may have occurred during the conversion of A(1)- to A(2)-retinal and insects may have acquired them, in order to absorb light in the blue-green wavelength region and to speed up the G-protein signaling cascade. PMID:22087641

  19. Hot-electron generation by ``cavitating'' Langmuir turbulence in the nonlinear stage of the two-plasmon-decay instability

    NASA Astrophysics Data System (ADS)

    Vu, H. X.; DuBois, D. F.; Russell, D. A.; Myatt, J. F.

    2012-10-01

    The kinetic reduced-description particle-in-cell simulation technique has been applied to study the nonlinear stage of two-plasmon-decay (TPD) instability in an inhomogeneous plasma driven by crossed laser beams. The TPD instability is found to be a prolific generator of "cavitating" Langmuir turbulence. Langmuir "cavitons"—localized longitudinal electric fields, oscillating near the local electron plasma frequency, trapped in ponderomotive density depressions—collapse to dimensions of a few electron Debye lengths, where the electric field energy is collisionlessly transferred to electron kinetic energy. The resulting hot electrons can attain instantaneous temperatures up to 100 keV with net suprathermal heat flux out of the system of up to a few percent of the input laser energy. Scaling laws for this hot-electron generation by TPD, in regimes motivated by recent experiments on the Omega laser, were presented recently by Vu et al. (H. X. Vu, D. F. DuBois, D. A. Russell, and J. F. Myatt, Phys. Plasmas 19, 102703 (2012)). This paper concentrates on the microscopic mechanisms for hot-electron generation. The spatial distribution of the maxima of the electric field envelope modulus is found to be very spiky, with the distribution of electric field envelope maxima obeying Gaussian statistics. The cavitons are produced in density-depletion trenches produced by the combined ponderomotive interference of the crossed laser beams and the ponderomotive beats of the primary backward-going TPD Langmuir waves (LWs) resulting from the crossed beams. The Langmuir turbulence is strongest in the electron-density region near 0.241× the laser's critical density, where the forward LWs from the crossed-beam TPD are degenerate. Nucleation of cavitons is assisted by the modulation of the electron density in the trenches, which in turn is caused by the beating of the common forward-going LW and the pair of backward-going LWs. The autocorrelation function of the LW envelope field provides a near-universal shape for intense cavitons—in the neighborhood of the local field maxima. The hot-electron temperature is found to be approximately a linear function of the "caviton temperature" determined from the Gaussian distribution of caviton maxima. These diagnostics provide strong evidence for the importance of Langmuir caviton collapse in the generation of hot electrons by TPD. Extended Zakharov model predictions for TPD exhibit the same qualitative phenomena.

  20. Microspectrophotometry of visual pigments and oil droplets in a marine bird, the wedge-tailed shearwater Puffinus pacificus: topographic variations in photoreceptor spectral characteristics.

    PubMed

    Hart, Nathan S

    2004-03-01

    Microspectrophotometric examination of the retina of a procellariiform marine bird, the wedge-tailed shearwater Puffinus pacificus, revealed the presence of five different types of vitamin A(1)-based visual pigment in seven different types of photoreceptor. A single class of rod contained a medium-wavelength sensitive visual pigment with a wavelength of maximum absorbance (lambda(max)) at 502 nm. Four different types of single cone contained visual pigments maximally sensitive in either the violet (VS, lambda(max) 406 nm), short (SWS, lambda(max) 450 nm), medium (MWS, lambda(max) 503 nm) or long (LWS, lambda(max) 566 nm) spectral ranges. In the peripheral retina, the SWS, MWS and LWS single cones contained pigmented oil droplets in their inner segments with cut-off wavelengths (lambda(cut)) at 445 (C-type), 506 (Y-type) and 562 nm (R-type), respectively. The VS visual pigment was paired with a transparent (T-type) oil droplet that displayed no significant absorption above at least 370 nm. Both the principal and accessory members of the double cone pair contained the same 566 nm lambda(max) visual pigment as the LWS single cones but only the principal member contained an oil droplet, which had a lambda(cut) at 413 nm. The retina had a horizontal band or 'visual streak' of increased photoreceptor density running across the retina approximately 1.5 mm dorsal to the top of the pecten. Cones in the centre of the horizontal streak were smaller and had oil droplets that were either transparent/colourless or much less pigmented than at the periphery. It is proposed that the reduction in cone oil droplet pigmentation in retinal areas associated with high visual acuity is an adaptation to compensate for the reduced photon capture ability of the narrower photoreceptors found there. Measurements of the spectral transmittance of the ocular media reveal that wavelengths down to at least 300 nm would be transmitted to the retina. PMID:14978063

  1. Hydrogen exchange study of membrane-bound rhodopsin. II. Light-induced protein structure change.

    PubMed

    Downer, N W; Englander, S W

    1977-11-25

    Hydrogen exchange studies of rhodopsin in disc membranes demonstrated that photolysis induces changes in the protein itself. Two different altered forms were detected. A late photointermediate in the bleaching sequence, which can be identified with metarhodopsin II, displays accelerated exchange. Subsequently, at the stage of fully bleached opsin, exchange becomes even slower than in rhodopsin. These changes involve only a small fraction of the protein's internally hydrogen-bonded peptide groups. The unusually large fraction of exposed peptide hydrogens observed previously for rhodopsin is unaltered in the photolyzed forms. PMID:21190

  2. Optobionic vision--a new genetically enhanced light on retinal prosthesis.

    PubMed

    Degenaar, Patrick; Grossman, Nir; Memon, Muhammad Ali; Burrone, Juan; Dawson, Martin; Drakakis, Emmanuel; Neil, Mark; Nikolic, Konstantin

    2009-06-01

    The recent discovery that neurons can be photostimulated via genetic incorporation of artificial opsins is creating a revolution in the field of neural stimulation. In this paper we show its potential in the field of retinal prosthesis. We show that we need typically 100 mW cm(-2) in instantaneous light intensity on the neuron in order to stimulate action potentials. We also show how this can be reduced down to safe levels in order to negate thermal and photochromic damage to the eye. We also describe a gallium nitride LED light source which is also able to generate patterns of the required intensity in order to transfer reliable images. PMID:19458396

  3. Evidence for light perception in a bioluminescent organ

    PubMed Central

    Tong, Deyan; Rozas, Natalia S.; Oakley, Todd H.; Mitchell, Jane; Colley, Nansi J.; McFall-Ngai, Margaret J.

    2009-01-01

    Here we show that bioluminescent organs of the squid Euprymna scolopes possess the molecular, biochemical, and physiological capability for light detection. Transcriptome analyses revealed expression of genes encoding key visual transduction proteins in light-organ tissues, including the same isoform of opsin that occurs in the retina. Electroretinograms demonstrated that the organ responds physiologically to light, and immunocytochemistry experiments localized multiple proteins of visual transduction cascades to tissues housing light-producing bacterial symbionts. These data provide evidence that the light-organ tissues harboring the symbionts serve as extraocular photoreceptors, with the potential to perceive directly the bioluminescence produced by their bacterial partners. PMID:19509343

  4. The ecoresponsive genome of Daphnia pulex

    SciTech Connect

    Colbourne, John K.; Pfrender, Michael E.; Gilbert, Donald; Thomas, W. Kelley; Tucker, Abraham; Oakley, Todd H.; Tokishita, Shinichi; Aerts, Andrea; Arnold, Georg J.; Basu, Malay Kumar; Bauer, Darren J.; Caceres, Carla E.; Carmel, Liran; Casola, Claudio; Choi, Jeong-Hyeon; Detter, John C.; Dong, Qunfeng; Dusheyko, Serge; Eads, Brian D.; Frohlich, Thomas; Geiler-Samerotte, Kerry A.; Gerlach, Daniel; Hatcher, Phil; Jogdeo, Sanjuro; Krijgsveld, Jeroen; Kriventseva, Evgenia V; Kültz, Dietmar; Laforsch, Christian; Lindquist, Erika; Lopez, Jacqueline; Manak, Robert; Muller, Jean; Pangilinan, Jasmyn; Patwardhan, Rupali P.; Pitluck, Samuel; Pritham, Ellen J.; Rechtsteiner, Andreas; Rho, Mina; Rogozin, Igor B.; Sakarya, Onur; Salamov, Asaf; Schaack, Sarah; Shapiro, Harris; Shiga, Yasuhiro; Skalitzky, Courtney; Smith, Zachary; Souvorov, Alexander; Sung, Way; Tang, Zuojian; Tsuchiya, Dai; Tu, Hank; Vos, Harmjan; Wang, Mei; Wolf, Yuri I.; Yamagata, Hideo; Yamada, Takuji; Ye, Yuzhen; Shaw, Joseph R.; Andrews, Justen; Crease, Teresa J.; Tang, Haixu; Lucas, Susan M.; Robertson, Hugh M.; Bork, Peer; Koonin, Eugene V.; Zdobnov, Evgeny M.; Grigoriev, Igor V.; Lynch, Michael; Boore, Jeffrey L.

    2011-02-04

    This document provides supporting material related to the sequencing of the ecoresponsive genome of Daphnia pulex. This material includes information on materials and methods and supporting text, as well as supplemental figures, tables, and references. The coverage of materials and methods addresses genome sequence, assembly, and mapping to chromosomes, gene inventory, attributes of a compact genome, the origin and preservation of Daphnia pulex genes, implications of Daphnia's genome structure, evolutionary diversification of duplicated genes, functional significance of expanded gene families, and ecoresponsive genes. Supporting text covers chromosome studies, gene homology among Daphnia genomes, micro-RNA and transposable elements and the 46 Daphnia pulex opsins. 36 figures, 50 tables, 183 references.

  5. Light and the evolution of vision.

    PubMed

    Williams, D L

    2016-02-01

    It might seem a little ridiculous to cover the period over which vision evolved, perhaps 1.5 billion years, in only 3000 words. Yet, if we examine the photoreceptor molecules of the most basic eukaryote protists and even before that, in those of prokaryote bacteria and cyanobacteria, we see how similar they are to those of mammalian rod and cone photoreceptor opsins and the photoreceptive molecules of light sensitive ganglion cells. This shows us much with regard the development of vision once these proteins existed, but there is much more to discover about the evolution of even more primitive vision systems. PMID:26541087

  6. Long wavelength infrared camera (LWIRC): a 10 micron camera for the Keck Telescope

    SciTech Connect

    Wishnow, E.H.; Danchi, W.C.; Tuthill, P.; Wurtz, R.; Jernigan, J.G.; Arens, J.F.

    1998-05-01

    The Long Wavelength Infrared Camera (LWIRC) is a facility instrument for the Keck Observatory designed to operate at the f/25 forward Cassegrain focus of the Keck I telescope. The camera operates over the wavelength band 7-13 {micro}m using ZnSe transmissive optics. A set of filters, a circular variable filter (CVF), and a mid-infrared polarizer are available, as are three plate scales: 0.05``, 0.10``, 0.21`` per pixel. The camera focal plane array and optics are cooled using liquid helium. The system has been refurbished with a 128 x 128 pixel Si:As detector array. The electronics readout system used to clock the array is compatible with both the hardware and software of the other Keck infrared instruments NIRC and LWS. A new pre-amplifier/A-D converter has been designed and constructed which decreases greatly the system susceptibility to noise.

  7. The role of the living with a star program in enhancing the capbility of the space intrastructure

    NASA Astrophysics Data System (ADS)

    Barth, J.; Brewer, D.; Label, K.

    The increased reliance of society on space infrastructure has heightened the need for scientific understanding of the natural space environment, its solar induced variability (i.e., space weather), and the response of technological systems exposed to the space environment. Our capability in space is enhanced by the insertion of enabling technologies into systems. Due the trend to use technologies that are not designed for the space environment and the rapid turnover of technology generations, the space environment and its effects pose difficult challenges for designers and operators of space systems. To achieve reliable systems, they must take into account environment interactions with spacecraft systems and instruments. The effects of the interactions include degradation of materials, thermal changes, contamination, excitation, spacecraft glow, charging, communication and navigation errors and dropouts, radiation damage and induced background interference. Most existing models of the space environment and its interactions with spacecraft and instruments are inaccurate and are not designed to meet current requirements because our scientific understanding of these phenomena has not kept pace with technology changes. Ideally, the accommodation of space environment effects is accomplished in the design phase of system development. However, in an increasing number of cases, the effects can be minimized but not completely eliminated, and the mission must assume a level of risk. Risk is managed by understanding space environment variations and by developing "space weather" guidelines that are used during the operation of the spacecraft to prevent deleterious effects. Also, spacecraft can perform unexpectedly during operations, i.e., experience an "anomaly". The anomaly must be resolved so that appropriate changes can be made to operational guidelines. Whether in the design, anomaly resolution, or operational phase of a mission, accurate information about the space environment and effects is needed, and each type of environment effect, system impact, and mission phase has unique requirements. Traditional science research programs are not designed to provide space environment data and models that meet requirements imposed by the need for increased capability in our space infrastructure. Also, opportunities to investigate the interaction of the space environment with spacecraft and instrument components are extremely limited. The lack of low cost access to space for research on understanding the mechanisms of environment damage, degradation, and interference severely hampers our ability to utilize enabling technologies in space systems. The NASA Living with a Star (LWS) Program offers a unique opportunity to achieve seamless transition of scientific understanding to applications. (The LWS Program will be discussed in detail in the Joint COSPAR/IAC Session EO.3.) The role of the Space Environment Testbed (SET) element of the LWS Program is to define the response of spacecraft and instrument components to the space environment thereby providing understanding of the mechanisms of degradation, damage, and interference on enabling technologies and validating space weather models. The final paper and presentation will describe technology issues that drive requirements for space environment models and will describe the role of the LWS/SET in understanding and mitigating space environment effects.

  8. The Solar Dynamics Observatory and Its Contributions to Space Weather

    NASA Technical Reports Server (NTRS)

    Chamberlin, Phillip C.

    2011-01-01

    The Solar Dynamics Observatory (SDO) was launched on 11 February 2010 and has worked flawlessly in its first year and a half of operation. SDO was the first mission launched for NASA's Living With a Star Program (LWS), so its focus is not only studying the causes and drivers of the variable Sun, but also how these variations force similar changes in the Earth and other objects within the Heliosphere. Due to SDO's many Space Weather goals, this presentation will not only show some of the recent, ground-breaking new results provided by SDO, but also focus on the real-time Space Weather advances provided by this spacecraft. A main theme throughout this talk will be methods and tools that researchers around the world can utilize to access and manipulate the SDO data real-time for both fundamental science and Space Weather monitoring purposes.

  9. Progress Towards the Solar Dynamics Observatory

    NASA Astrophysics Data System (ADS)

    Thompson, B.; Schwer, K.

    The Solar Dynamics Observatory, or SDO, is scheduled to be the first mission to launch in 2007 under the new Living With a Star (LWS) program. It builds on the success of SOHO and other recent solar missions, but will observe the Sun at greater resolution and faster time cadence with a set of remote sensing instruments generating data in excess of 100 Mbps. The Science Definition Team produced a report consisting of a series of science objectives and a baseline instrument complement. Instrument proposals were due in April 2002, with selection to occur in the late summer of 2002. The spacecraft is being built at NASA Goddard Spacecraft Center by a team of engineers which are currently undergoing the formulation process. The presentation will discuss the current status of the science investigation selection and the spacecraft formulation.

  10. Inner Heliospheric Sentinels Spacecraft Concept

    NASA Astrophysics Data System (ADS)

    Conde, R. F.; Potocki, K. A.; Szabo, A.; Kirby, K. W.; Maldonado, H. M.; Adamsen, P. B.; Bokulic, R. S.; Dakermanji, G.; Dellinger, W. F.; Downing, J. P.; Ercol, C. J.; Folta, D. C.; Fielhauer, K. B.; Kelley, J. S.; Le, B. Q.; Leary, B. A.; Lewis, W. S.; Ling, S. X.; Marr, G.; Malouf, P. M.; Napollilo, D. H.; Persons, D. F.; Troll, J. R.; Wallis, R. E.; Lin, R. P.

    2007-01-01

    The Sentinels mission is a key component of NASA's Living With a Star (LWS) program. The Sentinels Science and Technology Definition Team (STDT) has completed a study to define the science objectives, measurement requirements and observational strategies, and mission design for the Sentinels mission. The Inner Heliospheric Sentinels (IHS) are one of the three flight elements [the others are the Near Earth Sentinel and Far Side Sentinel] that make up the Sentinels mission. The four spin-stabilized IHS spacecraft are in elliptical heliocentric orbit with perihelia at ~0.25 AU and aphelia at ~0.75 AU. This orbit presents unique spacecraft thermal control and power challenges. This study has demonstrated mission feasibility by developing a spacecraft design concept using conventional technologies that satisfies the science and mission requirements defined by the Sentinels STDT.

  11. Solar EUV Variability from FISM and SDO/EVE During Solar Minimum, Active, and Flaring Time Periods

    NASA Technical Reports Server (NTRS)

    Chamberlin, Phillip C.

    2011-01-01

    The Living With a Star (LWS) Focus Science Team has identified three periods of different solar activity levels for which they will be determining the Earth's Ionosphere and Thermosphere response. Not only will the team be comparing individual models (e.g. FLIP, T1MEGCM, GLOW) outcome driven by the various levels of solar activity, but the models themselves will also be compared. These models all rely on the input solar EUV (0.1 -190 nm) irradiance to drive the variability. The Flare Irradiance Spectral Model (FISM) and the EUV Variability Experiment (EVE) onboard provide the Solar Dynamics Observatory (SDO) provide the most accurate quantification of these irradiances. Presented and discussed are how much the solar EUV irradiance changes during these three scenarios, both as a function of activity and wavelength.

  12. Characterizing the Properties of Coronal Magnetic Null Points

    NASA Astrophysics Data System (ADS)

    Barnes, Graham; DeRosa, Marc; Wagner, Eric

    2015-08-01

    The topology of the coronal magnetic field plays a role in a wide range of phenomena, from Coronal Mass Ejections (CMEs) through heating of the corona. One fundamental topological feature is the null point, where the magnetic field vanishes. These points are natural sites of magnetic reconnection, and hence the release of energy stored in the magnetic field. We present preliminary results of a study using data from the Helioseismic and Magnetic Imager aboard NASA's Solar Dynamics Observatory to characterize the properties and evolution of null points in a Potential Field Source Surface model of the coronal field. The main properties considered are the lifetime of the null points, their distribution with height, and how they form and subsequently vanish.This work is supported by NASA/LWS Grant NNX14AD45G, and by NSF/SHINE grant 1357018.

  13. Development of a long wavelength spectrometer for the 24-channel multispectral scanner: Instructions for installation, start-up, and adjustment

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The basic information is presented, which is required for start-up and operation of two long-wavelength focal-plane and cooler assemblies, including the amplifiers and temperature control systems. The focal plane systems, referred to as the long wavelength spectrometer (LWS) were developed for direct replacement of Arrays 3 and 4 into the multispectral scanner presently being operated by the NASA Manned Spacecraft Center Facility, and Laboratory Support Branch. The equipment is comprised of two major sub-assemblies: Array 3 with three indium antimonide detector channels and Array 4 with seven mercury doped Germanium detector channels. Each array is mounted on a cryogenic cooler and includes the vacuum housings, mounting hardware (x, y, z translation and rotation stages) and detector signal conditioning, temperature control and monitoring electronics. The two arrays were designed to operate independently and do not share common equipment (viz power supplies, housings, mounts, etc.).

  14. LWR Pressure Vessel Surveillance Dosimetry Improvement Program. Semiannual progress report, October 1983-March 1984. Volume 1

    SciTech Connect

    Lippincott, E.P.; McElroy, W.N.

    1984-11-01

    Research activities conducted by the Hanford Engineering Development Laboratory, the Oak Ridge National Laboratory, and Rockwell International are reviewed concerning LWR pressure vessel surveillance dosimetry. Topics discussed include: solid-state track recorder fission rate measurements at the PCA; embrittlement of compression specimens irradiated in the SSC-1 and SSC-2 capsules of the PSF experiment; nondestructive determination of reactor pressure vessel neutron exposure; characterization of gamma-ray spectra and energy deposition in LWR pressure vessels; calculated activities and spectral fluences for the PSF two-year irradiation experiment; power distribution calculations for the VENUS PWR mockup; SDMF irradiation experiment; Charpy test results in the ORR-PSF metallurgical irradiation experiment; and application of helium fluence monitors to LWS surveillance.

  15. Preface

    NASA Astrophysics Data System (ADS)

    Kitner, Paul M., Jr.

    In September 2002, the NASA-sponsored Living with a Star Geospace Mission Definition Team (GMDT) issued its report entitled "The LWS Geospace Storm Investigations: Exploring the Extremes of Space Weather." This report identified the mid-latitude ionosphere as a critical component of space weather. Preliminary results from John Foster and Anthea Coster combining TEC measurements from networks of GPS receivers across North America demonstrated for the first time that the response of the mid-latitude ionosphere during magnetic storms was organized. Earlier measurements from scattered sites had identified the positive and negative phases of mid-latitude ionospheric storms, but had not appreciated the organization over continent-size scales. This new model showed promise but it had not yet matured beyond a curiosity.

  16. A Physical Model of the Radiation Belt

    NASA Astrophysics Data System (ADS)

    Fok, M.

    2006-12-01

    A data-driven physical model of the radiation belt has been activated, based on the kinetic model previously developed by Fok and coworkers. This model calculates radiation belt electron fluxes from 10 keV to 4 MeV in the inner magnetosphere. The model takes into account realistic, time-varying magnetic field and considers effects of wave-particle interactions. The only inputs to the model are upstream solar wind and concurrent Dst data. With the real-time solar wind data supplied by NOAA and Dst data from the Kyoto University, the model is running in real time to provide now-casting of the radiation belt environment. In this paper, the model logic and formulation are discussed. The model results for several storm simulations are presented. The paper concludes with discussion of further improvements of the model to better achieve additional LWS goals.

  17. The NIRSPEC Data Reduction Pipeline for the Keck Observatory Archive

    NASA Astrophysics Data System (ADS)

    Tran, Hien D.; Cohen, R.; Mader, J. A.; Colson, A.; Berriman, G. Bruce; Gelino, Christopher R.; KOA Team

    2016-01-01

    The Keck Observatory Archive (KOA), a collaboration between the NASA Exoplanet Science Institute and the W. M. Keck Observatory, serves science and calibration data for all current and retired instruments from the twin Keck Telescopes. In addition to the raw data, we publicly serve quick-look, reduced data products for four instruments (HIRES, LWS, NIRC2 and OSIRIS), so that KOA users can easily assess the quality and scientific content of the data. In this paper we present the design and implementation of the data reduction pipeline (DRP) for the NIRSPEC instrument for use with KOA. We discuss the publicly available reduction packages for NIRSPEC, the challenges encountered when designing this fully automated DRP and the algorithm used to determine wavelength calibration from sky lines. The reduced data products from the NIRSPEC DRP are expected to be available in KOA by mid-2016.

  18. Spatiotemporal chaos and the dynamics of coupled Langmuir and ion-acoustic waves in plasmas.

    PubMed

    Banerjee, S; Misra, A P; Shukla, P K; Rondoni, L

    2010-04-01

    A simulation study is performed to investigate the dynamics of coupled Langmuir waves (LWs) and ion-acoustic waves (IAWs) in an unmagnetized plasma. The effects of dispersion due to charge separation and the density nonlinearity associated with the IAWs are considered to modify the properties of Langmuir solitons, as well as to model the dynamics of relatively large amplitude wave envelopes. It is found that the Langmuir wave electric field, indeed, increases by the effect of ion-wave nonlinearity (IWN). Use of a low-dimensional model, based on three Fourier modes, shows that a transition to temporal chaos is possible, when the length scale of the linearly excited modes is larger than that of the most unstable ones. The chaotic behaviors of the unstable modes are identified by the analysis of Lyapunov exponent spectra. The space-time evolution of the coupled LWs and IAWs shows that the IWN can cause the excitation of many unstable harmonic modes and can lead to strong IAW emission. This occurs when the initial wave field is relatively large or the length scale of IAWs is larger than the soliton characteristic size. Numerical simulation also reveals that many solitary patterns can be excited and generated through the modulational instability of unstable harmonic modes. As time goes on, these solitons are seen to appear in the spatially partial coherence state due to the free ion-acoustic radiation as well as in the state of spatiotemporal chaos due to collision and fusion in the stochastic motion. The latter results in the redistribution of initial wave energy into a few modes with small length scales, which may lead to the onset of Langmuir turbulence in laboratory as well as space plasmas. PMID:20481845

  19. High blood pressure and visual sensitivity

    NASA Astrophysics Data System (ADS)

    Eisner, Alvin; Samples, John R.

    2003-09-01

    The study had two main purposes: (1) to determine whether the foveal visual sensitivities of people treated for high blood pressure (vascular hypertension) differ from the sensitivities of people who have not been diagnosed with high blood pressure and (2) to understand how visual adaptation is related to standard measures of systemic cardiovascular function. Two groups of middle-aged subjects-hypertensive and normotensive-were examined with a series of test/background stimulus combinations. All subjects met rigorous inclusion criteria for excellent ocular health. Although the visual sensitivities of the two subject groups overlapped extensively, the age-related rate of sensitivity loss was, for some measures, greater for the hypertensive subjects, possibly because of adaptation differences between the two groups. Overall, the degree of steady-state sensitivity loss resulting from an increase of background illuminance (for 580-nm backgrounds) was slightly less for the hypertensive subjects. Among normotensive subjects, the ability of a bright (3.8-log-td), long-wavelength (640-nm) adapting background to selectively suppress the flicker response of long-wavelength-sensitive (LWS) cones was related inversely to the ratio of mean arterial blood pressure to heart rate. The degree of selective suppression was also related to heart rate alone, and there was evidence that short-term changes of cardiovascular response were important. The results suggest that (1) vascular hypertension, or possibly its treatment, subtly affects visual function even in the absence of eye disease and (2) changes in blood flow affect retinal light-adaptation processes involved in the selective suppression of the flicker response from LWS cones caused by bright, long-wavelength backgrounds.

  20. Wetland treatment of oil and gas well waste waters. Final report

    SciTech Connect

    Kadlec, R.; Srinivasan, K.

    1995-08-01

    Constructed wetlands are small on-site systems that possess three of the most desirable components of an industrial waste water treatment scheme: low cost, low maintenance and upset resistance. The main objective of the present study is to extend the knowledge base of wetland treatment systems to include processes and substances of particular importance to small, on-site systems receiving oil and gas well wastewaters. A list of the most relevant and comprehensive publications on the design of wetlands for water quality improvement was compiled and critically reviewed. Based on our literature search and conversations with researchers in the private sector, toxic organics such as Phenolics and b-naphthoic acid, (NA), and metals such as CU(II) and CR(VI) were selected as target adsorbates. A total of 90 lysimeters equivalent to a laboratory-scale wetland were designed and built to monitor the uptake and transformation of toxic organics and the immobilization of metal ions. Studies on the uptake of toxic organics such as phenol and b-naphthoic acid (NA) and heavy metals such as Cu(II) and Cr(VI), the latter two singly or as non-stoichiometric mixtures by laboratory-type wetlands (LWs) were conducted. These LWs were designed and built during the first year of this study. A road map and guidelines for a field-scale implementation of a wetland system for the treatment of oil and gas wastewaters have been suggested. Two types of wetlands, surface flow (SF) and sub surface flow (SSF), have been considered, and the relative merits of each configuration have been reviewed.

  1. Living with a Star: New Opportunities in Sun-Climate Research

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Living With a Star is a NASA initiative employing the combination of dedicated spacecraft with targeted research and modeling efforts to improve what we know of solar effects of all kinds on the Earth and its surrounding space environment, with particular emphasis on those that have significant practical impacts on life and society. The highest priority among these concerns is the subject of this report: the potential effects of solar variability on regional and global climate, including the extent to which solar variability has contributed to the well-documented warming of the Earth in the last 100 years. Understanding how the climate system reacts to external forcing from the Sun will also greatly improve our knowledge of how climate will respond to other climate drivers, including those of anthropogenic origin. A parallel element of the LWS program addresses solar effects on space weather : the impulsive emissions of charged particles, short-wave electromagnetic radiation and magnetic disturbances in the upper atmosphere and near-Earth environment that also affect life and society. These include a wide variety of solar impacts on aeronautics, astronautics, electric power transmission, and national defense. Specific examples are (1) the impacts of potentially- damaging high energy radiation and atomic particles of solar origin on satellites and satellite operations, spacecraft electronics systems and components, electronic communications, electric power distribution grids, navigational and GPS systems, and high altitude aircraft; and (2) the threat of sporadic, high-energy solar radiation to astronauts and high altitude aircraft passengers and crews. Elements of the LWS program include an array of dedicated spacecraft in near- Earth and near-Sun orbits that will closely study and observe both the Sun itself and the impacts of its variations on the Earth's radiation belts and magnetosphere, the upper atmosphere, and ionosphere. These spacecraft, positioned to study and monitor changing conditions in the Sun-Earth neighborhood, will also serve as sentinels of solar storms and impulsive events.

  2. 90 GHz and 150 GHz Observations of the Orion M42 Region. A Submillimeter to Radio Analysis

    NASA Technical Reports Server (NTRS)

    Dicker, S. R.; Mason, B. S.; Korngut, P. M.; Cotton, W. D.; Compiegne, M.; Devlin, M. J.; Martin, P. G.; Ade, P. A. R; Benford, D. J.; Irwin, K. D.; Maddalena, R. J.; McMullin, J. P.; Shepherd, D. S.; Sievers, A.; Staguhn, J. G.; Tucker, C.

    2009-01-01

    We have used the new 90GHz MUSTANG camera on the Robert C. Green Bank Telescope (GBT)to map the bright Huygens region of the star-forming region M42 with a resolution of 9" and a sensitivity of 2.8 mJy/beam. Ninety GHz is an interesting transition frequency, as MUSTANG detects both the free-free emission characteristic of the H II region created by the Trapezium stars, normally seen at lower frequencies, and thermal dust emission from the background OMCI molecular cloud, normally mapped at higher frequencies. We also present similar data from the 150 GHz GISMO camera taken on the IRAM 30 m telescope. This map has 15" resolution. By combining the MUSTANG data with 1.4, 8. and 31 GHz radio data from the VLA and GBT, we derive a new estimate of the emission measure averaged electron temperature of T(sub e) = 11376+/-1050 K by an original method relating free-free emission intensities at optically thin and optically thick frequencies. Combining Infrared Space Observatory-long wavelength spectrometer (ISO-LWS) data with our data, we derive a new estimate of the dust temperature and spectral emissivity index within the 80" ISO-LWS beam toward Orion KL/BN, T(sub d) = 42+/-3 K and Beta(sub d) = 1.3+/-0.1. We show that both T(sub d) and Beta(sub d) decrease when going from the H II region and excited OMCI interface to the denser UV shielded part OMCI (Orion KL/BN, Orion S). With a model consisting of only free-free and thermal dust emission, we are able to fit data taken at frequencies from 1.5 GHz to 854 GHz (350 micrometers).

  3. Solar Cycle Variation and Multipoint Studies of ICME Properties

    NASA Technical Reports Server (NTRS)

    Russell, C. T.

    2005-01-01

    The goal of the Living With a Star program is to understand the Sun-Earth connection sufficiently well that we can solve problems critical to life and society. This can most effectively be done in the short term using observations from our past and on-going programs. Not only can this approach solve some of the pressing issues but also it can provide ideas for the deployment of future spacecraft in the LWS program. The proposed effort uses data from NEAR, SOHO, Wind, ACE and Pioneer Venus in quadrature, multipoint, and solar cycle studies to study the interplanetary coronal mass ejection and its role in the magnetic flux cycle of the Sun. ICMEs are most important to the LWS objectives because the solar wind conditions associated with these structures are the most geoeffective of any solar wind phenomena. Their ability to produce strong geomagnetic disturbances arises first because of their high speed. This high speed overtakes the ambient solar wind producing a bow shock wave similar to the terrestrial bow shock. In the new techniques we develop as part of this effort we exploit this feature of ICMEs. This shocked plasma has a greater velocity, higher density and stronger magnetic field than the ambient solar wind, conditions that can enhance geomagnetic activity. The driving ICME is a large magnetic structure expanding outward in the solar wind [Gosling, 19961. The ICMEs magnetic field is generally much higher than that in the ambient solar wind and the velocity is high. The twisted nature of the magnetic field in an ICME almost ensures that sometime during the ICME conditions favorable for geomagnetic storm initiation will occur.

  4. ISO Key Project: Exploring The Full Range of Quasar/AGN Properties

    NASA Technical Reports Server (NTRS)

    Wilkes, Belinda; West, Donald K. (Technical Monitor)

    2002-01-01

    While most of the work on this program has been completed, as previously reported, the portion of the program dealing with the sub topic of ISO LWS data analysis and reduction for the LWS Extragalactic Science Team and its leader, Dr. Howard Smith, is still active. This program in fact continues to generate results, and newly available computer modeling has extended the value of the datasets, As a result the team has requested and been granted an obtained a no-cost extension to this program, through December 31, 2003. The essence of the proposal is to perform ISO spectroscopic studies, including data analysis and modeling, of star formation regions using an ensemble of archival space-based data from the Infrared Space Observatory's Long Wavelength Spectrometer and Short Wavelength Spectrometer, but including as well some other spectroscopic data bases. Four kinds of regions are considered in the studies: (1) disks around more evolved objects; (2) young, low or high mass pre-main sequence stars in star formation regions; (3) star formation in external, bright IR galaxies; and (4) the galactic center. One prime focus of the program is the OH lines in the far infrared. The program has the following goals: (1) refine the data analysis of ISO observations, to obtain deeper and better SNR results on selected sources. The ISO data itself underwent "pipeline 10" reductions in early 2001, and additional "hands-on data reduction packages" were supplied by the ISO teams in 2001. The Fabry-Perot database in particularly sensitive to noise can slight calibration errors. (2) model the atomic and molecular line shapes, in particular the OH lines, using revised Monte-Carlo techniques developed by the SWAS team at the Center for Astrophysics; (3) attend scientific meetings and workshops; (4) do E&PO activities related to infrared astrophysics and/or spectroscopy.

  5. Prograde lawsonite during the flow of continental crust in the Alpine subduction: Strain vs. metamorphism partitioning, a field-analysis approach to infer tectonometamorphic evolutions (Sesia-Lanzo Zone, Western Italian Alps)

    NASA Astrophysics Data System (ADS)

    Zucali, Michele; Spalla, Maria Iole

    2011-03-01

    Detailed mapping of superposed fabrics and their mineral support allows for reconstruction of the tectonometamorphic evolution of the Ivozio Complex, within the inner portion of the Sesia-Lanzo Zone (Western Italian Alps). The resulting evolution is characterized by a multi-stage structural and metamorphic re-equilibration during Alpine subduction, starting from the pre-Alpine igneous association (Amp 0 + Cpx 0). The prograde associations begin with S 1a marked by Amp I + Zo I which pre-date the growth of Grt I (S 1b); successive increase in pressure stabilizes a second generation of Amp + Grt (S 1c Amp II + ZoI + Grt II). The growth of prograde lawsonite and omphacite occur during S 1d (Omp I + Lws + Grt II + Amp II) within lawsonite-bearing eclogites, while S 1e is associated with the break-down of lawsonite, producing the association Omp I + Ky + Zo II + Grt II + Amp II ( lws-bearing eclogites); S 1d-e stages are associated with Amp II + ZoI + Grt II + Omp I in eclogites. The second generation of penetrative foliation (S 2), describing the retrograde evolution, is divided into S 2a (Amp II + GrtII + Pg + Zo II) and S 2b (Chl + AmpIII + Pg + Ab). The comparison between the reconstructed evolution of the Ivozio Complex and P-T paths inferred in the Southern Sesia-Lanzo Zone suggests a non-uniqueness of the Sesia-Lanzo Zone continental crust, during the Alpine subduction.

  6. Effects of simulated angler capture and live-release tournaments on walleye survival

    USGS Publications Warehouse

    Loomis, John H.; Schramm, Harold L., Jr.; Vondracek, Bruce C.; Gerard, Patrick D.; Chizinski, Christopher J.

    2015-01-01

    We examined the effects of acclimation water temperature,live-well (LW) water temperature,and LW dissolved oxygen (DO) concentration on survival of adult WalleyesSander vitreussubjected to simulated tournament conditions (angling,LW confinement,and weigh-in procedures) under controlled laboratory conditions. We tested three acclimation temperatures (12,18,and 24C),and three LW temperature differentials (?T= ?4,0,and +4C) were tested at each acclimation temperature. Survival was monitored after 8h of LW confinement and during a 5-d retention period in 1,700-L tanks. None of the Walleyes that were acclimated to 24C and subjected to simulated tournament procedures survived the 5-d retention period; for fish subjected only to simulated angling at 24C,survival during the 5-d retention period was 29%. Five-day survival was generally over 70% at acclimation temperatures of 12C and 18C,and we observed a significant interaction between acclimation temperature and ?T; survival was greatest in LWs at ?4C ?Tfor fish acclimated to 18C and in LWs at +4C ?Tfor fish acclimated to 12C. Best survival of Walleyes subjected to the stress of angling and tournament procedures was obtained at temperatures 68C below the optimum temperature for adult Walleyes (i.e.,optimum = 2022C). Five-day survival exceeded 70% when LW DO was 5 or 1215mg/L (at an acclimation and LW temperature of 18C),but survival was 0% when DO was 2mg/L. Anglers may increase survival of Walleyes through careful manipulation of LW temperature and DO when ambient temperature is at or below 18C,but high mortality of angled and LW-retained Walleyes should be expected when ambient water temperatures are 24C or greater.

  7. Hot-electron production and suprathermal heat flux scaling with laser intensity from the two-plasmon-decay instability

    SciTech Connect

    Vu, H. X.; DuBois, D. F.; Myatt, J. F.; Russell, D. A.

    2012-10-15

    The fully kinetic reduced-description particle-in-cell (RPIC) method has been applied to simulations of two-plasmon-decay (TPD) instability, driven by crossed laser beams, in an inhomogeneous plasma for parameters consistent with recent direct-drive experiments related to laser-driven inertial fusion. The nonlinear saturated state is characterized by very spiky electric fields, with Langmuir cavitation occurring preferentially inside density channels produced by the ponderomotive beating of the crossed laser beams and the primary TPD Langmuir waves (LWs). The heated electron distribution function is, in all cases, bi-Maxwellian, with instantaneous hot-electron temperatures in the range 60-100 keV. The net hot-electron energy flux out of the system is a small fraction ({approx}1% to 2%) of the input laser intensity in these simulations. Scalings of the hot-electron temperature and suprathermal heat flux as functions of the laser intensity are obtained numerically from RPIC simulations. These simulations lead to the preliminary conclusion that Langmuir cavitation and collapse provide dissipation by producing suprathermal electrons, which stabilize the system in saturation and drive the LW spectrum to the small dissipation scales at the Landau cutoff. The Langmuir turbulence originates at an electron density 0.241 Multiplication-Sign the laser's critical density, where the crossed laser beams excite a 'triad' mode-a common forward LW plus a pair of backward LWs. Remnants of this 'triad' evolve in k-space and dominate the time-averaged energy spectrum. At times exceeding 10 ps, the excited Langmuir turbulence spreads toward lower densities. Comparisons of RPIC simulations with the extended Zakharov model are presented in appropriate regimes, and the necessary requirements for the validity of a quasi-linear Zakharov model (where the spatially averaged electron-velocity distribution is evolved) are verified by RPIC simulation results.

  8. Photoreceptor types, visual pigments, and topographic specializations in the retinas of hydrophiid sea snakes.

    PubMed

    Hart, Nathan S; Coimbra, Joo Paulo; Collin, Shaun P; Westhoff, Guido

    2012-04-15

    Sea snakes have evolved numerous anatomical, physiological, and behavioral adaptations to suit their wholly aquatic lifestyle. However, although sea snakes use vision for foraging and mate selection, little is known about their visual abilities. We used microspectrophotometry, light microscopy, and scanning electron microscopy to characterize the retinal photoreceptors of spine-bellied (Lapemis curtus) and horned (Acalyptophis peronii) sea snakes. Both species have three types of visual pigment sensitive to short (SWS; wavelength of maximum absorbance, ?max 428-430 nm), medium (MWS; ?max 496 nm), and long wavelengths of light (LWS; ?max 555-559 nm) in each of three different subtypes of cone-like single photoreceptor. They also possess a cone-like double photoreceptor subtype, both the principal and accessory member of which contain the LWS visual pigment. Conventional rods were not observed, although the MWS photoreceptor may be a "transmuted" rod. We also used stereology to measure the total number and topographic distribution of neurons in the ganglion cell layer of L. curtus, the olive sea snake (Aipysurus laevis), and the olive-headed sea snake (Disteira major). All species have a horizontal visual streak with specialized areas in the nasal and temporal retina. Both L. curtus and D. major also have a specialized area in the ventral retina, which may reflect differences in habitat usage and/or foraging behavior compared to A. laevis. Maximal spatial resolution was estimated at 1.1, 1.6, and 2.3 cycles deg? in D. major, L. curtus, and A. laevis, respectively; the superior value for A. laevis may reflect its specialized crevice-foraging hunting technique. PMID:22020556

  9. Solitary-wave emission fronts, spectral chirping, and coupling to beam acoustic modes in RPIC simulation of SRS backscatter.

    SciTech Connect

    DuBois, D. F.; Yin, L.; Daughton, W. S.; Bezzerides, B.; Dodd, E. S.; Vu, H. X.

    2004-01-01

    Detailed diagnostics of quasi-2D RPIC simulations of backward stimulated Raman scattering (BSRS), from single speckles under putative NIF conditions, reveal a complex spatio-temporal behavior. The scattered light consists of localized packets, tens of microns in width, traveling toward the laser at an appreciable fraction of the speed of light. Sub pico-second reflectivity pulses occur as these packets leave the system. The LW activity consists of a front traveling with the light packets with a wake of free LWs traveling in the laser direction. The parametric coupling occurs in the front where the scattered light and LW overlap and are strongest. As the light leaves the plasma the LW quickly decays, liberating its trapped electrons. The high frequency part of the |n{sub e}(k,{omega})|{sup 2} spectrum, where n{sub e} is the electron density fluctuation, consists of a narrow streak or straight line with a slope that is the velocity of the parametric front. The time dependence of |n{sub e}(k,t)|{sup 2}, shows that during each pulse the most intense value of k also 'chirps' to higher values, consistent with the k excursions seen in the |n{sub e}(k,{omega})|{sup 2} spectrum. But k does not always return, in the subsequent pulses, to the original parametrically matched value, indicating that, in spite of side loss, the electron distribution function does not return to its original Maxwellian form. Liberated pulses of hot electrons result in down-stream, bump on tail distributions that excite LWs and beam acoustic modes deeper in the plasma. The frequency broadened spectra are consistent with Thomson scatter spectra observed in TRIDENT single-hot-spot experiments in the high k{lambda}{sub D}, trapping regime. Further details including a comparison of results from full PIC simulations, and movies of the spatio-temporal behavior, will be given in the poster by L Yin et al.

  10. 90 GHz AND 150 GHz OBSERVATIONS OF THE ORION M42 REGION. A SUBMILLIMETER TO RADIO ANALYSIS

    SciTech Connect

    Dicker, S. R.; Korngut, P. M.; Devlin, M. J.; Mason, B. S.; Cotton, W. D.; Compiegne, M.; Martin, P. G.; Ade, P. A. R; Tucker, C.; Benford, D. J.; Staguhn, J. G.; Irwin, K. D.; Maddalena, R. J.; McMullin, J. P.; Shepherd, D.S.; Sievers, A.

    2009-11-01

    We have used the new 90 GHz MUSTANG camera on the Robert C. Byrd Green Bank Telescope (GBT) to map the bright Huygens region of the star-forming region M42 with a resolution of 9'' and a sensitivity of 2.8 mJy beam{sup -1}. Ninety GHz is an interesting transition frequency, as MUSTANG detects both the free-free emission characteristic of the H II region created by the Trapezium stars, normally seen at lower frequencies, and thermal dust emission from the background OMC1 molecular cloud, normally mapped at higher frequencies. We also present similar data from the 150 GHz GISMO camera taken on the IRAM 30 m telescope. This map has 15'' resolution. By combining the MUSTANG data with 1.4, 8, and 21 GHz radio data from the VLA and GBT, we derive a new estimate of the emission measure averaged electron temperature of T{sub e} = 11376 +- 1050 K by an original method relating free-free emission intensities at optically thin and optically thick frequencies. Combining Infrared Space Observatory-long wavelength spectrometer (ISO-LWS) data with our data, we derive a new estimate of the dust temperature and spectral emissivity index within the 80'' ISO-LWS beam toward Orion KL/BN, T{sub d} = 42 +- 3 K and beta {sub d} = 1.3 +- 0.1. We show that both T{sub d} and beta {sub d} decrease when going from the H II region and excited OMC1 interface to the denser UV shielded part of OMC1 (Orion KL/BN, Orion S). With a model consisting of only free-free and thermal dust emission, we are able to fit data taken at frequencies from 1.5 GHz to 854 GHz (350 mum).

  11. Expression of carnitine palmitoyl-CoA transferase-1B is influenced by a cis-acting eQTL in two chicken lines selected for high and low body weight.

    PubMed

    Ka, Sojeong; Markljung, Ellen; Ring, Henrik; Albert, Frank W; Harun-Or-Rashid, Mohammad; Wahlberg, Per; Garcia-Roves, Pablo M; Zierath, Juleen R; Denbow, D Michael; Pbo, Svante; Siegel, Paul B; Andersson, Leif; Hallbk, Finn

    2013-05-01

    Carnitine palmitoyl-CoA transferase-1B is a mitochondrial enzyme in the fatty acid oxidation pathway. In a previous study, CPT1B was identified as differentially expressed in the hypothalamus of two lines of chickens established by long-term selection for high (HWS) or low (LWS) body weight. Mammals have three paralogs (CPT1a, b and c) while nonmammalian vertebrates only have two (CPT1A, B). CPT1A is expressed in liver and CPT1B in muscle. CPT1c is expressed in hypothalamus, where it regulates feeding and energy expenditure. We identified an intronic length polymorphism, fixed for different alleles in the two populations, and mapped the hitherto missing CPT1B locus in the chicken genome assembly, to the distal tip of chromosome 1p. Based on molecular phylogeny and gene synteny we suggest that chicken CPT1B is pro-orthologous of the mammalian CPT1c. Chicken CPT1B was differentially expressed in both muscle and hypothalamus but in opposite directions: higher levels in hypothalamus but lower levels in muscle in the HWS than in the LWS line. Using an advanced intercross population of the lines, we found CPT1B expression to be influenced by a cis-acting expression quantitative trait locus in muscle. The increased expression in hypothalamus and reduced expression in muscle is consistent with an increased food intake in the HWS line and at the same time reduced fatty acid oxidation in muscle yielding a net accumulation of energy intake and storage. The altered expression of CPT1B in hypothalamus and peripheral tissue is likely to be a mechanism contributing to the remarkable difference between lines. PMID:23512741

  12. The Outer Radiation Belt Injection, Transport, Acceleration and Loss Satellite (ORBITALS): A Canadian Mission to the Van Allen Belts

    NASA Astrophysics Data System (ADS)

    Mann, I. R.

    2008-12-01

    The Outer Radiation Belt Injection, Transport, Acceleration and Loss Satellite (ORBITALS) mission is proposed as a Canadian Space Agency satellite mission contribution to ILWS. The ORBITALS will provide a unique view of the largely previously unexplored inner magnetosphere, and will embrace a new paradigm of cross-energy coupling needed to understand Van Allen belt dynamics. Its mission goal to "understand the acceleration, global distribution, and variability of energetic electrons and ions in the inner magnetosphere" is perfectly aligned with the top geospace priority for the LWS and ILWS programs. In a 12 hour low inclination orbit, the ORBITALS will come into once daily apogee conjunctions with the extensive ground- based Canadian Geospace Monitoring (CGSM) instrumentation as well as with GOES East and West. Baseline raised perigee will provide both long outer radiation belt dwell times as well as coverage of the outer-most inner radiation belt. In combination, the ORBITALS-CGSM-GOES conjuctions will provide a unique data set with which to address fundamental radiation belt science questions such as the competition between ULF and VLF acceleration processes, the role of EMIC and VLF waves in loss, and the relationship between these processes and plasmaspheric cold plasma dynamics. The ORBITALS will also address inter- related science questions about the structure of inner magnetosphere electric and magnetic field structure, plasmaspheric dynamics, including thermal ion injection and loss, and the dynamics of the ring current population in the inner magnetosphere during storms. In combination with the approved NASA LWS RBSP mission, and the proposed Japanese ERG satellite, the ORBITALS-RBSP-ERG three petal constellation will resolve the spatio-temporal ambiguities which have clouded previous studies. Together, these mssions will uncover the processes responsible for the existence, and global dynamics and morphology, of the Earth's Van Allen radiation belts.

  13. The Geospace Mission Definition Team report

    NASA Astrophysics Data System (ADS)

    Kintner, P.; Spann, J.

    The Geospace Mission Definition Team (GMDT) is the portion of the Living With a Star (LWS) Program that has been charged by NASA to examine how the Geospace environment responds to solar variability. The goal is to provide science recommendations that guide NASA in the formulation of Geospace missions. The GMDT's first meeting with September 10, 2001 and has met on four subsequent dates. The top level space weather effects were initially defined by the LWS Science Architecture Team (SAT). From these effects the GMDT has distilled general objectives and specific objectives. These objectives have been prioritized and compelling science questions have been identified that are required to address the objectives. A set of candidate missions has been defined with minimum, baseline, and augmentation measurements identified. The priority science questions focus on two broad areas: (1) ionospheric variability, especially at mid-latitudes, that affects navigation and communications and (2) the source, acceleration mechanisms, and sinks of the radiation belts that degrade satellite lifetimes, produce surface charging, and threaten manned space flight. In addition the measurements required for understanding ionospheric variability will also address science issues associated with thermospheric satellite drag and orbital prediction. Candidate missions to address these science focii have been developed and studied. The team concludes that it is possible to address the compelling science questions with a cost effective program that yields major advances in our understanding of space weather science, that inspires and validates better ionospheric and magnetospheric models, and that will enable operational advances mitigating the societal impacts of space weather.

  14. Morphology and spectral absorption characteristics of retinal photoreceptors in the southern hemisphere lamprey (Geotria australis).

    PubMed

    Collin, Shaun P; Hart, Nathan S; Shand, Julia; Potter, Ian C

    2003-01-01

    The morphology and spectral absorption characteristics of the retinal photoreceptors in the southern hemisphere lamprey Geotria australis (Agnatha) were studied using light and electron microscopy and microspectrophotometry. The retinae of both downstream and upstream migrants of Geotria contained two types of cone photoreceptor and one type of rod photoreceptor. Visual pigments contained in the outer segments of these three photoreceptor types had absorbance spectra typical of porphyropsins and with wavelengths of maximum absorbance (downstream/upstream) at 610/616 nm (long-wavelength-sensitive cone, LWS), 515/515 nm (medium-wavelength-sensitive cone, MWS), and 506/500 nm (medium-wavelength-sensitive rod). A "yellow" photostable pigment was present in the myoid region of all three types of photoreceptor in the downstream migrant. The same short-wavelength-absorbing pigment, which prevents photostimulation of the beta band of the visual pigment in the outer segment, was present in the rods and LWS cones of the upstream migrant, but was replaced by a large transparent ellipsosome in the MWS cones. Using microspectrophotometric and anatomical data, the quantal spectral sensitivity of each photoreceptor type was calculated. Our results provide the first evidence of a jawless vertebrate, represented today solely by the lampreys and hagfishes, with two morphologically and physiologically distinct types of cone photoreceptors, in addition to a rod-like photoreceptor containing a colored filter (a cone-like characteristic). In contrast, all other lampreys studied thus far have either (1) one type of cone and one type of rod, or (2) a single type of rod-like photoreceptor. The evolution or retention of a second type of cone in adult Geotria is presumably an adaptation to life in the brightly lit surface waters of the Southern Ocean, where this species lives during the marine phase of its life cycle. The functional significance of the unique visual system of Geotria is discussed in relation to its life cycle and the potential for color vision. PMID:12916734

  15. ISO Key Project: Exploring the Full Range of Quasar/Agn Properties

    NASA Technical Reports Server (NTRS)

    Wilkes, Belinda; Oliversen, Ronald J. (Technical Monitor)

    2003-01-01

    While most of the work on this program has been completed, as previously reported, the portion of the program dealing with the subtopic of ISO LWS data analysis and reduction for the LWS Extragalactic Science Team and its leader, Dr. Howard Smith, is still active. This program in fact continues to generate results, and newly available computer modeling has extended the value of the datasets. As a result the team requests a one-year no-cost extension to this program, through 31 December 2004. The essence of the proposal is to perform ISO spectroscopic studies, including data analysis and modeling, of star-formation regions using an ensemble of archival space-based data from the Infrared Space Observatory's Long Wavelength Spectrometer and Short Wavelength Spectrometer, but including as well some other spectroscopic databases. Four kinds of regions are considered in the studies: (1) disks around more evolved objects; (2) young, low or high mass pre-main sequence stars in star-formation regions; (3) star formation in external, bright IR galaxies; and (4) the galactic center. One prime focus of the program is the OH lines in the far infrared. The program has the following goals: 1) Refine the data analysis of ISO observations to obtain deeper and better SNR results on selected sources. The ISO data itself underwent 'pipeline 10' reductions in early 2001, and additional 'hands-on data reduction packages' were supplied by the ISO teams in 2001. The Fabry-Perot database is particularly sensitive to noise and slight calibration errors; 2) Model the atomic and molecular line shapes, in particular the OH lines, using revised Monte-Carlo techniques developed by the SWAS team at the Center for Astrophysics; 3) Attend scientific meetings and workshops; 4) Perform E&PO activities related to infrared astrophysics and/or spectroscopy.

  16. Archaebacterial rhodopsin sequences: Implications for evolution

    NASA Technical Reports Server (NTRS)

    Lanyi, J. K.

    1991-01-01