Sample records for wave-sensitive lws opsins

  1. The molecular basis of color vision in colorful fish: Four Long Wave-Sensitive (LWS) opsins in guppies (Poecilia reticulata) are defined by amino acid substitutions at key functional sites

    PubMed Central

    2008-01-01

    Background Comparisons of functionally important changes at the molecular level in model systems have identified key adaptations driving isolation and speciation. In cichlids, for example, long wavelength-sensitive (LWS) opsins appear to play a role in mate choice and male color variation within and among species. To test the hypothesis that the evolution of elaborate coloration in male guppies (Poecilia reticulata) is also associated with opsin gene diversity, we sequenced long wavelength-sensitive (LWS) opsin genes in six species of the family Poeciliidae. Results Sequences of four LWS opsin genes were amplified from the guppy genome and from mRNA isolated from adult guppy eyes. Variation in expression was quantified using qPCR. Three of the four genes encode opsins predicted to be most sensitive to different wavelengths of light because they vary at key amino acid positions. This family of LWS opsin genes was produced by a diversity of duplication events. One, an intronless gene, was produced prior to the divergence of families Fundulidae and Poeciliidae. Between-gene PCR and DNA sequencing show that two of the guppy LWS opsins are linked in an inverted orientation. This inverted tandem duplication event occurred near the base of the poeciliid tree in the common ancestor of Poecilia and Xiphophorus. The fourth sequence has been uncovered only in the genus Poecilia. In the guppies surveyed here, this sequence is a hybrid, with the 5' end most similar to one of the tandem duplicates and the 3' end identical to the other. Conclusion Enhanced wavelength discrimination, a possible consequence of opsin gene duplication and divergence, might have been an evolutionary prerequisite for color-based sexual selection and have led to the extraordinary coloration now observed in male guppies and in many other poeciliids. PMID:18638376

  2. 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 ?max 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

  3. 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

  4. 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

  5. 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

  6. RT-qPCR reveals opsin gene upregulation associated with age and sex in guppies (Poecilia reticulata) - a species with color-based sexual selection and 11 visual-opsin genes

    PubMed Central

    2011-01-01

    Background PCR-based surveys have shown that guppies (Poecilia reticulata) have an unusually large visual-opsin gene repertoire. This has led to speculation that opsin duplication and divergence has enhanced the evolution of elaborate male coloration because it improves spectral sensitivity and/or discrimination in females. However, this conjecture on evolutionary connections between opsin repertoire, vision, mate choice, and male coloration was generated with little data on gene expression. Here, we used RT-qPCR to survey visual-opsin gene expression in the eyes of males, females, and juveniles in order to further understand color-based sexual selection from the perspective of the visual system. Results Juvenile and adult (male and female) guppies express 10 visual opsins at varying levels in the eye. Two opsin genes in juveniles, SWS2B and RH2-2, accounted for >85% of all visual-opsin transcripts in the eye, excluding RH1. This relative abundance (RA) value dropped to about 65% in adults, as LWS-A180 expression increased from approximately 3% to 20% RA. The juvenile-to-female transition also showed LWS-S180 upregulation from about 1.5% to 7% RA. Finally, we found that expression in guppies' SWS2-LWS gene cluster is negatively correlated with distance from a candidate locus control region (LCR). Conclusions Selective pressures influencing visual-opsin gene expression appear to differ among age and sex. LWS upregulation in females is implicated in augmenting spectral discrimination of male coloration and courtship displays. In males, enhanced discrimination of carotenoid-rich food and possibly rival males are strong candidate selective pressures driving LWS upregulation. These developmental changes in expression suggest that adults possess better wavelength discrimination than juveniles. Opsin expression within the SWS2-LWS gene cluster appears to be regulated, in part, by a common LCR. Finally, by comparing our RT-qPCR data to MSP data, we were able to propose the first opsin-to-?max assignments for all photoreceptor types in the cone mosaic. PMID:21447186

  7. Radiation Effects on LWS Detectors and Deglitching of LWS Data

    Microsoft Academic Search

    M. Burgdorf; A. Harwood; S. D. Sidher

    2003-01-01

    Glitches are caused by the effects of ionising particles (either a primary cosmic ray, interplanetary or belt electron, or a secondary generated in the spacecraft structure) on the detectors. There was roughly one glitch per ten seconds per detector during the normal period of LWS operation. These energetic particles cause a sudden jump in the ramp voltage, due to a

  8. 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

  9. 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.

  10. ISO/LWS: Detector status

    NASA Technical Reports Server (NTRS)

    Lenaour, C.; Delettrez, C.; Griffin, M.; Ade, P.; Robinson, D.; Vickers, D.

    1989-01-01

    The aim of the long wavelength spectrometer (LWS) of the Infrared Space Observatory is to perform spectrometry in the wavelength range 45 to 200 microns using two resolution modes. The resolution will be around 200 in the medium resolution mode while it will reach 10(exp 4) in the high resolution mode. The sensitivity of this instrument will be close to 10(exp -18) W/sq. root Hz. A schematic view of the focal plane unit is presented. The detectors divide the wavelength range into ten spectral channels. The spectral range and position of each detector is indicated. Each detector will cover approximately a spectral bandwidth sufficient to allow for a 50 percent redundancy in the case of detector failure. There are three types of detectors. SW1 is a Ge:Be photoconductor covering the 45 to 55 micron region. LW1, SW2, SW3, SW4, SW5 are unstressed Ge:Ga photoconductors which cover the 50 to 120 micron region. LW2, LW3, LW4, LW5 are uniaxially stressed Ge:GA photoconductors covering the range from 100 to 200 microns. The stress applied to each detector will be adjusted in order to get the peak response in the corresponding wavelength range, and to minimize the dark current of the shorter wavelength stressed detectors. Stressed and unstressed detectors are located alternatively in order to receive the first and second order of the diffracted beam.

  11. Spectral sensitivity of cone photoreceptors and opsin expression in two colour-divergent lineages of the lizard Ctenophorus decresii.

    PubMed

    Yewers, Madeleine S; McLean, Claire A; Moussalli, Adnan; Stuart-Fox, Devi; Bennett, Andrew T D; Knott, Ben

    2015-05-15

    Intraspecific differences in sensory perception are rarely reported but may occur when a species range extends across varying sensory environments, or there is coevolution between the sensory system and a varying signal. Examples in colour vision and colour signals are rare in terrestrial systems. The tawny dragon lizard Ctenophorus decresii is a promising candidate for such intraspecific variation, because the species comprises two geographically and genetically distinct lineages in which throat colour (a social signal used in intra- and inter-specific interactions) is locally adapted to the habitat and differs between lineages. Male lizards from the southern lineage have UV-blue throats, whereas males from the northern lineage are polymorphic with four discrete throat colours that all show minimal UV reflectance. Here, we determine the cone photoreceptor spectral sensitivities and opsin expression of the two lineages, to test whether they differ, particularly in the UV wavelengths. Using microspectrophotometry on retinal cone photoreceptors, we identified a long-wavelength-sensitive (LWS) visual pigment, a 'short' and 'long' medium-wavelength-sensitive (MWS) pigment and a short-wavelength-sensitive (SWS) pigment, all of which did not differ in ?max between lineages. Through transcriptome analysis of opsin genes we found that both lineages express four cone opsin genes, including the SWS1 opsin with peak sensitivity in the UV range, and that amino acid sequences did not differ between lineages with the exception of a single leucine to valine substitution in the RH2 opsin. Counts of yellow and transparent oil droplets associated with LWS+MWS and SWS+UVS cones, respectively, showed no difference in relative cone proportions between lineages. Therefore, contrary to predictions, we find no evidence of differences between lineages in single cone photoreceptor spectral sensitivity or opsin expression. However, we confirm the presence of four single cone classes, suggesting tetrachromacy in C. decresii, and we also provide the first evidence of UV sensitivity in agamid lizards. PMID:25827838

  12. 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

  13. Evolution of opsins and phototransduction

    PubMed Central

    Shichida, Yoshinori; Matsuyama, Take

    2009-01-01

    Opsins are the universal photoreceptor molecules of all visual systems in the animal kingdom. They can change their conformation from a resting state to a signalling state upon light absorption, which activates the G protein, thereby resulting in a signalling cascade that produces physiological responses. This process of capturing a photon and transforming it into a physiological response is known as phototransduction. Recent cloning techniques have revealed the rich and diverse nature of these molecules, found in organisms ranging from jellyfish to humans, functioning in visual and non-visual phototransduction systems and photoisomerases. Here we describe the diversity of these proteins and their role in phototransduction. Then we explore the molecular properties of opsins, by analysing site-directed mutants, strategically designed by phylogenetic comparison. This site-directed mutant approach led us to identify many key features in the evolution of the photoreceptor molecules. In particular, we will discuss the evolution of the counterion, the reduction of agonist binding to the receptor, and the molecular properties that characterize rod opsins apart from cone opsins. We will show how the advances in molecular biology and biophysics have given us insights into how evolution works at the molecular level. PMID:19720651

  14. 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.

  15. Opsin vs opsin: new materials for biotechnological applications

    E-print Network

    E. Alfinito; L. Reggiani

    2014-08-09

    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 \\textit{proteotronics}. Proteotronics is here 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.

  16. Catalogue of ISO LWS observations of asteroids

    NASA Astrophysics Data System (ADS)

    Hormuth, F.; Müller, T. G.

    2009-04-01

    Context: The long wavelength spectrometer (LWS) onboard the infrared space observatory (ISO) observed the four large main-belt asteroids (1) Ceres, (2) Pallas, (4) Vesta, and (10) Hygiea multiple times. The photometric and spectroscopic data cover the wavelength range between 43 and 197 ?m, and are a unique dataset for future investigations and detailed characterisations of these bodies. Aims: The standard ISO archive products, produced through the last post-mission LWS pipeline, were still affected by instrument artefacts. Our goal was to provide the best possible data products to exploit the full scientific potential of these observations. Methods: For all asteroid observations we analysed in detail the dark current, the calibration reference flashes, the space environment effects (glitches), memory effects, tracking influences, and various other sources of uncertainty. We performed a refined reduction of all measurements, corrected for the various effects, and re-calibrated the data. We outline the data reduction process and give an overview of the available data and the quality of the observations. We apply a thermophysical model to the flux measurements to derive far-IR based diameter and albedo values of the asteroids. The measured thermal rotational lightcurve of (4) Vesta is compared to model predictions. Results: The catalogue of LWS (long wavelength spectrometer) observations of asteroids contains 57 manually reduced datasets, including seven non-standard observations, which as such did not have final pipeline products available before. In total, the archive now contains 11 spectral scans and 46 fixed grating measurements with a simultaneous observation at 10 key wavelengths distributed over the full LWS range. The new data products are now accessible via the ISO data archive as highly processed data products (HPDP). Conclusions: The quality of the data products was checked against state-of-the-art thermophysical model predictions and an excellent agreement was found. The absolute photometric accuracy is better than 10%. The calibrated spectra will serve as a source for future mineralogical studies of dwarf planets and dwarf planet candidates. 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. The Microbial Opsin Family of Optogenetic Tools

    Microsoft Academic Search

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

    2011-01-01

    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

  18. BiP prevents rod opsin aggregation

    PubMed Central

    Athanasiou, Dimitra; Kosmaoglou, Maria; Kanuga, Naheed; Novoselov, Sergey S.; Paton, Adrienne W.; Paton, James C.; Chapple, J. Paul; Cheetham, Michael E.

    2012-01-01

    Mutations in rod opsin—the light-sensitive protein of rod cells—cause retinitis pigmentosa. Many rod opsin mutations lead to protein misfolding, and therefore it is important to understand the role of molecular chaperones in rod opsin biogenesis. We show that BiP (HSPA5) prevents the aggregation of rod opsin. Cleavage of BiP with the subtilase cytotoxin SubAB results in endoplasmic reticulum (ER) retention and ubiquitylation of wild-type (WT) rod opsin (WT–green fluorescent protein [GFP]) at the ER. Fluorescence recovery after photobleaching reveals that WT-GFP is usually mobile in the ER. By contrast, depletion of BiP activity by treatment with SubAB or coexpression of a BiP ATPase mutant, BiP(T37G), decreases WT-GFP mobility to below that of the misfolding P23H mutant of rod opsin (P23H-GFP), which is retained in the ER and can form cytoplasmic ubiquitylated inclusions. SubAB treatment of P23H-GFP–expressing cells decreases the mobility of the mutant protein further and leads to ubiquitylation throughout the ER. Of interest, BiP overexpression increases the mobility of P23H-GFP, suggesting that it can reduce mutant rod opsin aggregation. Therefore inhibition of BiP function results in aggregation of rod opsin in the ER, which suggests that BiP is important for maintaining the solubility of rod opsin in the ER. PMID:22855534

  19. 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

  20. The Microbial Opsin Family of Optogenetic Tools

    E-print Network

    Zhang, Feng

    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. ...

  1. 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

  2. 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.

  3. The Relationship between Opsin Overexpression and Photoreceptor Degeneration

    Microsoft Academic Search

    Elaine Tan; Quan Wang; Alexander B. Quiambao; Xiaoping Xu; Nasser M. Qtaishat; Neal S. Peachey; Janis Lem; Steven J. Fliesler; David R. Pepperberg; Muna I. Naash; Muayyad R. Al-Ubaidi

    2001-01-01

    PURPOSE. To characterize the process by which overexpression of normal opsin leads to photoreceptor degeneration. METHODS. Three transgenic mouse lines were generated that express different levels of an opsin with three amino acid modifications at the C terminus. These modifications created an epitopic site that can be readily distinguished from the endogenous protein using a bovine opsin-specific antibody. Evidence of

  4. 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

  5. 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

  6. 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 opsins—OPN1-SW, OPN2, OPN3 and OPN5—are 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 light–induced signaling pathways, possibly contributing to UVR phototransduction. PMID:25267311

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

    PubMed

    Liegertová, Michaela; Pergner, Ji?í; Kozmiková, Iryna; Fabian, Peter; Pombinho, Antonio R; Strnad, Hynek; Pa?es, Jan; Vl?ek, ?estmír; 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

  8. Two opsin genes from the vetch aphid, Megoura viciae.

    PubMed

    Gao, N; Foster, R G; Hardie, J

    2000-04-01

    The cDNAs of two opsins (Megopsin1 and Megopsin2) from the vetch aphid, Megoura viciae, have been sequenced and encoded for gene products with 378 and 371 amino acid residues, respectively. Phylogenetic analysis reveals that Megopsin1 falls into the insect long-wavelength opsin group and Megopsin2 is a member of the insect UV-wavelength opsins. Both opsins share the key features of G-protein-coupled receptors and the specific motifs of photopigments. In situ hybridization demonstrated that the transcripts of Megopsin1 and Megopsin2 were expressed in the retinula cells of the compound eyes. PMID:10762427

  9. 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

  10. 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.

  11. 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.

  12. Expression of opsin genes early in ocular development of humans and mice

    Microsoft Academic Search

    Emma E Tarttelin; James Bellingham; Lindsay C Bibb; Russell G Foster; Mark W Hankins; Kevin Gregory-Evans; Cheryl Y Gregory-Evans; Dominic J Wells; Robert J Lucas

    2003-01-01

    We have compared the onsets of expression of the classical visual opsins with those of the non-rod, non-cone opsins in foetal and post-natal eye tissue from mice and humans. Mouse Rgr-opsin, peropsin, encephalopsin and melanopsin are all expressed in foetal development by E11.5, unlike the murine rod and cone opsins that exhibit post-natal expression, e.g. P1 for ultraviolet cone opsin

  13. LWS/SET End-to-End Data System

    NASA Technical Reports Server (NTRS)

    Giffin, Geoff; Sherman, Barry; Colon, Gilberto (Technical Monitor)

    2002-01-01

    This paper describes the concept for the End-to-End Data System that will support NASA's Living With a Star Space Environment Testbed 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 End-to-end data system allows investigators to access the SET control center, command their experiments, and receive data from their experiments back at their home facility, using the Internet. The logical functioning of major components of the end-to-end data system are described, including the GSFC Payload Operations Control Center (POCC), SET Payloads, the GSFC SET Simulation Lab, SET Experiment PI Facilities, and Host Systems. Host Spacecraft Operations Control Centers (SOCC) and the Host Spacecraft are essential links in the end-to-end data system, but are not directly under the control of the SET Project. Formal interfaces will be established between these entities and elements of the SET Project. The paper describes data flow through the system, from PI facilities connecting to the SET operations center via the Internet, communications to SET carriers and experiments via host systems, to telemetry returns to investigators from their flight experiments. It also outlines the techniques that will be used to meet mission requirements, while holding development and operational costs to a minimum. Additional information is included in the original extended abstract.

  14. 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.

  15. Functional diversification of lepidopteran opsins following gene duplication.

    PubMed

    Briscoe, A D

    2001-12-01

    A comparative approach was taken for identifying amino acid substitutions that may be under positive Darwinian selection and are correlated with spectral shifts among orthologous and paralogous lepidopteran long wavelength-sensitive (LW) opsins. Four novel LW opsin fragments were isolated, cloned, and sequenced from eye-specific cDNAs from two butterflies, Vanessa cardui (Nymphalidae) and Precis coenia (Nymphalidae), and two moths, Spodoptera exigua (Noctuidae) and Galleria mellonella (Pyralidae). These opsins were sampled because they encode visual pigments having a naturally occurring range of lambda(max) values (510-530 nm), which in combination with previously characterized lepidopteran opsins, provide a complete range of known spectral sensitivities (510-575 nm) among lepidopteran LW opsins. Two recent opsin gene duplication events were found within the papilionid but not within the nymphalid butterfly families through neighbor-joining, maximum parsimony, and maximum likelihood phylogenetic analyses of 13 lepidopteran opsin sequences. An elevated rate of evolution was detected in the red-shifted Papilio Rh3 branch following gene duplication, because of an increase in the amino acid substitution rate in the transmembrane domain of the protein, a region that forms the chromophore-binding pocket of the visual pigment. A maximum likelihood approach was used to estimate omega, the ratio of nonsynonymous to synonymous substitutions per site. Branch-specific tests of selection (free-ratio) identified one branch with omega = 2.1044, but the small number of substitutions involved was not significantly different from the expected number of changes under the neutral expectation of omega = 1. Ancestral sequences were reconstructed with a high degree of certainty from these data. Reconstructed ancestral sequences revealed several instances of convergence to the same amino acid between butterfly and vertebrate cone pigments, and between independent branches of the butterfly opsin tree that are correlated with spectral shifts. PMID:11719576

  16. Reconstructing the ancestral butterfly eye: focus on the opsins.

    PubMed

    Briscoe, Adriana D

    2008-06-01

    The eyes of butterflies are remarkable, because they are nearly as diverse as the colors of wings. Much of eye diversity can be traced to alterations in the number, spectral properties and spatial distribution of the visual pigments. Visual pigments are light-sensitive molecules composed of an opsin protein and a chromophore. Most butterflies have eyes that contain visual pigments with a wavelength of peak absorbance, lambda(max), in the ultraviolet (UV, 300-400 nm), blue (B, 400-500 nm) and long wavelength (LW, 500-600 nm) part of the visible light spectrum, respectively, encoded by distinct UV, B and LW opsin genes. In the compound eye of butterflies, each individual ommatidium is composed of nine photoreceptor cells (R1-9) that generally express only one opsin mRNA per cell, although in some butterfly eyes there are ommatidial subtypes in which two opsins are co-expressed in the same photoreceptor cell. Based on a phylogenetic analysis of opsin cDNAs from the five butterfly families, Papilionidae, Pieridae, Nymphalidae, Lycaenidae and Riodinidae, and comparative analysis of opsin gene expression patterns from four of the five families, I propose a model for the patterning of the ancestral butterfly eye that is most closely aligned with the nymphalid eye. The R1 and R2 cells of the main retina expressed UV-UV-, UV-B- or B-B-absorbing visual pigments while the R3-9 cells expressed a LW-absorbing visual pigment. Visual systems of existing butterflies then underwent an adaptive expansion based on lineage-specific B and LW opsin gene multiplications and on alterations in the spatial expression of opsins within the eye. Understanding the molecular sophistication of butterfly eye complexity is a challenge that, if met, has broad biological implications. PMID:18490396

  17. 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

  18. Honeybee Blue-and Ultraviolet-Sensitive Opsins: Cloning, Heterologous Expression in Drosophila, and

    E-print Network

    Pierce, Naomi E.

    Honeybee Blue- and Ultraviolet-Sensitive Opsins: Cloning, Heterologous Expression in Drosophila, Massachusetts 02138 The honeybee (Apis mellifera) visual system contains three classes of retinal photoreceptor: Apis mellifera; honeybee; visual pigment; spectral tuning; ultraviolet-sensitive opsin; blue

  19. 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

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

    PubMed

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

    2010-02-23

    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

  1. 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

  2. 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

  3. 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.

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

    PubMed

    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

    2012-04-23

    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

  5. Diversity of animal opsin-based pigments and their optogenetic potential.

    PubMed

    Koyanagi, Mitsumasa; Terakita, Akihisa

    2014-05-01

    Most animal opsin-based pigments are typical G protein-coupled receptors (GPCR) and consist of a protein moiety, opsin, and 11-cis retinal as a chromophore. More than several thousand opsins have been identified from a wide variety of animals, which have multiple opsin genes. Accumulated evidence reveals the molecular property of opsin-based pigments, particularly non-conventional visual pigments including non-visual pigments. Opsin-based pigments are generally a bistable pigment having two stable and photointerconvertible states and therefore are bleach-resistant and reusable, unlike vertebrate visual pigments which become bleached. The opsin family contains Gt-coupled, Gq-coupled, Go-coupled, Gs-coupled, Gi-coupled, and Gi/Go-coupled opsins, indicating the existence of a large diversity of light-driven GPCR-signaling cascades. It is suggested that these molecular properties might contribute to different physiologies. In addition, various opsin based-pigments, especially nonconventional visual pigments having different molecular characteristics would facilitate the design and development of promising optogenetic tools for modulating GPCR-signaling, which is involved in a wide variety of physiological responses. We here introduce molecular and functional properties of various kinds of opsins and discuss their physiological function and also their potentials for optogenetic applications. This article is part of a Special Issue entitled: Retinal proteins - you can teach an old dog new tricks. PMID:24041647

  6. Beauty in the eye of the beholder: the two blue opsins of lycaenid butterflies and the opsin gene-driven evolution of sexually dimorphic eyes

    Microsoft Academic Search

    Marilou P. Sison-Mangus; Gary D. Bernard; Jochen Lampel; Adriana D. Briscoe

    2006-01-01

    Although previous investigations have shown that wing coloration is an important component of social signaling in butterflies, the contribution of opsin evolution to sexual wing color dichromatism and interspecific divergence remains largely unexplored. Here we report that the butterfly Lycaena rubidus has evolved sexually dimorphic eyes due to changes in the regulation of opsin expression patterns to match the contrasting

  7. Teleost multiple tissue ( tmt) opsin: a candidate photopigment regulating the peripheral clocks of zebrafish?

    Microsoft Academic Search

    Paraskevi Moutsaki; David Whitmore; James Bellingham; Katsuhiko Sakamoto; Zoë K. David-Gray; Russell G. Foster

    2003-01-01

    Isolated organs and cell lines from zebrafish exhibit circadian oscillations in clock gene expression that can be entrained to a 24-h light\\/dark cycle. The mechanism underlying this cellular photosensitivity is unknown. We report the identification of a novel opsin family, tmt-opsin, that has a genomic structure characteristic of vertebrate photopigments, an amino acid identity equivalent to the known photopigment opsins,

  8. The co-chaperone and reductase ERdj5 facilitates rod opsin biogenesis and quality control.

    PubMed

    Athanasiou, Dimitra; Bevilacqua, Dalila; Aguila, Monica; McCulley, Caroline; Kanuga, Naheed; Iwawaki, Takao; Paul Chapple, J; Cheetham, Michael E

    2014-12-15

    Mutations in rhodopsin, the light-sensitive protein of rod cells, are the most common cause of autosomal dominant retinitis pigmentosa (ADRP). Many rod opsin mutations, such as P23H, lead to misfolding of rod opsin with detrimental effects on photoreceptor function and viability. Misfolded P23H rod opsin and other mutations in the intradiscal domain are characterized by the formation of an incorrect disulphide bond between C185 and C187, as opposed to the correct and highly conserved C110-C187 disulphide bond. Therefore, we tested the hypothesis that incorrect disulphide bond formation might be a factor that affects the biogenesis of rod opsin by studying wild-type (WT) or P23H rod opsin in combination with amino acid substitutions that prevent the formation of incorrect disulphide bonds involving C185. These mutants had altered traffic dynamics, suggesting a requirement for regulation of disulphide bond formation/reduction during rod opsin biogenesis. Here, we show that the BiP co-chaperone and reductase protein ERdj5 (DNAJC10) regulates this process. ERdj5 overexpression promoted the degradation, improved the endoplasmic reticulum mobility and prevented the aggregation of P23H rod opsin. ERdj5 reduction by shRNA delayed rod opsin degradation and promoted aggregation. The reductase and co-chaperone activity of ERdj5 were both required for these effects on P23H rod opsin. Furthermore, mutations in these functional domains acted as dominant negatives that affected WT rod opsin biogenesis. Collectively, these data identify ERdj5 as a member of the proteostasis network that regulates rod opsin biogenesis and supports a role for disulphide bond formation/reduction in rod opsin biogenesis and disease. PMID:25055872

  9. The co-chaperone and reductase ERdj5 facilitates rod opsin biogenesis and quality control

    PubMed Central

    Athanasiou, Dimitra; Bevilacqua, Dalila; Aguila, Monica; McCulley, Caroline; Kanuga, Naheed; Iwawaki, Takao; Paul Chapple, J.; Cheetham, Michael E.

    2014-01-01

    Mutations in rhodopsin, the light-sensitive protein of rod cells, are the most common cause of autosomal dominant retinitis pigmentosa (ADRP). Many rod opsin mutations, such as P23H, lead to misfolding of rod opsin with detrimental effects on photoreceptor function and viability. Misfolded P23H rod opsin and other mutations in the intradiscal domain are characterized by the formation of an incorrect disulphide bond between C185 and C187, as opposed to the correct and highly conserved C110–C187 disulphide bond. Therefore, we tested the hypothesis that incorrect disulphide bond formation might be a factor that affects the biogenesis of rod opsin by studying wild-type (WT) or P23H rod opsin in combination with amino acid substitutions that prevent the formation of incorrect disulphide bonds involving C185. These mutants had altered traffic dynamics, suggesting a requirement for regulation of disulphide bond formation/reduction during rod opsin biogenesis. Here, we show that the BiP co-chaperone and reductase protein ERdj5 (DNAJC10) regulates this process. ERdj5 overexpression promoted the degradation, improved the endoplasmic reticulum mobility and prevented the aggregation of P23H rod opsin. ERdj5 reduction by shRNA delayed rod opsin degradation and promoted aggregation. The reductase and co-chaperone activity of ERdj5 were both required for these effects on P23H rod opsin. Furthermore, mutations in these functional domains acted as dominant negatives that affected WT rod opsin biogenesis. Collectively, these data identify ERdj5 as a member of the proteostasis network that regulates rod opsin biogenesis and supports a role for disulphide bond formation/reduction in rod opsin biogenesis and disease. PMID:25055872

  10. Immunoreactive opsin in the pineal organ of reptiles and birds.

    PubMed

    Vigh, B; Vigh-Teichmann, I; Röhlich, P; Aros, B

    1982-01-01

    The presence of opsin was investigated with light microscopic immunocytochemistry in pinealocytes of reptiles and birds (Emys orbicularis, Pseudemys scripta elegans, Lacerta agilis et viridis, Gallus domesticus, Columba livia, Melopsittacus undulatus, Serinus canaria, Taeniopyga punctate). The outer segments of pinealocytes selectively bound antiopsin antibody as revealed by indirect immunocytochemical techniques, indicating the occurrence of a rhodopsin-like photopigment in these structures. The results were compared with those obtained in retinal photoreceptors of the same species as well as in the pineal organ of fishes and amphibians (Cyprinus carpio, Carassius auratus, Rana esculenta). Corresponding to immunoreactive structures seen in the light microscope, we found typical outer segments on a large number of pinealocytes in most of the reptiles and birds studied. The presence of opsin in the numerous well developed pineal outer segments of these reptilian and avian species contradicts the earlier hypothesis on the gradual regression of pineal sensitive structures in the avian line of evolution. PMID:6213109

  11. Beauty in the eye of the beholder: the two blue opsins of lycaenid butterflies and the opsin gene-driven evolution of sexually dimorphic eyes.

    PubMed

    Sison-Mangus, Marilou P; Bernard, Gary D; Lampel, Jochen; Briscoe, Adriana D

    2006-08-01

    Although previous investigations have shown that wing coloration is an important component of social signaling in butterflies, the contribution of opsin evolution to sexual wing color dichromatism and interspecific divergence remains largely unexplored. Here we report that the butterfly Lycaena rubidus has evolved sexually dimorphic eyes due to changes in the regulation of opsin expression patterns to match the contrasting life histories of males and females. The L. rubidus eye contains four visual pigments with peak sensitivities in the ultraviolet (UV; lambdamax=360 nm), blue (B; lambdamax=437 nm and 500 nm, respectively) and long (LW; lambdamax=568 nm) wavelength range. By combining in situ hybridization of cloned opsin-encoding cDNAs with epi-microspectrophotometry, we found that all four opsin mRNAs and visual pigments are expressed in the eyes in a sex-specific manner. The male dorsal eye, which contains only UV and B (lambdamax=437 nm) visual pigments, indeed expresses two short wavelength opsin mRNAs, UVRh and BRh1. The female dorsal eye, which also has the UV and B (lambdamax=437 nm) visual pigments, also contains the LW visual pigment, and likewise expresses UVRh, BRh1 and LWRh mRNAs. Unexpectedly, in the female dorsal eye, we also found BRh1 co-expressed with LWRh in the R3-8 photoreceptor cells. The ventral eye of both sexes, on the other hand, contains all four visual pigments and expresses all four opsin mRNAs in a non-overlapping fashion. Surprisingly, we found that the 500 nm visual pigment is encoded by a duplicate blue opsin gene, BRh2. Further, using molecular phylogenetic methods we trace this novel blue opsin gene to a duplication event at the base of the Polyommatine+Thecline+Lycaenine radiation. The blue opsin gene duplication may help explain the blueness of blue lycaenid butterflies. PMID:16888057

  12. Coexpression of three opsins in cone photoreceptors of the salamander Ambystoma tigrinum.

    PubMed

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

    2014-07-01

    Although more than one type of visual opsin is present in the retina of most vertebrates, it was thought that each type of photoreceptor expresses 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 108:27-34). Two opsin types are expressed at levels more than 100 times lower than the level 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 coexpression 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

  13. 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 108:27–34). 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

  14. LWS-spectroscopy of Herbig Haro objects and molecular outflows in the Cha II dark cloud

    Microsoft Academic Search

    B. Nisini; D. Lorenzetti; M. Cohen; C. Ceccarelli; T. Giannini; R. Liseau; S. Molinari; A. Radicchi; P. Saraceno; L. Spinoglio; E. Tommasi; P. E. Clegg; P. A. R. Ade; C. Armand; M. J. Barlow; M. Burgdorf; E. Caux; P. Cerulli; S. E. Church; A. di Giorgio; J. Fischer; I. Furniss; W. M. Glencross; M. J. Griffin; C. Gry; K. J. King; T. Lim; D. A. Naylor; D. Texier; R. Orfei; Nguyen-Q-Rieu; S. Sidher; H. A. Smith; B. M. Swinyard; N. Trams; S. J. Unger; G. J. White

    1996-01-01

    We present the first far infrared spectra of the Herbig Haro objects HH 52-53-54 and of IRAS 12496-7650, all located in the nearby star forming region known as Chamaleon II dark cloud, obtained with the Long Wavelength Spectrometer (LWS) onboard the Infrared Space Observatory (ISO). The richest spectrum is found in HH 54, showing molecular transitions (CO with J_u_ from

  15. 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.

  16. 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

  17. Divergent Selection on Opsins Drives Incipient Speciation in Lake Victoria Cichlids

    E-print Network

    Divergent Selection on Opsins Drives Incipient Speciation in Lake Victoria Cichlids Yohey Terai1, et al. (2006) Divergent selection on opsins drives incipient speciation in Lake Victoria cichlids for the genetics of vertebrate speciation and adaptive radiation [8]. Lake Victoria, the largest of the African

  18. Kinetic, energetic, and mechanical differences between dark-state rhodopsin and opsin.

    PubMed

    Kawamura, Shiho; Gerstung, Moritz; Colozo, Alejandro T; Helenius, Jonne; Maeda, Akiko; Beerenwinkel, Niko; Park, Paul S-H; Müller, Daniel J

    2013-03-01

    Rhodopsin, the photoreceptor pigment of the retina, initiates vision upon photon capture by its covalently linked chromophore 11-cis-retinal. In the absence of light, the chromophore serves as an inverse agonist locking the receptor in the inactive dark state. In the absence of chromophore, the apoprotein opsin shows low-level constitutive activity. Toward revealing insight into receptor properties controlled by the chromophore, we applied dynamic single-molecule force spectroscopy to quantify the kinetic, energetic, and mechanical differences between dark-state rhodopsin and opsin in native membranes from the retina of mice. Both rhodopsin and opsin are stabilized by ten structural segments. Compared to dark-state rhodopsin, the structural segments stabilizing opsin showed higher interaction strengths and mechanical rigidities and lower conformational variabilities, lifetimes, and free energies. These changes outline a common mechanism toward activating G-protein-coupled receptors. Additionally, we detected that opsin was more pliable and frequently stabilized alternate structural intermediates. PMID:23434406

  19. 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

  20. 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 Schiff’s 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.

  1. Retinal Cone Photoreceptors of the Deer Mouse Peromyscus maniculatus: Development, Topography, Opsin Expression and Spectral Tuning

    PubMed Central

    Arbogast, Patrick; Glösmann, 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/mm2 and cone densities of 3000 - 6500/mm2. 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/mm2). 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

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

    PubMed

    Arbogast, Patrick; Glösmann, 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

  3. Three Different Cone Opsin Gene Array Mutational Mechanisms with Genotype–Phenotype 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. 2006 LWS TR & T Solar Wind Focused Science Topic Team: The ... http://www.agu.org/cgi-bin/SFgate/SFgate?language=English&verb... 1 of 2 11/14/06 11:27 AM

    E-print Network

    Ng, Chung-Sang

    2006 LWS TR & T Solar Wind Focused Science Topic Team: The ... http://www=ng HR: 0800h AN: SH11A-0371 TI: 2006 LWS TR & T Solar Wind Focused Science Topic Team: The Beginnings AU;2006 LWS TR & T Solar Wind Focused Science Topic Team: The ... http://www

  5. Effect of temperature, density, and technical factors on the shock-wave sensitivity of plastic TATB

    Microsoft Academic Search

    Y. A. Vlasov; V. B. Kosolapov; L. V. Fomicheva; I. P. Khabarov

    1998-01-01

    Results are presented from a study of the shock-wave sensitivity of plastic TATB over a wide range of temperatures. It is\\u000a shown that the temperature dependence of the shock-wave sensitivity of this explosive material is explained to a great extent\\u000a by the change in density owing to thermal expansion, and by relaxation processes that occur in the samples.

  6. New evidence for the role of heterochrony in the repeated evolution of cichlid opsin expression

    E-print Network

    Carleton, Karen L.

    -wavelength-sensitive profiles among unrelated cichlids in Lake Tanganyika (LT). To address these questions, we surveyed opsin the three East African Great Lakes: Lakes Tanganyika (LT), Malawi (LM), and Victoria (LV). Cichlids from

  7. Spontaneous activity of opsin apoprotein is a cause of Leber congenital amaurosis

    Microsoft Academic Search

    Michael L Woodruff; Zhongyan Wang; Hae Yun Chung; T Michael Redmond; Gordon L Fain; Janis Lem

    2003-01-01

    Mutations in Rpe65 disrupt synthesis of the opsin chromophore ligand 11-cis-retinal and cause Leber congenital amaurosis (LCA), a severe, early-onset retinal dystrophy. To test whether light-independent signaling by unliganded opsin causes the degeneration, we used Rpe65-null mice, a model of LCA. Dark-adapted Rpe65?\\/? mice behaved as if light adapted, exhibiting reduced circulating current, accelerated response turn-off, and diminished intracellular calcium.

  8. RT-qPCR reveals opsin gene upregulation associated with age and sex in guppies ( Poecilia reticulata ) - a species with color-based sexual selection and 11 visual-opsin genes

    Microsoft Academic Search

    Christopher RJ Laver; John S Taylor

    2011-01-01

    Background  PCR-based surveys have shown that guppies (Poecilia reticulata) have an unusually large visual-opsin gene repertoire. This has led to speculation that opsin duplication and divergence\\u000a has enhanced the evolution of elaborate male coloration because it improves spectral sensitivity and\\/or discrimination in\\u000a females. However, this conjecture on evolutionary connections between opsin repertoire, vision, mate choice, and male coloration\\u000a was generated with

  9. 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.

  10. Gas and dust in the Galactic Centre - ISO LWS, submillimetre line and continuum observations.

    NASA Astrophysics Data System (ADS)

    Etxaluze, M.; White, G. J.; Smith, H. A.; Gonzalez-Alfonso, E.; Stark, A. A.; Stacey, G. J.; Leeks, S. J.; Gatley, I.; Fisher, J.; Pierce-Price, D.; Richer, J. S.; Grundy, T. W.; Polehampton, E. T.

    2011-05-01

    The Infrared Space Observatory (ISO) Long wavelength Spectrometer (LWS) has been used to map distribution of the emission from a sample of 22 atomic, molecular and ionised lines toward the Circumnuclear Disk at the Galactic Centre. The circumnuclear disc is clearly seen in the maps of molecular lines such as CO and OH, whilst the central region dominates in other atomic and ionised lines such as [O III] and [N III]. The ISO-LWS spectrum toward Sgr A^* is best represented by the sum of three blackbody curves of 90, 44.5 and 16 K, superposed with 22 lines, including CO, OH, [O I], [O III], [N II], [C II] and H_2O. The CO 4.7 ?m absorption band head observed with the ISO SWS spectrometer toward SgrA^* is modeled as having a cold component with Trot = 10 K, for which we estimate N(CO)=7.7× 1018 cm-2, N(13CO) = 1.7× 1017 cm-2 and N(C18O)= 2.1× 1016 cm-2, and a warm component by n(H_2) = 1× 10^5 cm-3, T_k = 70 K, N(CO) = 3.9× 1018 cm-2, N(13CO)= N(CO)/40, N(C18O)= N(CO). Observations of hydrogen recombination lines toward SgrA^* are moddeled as representing a line of sight extiction A_V˜ 24 -28 magnitudes. The SCUBA data at 450 and 850 ?m are used in this paper in order to make an estimation of the CND mass of ˜ 2.3× 10^4 M?, after removal of the free-free contribution and the local background.

  11. ISO-LWS Observations Of Gas And Dust In The Galactic Centre

    NASA Astrophysics Data System (ADS)

    Etxaluze Azkonaga, Mireya; Smith, H.; Gonzalez-Alfonso, E.; White, G. J.

    2011-01-01

    The ISO-LWS observed Sagittarius A* over the wavelength range of 46-197 ?m. These previously unpublished spectra contain about 22 spectral lines in emission of atomic and ionic species (OI, OIII, CII, NII and NIII), as well as emission and absorption lines from molecular species (OH, CH, CO and o-H2O). ISO mapped the region in a 40 position, half-beam sampled grid, and used both the grating and Fabry-Perot modules. We have prepared spectral maps of most of the lines, but here discuss primarily the radiative transfer modelling of radiation within the central beam on Sgr A*. We used ISO-LWS spectra to constrain the physical conditions in Sgr A* by comparing the observed spectra with the emission and the absorption line intensities predicted via radiative transfer simulations. Preliminary results show that the spectral energy distribution of Sgr A* within the 80" ISO beam that includes the CND is due to thermal dust emission that can be fitted by the sum of an 85 K modified blackbody arising from a central cavity of r=1.2 pc in radius with a low column density of N(H2)=4.0x1021 cm2, and a 40.5 K modified blackbody curve and a higher column density, N(H2)= 3.0x1022 cm2. This simple model is able to reproduce most of the ionic lines, which are excited in the CND; the central cavity provides only a small contribution to the intensity of the spectral lines. The molecular lines, and in particular the OH absorption features, require substantive additional contributions from foreground absorption that is consistent with a visual extinction AV 30, the same value that is derived from other studies.

  12. 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

  13. Six Opsins from the Butterfly Papilio glaucus: Molecular Phylogenetic Evidence for Paralogous Origins of Red-Sensitive Visual Pigments in Insects

    E-print Network

    to the placement of six opsins from the swallowtail butterfly Papilio glaucus (PglRh1­ 6) in relationship to 46: Evolution -- Lepidoptera -- Cones -- Vertebrates -- Color vision -- Opsin phylogeny -- Swallowtail- izing the opsins from the swallowtail butterfly Papilio glaucus and examining their relationship other

  14. 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. (Univ. of Illinois, Urbana-Champaign (USA))

    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.

  15. A spinal opsin controls early neural activity and drives a behavioral light response.

    PubMed

    Friedmann, Drew; Hoagland, Adam; Berlin, Shai; Isacoff, Ehud Y

    2015-01-01

    Nonvisual detection of light by the vertebrate hypothalamus, pineal, and retina is known to govern seasonal and circadian behaviors. However, the expression of opsins in multiple other brain structures suggests a more expansive repertoire for light regulation of physiology, behavior, and development. Translucent zebrafish embryos express extraretinal opsins early on, at a time when spontaneous activity in the developing CNS plays a role in neuronal maturation and circuit formation. Though the presence of extraretinal opsins is well documented, the function of direct photoreception by the CNS remains largely unknown. Here, we show that early activity in the zebrafish spinal central pattern generator (CPG) and the earliest locomotory behavior are dramatically inhibited by physiological levels of environmental light. We find that the photosensitivity of this circuit is conferred by vertebrate ancient long opsin A (VALopA), which we show to be a G?(i)-coupled receptor that is expressed in the neurons of the spinal network. Sustained photoactivation of VALopA not only suppresses spontaneous activity but also alters the maturation of time-locked correlated network patterns. These results uncover a novel role for nonvisual opsins and a mechanism for environmental regulation of spontaneous motor behavior and neural activity in a circuit previously thought to be governed only by intrinsic developmental programs. PMID:25484291

  16. 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

  17. Binding of More Than One Retinoid to Visual Opsins

    PubMed Central

    Makino, Clint L.; Riley, Charles K.; Looney, James; Crouch, Rosalie K.; Okada, Tetsuji

    2010-01-01

    Visual opsins bind 11-cis retinal at an orthosteric site to form rhodopsins but increasing evidence suggests that at least some are capable of binding an additional retinoid(s) at a separate, allosteric site(s). Microspectrophotometric measurements on isolated, dark-adapted, salamander photoreceptors indicated that the truncated retinal analog, ?-ionone, partitioned into the membranes of green-sensitive rods; however, in blue-sensitive rod outer segments, there was an enhanced uptake of four or more ?-ionones per rhodopsin. X-ray crystallography revealed binding of one ?-ionone to bovine green-sensitive rod rhodopsin. Cocrystallization only succeeded with extremely high concentrations of ?-ionone and binding did not alter the structure of rhodopsin from the inactive state. Salamander green-sensitive rod rhodopsin is also expected to bind ?-ionone at sufficiently high concentrations because the binding site is present on its surface. Therefore, both blue- and green-sensitive rod rhodopsins have at least one allosteric binding site for retinoid, but ?-ionone binds to the latter type of rhodopsin with low affinity and low efficacy. PMID:20923672

  18. Shock-wave sensitivity of a TATB-based plasticized explosive

    Microsoft Academic Search

    Yu. A. Aminov; A. V. Vershinin; O. V. Kostitsyn; B. G. Loboiko; V. S. Lyubimov; S. N. Lyubyatinskii; G. N. Rykovanov; M. A. Strizhenok

    1995-01-01

    The results of numerical modelling of experiments on the investigation of shock-wave sensitivity of a TATB-based explosive are presented. A model for the macrokinetics of decomposition of the explosive has been constructed within the framework of a hypothesis of hot spots.

  19. 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

  20. 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.

  1. 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

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

    E-print Network

    Monteiro, Antónia

    Phenotypic plasticity in opsin expression in a butterfly compound eye complements sex role reversal complements sex role reversal Andrew Everett1* , Xiaoling Tong1 , Adriana D Briscoe2 and Antónia Monteiro1 forms, wet and dry, that vary in wing ornament brightness and in the identity of the sex that performs

  3. Homeobox transcription factor Six7 governs expression of green opsin genes in zebrafish.

    PubMed

    Ogawa, Yohey; Shiraki, Tomoya; Kojima, Daisuke; Fukada, Yoshitaka

    2015-08-01

    Colour discrimination in vertebrates requires cone photoreceptor cells in the retina, and high-acuity colour vision is endowed by a set of four cone subtypes expressing UV-, blue-, green- and red-sensitive opsins. Previous studies identified transcription factors governing cone photoreceptor development in mice, although loss of blue and green opsin genes in the evolution of mammals make it difficult to understand how high-acuity colour vision was organized during evolution and development. Zebrafish (Danio rerio) represents a valuable vertebrate model for studying colour vision as it retains all the four ancestral vertebrate cone subtypes. Here, by RT-qPCR and in situ hybridization analysis, we found that sine oculis homeobox homolog 7 (six7), a transcription factor widely conserved in ray-finned fish, is expressed predominantly in the cone photoreceptors in zebrafish at both the larval and the adult stages. TAL effector nuclease-based six7 knock-out revealed its roles in expression of green, red and blue cone opsin genes. Most prominently, the six7 deficiency caused a loss of expression of all the green opsins at both the larval and adult stages. six7 is indispensable for the development and/or maintenance of the green cones. PMID:26180064

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

    E-print Network

    Carleton, Karen L.

    Intraspecific cone opsin expression variation in the cichlids of Lake Malawi ADAM R. SMITH. The Fisherian model suggests that Correspondence: Adam R. Smith, Fax: (301) 314 6262; E-mail: adasmi@umd.edu Ó,* LINDSAY D'ANNUNZIO,* ABBI E. SMITH,* ANIT SHARMA,* CHRISTOPHER M. HOFMANN,* N. J. MARSHALL§ and KAREN L

  5. Color discrimination in the red range with only one long-wavelength sensitive opsin.

    PubMed

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

    2006-05-01

    The basic precondition for color vision is the presence of at least two receptor types with different spectral sensitivities. The sensitivity of a receptor is mostly defined by the opsin-based visual pigment expressed in it. We show here, through behavioral experiments, that the nymphalid butterfly Heliconius erato, although it expresses short and medium wavelength opsins and only one long wavelength opsin, discriminates colors in the long-wavelength range (590 nm, 620 nm and 640 nm), whereas another nymphalid, Vanessa atalanta, despite having color vision, is unable to do so. In the eyes of H. erato we identified filtering pigments very close to the rhabdom which differ between ommatidia and produce the yellow and red ommatidial reflection seen under orthodromic illumination. The eyes of V. atalanta lack the filtering pigments, and reflect a homogeneous orange. We hypothesize that the filtering pigments found in the eyes of H. erato may shift the spectral sensitivity peak of the long wavelength receptors in some ommatidia towards longer wavelengths. The comparison of the signals between the two new receptor types makes color discrimination in the red range possible. To our knowledge, this is the first behavioral proof of color vision based on receptors expressing the same opsin. PMID:16651559

  6. 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.

  7. New evidence for the role of heterochrony in the repeated evolution of cichlid opsin expression.

    PubMed

    O'Quin, Kelly E; Smith, Adam R; Sharma, Anit; Carleton, Karen L

    2011-01-01

    SUMMARY Lake Malawi (LM) cichlids have undergone heterochronic shifts in the expression of their cone opsin genes, the genes responsible for color vision. These shifts have generated species with short-, middle-, and long-wavelength-sensitive cone photoreceptors and visual systems. However, it is unclear when during the evolution of African cichlids these shifts occurred, or whether they could account for similar short- and middle-wavelength-sensitive profiles among unrelated cichlids in Lake Tanganyika (LT). To address these questions, we surveyed opsin expression in developing fry of two African cichlids, Astatotilapia burtoni from LT and Melanochromis auratus from LM. We found that A. burtoni expresses a series of three different single-cone opsins over the course of development, while M. auratus exhibits variation in the expression of only two. Neither A. burtoni nor M. auratus exhibits much variation in the expression of its double-cone opsins. These patterns reveal that A. burtoni exhibits progressive development in the sensitivity of its single-cone photoreceptors, but direct development in the sensitivity of its double-cone photoreceptors. M. auratus exhibits neotenic development in the sensitivity of both photoreceptor sets. Given the intermediate phylogenetic placement of A. burtoni between cichlids from LT and LM, our results suggest that the ancestor of LM's cichlids exhibited a progressive developmental pattern of opsin expression. These results indicate that the heterochronic shifts which produced the short- and middle-wavelength-sensitive profiles of LM's cichlids occurred recently, and suggest that the presence of similar profiles among LT's cichlids are due to parallel heterochronic shifts. PMID:21410875

  8. The ISO LWS high-resolution spectral survey towards Sagittarius B2

    NASA Astrophysics Data System (ADS)

    Polehampton, Edward T.; Baluteau, Jean-Paul; Swinyard, Bruce M.; Goicoechea, Javier R.; Brown, John M.; White, Glenn J.; Cernicharo, José; Grundy, Timothy W.

    2007-05-01

    A full spectral survey was carried out towards the giant molecular cloud complex, Sagittarius B2 (SgrB2), using the Infrared Space Observatory (ISO) Long Wavelength Spectrometer (LWS) Fabry-Pérot mode. This provided complete wavelength coverage in the range 47-196?m (6.38-1.53THz) with a spectral resolution of 30-40kms-1. This is a unique data set covering wavelengths inaccessible from the ground. It is an extremely important region of the spectrum as it contains both the peak of the thermal emission from dust, and crucial spectral lines of key atomic (OI, CII, OIII, NII and NIII) and molecular species (NH3, NH2, NH, H2O, OH, H3O+, CH, CH2, C3, HF and H2D+). In total, 95 spectral lines have been identified and 11 features with absorption depth greater than 3? remain unassigned. Most of the molecular lines are seen in absorption against the strong continuum, whereas the atomic and ionic lines appear in emission (except for absorption in the OI 63?m and CII 158?m lines). SgrB2 is located close to the Galactic Centre and so many of the features also show a broad absorption profile due to material located along the line of sight. A full description of the survey data set is given with an overview of each detected species and final line lists for both assigned and unassigned features. Based on observations with Infrared Space Observatory (ISO), an ESA project with instruments funded by ESA Member States (especially the PI countries: France, Germany, the Netherlands and the United Kingdom) with the participation of ISAS and NASA. E-mail: e.t.polehampton@rl.ac.uk

  9. Supplementary Figure S1. IHC of TG worms expressing (b)opsin in neurons and in muscles. a-g, Representative IHC images of live day 1 TG worms expressing (b)opsin in neurons Alexa-488-

    E-print Network

    Palczewski, Krzysztof

    Supplementary Figure S1. IHC of TG worms expressing (b)opsin in neurons and in muscles. a-g, Representative IHC images of live day 1 TG worms expressing (b)opsin in neurons Alexa-488- conjugated 1D4 mAb was injected into pseudocoelom of a worm head (a-d) or middle body section (e-g) together with Triton X-100

  10. 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

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

    2015-02-01

    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

  11. Expression of UV, blue-, long-wavelength-sensitive opsins and melatonin in extraretinal photoreceptors of the optic lobes of hawkmoths

    Microsoft Academic Search

    Jochen Lampel; Adriana D. Briscoe; Lutz T. Wasserthal

    2005-01-01

    Lepidopterans display biological rhythms associated with egg laying, eclosion and flight activity but the photoreceptors that mediate these behavioural patterns are largely unknown. To further our progress in identifying candidate light-input channels for the lepidopteran circadian system, we have developed polyclonal antibodies against ultraviolet (UV)-, blue- and extraretinal long-wavelength (LW)-sensitive opsins and examined opsin immunoreactivity in the adult optic lobes

  12. Rod and Cone Opsin Families Differ in Spectral Tuning Domains but Not Signal Transducing Domains as Judged by Saturated Evolutionary Trace Analysis

    Microsoft Academic Search

    Karen L. Carleton; Tyrone C. Spady; Rick H. Cote

    2005-01-01

    The visual receptor of rods and cones is a covalent complex of the apoprotein, opsin, and the light-sensitive chromophore, 11-cis-retinal. This pigment must fulfill many functions including photoactivation, spectral tuning, signal transmission, inactivation, and chromophore regeneration. Rod and cone photoreceptors employ distinct families of opsins. Although it is well known that these opsin families provide unique ranges in spectral sensitivity,

  13. Searching for Ejecta and Dust Formation Signatures in Young Supernova Remnants with ISO/LWS and Herschel

    NASA Astrophysics Data System (ADS)

    Park, Sung-Joon; Rho, J.

    2012-01-01

    We report infrared detected supernova remnants (SNRs) from ISO/LWS archival data. The ionic lines and continuum of mid- to far- infrared spectroscopy using ISO/LWS were carefully examined. We have found 10-15 useful detections of infrared emission in supernova remnants. As the first project using ISO data, we identified 4 new young SNRs showing broad ionic lines. Broad ionic lines are signatures of ejecta in which dust may form. G54.1+0.3 shows broad lines of [OIII] at 88 micron, [O I] at 63 micron and [N II] at 122 micron. G320.3-1.2 (MSH15-52) shows broad lines of both [OIII] at 52 and 88 micron and [N II] at 122 micron. G21.5-0.9 and MSH11-54 show a broad line of only [N II] at 122 micron. We detect [C II] lines at 158 micron from all of the four sample SNRs, but they are not resolved within instrument resolution. We also present the archival Herschel imaging data of the four SNRs and will estimate dust masses by combing the ISO spectra and Herschel. For other ISO detected-SNRs, we plan to make ISO catalog of IR-detected SNRs.

  14. 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

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

    PubMed

    Gong, Yiyang; Wagner, Mark J; Zhong Li, Jin; 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 signalling 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

  16. Light-controlled inhibition of malignant glioma by opsin gene transfer

    PubMed Central

    Yang, F; Tu, J; Pan, J-Q; Luo, H-L; Liu, Y-H; Wan, J; Zhang, J; Wei, P-F; Jiang, T; Chen, Y-H; Wang, L-P

    2013-01-01

    Glioblastomas are aggressive cancers with low survival rates and poor prognosis because of their highly proliferative and invasive capacity. In the current study, we describe a new optogenetic strategy that selectively inhibits glioma cells through light-controlled membrane depolarization and cell death. Transfer of the engineered opsin ChETA (engineered Channelrhodopsin-2 variant) gene into primary human glioma cells or cell lines, but not normal astrocytes, unexpectedly decreased cell proliferation and increased mitochondria-dependent apoptosis, upon light stimulation. These optogenetic effects were mediated by membrane depolarization-induced reductions in cyclin expression and mitochondrial transmembrane potential. Importantly, the ChETA gene transfer and light illumination in mice significantly inhibited subcutaneous and intracranial glioma growth and increased the survival of the animals bearing the glioma. These results uncover an unexpected effect of opsin ion channels on glioma cells and offer the opportunity for the first time to treat glioma using a light-controllable optogenetic approach. PMID:24176851

  17. Light- and electron-microscopic demonstration of immunoreactive opsin in the pinealocytes of various vertebrates.

    PubMed

    Vigh, B; Vigh-Teichmann, I

    1981-01-01

    An antibody to opsin isolated from rod outer segments of the frog retina was applied in light- and electron-microscopic immunocytochemical studies to the pineal organ of various vertebrates (Cyprinus carpio, Carassius auratus, Rana esculenta, Emys orbicularis, Pseudemys scripta elegans, Lacerta agilis and viridis. Gallus domesticus, Columba livia, Melopsittacus undulatus, Serinus canaria, Taeniopyga punctata, Didelphis virginiana, Erinaceus roumanicus, Myotis myotis, rabbit, rat, cat). PMID:6458362

  18. Honeybee Blue and Ultraviolet-Sensitive Opsins: Cloning, Heterologous Expression in Drosophila, and Physiological Characterization

    Microsoft Academic Search

    Steven M. Townson; Belinda S. W. Chang; Ernesto Salcedo; Linda V. Chadwell; Naomi E. Pierce; Steven G. Britt

    1998-01-01

    The honeybee (Apis mellifera) visual system contains three classes of retinal photoreceptor cells that are maximally sensi- tive to light at 440 nm (blue), 350 nm (ultraviolet), and 540 nm (green). We performed a PCR-based screen to identify the genes encoding the Apis blue- and ultraviolet (UV)-sensitive opsins. We obtained cDNAs that encode proteins having a high degree of sequence

  19. 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

  20. 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 ?-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

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

    PubMed Central

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

    2014-01-01

    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 (RhoP23H/+) 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 RhoP23H/P23H rods are ?17 000-fold less sensitive to light than Rho+/+ rods and produce abnormally fast photo-responses. By analyzing homozygous RhoP23H/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 RhoP23H/+ 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

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

    PubMed

    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

    2014-04-01

    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

  3. 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

  4. Research grants over last 6 years. 13. Institutional PI on NASA/LWS Grant (2013-2017) with Montana State University.

    E-print Network

    Mackay, Duncan

    Research grants over last 6 years. 13. Institutional PI on NASA/LWS Grant (2013-2017) with Montana State University. 1. PPARC/STFC Advanced Fellowship (2004-2009). 2. Royal Society Travel Grant for Conference in USA (2008). 3. Royal Society Research Grant (2007-2008). 4. British Council Research Exchange

  5. The structure of active opsin as a basis for identification of GPCR agonists by dynamic homology modelling and virtual screening assays

    E-print Network

    Gerwert, Klaus

    The structure of active opsin as a basis for identification of GPCR agonists by dynamic homologyAR) as a model system, we show that a dynamic homology model based on an ``active'' opsin structure 2011 Available online 21 October 2011 Edited by Robert B. Russell Keywords: Molecular dynamics

  6. Visual pigments and opsin expression in the juveniles of three species of fish (rainbow trout, zebrafish, and killifish) following prolonged exposure to thyroid hormone or retinoic acid.

    PubMed

    Suliman, Tarek; Novales Flamarique, Iñigo

    2014-01-01

    Thyroid hormone (TH) and retinoic acid (RA) are powerful modulators of photoreceptor differentiation during vertebrate retinal development. In the embryos and young juveniles of salmonid fishes and rodents, TH induces switches in opsin expression within individual cones, a phenomenon that also occurs in adult rodents following prolonged (12 week) hypothyroidism. Whether changes in TH levels also modulate opsin expression in the differentiated retina of fish is unknown. Like TH, RA is essential for retinal development, but its role in inducing opsin switches, if any, has not been studied. Here we investigate the action of TH and RA on single-cone opsin expression in juvenile rainbow trout, zebrafish, and killifish and on the absorbance of visual pigments in rainbow trout and zebrafish. Prolonged TH exposure increased the wavelength of maximum absorbance (?max ) of the rod and the medium (M, green) and long (L, red) wavelength visual pigments in all fish species examined. However, unlike the opsin switch that occurred following TH exposure in the single cones of small juvenile rainbow trout (alevin), opsin expression in large juvenile rainbow trout (smolt), zebrafish, or killifish remained unchanged. RA did not induce any opsin switches or change the visual pigment absorbance of photoreceptors. Neither ligand altered cone photoreceptor densities. We conclude that RA has no effect on opsin expression or visual pigment properties in the differentiated retina of these fishes. In contrast, TH affected both single-cone opsin expression and visual pigment absorbance in the rainbow trout alevin but only visual pigment absorbance in the smolt and in zebrafish. The latter results could be explained by a combination of opsin switches and chromophore shifts from vitamin A1 to vitamin A2. PMID:23818308

  7. Inferred L/M cone opsin polymorphism of ancestral tarsiers sheds dim light on the origin of anthropoid primates

    PubMed Central

    Melin, Amanda D.; Matsushita, Yuka; Moritz, Gillian L.; Dominy, Nathaniel J.; Kawamura, Shoji

    2013-01-01

    Tarsiers are small nocturnal primates with a long history of fuelling debate on the origin and evolution of anthropoid primates. Recently, the discovery of M and L opsin genes in two sister species, Tarsius bancanus (Bornean tarsier) and Tarsius syrichta (Philippine tarsier), respectively, was interpreted as evidence of an ancestral long-to-middle (L/M) opsin polymorphism, which, in turn, suggested a diurnal or cathemeral (arrhythmic) activity pattern. This view is compatible with the hypothesis that stem tarsiers were diurnal; however, a reversion to nocturnality during the Middle Eocene, as evidenced by hyper-enlarged orbits, predates the divergence of T. bancanus and T. syrichta in the Late Miocene. Taken together, these findings suggest that some nocturnal tarsiers possessed high-acuity trichromatic vision, a concept that challenges prevailing views on the adaptive origins of the anthropoid visual system. It is, therefore, important to explore the plausibility and antiquity of trichromatic vision in the genus Tarsius. Here, we show that Sulawesi tarsiers (Tarsius tarsier), a phylogenetic out-group of Philippine and Bornean tarsiers, have an L opsin gene that is more similar to the L opsin gene of T. syrichta than to the M opsin gene of T. bancanus in non-synonymous nucleotide sequence. This result suggests that an L/M opsin polymorphism is the ancestral character state of crown tarsiers and raises the possibility that many hallmarks of the anthropoid visual system evolved under dim (mesopic) light conditions. This interpretation challenges the persistent nocturnal–diurnal dichotomy that has long informed debate on the origin of anthropoid primates. PMID:23536597

  8. 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 rhodopsin’s 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

  9. 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

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

    PubMed Central

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

    2009-01-01

    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

  11. Allelic Variation in Malawi Cichlid Opsins: A Tale of Two Genera Adam R. Smith Karen L. Carleton

    E-print Network

    Carleton, Karen L.

    Allelic Variation in Malawi Cichlid Opsins: A Tale of Two Genera Adam R. Smith · Karen L. Carleton speciation (Kornfield and Smith 2000; Danley and Kocher 2001; Gen- ner and Turner 2005). Lakes Malawi00239-010-9355-x) contains supplementary material, which is available to authorized users. A. R. Smith

  12. 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

  13. 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

  14. 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.

  15. 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

  16. 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

  17. Chemical and radiative transfer modelling of the ISO-LWS Fabry-Perot spectra of Orion-KL water lines

    NASA Astrophysics Data System (ADS)

    Lerate, M. R.; Yates, J. A.; Barlow, M. J.; Viti, S.; Swinyard, B. M.

    2010-08-01

    We present chemical and radiative transfer models for the many far-infrared ortho- and para-H2O lines that were observed from the Orion-KL region in high resolution Fabry-Pérot (FP) mode by the Long Wavelength Spectrometer (LWS) on board the Infrared Space Observatory (ISO). The chemistry of the region was first studied by simulating the conditions in the different known components of Orion-KL: chemical models for a hot core, a plateau and a ridge were coupled with an accelerated ?-iteration radiative transfer model to predict H2O line fluxes and profiles. Our models include the first 45 energy levels of ortho- and para-H2O. We find that lines arising from energy levels below 560 K were best reproduced by a gas of density 3 × 105cm-3 at a temperature of 70-90 K, expanding at a velocity of 30kms-1 and with a H2O/H2 abundance ratio of the order of 2-3 × 10-5, similar to the abundance derived by Cernicharo et al. However, the model that best reproduces the fluxes and profiles of H2O lines arising from energy levels above 560 K has a significantly higher H2O/H2 abundance, 1-5 × 10-4, originating from gas of similar density, in the Plateau region, that has been heated to 300 K, relaxing to 90-100 K. We conclude that the observed water lines do not originate from high-temperature shocks.

  18. The Human Blue Opsin Promoter Directs Transgene Expression in Short-Wave Cones and Bipolar Cells in the Mouse Retina

    Microsoft Academic Search

    J. Chen; C. L. Tucker; B. Woodford; A. Szel; J. Lem; A. Gianella-Borradori; M. I. Simon; E. Bogenmann

    1994-01-01

    Transgenic mouse lines were generated using either 3.8 or 1.1 kb of 5' upstream flanking sequence from the human blue opsin gene fused to the lacZ or human growth hormone reporter gene. Mice were analyzed for appropriate cell-specific and developmental expression patterns. In 13 independently derived lines of animals, transgene expression was limited to photoreceptor and inner nuclear layer cells.

  19. 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.

  20. 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

  1. Adult stemmata of the butterfly Vanessa cardui express UV and green opsin mRNAs.

    PubMed

    Briscoe, Adriana D; White, Richard H

    2005-01-01

    Adult stemmata are distinctive insect photoreceptors located on the posterior surfaces of the optic lobes. They originate as larval eyes that migrate inward during metamorphosis. We used a combination of light microscopy and in situ hybridization to examine their anatomical organization in the butterfly Vanessa cardui and to test for the presence of visual pigments, the light sensitive components of the visual transduction pathway. The bilateral cluster of six internal stemmata is located near the ventral edge of the lamina. They retain the dark screening pigment and overlying crystalline cones of the larval stemmata. We found two opsin mRNAs expressed in the stemmata that are also expressed, respectively, in UV-sensitive and green-sensitive photoreceptor cells in the compound eye. A third mRNA that is expressed in blue-sensitive photoreceptor cells of the compound eye was not expressed in the stemmata. Our results reinforce the idea that the adult stemmata are not merely developmental remnants of larval eyes, but remain functional, possibly as components of the circadian input channel. PMID:15503147

  2. Color Vision Variation as Evidenced by Hybrid L/M Opsin Genes in Wild Populations of Trichromatic Alouatta New World Monkeys.

    PubMed

    Matsushita, Yuka; Oota, Hiroki; Welker, Barbara J; Pavelka, Mary S; Kawamura, Shoji

    2014-01-01

    Platyrrhine (New World) monkeys possess highly polymorphic color vision owing to allelic variation of the single-locus L/M opsin gene on the X chromosome. Most species consist of female trichromats and female and male dichromats. Howlers (genus Alouatta) are an exception; they are considered to be routinely trichromatic with L and M opsin genes juxtaposed on the X chromosome, as seen in catarrhine primates (Old World monkeys, apes, and humans). Yet it is not known whether trichromacy is invariable in howlers. We examined L/M opsin variation in wild howler populations in Costa Rica and Nicaragua (Alouatta palliata) and Belize (A. pigra), using fecal DNA. We surveyed exon 5 sequences (containing the diagnostic 277th and 285th residues for ?max) for 8 and 18 X chromosomes from Alouatta palliata and A. pigra, respectively. The wavelengths of maximal absorption (?max) of the reconstituted L and M opsin photopigments were 564 nm and 532 nm, respectively, in both species. We found one M-L hybrid sequence with a recombinant 277/285 haplotype in Alouatta palliata and two L-M hybrid sequences in A. pigra. The ?max values of the reconstituted hybrid photopigments were in the range of 546~554 nm, which should result in trichromat phenotypes comparable to those found in other New World monkey species. Our finding of color vision variation due to high frequencies of L/M hybrid opsin genes in howlers challenges the current view that howlers are routine and uniform trichromats. These results deepen our understanding of the evolutionary significance of color vision polymorphisms and routine trichromacy and emphasize the need for further assessment of opsin gene variation as well as behavioral differences among subtypes of trichromacy. PMID:24523565

  3. Evolution of phototransduction, vertebrate photoreceptors and retina.

    PubMed

    Lamb, Trevor D

    2013-09-01

    Evidence is reviewed from a wide range of studies relevant to the evolution of vertebrate photoreceptors and phototransduction, in order to permit the synthesis of a scenario for the major steps that occurred during the evolution of cones, rods and the vertebrate retina. The ancestral opsin originated more than 700 Mya (million years ago) and duplicated to form three branches before cnidarians diverged from our own lineage. During chordate evolution, ciliary opsins (C-opsins) underwent multiple stages of improvement, giving rise to the 'bleaching' opsins that characterise cones and rods. Prior to the '2R' rounds of whole genome duplication near the base of the vertebrate lineage, 'cone' photoreceptors already existed; they possessed a transduction cascade essentially the same as in modern cones, along with two classes of opsin: SWS and LWS (short- and long-wave-sensitive). These cones appear to have made synaptic contact directly onto ganglion cells, in a two-layered retina that resembled the pineal organ of extant non-mammalian vertebrates. Interestingly, those ganglion cells appear to be descendants of microvillar photoreceptor cells. No lens was associated with this two-layered retina, and it is likely to have mediated circadian timing rather than spatial vision. Subsequently, retinal bipolar cells evolved, as variants of ciliary photoreceptors, and greatly increased the computational power of the retina. With the advent of a lens and extraocular muscles, spatial imaging information became available for central processing, and gave rise to vision in vertebrates more than 500 Mya. The '2R' genome duplications permitted the refinement of cascade components suitable for both rods and cones, and also led to the emergence of five visual opsins. The exact timing of the emergence of 'true rods' is not yet clear, but it may not have occurred until after the divergence of jawed and jawless vertebrates. PMID:23792002

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

    PubMed

    Tian, Guilian; Lodowski, Kerrie H; Lee, Richard; Imanishi, Yoshikazu

    2014-11-01

    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

  5. Molecular characterization and expression of the UV opsin in bumblebees: three ommatidial subtypes in the retina and a new photoreceptor organ in the lamina

    Microsoft Academic Search

    Johannes Spaethe; Adriana D. Briscoe

    2005-01-01

    Ultraviolet-sensitive photoreceptors have been shown to be important for a variety of visual tasks performed by bees, such as orientation, color and polarization vision, yet little is known about their spatial distribution in the compound eye or optic lobe. We cloned and sequenced a UV opsin mRNA transcript from Bombus impatiens head- specific cDNA and, using western blot analysis, detected

  6. Characterization of a Novel Human Opsin Gene with Wide Tissue Expression and Identification of Embedded and Flanking Genes on Chromosome 1q43

    Microsoft Academic Search

    Stephanie Halford; James Bellingham; Suzanne L. Inglis; Subathra Poopalasundaram; Bobby G. Soni; Russell G. Foster; David M. Hunt

    2001-01-01

    As part of an ongoing search to identify novel mammalian photopigments that may mediate nonvisual tasks such as circadian entrainment and acute suppression of pineal melatonin levels, a number of recently cloned nonvisual opsin sequences were used to search dbEST. panopsin (OPN3) was one of the clones identified using this approach. Expression analysis detects two transcripts of approximately 2.1 and

  7. Opsin expression, physiological characterization and identification of photoreceptor cells in the dorsal rim area and main retina of the desert locust, Schistocerca gregaria.

    PubMed

    Schmeling, Fabian; Wakakuwa, Motohiro; Tegtmeier, Jennifer; Kinoshita, Michiyo; Bockhorst, Tobias; Arikawa, Kentaro; Homberg, Uwe

    2014-10-01

    For compass orientation many insects rely on the pattern of sky polarization, but some species also exploit the sky chromatic contrast. Desert locusts, Schistocerca gregaria, detect polarized light through a specialized dorsal rim area (DRA) in their compound eye. To better understand retinal mechanisms underlying visual navigation, we compared opsin expression, spectral and polarization sensitivities and response-stimulus intensity functions in the DRA and main retina of the locust. In addition to previously characterized opsins of long-wavelength-absorbing (Lo1) and blue-absorbing visual pigments (Lo2), we identified an opsin of an ultraviolet-absorbing visual pigment (LoUV). DRA photoreceptors exclusively expressed Lo2, had peak spectral sensitivities at 441 nm and showed high polarization sensitivity (PS 1.3-31.7). In contrast, ommatidia in the main eye co-expressed Lo1 and Lo2 in five photoreceptors, expressed Lo1 in two proximal photoreceptors, and Lo2 or LoUV in one distal photoreceptor. Correspondingly, we found broadband blue- and green-peaking spectral sensitivities in the main eye and one narrowly tuned UV peaking receptor. Polarization sensitivity in the main retina was low (PS 1.3-3.8). V-log I functions in the DRA were steeper than in the main retina, supporting a role in polarization vision. Desert locusts occur as two morphs, a day-active gregarious and a night-active solitarious form. In solitarious locusts, sensitivities in the main retina were generally shifted to longer wavelengths, particularly in ventral eye regions, supporting a nocturnal lifestyle at low light levels. The data support the role of the DRA in polarization vision and suggest trichromatic colour vision in the desert locust. PMID:25104757

  8. 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 14–448 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

  9. 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

  10. Supplementary Figure S1. Light-associated motor responses of worms expressing (b)opsin in neurons. a, Vigorously crawling TG animals pre-incubated with 10 M 9-cis-retinal and expressing

    E-print Network

    Palczewski, Krzysztof

    Supplementary Figure S1. Light-associated motor responses of worms expressing (b)opsin in neurons responses to light were recorded and scored. Data represent three independent experiments with 3- 10 worms) of these animals are shown. Data represent three independent experiments with 3-5 worms each. Error bars indicate S

  11. Gene duplication and spectral diversification of cone visual pigments of zebrafish.

    PubMed Central

    Chinen, Akito; Hamaoka, Takanori; Yamada, Yukihiro; Kawamura, Shoji

    2003-01-01

    Zebrafish is becoming a powerful animal model for the study of vision but the genomic organization and variation of its visual opsins have not been fully characterized. We show here that zebrafish has two red (LWS-1 and LWS-2), four green (RH2-1, RH2-2, RH2-3, and RH2-4), and single blue (SWS2) and ultraviolet (SWS1) opsin genes in the genome, among which LWS-2, RH2-2, and RH2-3 are novel. SWS2, LWS-1, and LWS-2 are located in tandem and RH2-1, RH2-2, RH2-3, and RH2-4 form another tandem gene cluster. The peak absorption spectra (lambdamax) of the reconstituted photopigments from the opsin cDNAs differed markedly among them: 558 nm (LWS-1), 548 nm (LWS-2), 467 nm (RH2-1), 476 nm (RH2-2), 488 nm (RH2-3), 505 nm (RH2-4), 355 nm (SWS1), 416 nm (SWS2), and 501 nm (RH1, rod opsin). The quantitative RT-PCR revealed a considerable difference among the opsin genes in the expression level in the retina. The expression of the two red opsin genes and of three green opsin genes, RH2-1, RH2-3, and RH2-4, is significantly lower than that of RH2-2, SWS1, and SWS2. These findings must contribute to our comprehensive understanding of visual capabilities of zebrafish and the evolution of the fish visual system and should become a basis of further studies on expression and developmental regulation of the opsin genes. PMID:12618404

  12. Opsins and mammalian photoentrainment

    Microsoft Academic Search

    James Bellingham; Russell G. Foster

    2002-01-01

    Research over the past decade has provided overwhelming evidence that photoreception in the vertebrate eye is not confined to the rod and cone photoreceptors. It appears that photoreceptor cells within the inner retina provide irradiance information to a wide variety of different photosensory tasks including photoentrainment, pupillary constriction and masking behaviour. Action spectra in mice lacking all rod and cone

  13. ORIGINAL PAPER M. Vorobyev D. Osorio A. T. D. Bennett

    E-print Network

    Menzel, Randolf - Institut für Biologie

    is at 410 nm, with that of the passerine Leiothrix, where the ultraviolet-sensitive peak is at 365 nm, gen Abbreviations LWS long-wave sensitive á MWS medium- wave-sensitive á SWS short-wave-sensitive á UVS ultraviolet

  14. Eyeshine and spectral tuning of long wavelength-sensitive rhodopsins: no evidence for red-sensitive photoreceptors among five Nymphalini butterfly species.

    PubMed

    Briscoe, Adriana D; Bernard, Gary D

    2005-02-01

    Spectral tuning of rhodopsins commonly refers to the effects of opsin amino acid substitutions on the wavelength for peak sensitivity of the rhodopsin absorption spectrum. Nymphalini butterflies provide an opportunity for identifying some of the amino acid substitutions responsible for insect rhodopsin spectral tuning because the majority of photoreceptor cells (R3-9) in the adult retina express only a single long wavelength-sensitive (LWS) opsin mRNA transcript. Therefore, the opsin genotype can be directly correlated with its phenotype. We determined the LWS opsin gene sequence from cDNA of the mourning cloak Nymphalis antiopa, and from genomic DNA of the malachite Siproeta stelenes and the peacock Inachis io. Using an epi-microspectrophotometer we examined each butterfly's eyeshine for photochemical evidence of multiple LWS rhodopsins and found only one. We then performed partial-bleaching experiments to obtain absorbance spectra for the LWS rhodopsins of all three species as well as from another nymphalid, the buckeye Junonia coenia. The isolated LWS opsin gene sequences varied in length from 1437-1612 bp and encode rhodopsins R522 (S. stelenes), R530 (I. io), R534 (N. antiopa) and, together with a previously published sequence, R510 (J. coenia). Comparative sequence analysis indicates that the S. stelenes rhodopsin is slightly blue-shifted compared to the typical 530 nm lepidopteran rhodopsin because of the presence of a S138A substitution at a homologous site that in mammalian MWS/LWS rhodopsins causes a 5 nm blue-shift. The difference in peak absorption between R522 of S. stelenes and R530 of Inachis io is therefore largely accounted for by this substitution. This suggests that spectral tuning mechanisms employing the S138A may have evolved in parallel in mammalian and butterfly MWS/LWS rhodopsins across 500 million years of evolution. PMID:15695761

  15. BARREL: An LWS Geospace Mission of Opportunity

    NASA Astrophysics Data System (ADS)

    Millan, Robyn; Sample, J. G.; Smith, D. M.; McCarthy, M. P.; Lin, R. P.; Hudson, M. K.; Woodger, L. A.; Hewitt, J.; Comess, M.

    2009-01-01

    BARREL (Balloon Array for RBSP Relativistic Electron Losses) is a multiple-balloon investigation that will study electron losses from Earth's Van Allen Radiation Belts. Atmospheric losses of relativistic electrons play an important role in radiation belt dynamics; precipitation into the atmosphere may even completely deplete the radiation belts during the main phase of some geomagnetic storms. BARREL is the first Living with a Star Geospace Mission of Opportunity, and will support NASA's Radiation Belt Storm Probes mission. BARREL will consist of two Antarctic balloon campaigns conducted during the Austral summers of 2012 and 2013. During each campaign, a total of 20 small ( 20 kg) balloon payloads will be launched to an altitude of 30-35 km to maintain an array of 5-8 payloads extending across up to 8 hours of magnetic local time for 40 days. Each balloon will carry a NaI scintillator to measure the bremsstrahlung X-rays produced by precipitating relativistic electrons as they collide with neutrals in Earth's atmosphere. We present an overview of the BARREL investigation which will provide the first balloon measurements of relativistic electron precipitation while in situ measurements of both plasma waves and energetic particle distributions are available.

  16. Genetic analyses of visual pigments of the pigeon (Columba livia).

    PubMed Central

    Kawamura, S; Blow, N S; Yokoyama, S

    1999-01-01

    We isolated five classes of retinal opsin genes rh1(Cl), rh2(Cl), sws1(Cl), sws2(Cl), and lws(Cl) from the pigeon; these encode RH1(Cl), RH2(Cl), SWS1(Cl), SWS2(Cl), and LWS(Cl) opsins, respectively. Upon binding to 11-cis-retinal, these opsins regenerate the corresponding photosensitive molecules, visual pigments. The absorbance spectra of visual pigments have a broad bell shape with the peak, being called lambdamax. Previously, the SWS1(Cl) opsin cDNA was isolated from the pigeon retinal RNA, expressed in cultured COS1 cells, reconstituted with 11-cis-retinal, and the lambdamax of the resulting SWS1(Cl) pigment was shown to be 393 nm. In this article, using the same methods, the lambdamax values of RH1(Cl), RH2(Cl), SWS2(Cl), and LWS(Cl) pigments were determined to be 502, 503, 448, and 559 nm, respectively. The pigeon is also known for its UV vision, detecting light at 320-380 nm. Being the only pigments that absorb light below 400 nm, the SWS1(Cl) pigments must mediate its UV vision. We also determined that a nonretinal P(Cl) pigment in the pineal gland of the pigeon has a lambdamax value at 481 nm. PMID:10581289

  17. 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.

  18. Visual system evolution and the nature of the ancestral snake.

    PubMed

    Simões, B F; Sampaio, F L; Jared, C; Antoniazzi, M M; Loew, E R; Bowmaker, J K; Rodriguez, A; Hart, N S; Hunt, D M; Partridge, J C; Gower, D J

    2015-07-01

    The dominant hypothesis for the evolutionary origin of snakes from 'lizards' (non-snake squamates) is that stem snakes acquired many snake features while passing through a profound burrowing (fossorial) phase. To investigate this, we examined the visual pigments and their encoding opsin genes in a range of squamate reptiles, focusing on fossorial lizards and snakes. We sequenced opsin transcripts isolated from retinal cDNA and used microspectrophotometry to measure directly the spectral absorbance of the photoreceptor visual pigments in a subset of samples. In snakes, but not lizards, dedicated fossoriality (as in Scolecophidia and the alethinophidian Anilius scytale) corresponds with loss of all visual opsins other than RH1 (?max 490-497 nm); all other snakes (including less dedicated burrowers) also have functional sws1 and lws opsin genes. In contrast, the retinas of all lizards sampled, even highly fossorial amphisbaenians with reduced eyes, express functional lws, sws1, sws2 and rh1 genes, and most also express rh2 (i.e. they express all five of the visual opsin genes present in the ancestral vertebrate). Our evidence of visual pigment complements suggests that the visual system of stem snakes was partly reduced, with two (RH2 and SWS2) of the ancestral vertebrate visual pigments being eliminated, but that this did not extend to the extreme additional loss of SWS1 and LWS that subsequently occurred (probably independently) in highly fossorial extant scolecophidians and A. scytale. We therefore consider it unlikely that the ancestral snake was as fossorial as extant scolecophidians, whether or not the latter are para- or monophyletic. PMID:26012745

  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; Grützner, 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. 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

  1. 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 ? 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

  2. Opsin Stability and Folding: Modulation by Phospholipid Bicelles

    E-print Network

    Wallace, Bonnie Ann

    . McKibbin, Faculty of Life Sciences, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK; C segment; LDAO, N,N-dimethyldodecylamine N-oxide. doi:10.1016/j.jmb.2007.10.018 J. Mol. Biol. (2007) 374

  3. 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.

  4. 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.

  5. Parallel and Convergent Evolution of the Dim-Light Vision Gene RH1 in Bats (Order: Chiroptera)

    PubMed Central

    Shen, Yong-Yi; Liu, Jie; Irwin, David M.; Zhang, Ya-Ping

    2010-01-01

    Rhodopsin, encoded by the gene Rhodopsin (RH1), is extremely sensitive to light, and is responsible for dim-light vision. Bats are nocturnal mammals that inhabit poor light environments. Megabats (Old-World fruit bats) generally have well-developed eyes, while microbats (insectivorous bats) have developed echolocation and in general their eyes were degraded, however, dramatic differences in the eyes, and their reliance on vision, exist in this group. In this study, we examined the rod opsin gene (RH1), and compared its evolution to that of two cone opsin genes (SWS1 and M/LWS). While phylogenetic reconstruction with the cone opsin genes SWS1 and M/LWS generated a species tree in accord with expectations, the RH1 gene tree united Pteropodidae (Old-World fruit bats) and Yangochiroptera, with very high bootstrap values, suggesting the possibility of convergent evolution. The hypothesis of convergent evolution was further supported when nonsynonymous sites or amino acid sequences were used to construct phylogenies. Reconstructed RH1 sequences at internal nodes of the bat species phylogeny showed that: (1) Old-World fruit bats share an amino acid change (S270G) with the tomb bat; (2) Miniopterus share two amino acid changes (V104I, M183L) with Rhinolophoidea; (3) the amino acid replacement I123V occurred independently on four branches, and the replacements L99M, L266V and I286V occurred each on two branches. The multiple parallel amino acid replacements that occurred in the evolution of bat RH1 suggest the possibility of multiple convergences of their ecological specialization (i.e., various photic environments) during adaptation for the nocturnal lifestyle, and suggest that further attention is needed on the study of the ecology and behavior of bats. PMID:20098620

  6. Increase in shock-wave sensitivity of damaged samples of TATB

    Microsoft Academic Search

    V. A. Komrachkov; A. D. Kovtun; Yu. M. Makarov

    1999-01-01

    Shock-wave loading conditions leading to damage of samples of plasticized TATB are described. Results of loading of the damaged\\u000a TATB samples by an explosion of a mounted initiator were recorded by pulse radiography, and they show that the shock-wave\\u000a sensitivity of the samples increases.

  7. Bridging particle and wave sensitivity in a detector of configurable positive operator-valued measures

    E-print Network

    Graciana Puentes; Jeff S. Lundeen; Matthijs P. A. Branderhorst; Hendrik B. Coldenstrodt-Ronge; Brian J. Smith; Ian A. Walmsley

    2009-02-09

    We report an optical detector with tunable positive operator-valued measures (POVMs). The device is based on a combination of weak-field homodyne techniques and photon-number-resolving detection. The resulting POVMs can be continuously tuned from Fock-state projectors to a variety of phase-dependent quantum-state measurements by adjusting different system parameters such as local oscillator coupling, amplitude and phase, allowing thus not only detection but also preparation of exotic quantum states. Experimental tomographic reconstructions of classical benchmark states are presented as a demonstration of the detector capabilities.

  8. BN Danforth Opsin primers for bees/wasps (1/6/2005)

    E-print Network

    Danforth, Bryan Nicholas

    where clones heterozygous for mutations in ribosomal genes (Minutes) were found to be outcompeted , Juan F. Poyatos1, , Irene Fernández-Ruiz1 , Jesús M. López-Gay1 , Offer Gerlitz2 and Eduardo Moreno1

  9. Adaptive Molecular Evolution in the Opsin Genes of Rapidly Speciating Cichlid Species

    E-print Network

    Carleton, Karen L.

    in the rods of freshwater teleosts. Among the cot- toids of Lake Baikal, the world's deepest lake, rhodopsin in cone spectral sensitivity associated with disparities in photic environment. Both deep-dwelling Lake Baikal cottoids and coelacanths show a marked shortwave shift in cone spectral sensitivities (Bowmaker et

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

    Microsoft Academic Search

    Ilke van Hazel; Francesco Santini; Johannes Müller; Belinda SW Chang

    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

  11. Adult stemmata of the butterfly Vanessa cardui express UV and green opsin mRNAs

    Microsoft Academic Search

    Adriana D. Briscoe; Richard H. White

    2005-01-01

    Adult stemmata are distinctive insect photoreceptors located on the posterior surfaces of the optic lobes. They originate as larval eyes that migrate inward during metamorphosis. We used a combination of light microscopy and in situ hybridization to examine their anatomical organization in the butterfly Vanessa cardui and to test for the presence of visual pigments, the light sensitive components of

  12. 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

  13. VA Opsin, Melanopsin, and an Inherent Light Response within Retinal Interneurons

    Microsoft Academic Search

    Aaron Jenkins; Marta Muñoz; Emma E. Tarttelin; James Bellingham; Russell G. Foster; Mark W. Hankins

    2003-01-01

    Background: Although photoreception is best understood in rods and cones, it is increasingly clear that these are not the only photoreceptive cells of the vertebrate retina. While considerable attention has been paid to the role of melanopsin in the generation of intrinsic light sensitivity in the retinal ganglion cells of mammals, nothing is known about the photoreceptive capacity of the

  14. Informational lesions: optical perturbation of spike timing and neural synchrony via microbial opsin gene fusions

    E-print Network

    Han, Xue

    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 ...

  15. Phylogenetic Utility of the Major Opsin in Bees (Hymenoptera: Apoidea): A Reassessment

    E-print Network

    Danforth, Bryan Nicholas

    for recovering Mesozoic divergences in insects are few. LW Rh is a member of a multigene family encoding visual and references therein). These are the Euglossini (orchid bees, 175 known species, five gen- era), Bombini, numerous genera). The corbiculate bee tribes are thought to be of Mesozoic age because a fossil meliponine

  16. 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

  17. Global Measurements of the Magnetic Field of the Inner Heliosphere with the Mileura Wide- Field Array in Support of LWS Sentinels

    NASA Astrophysics Data System (ADS)

    Kasper, J. C.; D, O.; Salah, J. E.; Lonsdale, C. J.

    2006-12-01

    The Mileura Wide-Field Array Low Frequency Demonstrator (MWA) is an 80-300 MHz interferometric radio array consisting of 8000 antennas distributed in 16-antenna tiles over several square kilometers in Mileura Station, Western Australia. Selected by the NSF in June 2006, antenna deployment will begin in 2007, and the array is scheduled to become operational within three years. The primary goal of MWA-LFD is to demonstrate the capabilities of a digital array for conducting groundbreaking heliospheric and astrophysical science through wide fields of view, high sensitivity, and multiple beam capabilities. The heliospheric science goals of MWA are to characterize the density, velocity, and magnetic field of the inner heliosphere, from the outer corona to interplanetary space, and to image and localize solar radio bursts. The recently released Sentinels Science and Technology Definition Team report describes the value of supporting observations from ground-based instruments such as the MWA. We will present the MWA and discuss how we will use the array to reconstruct the magnetic connection between the corona and the inner heliosphere, both during quiet times and in the presence of CMEs. In particular, we will demonstrate how observing simultaneously the Faraday rotation of polarized radio emission from hundreds of galaxies within 80 Rs of the Sun will be used to trace the magnetic field topology out to the planned Sentinels orbit. These measurements will provide a global context for the Sentinels observations.

  18. Global Measurements of the Magnetic Field of the Inner Heliosphere with the Mileura Wide Field Array in Support of LWS Sentinels

    Microsoft Academic Search

    J. C. Kasper; O. D; J. E. Salah; C. J. Lonsdale

    2006-01-01

    The Mileura Wide-Field Array Low Frequency Demonstrator (MWA) is an 80-300 MHz interferometric radio array consisting of 8000 antennas distributed in 16-antenna tiles over several square kilometers in Mileura Station, Western Australia. Selected by the NSF in June 2006, antenna deployment will begin in 2007, and the array is scheduled to become operational within three years. The primary goal of

  19. Outflows from young objects observed with the ISO-LWS. I. Fine structure lines [O I] 63 ?m, [O I] 145 ?m and [C II] 157 ?m

    NASA Astrophysics Data System (ADS)

    Liseau, R.; Justtanont, K.; Tielens, A. G. G. M.

    2006-02-01

    Far infrared fine structure line data from the ISO archive have been extracted for several hundred YSOs and their outflows, including molecular (CO) outflows, optical jets and Herbig-Haro (HH) objects. Given the importance of these lines to astrophysics, their excitation and transfer ought to be investigated in detail and, at this stage, the reliability of the diagnostic power of the fine structure transitions of O I and C II has been examined. Several issues, such as the extremely small intensity ratios of the oxygen 63 ?m to 145 ?m lines, are still awaiting an explanation. It is demonstrated that, in interstellar cloud conditions, the 145 ?m line is prone to masing, but that this effect is likely an insufficient cause of the line ratio anomaly observed from cold dark clouds. Very optically thick emission could in principle also account for this, but would need similar, prohibitively high column densities and must therefore be abondoned as a viable explanation. One is left with [O i] 63 ?m self absorption by cold and tenuous foreground gas, as has been advocated for distant luminous sources. Recent observations with the submillimeter observatory Odin support this scenario also in the case of nearby dark molecular clouds. On the basis of this large statistical material we are led to conclude that in star forming regions, the [O I] and [C II] lines generally have only limited diagnostic value.

  20. Gas and dust cooling along the major axis of M 33 (HerM33es). ISO/LWS [C ii] observations

    NASA Astrophysics Data System (ADS)

    Kramer, C.; Abreu-Vicente, J.; García-Burillo, S.; Relaño, M.; Aalto, S.; Boquien, M.; Braine, J.; Buchbender, C.; Gratier, P.; Israel, F. P.; Nikola, T.; Röllig, M.; Verley, S.; van der Werf, P.; Xilouris, E. M.

    2013-05-01

    Aims: We aim to better understand the heating of gas by observing the prominent gas cooling line [C ii] at 158 ?m in the low-metallicity environment of the Local Group spiral galaxy M 33 on scales of 280 pc. In particular, we describe the variation of the photoelectric heating efficiency with the galactic environment. Methods: In this study, we present [C ii] observations along the major axis of M 33 using the Infrared Space Observatory in combination with Herschel continuum maps, IRAM 30 m CO 2-1, and VLA H i data to study the variation in velocity integrated intensities. The ratio of [C ii] emission over the far-infrared continuum is used as a proxy for the heating efficiency, and models of photon-dominated regions are used to study the local physical densities, far-ultraviolet radiation fields, and average column densities of the molecular clouds. Results: The heating efficiency stays constant at 0.8% in the inner 4.5 kpc radius of the galaxy, where it increases to reach values of ~3% in the outskirts at about a 6 kpc radial distance. The rise of efficiency is explained in the framework of PDR models by lowered volume densities and FUV fields for optical extinctions of only a few magnitudes at constant metallicity. For the significant fraction of H i emission stemming from PDRs and for typical pressures found in the Galactic cold neutral medium (CNM) traced by H i emission, the CNM contributes ~15% to the observed [C ii] emission in the inner 2 kpc radius of M 33. The CNM contribution remains largely undetermined in the south, while positions between radial distances of 2 and 7.3 kpc in the north of M 33 show a contribution of ~40% ± 20%. Herschel is an ESA space observatory with science instruments provided by European-led PrincipalInvestigator consortia and with important participation from NASA.Appendices are available in electronic form at http://www.aanda.org

  1. 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

  2. From CIE 2006 physiological model to improved age-dependent and average colorimetric observers.

    PubMed

    Sarkar, Abhijit; Autrusseau, Florent; Viénot, Françoise; Le Callet, Patrick; Blondé, Laurent

    2011-10-01

    In the context of color perception on modern wide-gamut displays with narrowband spectral primaries, we performed a theoretical analysis on various aspects of physiological observers proposed by CIE TC 1-36 (CIEPO06). We allowed certain physiological factors to vary, which was not considered in the CIEPO06 framework. For example, we analyzed that the long-wave-sensitive (LWS) or medium-wave-sensitive (MWS) peak wavelength shift in the photopigment absorption spectra, a factor not modeled in CIEPO06, contributed more toward observer variability than some of the factors considered in the model. Further, we compared the color-matching functions derived from the CIEPO06 model and the CIE 10° standard colorimetric observer to the average observer data from three distinct subgroups of Stiles-Burch observers, formed on the basis of observer ages (22-23 years, 27-29 years, and 49-50 years). The errors in predicting the x(?) and y(?) color-matching functions of the intragroup average observers in the long-wave range and in the medium-wave range, respectively, were generally more in the case of the CIEPO06 model compared to the 10° standard colorimetric observer and manifested in both spectral and chromaticity space. In contrast, the short-wave-sensitive z??(?) function of the 10° standard colorimetric observer performed poorly compared to the CIEPO06 model for all three subgroups. Finally, a constrained nonlinear optimization on the CIEPO06 model outputs showed that a peak wavelength shift of photopigment density alone could not improve the model prediction errors at higher wavelengths. As an alternative, two optimized weighting functions for each of the LWS and MWS cone photopigment densities led to significant improvement in the prediction of intra-age-group average data for both the 22-23 year and 49-50 year age groups. We hypothesize that the assumption in the CIEPO06 model that the peak optical density of visual pigments does not vary with age is false and is the source of these prediction errors at higher wavelengths. Correcting these errors in the model can lead to an improved age-dependent observer and can also help update the current CIE 10° standard colorimetric observer. Accordingly, it would reduce the discrepancies between color matches with broadband spectral primaries and color matches with narrowband spectral primaries. PMID:21979508

  3. Acoustic mode coupling induced by shallow water nonlinear internal waves: sensitivity to environmental conditions and space-time scales of internal waves.

    PubMed

    Colosi, John A

    2008-09-01

    While many results have been intuited from numerical simulation studies, the precise connections between shallow-water acoustic variability and the space-time scales of nonlinear internal waves (NLIWs) as well as the background environmental conditions have not been clearly established analytically. Two-dimensional coupled mode propagation through NLIWs is examined using a perturbation series solution in which each order n is associated with nth-order multiple scattering. Importantly, the perturbation solution gives resonance conditions that pick out specific NLIW scales that cause coupling, and seabed attenuation is demonstrated to broaden these resonances, fundamentally changing the coupling behavior at low frequency. Sound-speed inhomogeneities caused by internal solitary waves (ISWs) are primarily considered and the dependence of mode coupling on ISW amplitude, range width, depth structure, location relative to the source, and packet characteristics are delineated as a function of acoustic frequency. In addition, it is seen that significant energy transfer to modes with initially low or zero energy involves at least a second order scattering process. Under moderate scattering conditions, comparisons of first order, single scattering theoretical predictions to direct numerical simulation demonstrate the accuracy of the approach for acoustic frequencies upto 400 Hz and for single as well as multiple ISW wave packets. PMID:19045637

  4. The molecular mechanism for the spectral shifts between vertebrate ultraviolet- and violet-sensitive cone visual pigments.

    PubMed Central

    Cowing, Jill A; Poopalasundaram, Subathra; Wilkie, Susan E; Robinson, Phyllis R; Bowmaker, James K; Hunt, David M

    2002-01-01

    The short-wave-sensitive (SWS) visual pigments of vertebrate cone photoreceptors are divided into two classes on the basis of molecular identity, SWS1 and SWS2. Only the SWS1 class are present in mammals. The SWS1 pigments can be further subdivided into violet-sensitive (VS), with lambda(max) (the peak of maximal absorbance) values generally between 400 and 430 nm, and ultraviolet-sensitive (UVS), with a lambda(max)<380 nm. Phylogenetic evidence indicates that the ancestral pigment was UVS and that VS pigments have evolved separately from UVS pigments in the different vertebrate lineages. In this study, we have examined the mechanism of evolution of VS pigments in the mammalian lineage leading to present day ungulates (cow and pig). Amino acid sequence comparisons of the UVS pigments of teleost fish, amphibia, reptiles and rodents show that site 86 is invariably occupied by Phe but is replaced in bovine and porcine VS pigments by Tyr. Using site-directed mutagenesis of goldfish UVS opsin, we have shown that a Phe-86-->Tyr substitution is sufficient by itself to shift the lambda(max) of the goldfish pigment from a wild-type value of 360 nm to around 420 nm, and the reverse substitution of Tyr-86-Phe into bovine VS opsin produces a similar shift in the opposite direction. The substitution of this single amino acid is sufficient to account therefore for the evolution of bovine and porcine VS pigments. The replacement of Phe with polar Tyr at site 86 is consistent with the stabilization of Schiff-base protonation in VS pigments and the absence of protonation in UVS pigments. PMID:12099889

  5. The molecular mechanism for the spectral shifts between vertebrate ultraviolet- and violet-sensitive cone visual pigments.

    PubMed

    Cowing, Jill A; Poopalasundaram, Subathra; Wilkie, Susan E; Robinson, Phyllis R; Bowmaker, James K; Hunt, David M

    2002-10-01

    The short-wave-sensitive (SWS) visual pigments of vertebrate cone photoreceptors are divided into two classes on the basis of molecular identity, SWS1 and SWS2. Only the SWS1 class are present in mammals. The SWS1 pigments can be further subdivided into violet-sensitive (VS), with lambda(max) (the peak of maximal absorbance) values generally between 400 and 430 nm, and ultraviolet-sensitive (UVS), with a lambda(max)<380 nm. Phylogenetic evidence indicates that the ancestral pigment was UVS and that VS pigments have evolved separately from UVS pigments in the different vertebrate lineages. In this study, we have examined the mechanism of evolution of VS pigments in the mammalian lineage leading to present day ungulates (cow and pig). Amino acid sequence comparisons of the UVS pigments of teleost fish, amphibia, reptiles and rodents show that site 86 is invariably occupied by Phe but is replaced in bovine and porcine VS pigments by Tyr. Using site-directed mutagenesis of goldfish UVS opsin, we have shown that a Phe-86-->Tyr substitution is sufficient by itself to shift the lambda(max) of the goldfish pigment from a wild-type value of 360 nm to around 420 nm, and the reverse substitution of Tyr-86-Phe into bovine VS opsin produces a similar shift in the opposite direction. The substitution of this single amino acid is sufficient to account therefore for the evolution of bovine and porcine VS pigments. The replacement of Phe with polar Tyr at site 86 is consistent with the stabilization of Schiff-base protonation in VS pigments and the absence of protonation in UVS pigments. PMID:12099889

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

    PubMed

    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

    2013-07-01

    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

  7. Mutations of the Opsin Gene (Y102H and I307N) Lead to Light-induced Degeneration of Photoreceptors and

    E-print Network

    Wensel, Theodore G.

    . Hicks , Theodore G. Wensel§§ , Jurgen K. Naggert , and Patsy M. Nishina1 From the The Jackson Laboratory, Bar Harbor, Maine 04609, the § Department of Vision Sciences, University of Alabama, Birmingham

  8. Introduction Color vision enables animals to reliably detect and recognize

    E-print Network

    ), whereas another nymphalid, Vanessa atalanta, despite having color vision, is unable to do so. In the eyes, both S opsin or one M opsin and one S opsin: Vanessa cardui (Briscoe et al., 2003); Danaus plexippus either broadband light (300­700·nm) as in Vanessa cardui (Briscoe et al., 2003), or relatively narrow

  9. Photochemical Nature of Parietopsin

    PubMed Central

    Sakai, Kazumi; Imamoto, Yasushi; Su, Chih-Ying; Tsukamoto, Hisao; Yamashita, Takahiro; Terakita, Akihisa; Yau, King-Wai; Shichida, Yoshinori

    2012-01-01

    Parietopsin is a non-visual green-light-sensitive opsin closely related to vertebrate visual opsins, and was originally identified in lizard parietal-eye photoreceptor cells. To obtain insight into the functional diversity of opsins, we investigated by UV-visible absorption spectroscopy the molecular properties of parietopsin and its mutants exogenously expressed in cultured cells, and compared to vertebrate and invertebrate visual opsins. Our mutational analysis revealed that the counterion in parietopsin is the glutamic acid (Glu) in the second extracellular loop, corresponding to Glu181 in bovine rhodopsin. This arrangement is characteristic of invertebrate rather than vertebrate visual opsins. The photosensitivity and the molar extinction coefficient of parietopsin were also lower than those of vertebrate visual opsins, features likewise characteristic of invertebrate visual opsins. On the other hand, irradiation of parietopsin yielded meta-I, meta-II, and meta-III intermediates after batho- and lumi-intermediates, similar to vertebrate visual opsins. The pH-dependent equilibrium profile between meta-I and meta-II intermediates was, however, similar to that between acid and alkaline metarhodopsins in invertebrate visual opsins. Thus, parietopsin behaves as an “evolutionary intermediate” between invertebrate and vertebrate visual opsins. PMID:22303823

  10. Calibration and performance of the ISO Long-Wavelength Spectrometer

    Microsoft Academic Search

    B. M. Swinyard; P. E. Clegg; P. A. R. Ade; C. Armand; J.-P. Baluteau; M. J. Barlow; J.-C. Berges; M. Burgdorf; E. Caux; C. Ceccarelli; R. Cerulli; S. E. Church; S. Colgan; F. Cotin; P. Cox; P. Cruvellier; G. R. Davis; A. Digiorgio; R. J. Emery; D. Ewart; J. Fischer; I. Furniss; W. M. Glencross; M. Greenhouse; M. J. Griffin; M. R. Gry; C. Haas; M. Joubert; K. J. King; T. Lim; R. Liseau; S. Lord; D. Lorenzetti; S. Molinari; D. A. Naylor; B. Nisini; A. Omont; R. Orfei; T. Patrick; D. Pequignot; D. Pouliquen; M. C. Price; Nguyen-Q-Rieu; F. D. Robinson; M. Saisse; P. Saraceno; G. Serra; S. D. Sidher; H. A. Smith; L. Spinoglio; D. Texier; W. A. Towlson; N. Trams; S. J. Unger; G. J. White

    1996-01-01

    The wavelength and flux calibration, and the in-orbit performance of the Infrared Space Observatory Long-Wavelength Spectrometer (LWS) are described. The LWS calibration is mostly complete and the instrument's performance in orbit is largely as expected before launch. The effects of ionising radiation on the detectors, and the techniques used to minimise them are outlined. The overall sensitivity figures achieved in

  11. 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.

  12. Morphological, Physiological, and Biochemical Changes in Rhodopsin Knockout Mice

    Microsoft Academic Search

    J. Lem; N. V. Krasnoperova; P. D. Calvert; B. Kosaras; D. A. Cameron; M. Nicolo; C. L. Makino; R. L. Sidman

    1999-01-01

    Mutations in rod opsin, the visual pigment protein of rod photoreceptors, account for ≈ 15% of all inherited human retinal degenerations. However, the physiological and molecular events underlying the disease process are not well understood. One approach to this question has been to study transgenic mice expressing opsin genes containing defined mutations. A caveat of this approach is that even

  13. 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.

  14. [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.

  15. 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.

  16. 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.

  17. Prickly pear nopals pectin from Opuntia ficus-indica physico-chemical study in dilute and semi-dilute solutions

    Microsoft Academic Search

    H Majdoub; S Roudesli; L Picton; D Le Cerf; G Muller; M Grisel

    2001-01-01

    The water soluble fraction of peeled prickly pear nopals called native sample (NS) has been characterised mainly by SEC\\/MALLS analysis. Two main components have been identified: one with high average molar mass (Mw of 13×106gmol?1) called the high weight sample (HWS), the other being a low Mw fraction (LWS). After extensive ultra filtration of NS, isolated HWS and LWS are

  18. Characterization of retinoic acid-induced neurobehavioral effects in developing zebrafish.

    PubMed

    Wang, Yujiang; Chen, Jiangfei; Du, Changchun; Li, Chunqi; Huang, Changjiang; Dong, Qiaoxiang

    2014-02-01

    Retinoic signaling plays an important role in cell proliferation and differentiation. Disruption of retinoic signaling via excessive or deficient retinoic acid can cause teratogenic effects on developing embryos. Similar to retinoic acid, many xenobiotic environmental pollutants have been found to disrupt retinoic signaling through binding and eliciting agonistic activity on retinoic acid receptors. Currently, studies of retinoic acid or retinoic acid-like compounds in aquatic organisms have mainly focused on teratogenicity and few studies have explored their neurobehavioral toxicity. In the present study, the authors used retinoic acid as an example to explore the neurobehavioral toxicity associated with developmental exposure of retinoic acid-like compounds in zebrafish. The findings confirmed retinoic acid's teratogenic effects such as bent spine, malformed tail, and pericardial edema in developing zebrafish with a median effective concentration of 2.47 nM. Retinoic acid-induced cell apoptosis at 24?h postfertilization was consistently found in the eye and tail regions of embryos. Spontaneous movement as characterized by tail bend frequency was significantly increased in zebrafish embryos following exposure to 2 nM and 8 nM retinoic acid. Relatively low-dose retinoic acid exposure of 2 nM led to fast locomotion behavior in the dark period and hyperactivity during light-dark photoperiod stimulation. The 2-nM retinoic acid exposure also led to alterations of neurobehavior- and optic nerve-related genes, with the transforming growth factor-? signal transduction inhibitor noggin (nog) and the spinal cord marker homeobox c3a (hox) being underexpressed and the retinal G protein-coupled receptor a (rgr), the photoreceptor cell marker rhodopsin (rho), and the short wave-sensitive cone pigment opsin 1 (opn1sw1) being overexpressed. Increased expression of opn1sw1 and rho was confirmed by whole-mount in situ hybridization. Whether the misexpression of these genes leads to the neurobehavioral changes merits further study. The findings demonstrated that low-dose retinoic acid exposure perturbed the visual system and optic nerve development and caused hyperactivity in developing zebrafish. PMID:24395056

  19. Targeted effects of retinoic acid signaling upon photoreceptor development in zebrafish.

    PubMed

    Prabhudesai, Shubhangi N; Cameron, David A; Stenkamp, Deborah L

    2005-11-01

    Retinoic acid (RA) is a signaling molecule important for photoreceptor development in vertebrates. The purpose of this study was to examine the mechanisms of the effects of RA upon developing rod and cone photoreceptors in the embryonic zebrafish. Exposure to exogenous RA increased the number of photoreceptors expressing rod opsin and red cone opsin, and decreased the number of photoreceptors expressing the blue and UV cone opsins, suggesting targeted effects of RA on photoreceptor development. RA exposure also increased opsin expression in individual rods and red cones, but decreased opsin expression in individual blue and UV cones, as indicated by differences in the strength of opsin hybridization in identified photoreceptors. RA exposure did not, however, significantly alter quantitative measures of photoreceptor pattern in a manner expected for changes in photoreceptor fate. These observations collectively indicate that RA treatment does not affect photoreceptor fate, but rather differentially influences opsin transcription in determined photoreceptors. An enzyme involved in RA synthesis, RALDH2, was immunocytochemically localized to retinal progenitor cells and the retinal pigmented epithelium (RPE), suggesting the presence of RA in the vicinity of developing photoreceptors. However, expression of an RA response element-driven transgene was restricted to the RPE, retinal progenitors, and a small population of neurons in ventral retina, suggesting that the endogenous RA signaling system is spatially limited within the eye. PMID:16197938

  20. Targeted effects of retinoic acid signaling upon photoreceptor development in zebrafish

    PubMed Central

    Prabhudesai, Shubhangi N.; Cameron, David A.; Stenkamp, Deborah L.

    2009-01-01

    Retinoic acid (RA) is a signaling molecule important for photoreceptor development in vertebrates. The purpose of this study was to examine the mechanisms of the effects of RA upon developing rod and cone photoreceptors in the embryonic zebrafish. Exposure to exogenous RA increased the number of photoreceptors expressing rod opsin and red cone opsin, and decreased the number of photoreceptors expressing the blue and UV cone opsins, suggesting targeted effects of RA on photoreceptor development. RA exposure also increased opsin expression in individual rods and red cones, but decreased opsin expression in individual blue and UV cones, as indicated by differences in the strength of opsin hybridization in identified photoreceptors. RA exposure did not, however, significantly alter quantitative measures of photoreceptor pattern in a manner expected for changes in photoreceptor fate. These observations collectively indicate that RA treatment does not affect photoreceptor fate, but rather differentially influences opsin transcription in determined photoreceptors. An enzyme involved in RA synthesis, RALDH2, was immunocytochemically localized to retinal progenitor cells and the retinal pigmented epithelium (RPE), suggesting the presence of RA in the vicinity of developing photoreceptors. However, expression of an RA response element-driven transgene was restricted to the RPE, retinal progenitors, and a small population of neurons in ventral retina, suggesting that the endogenous RA signaling system is spatially limited within the eye. PMID:16197938

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

    PubMed Central

    Jiménez-López, Manuel; Alburquerque-Béjar, Juan J.; Nieto-López, Leticia; García-Ayuso, Diego; Villegas-Pérez, 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

  2. Positive selection of a duplicated UV-sensitive visual pigment coincides with wing pigment evolution in

    E-print Network

    , rhodopsins, produced byan11-cis-3-hydroxyretinalchromophoretogetherwithlongwave- length (LWRh), blue (BRh with max = 355 nm and 398 nm. Along with the additional UV opsin, Heliconius have also evolved 3- hydroxy

  3. Current Biology Vol 15 No 19 Ann E.O. Trezise and

    E-print Network

    Carleton, Karen L.

    are derived from a common ancestral gene, and he would then have posed the next logical question: where did by an ancient subfamily of the G protein coupled receptors: the opsin genes. In animals, photosensitivity serves

  4. Supporting Information Section S1: Known Spectral Tuning Sites

    E-print Network

    Carleton, Karen L.

    , Seehausen O (2005) Colour vision and speciation in Lake Victoria cichlids of the genus Pundamilia. Mol Ecol selection on opsins drives incipient speciation in Lake Victoria cichlids. PLoS Biol 4: 2244-2251. Section S

  5. RESEARCH ARTICLE Open Access Complex patterns of divergence among green-

    E-print Network

    Chang, Belinda

    cichlid opsins revealed by Clade model analyses Cameron J Weadick1,2 and Belinda SW Chang3* Abstract evolution * Correspondence: belinda.chang@utoronto.ca 3 Department of Ecology and Evolutionary Biology

  6. Cone pigments in a North American marsupial, the opossum ( Didelphis virginiana )

    Microsoft Academic Search

    Gerald H. JacobsGary; Gary A. Williams

    2010-01-01

    Only two of the four cone opsin gene families found in vertebrates are represented in contemporary eutherian and marsupial\\u000a species. Recent genetic studies of two species of South American marsupial detected the presence of representatives from two\\u000a of the classes of cone opsin genes and the structures of these genes predicted cone pigments with respective peaks in the\\u000a ultraviolet and

  7. 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.

  8. 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.

  9. Spectral tuning in salamander visual pigments studied with dihydroretinal chromophores.

    PubMed Central

    Makino, C L; Groesbeek, M; Lugtenburg, J; Baylor, D A

    1999-01-01

    In visual pigments, opsin proteins regulate the spectral absorption of a retinal chromophore by mechanisms that change the energy level of the excited electronic state relative to the ground state. We have studied these mechanisms by using photocurrent recording to measure the spectral sensitivities of individual red rods and red (long-wavelength-sensitive) and blue (short-wavelength-sensitive) cones of salamander before and after replacing the native 3-dehydro 11-cis retinal chromophore with retinal analogs: 11-cis retinal, 3-dehydro 9-cis retinal, 9-cis retinal, and 5,6-dihydro 9-cis retinal. The protonated Schiff's bases of analogs with unsaturated bonds in the ring had broader spectra than the same chromophores bound to opsins. Saturation of the bonds in the ring reduced the spectral bandwidths of the protonated Schiff's bases and the opsin-bound chromophores and made them similar to each other. This indicates that torsion of the ring produces spectral broadening and that torsion is limited by opsin. Saturating the 5,6 double bond in retinal reduced the perturbation of the chromophore by opsin in red and in blue cones but not in red rods. Thus an interaction between opsin and the chromophoric ring shifts the spectral maxima of the red and blue cone pigments, but not that of the red rod pigment. PMID:10423447

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

    PubMed Central

    Mäthger, Lydia M.; Roberts, Steven B.; Hanlon, Roger T.

    2010-01-01

    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

  11. 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 5–58) 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

  12. NASA space shuttle lightweight seat

    NASA Technical Reports Server (NTRS)

    Hansen, Chris; Jermstad, Wayne; Lewis, James; Colangelo, Todd

    1996-01-01

    The Space Shuttle Lightweight Seat-Mission Specialist (LWS-MS) is a crew seat for the mission specialists who fly aboard the Space Shuttle. The LWS-MS is a lightweight replacement for the mission specialist seats currently flown on the Shuttle. Using state-of-the-art analysis techniques, a team of NASA and Lockheed engineers from the Johnson Space Center (JSC) designed a seat that met the most stringent requirements demanded of the new seats by the Shuttle program, and reduced the weight of the seats by 52%.

  13. 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.

  14. 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.

  15. Involvement of distinct arrestin-1 elements in binding to different functional forms of rhodopsin.

    PubMed

    Zhuang, Tiandi; Chen, Qiuyan; Cho, Min-Kyu; Vishnivetskiy, Sergey A; Iverson, Tina M; Gurevich, Vsevolod V; Sanders, Charles R

    2013-01-15

    Solution NMR spectroscopy of labeled arrestin-1 was used to explore its interactions with dark-state phosphorylated rhodopsin (P-Rh), phosphorylated opsin (P-opsin), unphosphorylated light-activated rhodopsin (Rh*), and phosphorylated light-activated rhodopsin (P-Rh*). Distinct sets of arrestin-1 elements were seen to be engaged by Rh* and inactive P-Rh, which induced conformational changes that differed from those triggered by binding of P-Rh*. Although arrestin-1 affinity for Rh* was seen to be low (K(D) > 150 ?M), its affinity for P-Rh (K(D) ~80 ?M) was comparable to the concentration of active monomeric arrestin-1 in the outer segment, suggesting that P-Rh generated by high-gain phosphorylation is occupied by arrestin-1 under physiological conditions and will not signal upon photo-activation. Arrestin-1 was seen to bind P-Rh* and P-opsin with fairly high affinity (K(D) of~50 and 800 nM, respectively), implying that arrestin-1 dissociation is triggered only upon P-opsin regeneration with 11-cis-retinal, precluding noise generated by opsin activity. Based on their observed affinity for arrestin-1, P-opsin and inactive P-Rh very likely affect the physiological monomer-dimer-tetramer equilibrium of arrestin-1, and should therefore be taken into account when modeling photoreceptor function. The data also suggested that complex formation with either P-Rh* or P-opsin results in a global transition in the conformation of arrestin-1, possibly to a dynamic molten globule-like structure. We hypothesize that this transition contributes to the mechanism that triggers preferential interactions of several signaling proteins with receptor-activated arrestins. PMID:23277586

  16. The evolution of complexity in the visual systems of stomatopods: insights from transcriptomics.

    PubMed

    Porter, Megan L; Speiser, Daniel I; Zaharoff, Alexander K; Caldwell, Roy L; Cronin, Thomas W; Oakley, Todd H

    2013-07-01

    Stomatopod crustaceans have complex visual systems containing up to 16 different spectral classes of photoreceptors, more than described for any other animal. A previous molecular study of this visual system focusing on the expression of opsin genes found many more transcripts than predicted on the basis of physiology, but was unable to fully document the expressed opsin genes responsible for this diversity. Furthermore, questions remain about how other components of phototransduction cascades are involved. This study continues prior investigations by examining the molecular function of stomatopods' visual systems using new whole eye 454 transcriptome datasets from two species, Hemisquilla californiensis and Pseudosquilla ciliata. These two species represent taxonomic diversity within the order Stomatopoda, as well as variations in the anatomy and physiology of the visual system. Using an evolutionary placement algorithm to annotate the transcriptome, we identified the presence of nine components of the stomatopods' G-protein-coupled receptor (GPCR) phototransduction cascade, including two visual arrestins, subunits of the heterotrimeric G-protein, phospholipase C, transient receptor potential channels, and opsin transcripts. The set of expressed transduction genes suggests that stomatopods utilize a Gq-mediated GPCR-signaling cascade. The most notable difference in expression between the phototransduction cascades of the two species was the number of opsin contigs recovered, with 18 contigs found in retinas of H. californiensis, and 49 contigs in those of P. ciliata. Based on phylogenetic placement and fragment overlap, these contigs were estimated to represent 14 and 33 expressed transcripts, respectively. These data expand the known opsin diversity in stomatopods to clades of arthropod opsins that are sensitive to short wavelengths and ultraviolet wavelengths and confirm the results of previous studies recovering more opsin transcripts than spectrally distinct types of photoreceptors. Many of the recovered transcripts were phylogenetically placed in an evolutionary clade of crustacean opsin sequences that is rapidly expanding as the visual systems from more species are investigated. We discuss these results in relation to the emerging pattern, particularly in crustacean visual systems, of the expression of multiple opsin transcripts in photoreceptors of the same spectral class, and even in single photoreceptor cells. PMID:23727979

  17. Evolution and mechanism of spectral tuning of blue-absorbing visual pigments in butterflies.

    PubMed

    Wakakuwa, Motohiro; Terakita, Akihisa; Koyanagi, Mitsumasa; Stavenga, Doekele G; Shichida, Yoshinori; Arikawa, Kentaro

    2010-01-01

    The eyes of flower-visiting butterflies are often spectrally highly complex with multiple opsin genes generated by gene duplication, providing an interesting system for a comparative study of color vision. The Small White butterfly, Pieris rapae, has duplicated blue opsins, PrB and PrV, which are expressed in the blue (?(max)?=?453 nm) and violet receptors (?(max)?=?425 nm), respectively. To reveal accurate absorption profiles and the molecular basis of the spectral tuning of these visual pigments, we successfully modified our honeybee opsin expression system based on HEK293s cells, and expressed PrB and PrV, the first lepidopteran opsins ever expressed in cultured cells. We reconstituted the expressed visual pigments in vitro, and analysed them spectroscopically. Both reconstituted visual pigments had two photointerconvertible states, rhodopsin and metarhodopsin, with absorption peak wavelengths 450 nm and 485 nm for PrB and 420 nm and 482 nm for PrV. We furthermore introduced site-directed mutations to the opsins and found that two amino acid substitutions, at positions 116 and 177, were crucial for the spectral tuning. This tuning mechanism appears to be specific for invertebrates and is partially shared by other pierid and lycaenid butterfly species. PMID:21124838

  18. Evolution and Mechanism of Spectral Tuning of Blue-Absorbing Visual Pigments in Butterflies

    PubMed Central

    Wakakuwa, Motohiro; Terakita, Akihisa; Koyanagi, Mitsumasa; Stavenga, Doekele G.; Shichida, Yoshinori; Arikawa, Kentaro

    2010-01-01

    The eyes of flower-visiting butterflies are often spectrally highly complex with multiple opsin genes generated by gene duplication, providing an interesting system for a comparative study of color vision. The Small White butterfly, Pieris rapae, has duplicated blue opsins, PrB and PrV, which are expressed in the blue (?max?=?453 nm) and violet receptors (?max?=?425 nm), respectively. To reveal accurate absorption profiles and the molecular basis of the spectral tuning of these visual pigments, we successfully modified our honeybee opsin expression system based on HEK293s cells, and expressed PrB and PrV, the first lepidopteran opsins ever expressed in cultured cells. We reconstituted the expressed visual pigments in vitro, and analysed them spectroscopically. Both reconstituted visual pigments had two photointerconvertible states, rhodopsin and metarhodopsin, with absorption peak wavelengths 450 nm and 485 nm for PrB and 420 nm and 482 nm for PrV. We furthermore introduced site-directed mutations to the opsins and found that two amino acid substitutions, at positions 116 and 177, were crucial for the spectral tuning. This tuning mechanism appears to be specific for invertebrates and is partially shared by other pierid and lycaenid butterfly species. PMID:21124838

  19. 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 ?max 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

  20. 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

  1. Sensitization of bleached rod photoreceptors by 11-cis-locked analogues of retinal.

    PubMed Central

    Corson, D W; Cornwall, M C; MacNichol, E F; Jin, J; Johnson, R; Derguini, F; Crouch, R K; Nakanishi, K

    1990-01-01

    Photoactivation of rhodopsin initiates both excitation and adaptation in vertebrate rod photoreceptors. Bleaching of rhodopsin to free opsin and all-trans-retinal in isolated rods produces a stable desensitization (bleaching adaptation) that is much larger than expected from pigment depletion alone. In our experiments, a 93% bleach produced a 500-fold increase in the light intensity required for saturation of the light response. This component of adaptation was 32-fold larger than the 16-fold increase expected from pigment depletion alone. 11-cis-Retinal, when delivered to isolated rods from liposomes, combines with free opsin to form a bleachable photopigment that fully restores sensitivity. 11-cis-Locked analogues of retinal combine with opsin to form unbleachable pigments in isolated bleached rods from the tiger salamander. They restore sensitivity to a substantial (16- to 25-fold) but incomplete extent. The analogues apparently relieve a stable component of adaptation when they interact with opsin. Because these analogues do not detectably excite rods, the structural requirements of both retinal and opsin for the relief of adaptation are different from those of excitation. The biochemical basis of light adaptation resulting from pigment bleaching and the minimum structural requirements of retinal for its relief remain to be determined. PMID:2395874

  2. The molecular genetics and evolution of red and green color vision in vertebrates.

    PubMed

    Yokoyama, S; Radlwimmer, F B

    2001-08-01

    To better understand the evolution of red-green color vision in vertebrates, we inferred the amino acid sequences of the ancestral pigments of 11 selected visual pigments: the LWS pigments of cave fish (Astyanax fasciatus), frog (Xenopus laevis), chicken (Gallus gallus), chameleon (Anolis carolinensis), goat (Capra hircus), and human (Homo sapiens);and the MWS pigments of cave fish, gecko (Gekko gekko), mouse (Mus musculus), squirrel (Sciurus carolinensis), and human. We constructed these ancestral pigments by introducing the necessary mutations into contemporary pigments and evaluated their absorption spectra using an in vitro assay. The results show that the common ancestor of vertebrates and most other ancestors had LWS pigments. Multiple regression analyses of ancestral and contemporary MWS and LWS pigments show that single mutations S180A, H197Y, Y277F, T285A, A308S, and double mutations S180A/H197Y shift the lambda(max) of the pigments by -7, -28, -8, -15, -27, and 11 nm, respectively. It is most likely that this "five-sites" rule is the molecular basis of spectral tuning in the MWS and LWS pigments during vertebrate evolution. PMID:11545071

  3. 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...

  4. Application of artificial neural networks for damage indices classification with the use of Lamb waves for the aerospace structures.

    E-print Network

    of guided waves. Aircraft structural elements have to stand high safety standards, therefore an inc to a complex structure, for instance, an aircraft component with riveted joints and stringers characterized in the literature. In this paper, comparison a number of damage indices applied to LWs testing in aircraft aluminum

  5. A heliospheric simulation-based approach to SEP source and transport modeling

    E-print Network

    California at Berkeley, University of

    and someday the LWS Sentinels missions have increased capabilities for resolving some of the outstanding SEP event. Our approach assumes that the simulated shock is the moving source of the ions the observer-connected shock source time history, which is difficult to include in a SEP event model without

  6. Astron. Astrophys. 315, L389L392 (1996) ASTROPHYSICS

    E-print Network

    Naylor, David A.

    1996-01-01

    , Lab. Astrophysics, Washington, DC 20560, USA 10 LWS Instrument Dedicated Team, P.O. Box 50727, E-28080/H ratio in hydrogen of 2.310 5 ; D/H values be- tween 1.510 5 and 3.510 5 are however also compatible of methane and its deuterated isotope, and the preliminary determination of the jovian D/H ratio measured

  7. Probing Solar Open Magnetic Fields With Near-relativistic Electron Beams

    Microsoft Academic Search

    Dennis K. Haggerty; D. Rust; N. R. Sheeley; Y. Wang

    2006-01-01

    To achieve better understanding of our Sun-Earth environment, NASA's Living with a Star (LWS) program addresses question that cut across discipline boundaries. We present preliminary results on probing solar open magnetic fields with near-relativistic electron beams. This effort is directed at the major question: What determines the topology and evolution of the magnetic fields that stretch from the surface of

  8. Phenotypic variation and genetic heterogeneity in Léri-Weill syndrome

    Microsoft Academic Search

    Simone Schiller; Stephanie Spranger; Birgit Schechinger; Maki Fukami; Sabine Merker; Stenvert LS Drop; Jochen Tröger; Hans Knoblauch; Jürgen Kunze; Jörg Seidel; Gudrun A Rappold

    2000-01-01

    Léri-Weill syndrome (LWS) or dyschondrosteosis represents a short stature syndrome characterised by the mesomelic shortening of the forearms and lower legs and by bilateral Madelung deformity of the wrists. Recently, mutations in the pseudoautosomal homeobox gene SHOX have been shown to be causative for this disorder. This gene has previously been described as the short stature gene implicated in Turner

  9. Prosodic Word Boundaries Prediction for Mandarin Text-to-Speech

    Microsoft Academic Search

    YanQiu Shao; JiQing Han; Ting Liu; YongZhen Zhao

    In Mandarin speech, the Prosodic Word (PW) is the basic rhythmic unit instead of Lexical Word (LW), and the naturalness of TTS will be directly influenced by the segmentation of PW. Most of the PWs are the combination of some LWs. In this paper, three models, i.e. a directed acyclic graph (DAG) model, segmentation model and Markov Model (MM) combined

  10. The Outer Radiation Belt Injection, Transport, Acceleration and Loss Satellite (ORBITALS): A Canadian Mission to the Inner Magnetosphere

    Microsoft Academic Search

    I. R. Mann; T. Loto'Aniu; D. K. Milling; R. Rankin; R. Fedosejevs; Y. Y. Tsui; D. Knudsen; A. Yau; K. Balmain; D. McCabe; D. N. Baker; J. R. Wygant; J. F. Fennel; L. Kistler; G. Reeves

    2006-01-01

    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 is currently approved by the CSA for Phase A, and the NASA LWS Mission of Opportunity 4-instrument payload MORE (Mission of Opportunity Radbelt Experiment) for the ORBITALS satellite is undergoing NASA funded Phase A

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

    The subduction complex near Halilba?? (Central Anatolia) is among the best sites to investigate deep-seated tectonic, petrologic, and geochemical processes taking place in subduction zones. The Halilba?? 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 Halilba?? 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 Halilba?? 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, Tav?anl? 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.

  12. Binding specificity of retinal analogs to photoactivated visual pigments suggest mechanism for fine-tuning GPCR-ligand interactions.

    PubMed

    Srinivasan, Sundaramoorthy; Ramon, Eva; Cordomí, Arnau; Garriga, Pere

    2014-03-20

    11-cis-retinal acts as an inverse agonist stabilizing the inactive conformation of visual pigments, and upon photoactivation, it isomerizes to all-trans-retinal, initiating signal transduction. We have analyzed opsin regeneration with retinal analogs for rhodopsin and red cone opsin. We find differential binding of the analogs to the receptors after photobleaching and a dependence of the binding kinetics on the oligomerization state of the protein. The results outline the sensitivity of retinal entry to the binding pocket of visual receptors to the specific conformation adopted by the receptor and by the molecular architecture defined by specific amino acids in the binding pocket and the retinal entry site, as well as the topology of the retinal analog. Overall, our findings highlight the specificity of the ligand-opsin interactions, a feature that can be shared by other G-protein-coupled receptors. PMID:24560606

  13. A Cluster Randomized Trial to Evaluate a Health Education Programme “Living with Sun at School”

    PubMed Central

    Sancho-Garnier, Hélène; Pereira, Bruno; Césarini, Pierre

    2012-01-01

    Over-exposure to sunlight increases the risk of skin cancers, particularly when exposure occurs during childhood. School teachers can play an active role in providing an education programme that can help prevent this. “Living with the Sun,” (LWS) is a sun safety education program for school children based on a handy guide for classroom activities designed to improve children’s knowledge, but moreover to positively modify their sun safety attitudes and behaviours. The goal of our study was to determine the effectiveness of this programme by examining children’s knowledge, attitude and sun exposure behaviours prior to and after the completion of the programme. We carried out a cluster randomised trial in which the classes were randomly assigned to one of two groups; one using the LWS programme and another that didn’t, serving as the control. Data was collected before completion of the programme and an additional three times in the year after completion. The 70 participating classes (1,365 schoolchildren) were distributed throughout France. Statistical analysis confirmed that knowledge of sun risk increased significantly in the LWS classes (p < 0.001). Both groups positively changed their attitudes when considering the best sun protection, but the LWS group proved to consistently be more convinced (p = 0.04). After the summer holidays, differences between the two groups decreased throughout the year but stayed globally significant. We also observed some significant behaviour modification during the holidays. For instance, the LWS group applied sunscreen more frequently than the control group, and were more likely to wear a hat (72% versus 59%) and use a sun umbrella on the beach (75% versus 64%). PMID:22851947

  14. Engineering of an Artificial Light-Modulated Potassium Channel

    PubMed Central

    Caro, Lydia N.; Moreau, Christophe J.; Estrada-Mondragón, Argel; Ernst, Oliver P.; Vivaudou, Michel

    2012-01-01

    Ion Channel-Coupled Receptors (ICCRs) are artificial receptor-channel fusion proteins designed to couple ligand binding to channel gating. We previously validated the ICCR concept with various G protein-coupled receptors (GPCRs) fused with the inward rectifying potassium channel Kir6.2. Here we characterize a novel ICCR, consisting of the light activated GPCR, opsin/rhodopsin, fused with Kir6.2. To validate our two-electrode voltage clamp (TEVC) assay for activation of the GPCR, we first co-expressed the apoprotein opsin and the G protein-activated potassium channel Kir3.1F137S (Kir3.1*) in Xenopus oocytes. Opsin can be converted to rhodopsin by incubation with 11-cis retinal and activated by light-induced retinal cis?trans isomerization. Alternatively opsin can be activated by incubation of oocytes with all-trans-retinal. We found that illumination of 11-cis-retinal-incubated oocytes co-expressing opsin and Kir3.1* caused an immediate and long-lasting channel opening. In the absence of 11-cis retinal, all-trans-retinal also opened the channel persistently, although with slower kinetics. We then used the oocyte/TEVC system to test fusion proteins between opsin/rhodopsin and Kir6.2. We demonstrate that a construct with a C-terminally truncated rhodopsin responds to light stimulus independent of G protein. By extending the concept of ICCRs to the light-activatable GPCR rhodopsin we broaden the potential applications of this set of tools. PMID:22928030

  15. 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

  16. X chromosome: gene for color blindness, Matt RidleySite: DNA Interactive (www.dnai.org)

    NSDL National Science Digital Library

    2008-10-06

    Interviewee: Matt Ridley DNAi Location:Genome>tour>genome spot>Color vision Location: chromosome X gene name: OPN1MW/OPN1LW (green opsin; red opsin) The two genes that produce red and green light-sensitive proteins are located on the X chromosome. Mutations in these genes can cause color blindness. Color blindness is a common inherited sex-linked disorder that affects a personÂ?s ability to see or recognize certain colors. Eight to ten percent of all males and one half of a percent of all females are color-blind.

  17. Nilsson [6] has referred to eyes such as these as `burglar alarms'. None of

    E-print Network

    Maine, Eleanor

    those of chitons, is a `true' motion detector: that is, they do not compare sequential stimulation to the vertebrate opsins [7]. Chitons, which are only distant relatives of gastropods and bivalves, have no head­210. 2. Crozier, W.J., and Arey, L.B. (1918). On the significance of the reaction to shading in chiton

  18. Direct Innervation of GnRH Neurons by Encephalic Photoreceptors in Birds

    PubMed Central

    Saldanha, Colin J.; Silverman, Ann-Judith; Silver, Rae

    2012-01-01

    In nonmammalian vertebrates, photic cues that regulate the timing of seasonal reproductive cyclicity are detected by nonretinal, nonpineal deep brain photoreceptors. It has long been assumed that the underlying mechanism involves the transmission of photic information from the photoreceptor to a circadian system, and thence to the reproductive axis. An alternative hypothesis is that there is direct communication between the brain photoreceptor and the reproductive axis. In the present study, light and confocal microscopy reveal that gonadotropin releasing hormone (GnRH) neurons and processes are scattered among photoreceptor cells (identified by their opsin-immunoreactivity) in the lateral septum (SL). In the median eminence (ME), opsin and GnRH immunoreactive fibers overlap extensively. Single and double label ultrastructural immunocytochemistry indicate that in the SL and preoptic area (POA), opsin positive terminals form axo-dendritic synapses onto GnRH dendrites. In the ME, opsin and GnRH terminals lie adjacent to each other, make contact with tanycytes, or terminate on the hypophyseal portal capillaries. These results reveal that brain photoreceptors communicate directly with GnRH-neurons; this represents a means by which photoperiodic information reaches the reproductive axis. PMID:11220777

  19. 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

  20. ORIGINAL ARTICLE doi:10.1111/j.1558-5646.2012.01779.x

    E-print Network

    Gabor, Caitlin - Department of Biology, Texas State University

    EXPANSION IN A GYNOGENETIC FISH, THE AMAZON MOLLY (POECILIA FORMOSA): A TEST OF THE HYBRID-SENSORY EXPANSION. We compared opsin sequences of the Amazon molly, Poecilia formosa, to those of the parental species or intermediate to the parental species P. mexicana and P. latipinna. Together these results strongly support

  1. Animal behaviour Evidence for distributed

    E-print Network

    Hanlon, Roger T.

    role of distributed light sensing for dynamic camouflage and signalling. The mRNA coding for opsin from amino acid. The diverse camouflage and signalling body patterns of cephalopods are visu- ally controlled the other- wise visually driven dynamic camouflage system by assisting with colour or brightness matching

  2. An Array of Early Differentiating Cones Precedes the Emergence of the Photoreceptor Mosaic in the Fetal Monkey Retina

    Microsoft Academic Search

    Kenneth C. Walker; Pasko Rakic

    1994-01-01

    We previously have demonstrated that ≈10% of cones in the fetal monkey retina precociously express the red\\/green opsin. These data suggested the possibility that a subset of cones differentiates prior to their nascent cone neighbors. To further assess this early cone differentiation in the fetal monkey retina, we used monoclonal antibodies proven to be important developmental markers of photoreceptor phenotypes

  3. Functional diversity in the color vision of cichlid fishes

    Microsoft Academic Search

    Shai Sabbah; Raico Lamela Laria; Suzanne M Gray; Craig W Hawryshyn

    2010-01-01

    BACKGROUND: Color vision plays a critical role in visual behavior. An animal's capacity for color vision rests on the presence of differentially sensitive cone photoreceptors. Spectral sensitivity is a measure of the visual responsiveness of these cones at different light wavelengths. Four classes of cone pigments have been identified in vertebrates, but in teleost fishes, opsin genes have undergone gene

  4. Extensive duplications of phototransduction genes in early vertebrate evolution correlate with block (chromosome) duplications

    Microsoft Academic Search

    Karin Nordström; Tomas A Larsson; Dan Larhammar

    2004-01-01

    Many gene families in mammals have members that are expressed more or less uniquely in the retina or differentially in specific retinal cell types. We describe here analyses of nine such gene families with regard to phylogenetic relationships and chromosomal location. The families are opsins, G proteins (?, ?, and ? subunits), phosphodiesterases type 6, cyclic nucleotide-gated channels, G-protein-coupled receptor

  5. Paleomolecular biology unravels the evolutionary mystery of vertebrate UV vision

    E-print Network

    Zhang, Jianzhi

    . Vertebrate opsins may be clas- sified into five groups according to their phylogenetic relationships: SWS1 UV. Extensive phylogenetic surveys showed that UV vision is present in some, but not all, species of fishes, amphibians, reptiles, birds, and mammals (ref. 3; see Fig. 1C), which raised three interrelated

  6. Do female tamarins use visual cues to detect fruit rewards more successfully than do males?

    Microsoft Academic Search

    Nathaniel J. Dominy; Paul A. Garber; Júlio César Bicca-Marques; Maria Aparecida de O. Azevedo-Lopes

    2003-01-01

    Primates are unique among eutherian mammals for possessing trichromatic colour vision. It is generally proposed that trichromacy evolved to aid detection of ripe fruits against mature foliage. However, while trichromacy is routine in all Old World monkeys and apes (the catarrhines), a cone opsin polymorphism in New World monkeys (the platyrrhines) results in foraging groups with mixed capacities for chromatic

  7. Not all butterfly eyes are created equal: Rhodopsin absorption spectra, molecular identification, and localization of ultraviolet-, blue-, and green-sensitive rhodopsin-encoding mRNAs in the retina ofVanessa cardui

    Microsoft Academic Search

    Adriana D. Briscoe; Gary D. Bernard; Allan S. Szeto; Lisa M. Nagy; Richard H. White

    2003-01-01

    Surveys of spectral sensitivities, visual pigment spectra, and opsin gene sequences have indicated that all butterfly eyes contain ultraviolet-, blue-, and green-sensitive rhodopsins. Some species also contain a fourth or fifth type, related in amino acid sequence to green-sensitive insect rhodopsins, but red shifted in absorbance. By combining electron microscopy, epi- microspectrophotometry, and polymerase chain reaction cloning, we found that

  8. Cell Tissue Res (2005) 319: 175179 DOI 10.1007/s00441-004-0994-3

    E-print Network

    2005-01-01

    . Briscoe . Richard H. White Adult stemmata of the butterfly Vanessa cardui express UV and green opsin m in the butterfly Vanessa cardui and to test for the presence of visual pigments, the light sensitive components . Photoreceptor . Visual pigment . Vanessa cardui (Insecta) Introduction The larval photoreceptor organs

  9. In Vivo Application of Optogenetics for Neural Circuit Analysis Biomedical Engineering Department, Boston University, Boston, Massachusetts, United States

    E-print Network

    Han, Xue

    genes of under a kilobase long. Three major classes of microbial opsins have been adapted genetically transduced cells, optogenetics has enabled the examination of the causal role of certain cellular transmembrane domains, widely spread in archaea, bacteria, algae, and fungi, where they are critical for light

  10. Eyeshine and spectral tuning of long wavelength-sensitive rhodopsins: no evidence for red-sensitive photoreceptors among five Nymphalini butterfly species

    Microsoft Academic Search

    Adriana D. Briscoe; Gary D. Bernard

    2005-01-01

    Spectral tuning of rhodopsins commonly refers to the effects of opsin amino acid substitutions on the wavelength for peak sensitivity of the rhodopsin absorption spectrum. Nymphalini butterflies provide an opportunity for identifying some of the amino acid substitutions responsible for insect rhodopsin spectral tuning because the majority of photoreceptor cells (R3-9) in the adult retina express only a single long

  11. Vitamin B2-based Blue-Light Photoreceptors in the Retinohypothalamic Tract as the Photoactive Pigments for Setting the Circadian Clock in Mammals

    Microsoft Academic Search

    Yasuhide Miyamoto; Aziz Sancar

    1998-01-01

    In mammals the retina contains photoactive molecules responsible for both vision and circadian photoresponse systems. Opsins, which are located in rods and cones, are the pigments for vision but it is not known whether they play a role in circadian regulation. A subset of retinal ganglion cells with direct projections to the suprachiasmatic nucleus (SCN) are at the origin of

  12. The Eyes Have It: Regulatory and Structural Changes Both Underlie Cichlid Visual Pigment Diversity

    E-print Network

    Carleton, Karen L.

    The Eyes Have It: Regulatory and Structural Changes Both Underlie Cichlid Visual Pigment Diversity-wavelength visual pigments have elevated numbers of potentially functional substitutions. Thus, we present a model generate large shifts in visual pigment sensitivity across the collective opsin spectral range, but changes

  13. ?-ionone activates and bleaches visual pigment in salamander photoreceptors

    PubMed Central

    ISAYAMA, TOMOKI; ENGLAND, S.L. McCABE; CROUCH, R.K.; ZIMMERMAN, A.L.; MAKINO, C.L.

    2011-01-01

    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 ?-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 ?-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 ?-ionone, recovery was incomplete unless 9-cis retinal was given, indicating that visual pigment had been bleached. Therefore, we propose that ?-ionone activates and bleaches some types of visual pigments, mimicking the effects of light. PMID:19500430

  14. 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

  15. Introduction The butterfly eye is a marvel of evolution. Butterfly vision, like that

    E-print Network

    1805 Introduction The butterfly eye is a marvel of evolution. Butterfly vision, like that of other of the butterfly visual pigments, the three major spectral classes are encoded by ancient duplications, which produced distinct UV, B and LW opsin genes. Unlike those of bees, the eyes of butterflies are anatomically

  16. A butterfly eye's view of birds Francesca D. Frentiu1

    E-print Network

    A butterfly eye's view of birds Francesca D. Frentiu1 and Adriana D. Briscoe2 * Summary The striking color patterns of butterflies and birds have long interested biologists. But how these animals see. Color vision has evolved in butterflies through opsin gene duplications, through positive selection

  17. An Explicit Signature of Balancing Selection for Color-Vision Variation in New World Monkeys

    E-print Network

    Fedigan, Linda M.

    Tomohide Hiwatashi,1 Yugo Okabe,1 Toko Tsutsui,1 Chihiro Hiramatsu, ,1 Amanda D. Melin,2 Hiroki Oota,1 in the long to middle wavelength­ sensitive (L-M or red­green) opsin gene as compared with that of other of red­green color contrast (Jacobs 1996). The selective ad- vantage of trichromacy has been supported

  18. Fig Foraging by Dichromatic and Trichromatic Cebus capucinus in a Tropical Dry Forest

    E-print Network

    Fedigan, Linda M.

    Fig Foraging by Dichromatic and Trichromatic Cebus capucinus in a Tropical Dry Forest Amanda D (color change from greenish to reddish during ripening) or cryptic (green throughout ripening-M or red-green) opsin gene on the X chromosome in addition to a single-allelic short-wavelength sensitive

  19. Structure of cone photoreceptors Debarshi Mustafi a

    E-print Network

    Palczewski, Krzysztof

    Basel, Switzerland Keywords: Cone photoreceptors Rod photoreceptors Retinoids Retinoid cycle Chromophore Opsins Retina Vision Rhodopsin Cone pigments Enhanced S-cone syndrome Retinitis pigmentosa Age-related macular degeneration a b s t r a c t Although outnumbered more than 20:1 by rod photoreceptors, cone cells

  20. Alouatta trichromatic color vision: cone spectra and physiological responses studied with microspectrophotometry and single unit retinal electrophysiology.

    PubMed

    Silveira, Luiz Carlos L; Saito, Cézar 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

  1. Alouatta Trichromatic Color Vision: Cone Spectra and Physiological Responses Studied with Microspectrophotometry and Single Unit Retinal Electrophysiology

    PubMed Central

    Silveira, Luiz Carlos L.; Saito, Cézar 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

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

    SciTech Connect

    Malaspina, David M. [Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80303 (United States); Cairns, Iver H. [School of Physics, University of Sydney, New South Wales 2006 (Australia); Ergun, Robert E., E-mail: David.Malaspina@lasp.colorado.edu, E-mail: cairns@physics.usyd.edu.au, E-mail: ree@lasp.colorado.edu [Laboratory for Atmospheric and Space Physics, Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80303 (United States)

    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.

  3. Complete ISOPHOT (C200) Maps of a Nearby Prototypical GMC: W3 (Spring) or NGC7538 (Fall)

    NASA Technical Reports Server (NTRS)

    Sanders, David B.

    2001-01-01

    We were originally awarded Priority 3 time (approximately 60,000 sec) with Infrared Space Observatory (ISO) to obtain a complete ISOPHOT (PHT32-C200) map of a nearby prototypical giant molecular cloud (GMC). Following the FALL launch and revised estimates for the sensitivity of the ISOPHOT detectors, our program was modified to fit within the time constraints while still carrying out the main science requirements. The revised program requested long strip maps of our FALL target (NGC7538) using sequences of PHT37/38/39 observations with LWS observations of the brightest regions. The large number of AOTs required to cover each GMC required that our observations be spread over four separate proposals (PROP-01, PROP-02, PROP-03, PROP-04) which together comprise a single observing program. Our program was executed in early 1997; nearly 50,000 sec of data were obtained, including all of our requested ISOPHOT C200 observations. None of the LWS data were taken.

  4. 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

  5. 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.

  6. The far-IR spectrum of Sagittarius B2 region: Extended molecular absorption, photodissociation and photoionization

    E-print Network

    J. R. Goicoechea; N. J. Rodriguez-Fernandez; J. Cernicharo

    2003-09-12

    We present large scale 9'x 27'(25 pc x 70 pc) far-IR observations around Sgr B2 using the Long-wavelength spectrometer (LWS) on board the Infrared Space Observatory (ISO). The spectra are dominated by the strong continuum emission of dust, the widespread molecular absorption of light hydrides (OH, CH and H2O) and the fine structure lines of [NII], [NIII], [OIII], [CII] and [OI]. The molecular richness in the outer layers of Sgr B2 is probed by the ISO-LWS Fabry-Perot (35 km s^-1) detections towards Sgr B2(M), where more that 70 lines from 15 molecular and atomic species are observed at high signal to noise ratio.

  7. Atomic silicon towards the Orion-KL nebula

    Microsoft Academic Search

    C. Gry; G. Pineau des Forêts; C. M. Walmsley

    1999-01-01

    We have used the Long Wavelength Spectrometer (LWS) on board ISO to observe the fine structure lines of atomic silicon at 68.5 and 129.7 microns towards the Orion Kleinmann-Low nebula. Our data show evidence for the detection of the J=2-1 transition at 68.5mum with a signal-to-noise ratio of 5. We consider the formation of the observed emission line and conclude

  8. The ISO Long-Wavelength Spectrometer

    Microsoft Academic Search

    Paolo Saraceno; P. A. R. Ade; C. Armand; J.-P. Baluteau; M. J. Barlow; M. A. Buckley; J.-C. Berges; M. Burgdorf; E. Caux; C. Ceccarelli; R. Cerulli; S. E. Church; F. Cotin; P. Cox; P. Cruvellier; J. L. Culhane; G. R. Davis; A. di Giorgio; B. R. Diplock; D. L. Drummond; R. J. Emery; J. D. Ewart; J. Fischer; I. Furniss; W. M. Glencross; M. A. Greenhouse; M. J. Griffin; C. Gry; A. S. Harwood; A. S. Hazell; M. Joubert; K. J. King; T. Lim; R. Liseau; J. A. Long; D. Lorenzetti; S. Molinari; A. G. Murray; D. A. Naylor; B. Nisini; K. Norman; A. Omont; R. Orfei; T. J. Patrick; D. Pequignot; D. Pouliquen; M. C. Price; Nguyen-Q-Rieu; A. J. Rogers; F. D. Robinson; M. Saisse; G. Serra; S. D. Sidher; A. F. Smith; H. A. Smith; L. Spinoglio; B. M. Swinyard; D. Texier; W. A. Towlson; N. R. Trams; S. J. Unger; G. J. White

    1996-01-01

    The Long-Wavelength Spectrometer (LWS) is one of two complementary spectrometers aboard the European Space Agency's Infrared Space Observatory (ISO) (Kessler et al., 1996A&A...315L..49D). It operates over the wavelength range 43-196.9mum at either medium (about 150 to 200) or high (6800 to 9700) spectral resolving power. This Letter describes the instrument and its modes of operation; a companion paper (Swinyard et

  9. 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.

  10. Shocks in Protostellar Outflows

    Microsoft Academic Search

    Dirk Froebrich; Michael D. Smith; Jochen Eislöffel

    2003-01-01

    We present our analysis of four molecular outflows from Class 0 (Cep E,L 1448) sources and higher mass objects (Cep A, DR\\u000a 21). The emission line spectra of these outflows were observed in the mid- and far-infrared using the spectrometers (SWS,\\u000a LWS) and the camera (ISOCAM) aboard the ISO satellite. We interpret the spectra using J- and C-type bow shock

  11. The 69-mm forsterite band as a dust temperature indicator J. E. Bowey,1P

    E-print Network

    Bowey, Janet

    The 69-mm forsterite band as a dust temperature indicator J. E. Bowey,1P M. J. Barlow,1 F. J; in original form 2001 October 12 A B S T R AC T A band of pure crystalline forsterite (100 per cent Mg2SiO4 feature is at *73 mm. The Mg-rich forsterite feature is observed in a variety of ISO LWS spectra

  12. 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.

  13. A Sun-to-Earth Campaign Joining Observations from the Great Observatory with Worldwide Satellite and Ground-Based Resources to Investigate System Science Frontiers

    Microsoft Academic Search

    J. U. Kozyra; K. Shibata; R. J. Barnes; S. Basu; J. M. Davila; N. J. Fox; N. Gopalswamy; M. M. Kuznetsova; D. Pallamraju; L. J. Paxton; A. Ridley; M. Weiss; C. A. Young; L. J. Zanetti

    2006-01-01

    An Internet-based cross-disciplinary analysis campaign that will make heavy use of Great Observatory missions as well as international satellite and ground-based assets is being undertaken with joint support from the CAWSES, IHY, LWS, and ICESTAR programs planned for late April or early May 2006. An evolving list of open science questions that serve as sun-to-Earth focus areas for the worldwide

  14. First detection of far-infrared methane features in Saturn

    Microsoft Academic Search

    G. R. Davis; P. G. Oldham; M. J. Griffin; D. A. Naylor; B. M. Swinyard; P. A. R. Ade; M. Burgdorf; G. S. Orton; S. B. Calcutt; P. G. J. Irwin; D. Gautier; Th. Encrenaz; E. Lellouch; Th. de Graauw

    1997-01-01

    The Long Wavelength Spectrometer (LWS) is one of four instruments on the ESA Infrared Space Observatory (ISO) satellite. The far-infrared spectrum of Saturn was measured on 16 July 1996, with spectral resolutions of 0.29mu m (43--90mu m) and 0.6mu m (90--197mu m). Weak methane features due to forbidden rotational transitions were detected in absorption against the hydrogen continuum at 106,

  15. The ISO Long-Wavelength Spectrometer.

    NASA Astrophysics Data System (ADS)

    Clegg, P. E.; Ade, P. A. R.; Armand, C.; Baluteau, J.-P.; Barlow, M. J.; Buckley, M. A.; Berges, J.-C.; Burgdorf, M.; Caux, E.; Ceccarelli, C.; Cerulli, R.; Church, S. E.; Cotin, F.; Cox, P.; Cruvellier, P.; Culhane, J. L.; Davis, G. R.; di Giorgio, A.; Diplock, B. R.; Drummond, D. L.; Emery, R. J.; Ewart, J. D.; Fischer, J.; Furniss, I.; Glencross, W. M.; Greenhouse, M. A.; Griffin, M. J.; Gry, C.; Harwood, A. S.; Hazell, A. S.; Joubert, M.; King, K. J.; Lim, T.; Liseau, R.; Long, J. A.; Lorenzetti, D.; Molinari, S.; Murray, A. G.; Naylor, D. A.; Nisini, B.; Norman, K.; Omont, A.; Orfei, R.; Patrick, T. J.; Pequignot, D.; Pouliquen, D.; Price, M. C.; Nguyen-Q-Rieu; Rogers, A. J.; Robinson, F. D.; Saisse, M.; Saraceno, P.; Serra, G.; Sidher, S. D.; Smith, A. F.; Smith, H. A.; Spinoglio, L.; Swinyard, B. M.; Texier, D.; Towlson, W. A.; Trams, N. R.; Unger, S. J.; White, G. J.

    1996-11-01

    The Long-Wavelength Spectrometer (LWS) is one of two complementary spectrometers aboard the European Space Agency's Infrared Space Observatory (ISO) (Kessler et al., 1996A&A...315L..49D). It operates over the wavelength range 43-196.9?m at either medium (about 150 to 200) or high (6800 to 9700) spectral resolving power. This Letter describes the instrument and its modes of operation; a companion paper (Swinyard et al, 1996) describes its performance and calibration.

  16. The expression of retinal cell markers in human retinal pigment epithelial cells and their augmentation by the synthetic retinoid fenretinide

    PubMed Central

    Vugler, Anthony A.; Yu, Lu; Semo, Maayan; Coffey, Pete; Moss, Stephen E.; Greenwood, John

    2011-01-01

    Purpose In several species the retinal pigment epithelium (RPE) has the potential to transdifferentiate into retinal cells to regenerate functional retinal tissue after injury. However, this capacity for regeneration is lost in mammals. The synthetic retinoic acid derivative, fenretinide [N(4-hydroxyphenyl) retinamide], induces a neuronal-like phenotype in the human adult retinal pigment epithelial cell line (ARPE-19). These changes are characterized by the appearance of neural-like processes and the expression of neuronal markers not normally associated with RPE cells. Here we assess whether fenretinide can induce a neuroretinal cell phenotype in ARPE-19 cells, by examining retinal cell marker expression. Methods ARPE-19 cells were treated daily with culture medium containing either 3 ?M fenretinide or dimethyl sulfoxide as a control for 7 days. Cells were processed for immunocytochemistry, western blotting, and for analysis by PCR to examine the expression of a panel of RPE, neural, and retinal-associated cellular markers, including classical and non-canonical opsins. Results Treatment with fenretinide for 7 days induced the formation of neuronal-like processes in ARPE-19 cells. Fenretinide induced the expression of the cone long wavelength sensitive opsin (OPN1lw) but not rhodopsin (RHO), while decreasing the expression of RPE cell markers. Many of the neuronal and retinal specific markers examined were expressed in both control and fenretinide treated cells, including those involved in photoreceptor cell development and the multipotency of neural retinal progenitor cells. Interestingly, ARPE-19 cells also expressed both photoreceptor specific and non-specific canonical opsins. Conclusions The expression of retinal-associated markers and loss of RPE cell markers in control ARPE-19 cells suggests that these cells might have dedifferentiated from an RPE cell phenotype under standard culture conditions. The expression of molecules, such as the transcription factors paired box 6 gene (PAX6), sex determining region Y-box 2 (SOX2), cone-rod homeobox (CRX), and neural retina leucine zipper (NRL), further implies that in culture these cells are predisposed toward a retinal progenitor-like state. The fenretinide-induced increase in photoreceptor cell markers, accompanied by a decrease in RPE cell markers, suggests that retinoids may play a role in the transdifferentiation of RPE cells. Importantly, our data show for the first time the expression of a vertebrate ciliary opsin (OPN1lw) and rhabdomeric-like opsin, opsin 4 (OPN4 also known as melanopsin) in a clonal cell line. Together these data suggest that ARPE-19 cells are primed for and possess the capacity to differentiate toward a retinal cell-like lineage. PMID:21738400

  17. 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

  18. Connecting the navigational clock to sun compass input in monarch butterfly brain.

    PubMed

    Sauman, Ivo; Briscoe, Adriana D; Zhu, Haisun; Shi, Dingding; Froy, Oren; Stalleicken, Julia; Yuan, Quan; Casselman, Amy; Reppert, Steven M

    2005-05-01

    Migratory monarch butterflies (Danaus plexippus) use a time-compensated sun compass to navigate to their overwintering grounds in Mexico. Although polarized light is one of the celestial cues used for orientation, the spectral content (color) of that light has not been fully explored. We cloned the cDNAs of three visual pigment-encoding opsins (ultraviolet [UV], blue, and long wavelength) and found that all three are expressed uniformly in main retina. The photoreceptors of the polarization-specialized dorsal rim area, on the other hand, are monochromatic for the UV opsin. Behavioral studies support the importance of polarized UV light for flight orientation. Next, we used clock protein expression patterns to identify the location of a circadian clock in the dorsolateral protocerebrum of butterfly brain. To provide a link between the clock and the sun compass, we identified a CRYPTOCHROME-staining neural pathway that likely connects the circadian clock to polarized light input entering brain. PMID:15882645

  19. 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

  20. 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

  1. 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

  2. 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 ?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

  3. A unique visual pigment expressed in green, red and deep-red receptors in the eye of the small white butterfly, Pieris rapae crucivora

    Microsoft Academic Search

    Motohiro Wakakuwa; Doekele G. Stavenga; Masumi Kurasawa; Kentaro Arikawa

    2004-01-01

    The full primary structure of a long-wavelength absorbing visual pigment of the small white butterfly, Pieris rapae crucivora, was determined by molecular cloning. In situ hybridization of the opsin mRNA of the novel visual pigment (PrL) demonstrated that it is expressed in the two distal photoreceptor cells (R3 and R4) as well as in the proximal photoreceptors (R5-8) in all

  4. Physiological characterization of the compound eye in monarch butterflies with focus on the dorsal rim area

    Microsoft Academic Search

    Julia Stalleicken; Thomas Labhart; Henrik Mouritsen

    2006-01-01

    The spectral, angular and polarization sensitivities of photoreceptors in the compound eye of the monarch butterfly (Danaus plexippus) are examined using electrophysiological methods. Intracellular recordings reveal a spectrally homogenous population of UV\\u000a receptors with optical axes directed upwards and ?10° to the contralateral side. Based on optical considerations and on the\\u000a opsin expression pattern (Sauman et al. 2005), we conclude

  5. Influence of carotenoid deficiency on visual sensitivity, visual pigment and P-face particles of photoreceptor membrane in the moth Manduca sexta

    Microsoft Academic Search

    Ruth R. Bennett; Richard H. White

    1989-01-01

    1.Several larval diets (Table 1) were developed for rearing the tobacco hornworm mothManduca sexta in an effort to control the synthesis of adult visual pigments (generically, ‘rhodopsins’) through the availability of their chromophore, retinaldehyde or, more likely, 3-hydroxyretinaldehyde.2.Rhodopsin was measured in difference spectra from detergent extracts of adult retinas. Opsin was identified and measured on SDS gels after electrophoretic separation

  6. 2006 Nature Publishing Group Stochastic spineless expression creates

    E-print Network

    Desplan, Claude

    : ,30% of ommatidia express ultraviolet-sensitive Rh3 in R7 cells and blue-sensitive Rh5 in R8 cells). The remaining ,70% express another ultraviolet-sensitive opsin (Rh4) in R7 and green-sensitive Rh6 in R8, making in which both R7 and R8 express ultraviolet-sensitive Rh3 (refs 18, 19). These omma- tidia are used

  7. Illumination of the Melanopsin Signaling Pathway

    Microsoft Academic Search

    Satchidananda Panda; Surendra K. Nayak; Brice Campo; John R. Walker; John B. Hogenesch; Tim Jegla

    2005-01-01

    In mammals, a small population of intrinsically photosensitive retinal ganglion cells (ipRGCs) plays a key role in the regulation of nonvisual photic responses, such as behavioral responses to light, pineal melatonin synthesis, pupillary light reflex, and sleep latency. These ipRGCs also express melanopsin (Opn4), a putative opsin-family photopigment that has been shown to play a role in mediating these nonvisual

  8. 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

  9. 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

  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. 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

  12. bop gene cluster expression in bacteriorhodopsin-overproducing mutants of Halobacterium halobium.

    PubMed Central

    Shand, R F; Betlach, M C

    1994-01-01

    mRNA levels from the bop (bacterio-opsin), brp (bacterio-opsin-related protein), and bat (bacterio-opsin activator) genes in wild-type Halobacterium halobium and two bacteriorhodopsin-overproducing mutants (ET1001 and II-7) were quantitated under conditions in which oxygen levels were steadily depleted and then cultures were either kept in the dark or exposed to light. All three strains showed similar responses to depleted oxygen tensions and the lack of light: bop gene cluster transcript levels first increased in response to steadily declining oxygen, and once oxygen was depleted, transcript levels decreased and became undetectable within 20 to 40 h. In contrast, each strain responded differently to conditions of depleted oxygen and the presence of light. In the wild-type strain, bop gene cluster transcript levels increased 2.4- to 9.2-fold above the highest levels obtained in the dark. In mutant ET1001, bop gene cluster transcript levels did not increase above the highest levels obtained in the dark. In mutant II-7, bop and brp transcript levels did not increase above the highest levels obtained in the dark, but bat transcript levels increased approximately 5.7-fold. This differing response to identical physiological conditions indicates that the mutations resulting in the bacteriorhodopsin-overproducing phenotype in these two mutants are different. PMID:8132460

  13. 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

  14. 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

  15. Functional diversity in the color vision of cichlid fishes

    PubMed Central

    2010-01-01

    Background Color vision plays a critical role in visual behavior. An animal's capacity for color vision rests on the presence of differentially sensitive cone photoreceptors. Spectral sensitivity is a measure of the visual responsiveness of these cones at different light wavelengths. Four classes of cone pigments have been identified in vertebrates, but in teleost fishes, opsin genes have undergone gene duplication events and thus can produce a larger number of spectrally distinct cone pigments. In this study, we examine the question of large-scale variation in color vision with respect to individual, sex and species that may result from differential expression of cone pigments. Cichlid fishes are an excellent model system for examining variation in spectral sensitivity because they have seven distinct cone opsin genes that are differentially expressed. Results To examine the variation in the number of cones that participate in cichlid spectral sensitivity, we used whole organism electrophysiology, opsin gene expression and empirical modeling. Examination of over 100 spectral sensitivity curves from 34 individuals of three species revealed that (1) spectral sensitivity of individual cichlids was based on different subsets of four or five cone pigments, (2) spectral sensitivity was shaped by multiple cone interactions and (3) spectral sensitivity differed between species and correlated with foraging mode and the spectral reflectance of conspecifics. Our data also suggest that there may be significant differences in opsin gene expression between the sexes. Conclusions Our study describes complex opponent and nonopponent cone interactions that represent the requisite neural processing for color vision. We present the first comprehensive evidence for pentachromatic color vision in vertebrates, which offers the potential for extraordinary spectral discrimination capabilities. We show that opsin gene expression in cichlids, and possibly also spectral sensitivity, may be sex-dependent. We argue that females and males sample their visual environment differently, providing a neural basis for sexually dimorphic visual behaviour. The diversification of spectral sensitivity likely contributes to sensory adaptations that enhance the contrast of transparent prey and the detection of optical signals from conspecifics, suggesting a role for both natural and sexual selection in tuning color vision. PMID:21029409

  16. 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.

  17. The Outer Radiation Belt Injection, Transport, Acceleration and Loss Satellite (ORBITALS): A Canadian Mission to the Inner Magnetosphere

    NASA Astrophysics Data System (ADS)

    Mann, I. R.; Loto'Aniu, T.; Milling, D. K.; Rankin, R.; Fedosejevs, R.; Tsui, Y. Y.; Knudsen, D.; Yau, A.; Balmain, K.; McCabe, D.; Baker, D. N.; Wygant, J. R.; Fennel, J. F.; Kistler, L.; Reeves, G.

    2006-12-01

    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 is currently approved by the CSA for Phase A, and the NASA LWS Mission of Opportunity 4-instrument payload MORE (Mission of Opportunity Radbelt Experiment) for the ORBITALS satellite is undergoing NASA funded Phase A study. The ORBITALS will provide a unique view of the largely previously unexplored inner magnetosphere. 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 conjunctions 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 and global dynamics and morphology of the Earths radiation belts.

  18. The relation of cold temperature to seedling blight incited by seed-borne and soil-borne organisms 

    E-print Network

    Stewart, Robert Blaylock

    1953-01-01

    LeeaSl Reea S Saga eeM 4reAeai ieeyeeaewe Se Seeeee SLeea SLeehlea4 Sech eeLL heLSea oeQ, SteeLea setl SSS a 100 85 a 4NS 80$ a SNf 8$ z NS SL a NS eSS a NL NS a SSS LVSS a 4NS LWS z NS LNS a SN L~a NS Lpga NL LSN z lCPO NS xNL NS a XTSI SSS...

  19. Pre-Main Sequence Stars Seen by ISO

    NASA Astrophysics Data System (ADS)

    Lorenzetti, Dario

    2005-08-01

    Observations of pre-main sequence objects (T Tauri, Herbig Ae/Be and FU Orionis stars) obtained with the instrumentation on board the Infrared Space Observatory (ISO) are reviewed. All the observations have been mainly carried out by using the two spectrographs SWS and LWS, adopting their low resolution modes and such data have been used both for lines detection and to reconstruct the spectral energy distributions. Line emission and photometric behaviour of pre-main sequence objects have been analyzed in the framework of the current models, discussing the agreement (or disagreement) with them and trying to derive the questions which should be answered by the forthcoming FIR instrumentation.

  20. Thermal Evolution of Juvenile Subduction Zones ' New Constraints from Lu-Hf Geochronology on HP oceanic rocks (Halilba?i, 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; Halilba?? 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 Halilba?? 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 Halilba?? 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).

  1. 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.

  2. 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.

  3. 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.

  4. The relation of cold temperature to seedling blight incited by seed-borne and soil-borne organisms

    E-print Network

    Stewart, Robert Blaylock

    1953-01-01

    LeeaSl Reea S Saga eeM 4reAeai ieeyeeaewe Se Seeeee SLeea SLeehlea4 Sech eeLL heLSea oeQ, SteeLea setl SSS a 100 85 a 4NS 80$ a SNf 8$ z NS SL a NS eSS a NL NS a SSS LVSS a 4NS LWS z NS LNS a SN L~a NS Lpga NL LSN z lCPO NS xNL NS a XTSI SSS...

  5. The Outer Radiation Belt Injection, Transport, Acceleration and Loss Satellite (ORBITALS): A Potential Canadian Mission Contribution to ILWS

    NASA Astrophysics Data System (ADS)

    Mann, I. R.; Milling, D. K.; Rankin, R.; Fedosejevs, R.; Tsui, Y. Y.; Knudsen, D.; Yau, A. W.; Wygant, J. R.; Fennel, J. F.; Blake, J. B.; O'Brien, T. P.; Clemmons, J. H.; Summers, D.; Sofko, G.; Boteler, D.

    2004-05-01

    The Outer Radiation Belt Injection, Transport, Acceleration and Loss Satellite (ORBITALS) mission is presently undergoing Concept Study as a Canadian Space Agency satellite mission contribution to ILWS. The ORBITALS will provide a unique view of the largely previously unexplored inner magnetosphere. 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. Moreover, the ORBITALS would meet the plea from the LWS Mission Operations Working Group for the international provision of additional probe coverage to complement the Radiation Belt Storm Probes (RBSP) within LWS. ORBITALS will hence provide Canada with a unique leadership role at the forefront of the highest priority science goals for ILWS. In a 12 hour low inclination orbit (perigee L=2, apogee L=6), 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, the raised perigee providing both long outer radiation belt dwell times as well as coverage of the outer-most inner radiation belt. In combination, the ORBITALS-CGSM-GOES conjunctions 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 magetic fields, the dynamics of the plasmasphere, including thermal ion injection and loss, and the dynamics of the ring current population in the inner magnetosphere during storms. In this poster we outline the motivating ORBITALS mission science, and highlight the concept mission orbit and strawman payload. In combination with the approved NASA LWS RBSP, the ORBITALS-RBSP constellation will have the necessary spatial coverage to resolve the spatio-temporal ambiguities and global dynamics and morphology of the Earth's radiation belts. Further satellite mission collaborations, perhaps bilaterally with ORBITALS, which would re-create the original ILWS mission goal of three-petal local-time coverage would represent an excellent additional mission infrastructure complement to the proposed contemporaneous ORBITALS-RBSP measurements.

  6. 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.

  7. Global-scale Observations of the Limb and Disk (GOLD): Science Objectives

    NASA Astrophysics Data System (ADS)

    Eastes, R.; McClintock, W.; Aksnes, A.; Anderson, D.; Andersson, L.; Burns, A.; Codrescu, M.; Daniell, R.; Eparvier, F.; Harvey, J.; Krywonos, A.; Lumpe, J.; Prölss, G.; Richmond, A.; Rusch, D.; Solomon, S.; Strickland, D.; Woods, T.

    2006-12-01

    Developing the scientific understanding necessary to address aspects of the connected Sun-Earth system that directly affect life and society is a challenge for the scientific community in general and the Living With a Star (LWS) program in particular. Far Ultraviolet (FUV) observations from satellites have made vital contributions to this understanding. The Global-scale Observations of the Earth and Disk (GOLD) experiment, a FUV imager being considered for flight on a geostationary (GEO) satellite as part of the upcoming Radiation Belt Storm Probes (RBSP) mission, will, due to its capabilities and the orbit, provide data needed to answer outstanding science questions. GOLD will provide the first global-scale measurements of temperatures in the lower thermosphere. In addition it will provide more familiar measurements, such as the atomic oxygen to molecular nitrogen (O/N2) ratio. From GEO, GOLD will almost continuously observe the same hemisphere and provide data at all local times each day. These data will allow us to: (1) understand the global-scale response of the thermosphere and ionosphere to geomagnetic and solar forcing; (2) understand the global-scale tidal amplitude and phase variations; and (3) better understand the causes of small-scale ionospheric density irregularities. Such observations are necessary for achieving the LWS program objectives.

  8. Influence of molecular weight of chemically sulfated citrus pectin fractions on their antithrombotic and bleeding effects.

    PubMed

    Cipriani, Thales R; Gracher, Ana Helena P; de Souza, Lauro M; Fonseca, Roberto J C; Belmiro, Celso L R; Gorin, Philip A J; Sassaki, Guilherme L; Iacomini, Marcello

    2009-05-01

    Evaluated were the anticoagulant and antithrombotic activities, and bleeding effect of two chemically sulfated polysaccharides, obtained from citric pectin, with different average molar masses. Both low-molecular-weight (Pec-LWS, 3,600 g/mol) and high-molecular-weight sulfated pectins (Pec-HWS, 12,000 g/mol) had essentially the same structure, consisting of a (1-->4)-linked alpha-D-GalpA chain with almost all its HO-2 and HO-3 groups substituted by sulfate. Both polysaccharides had anticoagulant activity in vitro, although Pec-HWS was a more potent antithrombotic agent in vivo, giving rise to total inhibition of venous thrombosis at a dose of 3.5 mg/kg body weight. Surprisingly, in contrast with heparin, Pec-HWS and Pec-LWS are able to directly inhibit alpha-thrombin and factor Xa by a mechanism independent of antithrombin (AT) and/or heparin co-factor II (HCII). Moreover, Pec-HWS provided a lower risk of bleeding than heparin at a dose of 100% effectiveness against venous thrombosis, indicating it to be a promising antithrombotic agent. PMID:19404539

  9. The structure of the carbon black flame 

    E-print Network

    Anderson, W. Kermi

    1945-01-01

    EygyvR SHoPWdy lWS W S1moR cyvER1 mP ynE1R nvd1 SRWvfWof d1Wvvyc nomv 1ycf AB gyWvS mP WvEcy nomv AoWdyS WR W 1ynE1R mP Rlm Wvf R1oyy zHWoRyoS nvd1yS WAmuy R1y Rnb. 4yvRncWRnmv Pmo AmRRmg foWPR lWS WddmgbcnS1yf AB fonccnvE W vHgAyo mP mvy 1WcP nvd1 1mcy... 56WqnS. 4WcHyS Pmo q nv R1y WHqncnWoB dmmofnvWRy SBSRyg lyoy fyRyognvyf WR mvy RyvR1 nvd1 nvRyouWcS AyEnvvnvE WR R1y dyvRyo mP R1y PcWgy Wvf yqRyvfnvE mHRlWof Rm mvy yfEy. xnvdy R1y PcWgy dmHcf Ay WSSHgyf SBggyRondWc lnR1 vm cmSS nv EyvyoWcnRB, R...

  10. Design and evaluation of net radiometers

    Microsoft Academic Search

    Leo J. Fritschen; Charles L. Fritschen

    1991-01-01

    Net radiometer designs were evaluated with respect to long and short wave sensitivities and to the effect of ambient wind on the signal. The design features of the instrument with the best overall performance include: equal sensitivity to long and short wave radiation, a thermal pile which is thermally isolated from the frame, a white guard ring, pathways for internal

  11. Time-lapse changes in tube and guided waves in cross-well Mallik experiment Andrey Bakulin, Shell International Exploration and Production Inc, Valeri Korneev*, Lawrence Berkeley

    E-print Network

    Korneev, Valeri A.

    Time-lapse changes in tube and guided waves in cross-well Mallik experiment Andrey Bakulin, Shell-well seismic data from the Mallik experiment and demonstrate time-lapse changes in tube and guided waves sensitivity of tube and guided waves to small production-related changes and their feasibility for reservoir

  12. Modelling and Prediction of Sensitivity in Energetic Materials

    Microsoft Academic Search

    D. Mathieu; P. Simonetti; R. Belmas; N. Garmasheva; V. Filin; A. Averin

    2001-01-01

    The search for new explosives needs predictive calculations of sensitivity. This is a complex problem as there are various definitions of this term : the drop weight impact test is often used to characterize sensitivity, but calculations are also related to shock waves sensitivity tests. Moreover, there are many parameters which influence the results, at molecular, mesoscopic and macroscopic levels.

  13. Ciliary photoreceptors in the cerebral eyes of a protostome larva

    PubMed Central

    2011-01-01

    Background Eyes in bilaterian metazoans have been described as being composed of either ciliary or rhabdomeric photoreceptors. Phylogenetic distribution, as well as distinct morphologies and characteristic deployment of different photopigments (ciliary vs. rhabdomeric opsins) and transduction pathways argue for the co-existence of both of these two photoreceptor types in the last common bilaterian ancestor. Both receptor types exist throughout the Bilateria, but only vertebrates are thought to use ciliary photoreceptors for directional light detection in cerebral eyes, while all other invertebrate bilaterians studied utilize rhabdomeric photoreceptors for this purpose. In protostomes, ciliary photoreceptors that express c-opsin have been described only from a non-visual deep-brain photoreceptor. Their homology with vertebrate rods and cones of the human eye has been hypothesized to represent a unique functional transition from non-visual to visual roles in the vertebrate lineage. Results To test the hypothesis that protostome cerebral eyes employ exclusively rhabdomeric photoreceptors, we investigated the ultrastructure of the larval eyes in the brachiopod Terebratalia transversa. We show that these pigment-cup eyes consist of a lens cell and a shading pigment cell, both of which are putative photoreceptors, deploying a modified, enlarged cilium for light perception, and have axonal connections to the larval brain. Our investigation of the gene expression patterns of c-opsin, Pax6 and otx in these eyes confirms that the larval eye spots of brachiopods are cerebral eyes that deploy ciliary type photoreceptors for directional light detection. Interestingly, c-opsin is also expressed during early embryogenesis in all potential apical neural cells, becoming restricted to the anterior neuroectoderm, before expression is initiated in the photoreceptor cells of the eyes. Coincident with the expression of c-opsin in the presumptive neuroectoderm, we found that middle gastrula stage embryos display a positive photoresponse behavior, in the absence of a discrete shading pigment or axonal connections between cells. Conclusions Our results indicate that the dichotomy in the deployment of ciliary and rhabdomeric photoreceptors for directional light detection is not as clear-cut as previously thought. Analyses of brachiopod larval eyes demonstrate that the utilization of c-opsin expressing ciliary photoreceptors in cerebral eyes is not limited to vertebrates. The presence of ciliary photoreceptor-based eyes in protostomes suggests that the transition between non-visual and visual functions of photoreceptors has been more evolutionarily labile than previously recognized, and that co-option of ciliary and rhabdomeric photoreceptor cell types for directional light detection has occurred multiple times during animal evolution. In addition, positive photoresponse behavior in gastrula stage embryos suggests that a discrete shading pigment is not requisite for directional photoreception in metazoans. Scanning photoreception of light intensities mediating cell-autonomous changes of ciliary movement may represent an ancient mechanism for regulating locomotory behavior, and is likely to have existed prior to the evolution of eye-mediated directional light detection employing axonal connections to effector cells and a discreet shading pigment. PMID:21362157

  14. Effect of 11-Cis 13-Demethylretinal on Phototransduction in Bleach-Adapted Rod and Cone Photoreceptors

    PubMed Central

    Corson, D.Wesley; Kefalov, Vladimir J.; Cornwall, M. Carter; Crouch, Rosalie K.

    2000-01-01

    We used 11-cis 13-demethylretinal to examine the physiological consequences of retinal's noncovalent interaction with opsin in intact rod and cone photoreceptors during visual pigment regeneration. 11-Cis 13-demethylretinal is an analog of 11-cis retinal in which the 13 position methyl group has been removed. Biochemical experiments have shown that it is capable of binding in the chromophore pocket of opsin, forming a Schiff-base linkage with the protein to produce a pigment, but at a much slower rate than the native 11-cis retinal (Nelson, R., J. Kim deReil, and A. Kropf. 1970. Proc. Nat. Acad. Sci. USA. 66:531–538). Experimentally, this slow rate of pigment formation should allow separate physiological examination of the effects of the initial binding of retinal in the pocket and the subsequent formation of the protonated Schiff-base linkage. Currents from solitary rods and cones from the tiger salamander were recorded in darkness before and after bleaching and then after exposure to 11-cis 13-demethylretinal. In bleach-adapted rods, 11-cis 13-demethylretinal caused transient activation of phototransduction, as evidenced by a decrease of the dark current and sensitivity, acceleration of the dim flash responses, and activation of cGMP phosphodiesterase and guanylyl cyclase. The steady state of phototransduction activity was still higher than that of the bleach-adapted rod. In contrast, exposure of bleach-adapted cones to 11-cis 13-demethylretinal resulted in an immediate deactivation of transduction as measured by the same parameters. These results extend the validity of a model for the effects of the noncovalent binding of a retinoid in the chromophore pockets of rod and cone opsins to analogs capable of forming a Schiff-base and imply that the noncovalent binding by itself may play a role for the dark adaptation of photoreceptors. PMID:10919871

  15. Establishing a fiber-optic-based optical neural interface.

    PubMed

    Adamantidis, Antoine R; Zhang, Feng; de Lecea, Luis; Deisseroth, Karl

    2014-08-01

    Selective expression of opsins in genetically defined neurons makes it possible to control a subset of neurons without affecting nearby cells and processes in the intact brain, but light must still be delivered to the target brain structure. Light scattering limits the delivery of light from the surface of the brain. For this reason, we have developed a fiber-optic-based optical neural interface (ONI), which allows optical access to any brain structure in freely moving mammals. The ONI system is constructed by modifying the small animal cannula system from PlasticsOne. The system for bilateral stimulation consists of a bilateral cannula guide that has been stereotactically implanted over the target brain region, a screw cap for securing the optical fiber to the animal's head, a fiber guard modified from the internal cannula adapter, and a bare fiber whose length is customized based on the depth of the target region. For unilateral stimulation, a single-fiber system can be constructed using unilateral cannula parts from PlasticsOne. We describe here the preparation of the bilateral ONI system and its use in optical stimulation of the mouse or rat brain. Delivery of opsin-expressing virus and implantation of the ONI may be conducted in the same surgical session; alternatively, with a transgenic animal no opsin virus is delivered during the surgery. Similar procedures are useful for deep or superficial injections (even for neocortical targets, although in some cases surface light-emitting diodes or cortex-apposed fibers can be used for the most superficial cortical targets). PMID:25086020

  16. QM/MM Structure, Enantioselectivity and Spectroscopy of HydroxyRetinals and Insights into the Evolution of Color Vision in Small White Butterflies

    PubMed Central

    Sekharan, Sivakumar; Yokoyama, Shozo

    2011-01-01

    Since Vogt’s discovery of A3-retinal or 3-hydroxyretinal in insects in 1983 and Matsui’s discovery of A4-retinal or 4-hydroxyretinal in firefly squid in 1988, hydroxyretinal-protein interactions mediating vision remains largely unexplored. In the present study, A3- and A4-retinals are theoretically incorporated into squid and bovine visual pigments using the hybrid quantum mechanics/molecular mechanics (SORCI+Q//B3LYP/6-31G(d):Amber96) method and insights into the structure, enantioselectivity and spectroscopy are gathered and presented for the first time. Contrary to general perception, our findings rule out the formation of hydrogen bond between the hydroxyl-bearing ?-ionone ring part of retinal and opsin. Compared to A1-pigments, A3- and A4-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 scintillians) opsin is very similar to that of the Japanese common squid (Todarodes pacificus) opsin, (ii) Molecular mechanism of spectral tuning in the small white butterflies involve sites S116, T185 and breaking of hydrogen bond between sites E180 and T185; and finally, (iii) A3-retinal may have occurred during the conversion of A1- to A2-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

  17. 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 ?-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

  18. Reconstitution of ancestral green visual pigments of zebrafish and molecular mechanism of their spectral differentiation.

    PubMed

    Chinen, Akito; Matsumoto, Yoshifumi; Kawamura, Shoji

    2005-04-01

    We previously reported that zebrafish have four tandemly duplicated green (RH2) opsin genes (RH2-1, RH2-2, RH2-3, and RH2-4). Absorption spectra vary widely among the four photopigments reconstituted with 11-cis retinal, with their peak absorption spectra (lambda(max)) being 467, 476, 488, and 505 nm, respectively. In this study, we inferred the ancestral amino acid (aa) sequences of the zebrafish RH2 opsins by likelihood-based Bayesian statistics and reconstituted the ancestral opsins by site-directed mutagenesis. The ancestral pigment (A1) to the four zebrafish RH2 pigments and that (A3) to RH2-3 and RH2-4 showed lambda(max) at 506 nm, while that (A2) to RH2-1 and RH2-2 showed a lambda(max) at 474 nm, indicating that a spectral shift had occurred toward the shorter wavelength on the evolutionary lineages A1 to A2 by 32 nm, A2 to RH2-1 by 7 nm, and A3 to RH2-3 by 18 nm. Pigment chimeras and site-directed mutagenesis revealed a large contribution (approximately 15 nm) of glutamic acid to glutamine substitution at residue 122 (E122Q) to the A1 to A2 and A3 to RH2-3 spectral shifts. However, the remaining spectral differences appeared to result from complex interactive effects of a number of aa replacements, each of which has only a minor spectral contribution (1-3 nm). The four zebrafish RH2 pigments cover nearly an entire range of lambda(max) distribution among vertebrate RH2 pigments and provide an excellent model to study spectral tuning mechanisms of RH2 in vertebrates. PMID:15647516

  19. WONOEP appraisal: optogenetic tools to suppress seizures and explore the mechanisms of epileptogenesis.

    PubMed

    Ritter, Laura Mantoan; Golshani, Peyman; Takahashi, Koji; Dufour, Suzie; Valiante, Taufik; Kokaia, Merab

    2014-11-01

    Optogenetics is a novel technology that combines optics and genetics by optical control of microbial opsins, targeted to living cell membranes. The versatility and the electrophysiologic characteristics of the light-sensitive ion-channels channelrhodopsin-2 (ChR2), halorhodopsin (NpHR), and the light-sensitive proton pump archaerhodopsin-3 (Arch) make these optogenetic tools potent candidates in controlling neuronal firing in models of epilepsy and in providing insights into the physiology and pathology of neuronal network organization and synchronization. Opsins allow selective activation of excitatory neurons and inhibitory interneurons, or subclasses of interneurons, to study their activity patterns in distinct brain-states in vivo and to dissect their role in generation of synchrony and seizures. The influence of gliotransmission on epileptic network function is another topic of great interest that can be further explored by using light-activated Gq protein-coupled opsins for selective activation of astrocytes. The ever-growing optogenetic toolbox can also be combined with emerging techniques that have greatly expanded our ability to record specific subtypes of cortical and hippocampal neurons in awake behaving animals such as juxtacellular recording and two-photon guided whole-cell recording, to identify the specific subtypes of neurons that are altered in epileptic networks. Finally, optogenetic tools allow rapid and reversible suppression of epileptic electroencephalography (EEG) activity upon photoactivation. This review outlines the most recent advances achieved with optogenetic techniques in the field of epilepsy by summarizing the presentations contributed to the 13th ILAE WONOEP meeting held in the Laurentian Mountains, Quebec, in June 2013. PMID:25303540

  20. 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

  1. Not all butterfly eyes are created equal: rhodopsin absorption spectra, molecular identification, and localization of ultraviolet-, blue-, and green-sensitive rhodopsin-encoding mRNAs in the retina of Vanessa cardui.

    PubMed

    Briscoe, Adriana D; Bernard, Gary D; Szeto, Allan S; Nagy, Lisa M; White, Richard H

    2003-04-14

    Surveys of spectral sensitivities, visual pigment spectra, and opsin gene sequences have indicated that all butterfly eyes contain ultraviolet-, blue-, and green-sensitive rhodopsins. Some species also contain a fourth or fifth type, related in amino acid sequence to green-sensitive insect rhodopsins, but red shifted in absorbance. By combining electron microscopy, epi-microspectrophotometry, and polymerase chain reaction cloning, we found that the compound eye of Vanessa cardui has the typical ultrastructural features of the butterfly retina but contains only the three common insect rhodopsins. We estimated lambda-max values and relative densities of the rhodopsins in the Vanessa retina (0.72, P530; 0.12, P470; and 0.15, P360) from microspectrophotometric measurements and calculations based on a computational model of reflectance spectra. We isolated three opsin-encoding cDNA fragments that were identified with P530, P470, and P360 by homology to the well-characterized insect rhodopsin families. The retinal mosaic was mapped by opsin mRNA in situ hybridization and found to contain three kinds of ommatidia with respect to their patterns of short wavelength rhodopsin expression. In some ommatidia, P360 or P470 was expressed in R1 and R2 opposed receptor cells; in others, one cell expressed P360, whereas its complement expressed P470. P530 was expressed in the other seven cells of all ommatidia. P470-expressing cells were abundant in the ventral retina but nearly absent dorsally. Our results indicated that there are major differences between the color vision systems of nymphalid and papilionid butterflies: the nymphalid Vanessa has a simpler, trichromatic, system than do the tetrachromatic papilionids that have been studied. PMID:12619069

  2. The C9 methyl group of retinal interacts with glycine-121 in?rhodopsin

    PubMed Central

    Han, May; Groesbeek, Michel; Sakmar, Thomas P.; Smith, Steven O.

    1997-01-01

    The visual pigment rhodopsin is a prototypical G protein-coupled receptor. These receptors have seven transmembrane helices and are activated by specific receptor–ligand interactions. Rhodopsin is unusual in that its retinal prosthetic group serves as an antagonist in the dark in the 11-cis conformation but is rapidly converted to an agonist on photochemical cis to trans isomerization. Receptor–ligand interactions in rhodopsin were studied in the light and dark by regenerating site-directed opsin mutants with synthetic retinal analogues. A progressive decrease in light-dependent transducin activity was observed when a mutant opsin with a replacement of Gly121 was regenerated with 11-cis-retinal analogues bearing progressively larger R groups (methyl, ethyl, propyl) at the C9 position of the polyene chain. A progressive decrease in light activity was also observed as a function of increasing size of the residue at position 121 for both the 11-cis-9-ethyl- and the 11-cis-9-propylretinal pigments. In contrast, a striking increase of receptor activity in the dark—i.e., without chromophore isomerization—was observed when the molecular volume at either position 121 of opsin or C9 of retinal was increased. The ability of bulky replacements at either position to hinder ligand incorporation and to activate rhodopsin in the dark suggests a direct interaction between these two sites. A molecular model of the retinal-binding site of rhodopsin is proposed that illustrates the specific interaction between Gly121 and the C9 methyl group of 11-cis-retinal. Steric interactions in this region of rhodopsin are consistent with the proposal that movement of transmembrane helices 3 and 6 is concomitant with receptor activation. PMID:9391044

  3. 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

  4. Optobionic vision—a new genetically enhanced light on retinal prosthesis

    NASA Astrophysics Data System (ADS)

    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.

  5. A modified approach to the measurement problem: objective reduction in the retinal molecule prior to conformational change.

    PubMed

    Thaheld, Fred H

    2008-05-01

    A new analysis of the measurement problem reveals the possibility that collapse of the wavefunction may now take place just before photoisomerization of the rhodopsin molecule in the retinal rods. It is known that when a photon is initially absorbed by the retinal molecule which, along with opsin comprises the rhodopsin molecule, an electron in the highest pi orbital is immediately excited to a pi* orbital. This means that a measurement or transfer of information takes place at the quantum level before the retinal molecule commences the conformational change from cis to trans. This could have profound implications for resolving some of the foundational issues confronting quantum mechanics. PMID:18308463

  6. Hot-electron generation by 'cavitating' Langmuir turbulence in the nonlinear stage of the two-plasmon-decay instability

    SciTech Connect

    Vu, H. X. [Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, California 92093 (United States); DuBois, D. F. [Lodestar Research Corporation, Boulder, Colorado 80301 (United States); Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Russell, D. A. [Lodestar Research Corporation, Boulder, Colorado 80301 (United States); Myatt, J. F. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States)

    2012-10-15

    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 Multiplication-Sign 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.

  7. 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.

  8. Isolation and characterization of melanopsin and pinopsin expression within photoreceptive sites of reptiles

    NASA Astrophysics Data System (ADS)

    Frigato, Elena; Vallone, Daniela; Bertolucci, Cristiano; Foulkes, Nicholas S.

    2006-08-01

    Non-mammalian vertebrates have multiple extraocular photoreceptors, mainly localised in the pineal complex and the brain, to mediate irradiance detection. In this study, we report the full-length cDNA cloning of ruin lizard melanopsin and pinopsin. The high level of identity with opsins in both the transmembrane regions, where the chromophore binding site is located, and the intracellular loops, where the G-proteins interact, suggests that both melanopsin and pinopsin should be able to generate a stable photopigment, capable of triggering a transduction cascade mediated by G-proteins. Phylogenetic analysis showed that both opsins are located on the expected branches of the corresponding sequences of ortholog proteins. Subsequently, using RT-PCR and RPA analysis, we verified the expression of ruin lizard melanopsin and pinopsin in directly photosensitive organs, such as the lateral eye, brain, pineal gland and parietal eye. Melanopsin expression was detected in the lateral eye and all major regions of the brain. However, different from the situation in Xenopus and chicken, melanopsin is not expressed in the ruin lizard pineal. Pinopsin mRNA expression was only detected in the pineal complex. As a result of their phylogenetic position and ecology, reptiles provide the circadian field with some of the most interesting models for understanding the evolution of the vertebrate circadian timing system and its response to light. This characterization of melanopsin and pinopsin expression in the ruin lizard will be important for future studies aimed at understanding the molecular basis of circadian light detection in reptiles.

  9. Functional Comparison of Rod and Cone G?t on the Regulation of Light Sensitivity*

    PubMed Central

    Mao, Wen; Miyagishima, K. J.; Yao, Yun; Soreghan, Brian; Sampath, Alapakkam P.; Chen, Jeannie

    2013-01-01

    The signaling cascades mediated by G protein-coupled receptors (GPCRs) exhibit a wide spectrum of spatial and temporal response properties to fulfill diverse physiological demands. However, the mechanisms that shape the signaling response of the GPCR are not well understood. In this study, we replaced cone transducin ? (cT?) for rod transducin ? (rT?) in rod photoreceptors of transgenic mice, which also express S opsin, to evaluate the role of G? subtype on signal amplification from different GPCRs in the same cell; such analysis may explain functional differences between retinal rod and cone photoreceptors. We showed that ectopically expressed cT? 1) forms a heterotrimeric complex with rod G?1?1, 2) substitutes equally for rT? in generating photoresponses initiated by either rhodopsin or S-cone opsin, and 3) exhibited similar light-activated translocation as endogenous rT? in rods and endogenous cT? in cones. Thus, rT? and cT? appear functionally interchangeable. Interestingly, light sensitivity appeared to correlate with the concentration of cT? when expression is reduced below 35% of normal. However, quantification of endogenous cT? concentration in cones showed a higher level to rT? in rods. Thus, reduced sensitivity in cones cannot be explained by reduced coupling efficiency between the GPCR and G protein or a lower concentration of G protein in cones versus rods. PMID:23288843

  10. Retinal pigment epithelium protein of 65 kDA gene-linked retinal degeneration is not modulated by chicken acidic leucine-rich epidermal growth factor-like domain containing brain protein/Neuroglycan C/ chondroitin sulfate proteoglycan 5

    PubMed Central

    Cottet, Sandra; Jüttner, René; Voirol, Nathalie; Chambon, Pierre; Rathjen, Fritz G.; Schorderet, Daniel F.

    2013-01-01

    Purpose To analyze in vivo the function of chicken acidic leucine-rich epidermal growth factor-like domain containing brain protein/Neuroglycan C (gene symbol: Cspg5) during retinal degeneration in the Rpe65?/? mouse model of Leber congenital amaurosis. Methods We resorted to mice with targeted deletions in the Cspg5 and retinal pigment epithelium protein of 65 kDa (Rpe65) genes (Cspg5?/?/Rpe65?/?). Cone degeneration was assessed with cone-specific peanut agglutinin staining. Transcriptional expression of rhodopsin (Rho), S-opsin (Opn1sw), M-opsin (Opn1mw), rod transducin ? subunit (Gnat1), and cone transducin ? subunit (Gnat2) genes was assessed with quantitative PCR from 2 weeks to 12 months. The retinal pigment epithelium (RPE) was analyzed at P14 with immunodetection of the retinol-binding protein membrane receptor Stra6. Results No differences in the progression of retinal degeneration were observed between the Rpe65?/? and Cspg5?/?/Rpe65?/? mice. No retinal phenotype was detected in the late postnatal and adult Cspg5?/? mice, when compared to the wild-type mice. Conclusions Despite the previously reported upregulation of Cspg5 during retinal degeneration in Rpe65?/? mice, no protective effect or any involvement of Cspg5 in disease progression was identified. PMID:24265546

  11. Formation and decay of the arrestin·rhodopsin complex in native disc membranes.

    PubMed

    Beyrière, Florent; Sommer, Martha E; Szczepek, Michal; Bartl, Franz J; Hofmann, Klaus Peter; Heck, Martin; Ritter, Eglof

    2015-05-15

    In the G protein-coupled receptor rhodopsin, light-induced cis/trans isomerization of the retinal ligand triggers a series of distinct receptor states culminating in the active Metarhodopsin II (Meta II) state, which binds and activates the G protein transducin (Gt). Long before Meta II decays into the aporeceptor opsin and free all-trans-retinal, its signaling is quenched by receptor phosphorylation and binding of the protein arrestin-1, which blocks further access of Gt to Meta II. Although recent crystal structures of arrestin indicate how it might look in a precomplex with the phosphorylated receptor, the transition into the high affinity complex is not understood. Here we applied Fourier transform infrared spectroscopy to monitor the interaction of arrestin-1 and phosphorylated rhodopsin in native disc membranes. By isolating the unique infrared signature of arrestin binding, we directly observed the structural alterations in both reaction partners. In the high affinity complex, rhodopsin adopts a structure similar to Gt-bound Meta II. In arrestin, a modest loss of ?-sheet structure indicates an increase in flexibility but is inconsistent with a large scale structural change. During Meta II decay, the arrestin-rhodopsin stoichiometry shifts from 1:1 to 1:2. Arrestin stabilizes half of the receptor population in a specific Meta II protein conformation, whereas the other half decays to inactive opsin. Altogether these results illustrate the distinct binding modes used by arrestin to interact with different functional forms of the receptor. PMID:25847250

  12. Hybridization leads to sensory repertoire expansion in a gynogenetic fish, the Amazon molly (poecilia formosa): a test of the hybrid-sensory expansion hypothesis.

    PubMed

    Sandkam, Benjamin A; Joy, Jeffrey B; Watson, Corey T; Gonzalez-Bendiksen, Pablo; Gabor, Caitlin R; Breden, Felix

    2013-01-01

    Expansions in sensory systems usually require processes such as gene duplication and divergence, and thus evolve slowly. We evaluate a novel mechanism leading to rapid sensory repertoire expansion: hybrid-sensory expansion (HSE). HSE occurs when two species with differently tuned sensory systems form a hybrid, bringing together alleles from each of the parental species. In one generation, a sensory repertoire is created that is the sum of the variance between parental species. The Amazon molly presents a unique opportunity to test the HSE hypothesis in a "frozen" hybrid. We compared opsin sequences of the Amazon molly, Poecilia formosa, to those of the parental species. Both parental species are homozygous at the RH2-1 locus and each of the four long wavelength sensitive loci, while P. formosa possess two different alleles at these loci; one matching each parental allele. Gene expression analysis showed P. formosa use the expanded opsin repertoire that was the result of HSE. Additionally, behavioral tests revealed P. formosa respond to colored stimuli in a manner similar or intermediate to the parental species P. mexicana and P. latipinna. Together these results strongly support the HSE hypothesis. Hybrid-sensory repertoire expansion is likely important in other hybrid species and in other sensory systems. PMID:23289566

  13. Multiple shifts between violet and ultraviolet vision in a family of passerine birds with associated changes in plumage coloration

    PubMed Central

    Ödeen, Anders; Pruett-Jones, Stephen; Driskell, Amy C.; Armenta, Jessica K.; Håstad, Olle

    2012-01-01

    Colour vision in diurnal birds falls into two discrete classes, signified by the spectral sensitivity of the violet- (VS) or ultraviolet-sensitive (UVS) short wavelength-sensitive type 1 (SWS1) single cone. Shifts between sensitivity classes are rare; three or four are believed to have happened in the course of avian evolution, one forming UVS higher passerines. Such shifts probably affect the expression of shortwave-dominated plumage signals. We have used genomic DNA sequencing to determine VS or UVS affinity in fairy-wrens and allies, Maluridae, a large passerine family basal to the known UVS taxa. We have also spectrophotometrically analysed male plumage coloration as perceived by the VS and UVS vision systems. Contrary to any other investigated avian genus, Malurus (fairy-wrens) contains species with amino acid residues typical of either VS or UVS cone opsins. Three bowerbird species (Ptilonorhynchidae) sequenced for outgroup comparison carry VS opsin genes. Phylogenetic reconstructions render one UVS gain followed by one or more losses as the most plausible evolutionary scenario. The evolution of avian ultraviolet sensitivity is hence more complex, as a single shift no longer explains its distribution in Passeriformes. Character correlation analysis proposes that UVS vision is associated with shortwave-reflecting plumage, which is widespread in Maluridae. PMID:21976683

  14. Physiological characterization of the compound eye in monarch butterflies with focus on the dorsal rim area.

    PubMed

    Stalleicken, Julia; Labhart, Thomas; Mouritsen, Henrik

    2006-03-01

    The spectral, angular and polarization sensitivities of photoreceptors in the compound eye of the monarch butterfly (Danaus plexippus) are examined using electrophysiological methods. Intracellular recordings reveal a spectrally homogenous population of UV receptors with optical axes directed upwards and >or=10 degrees to the contralateral side. Based on optical considerations and on the opsin expression pattern (Sauman et al. 2005), we conclude that these UV receptors belong to the anatomically specialized dorsal rim area (DRA) of the eye. Photoreceptors in the main retina with optical axes <10 degrees contralateral or ipsilateral have maximal sensitivities in the UV (lambda(max)opsin expression patterns described in these eye regions. The data are discussed in the light of present knowledge about polarized skylight navigation in Lepidopterans. PMID:16317560

  15. Ultraviolet visual sensitivity in three avian lineages: paleognaths, parrots, and passerines.

    PubMed

    Aidala, Zachary; Huynen, Leon; Brennan, Patricia L R; Musser, Jacob; Fidler, Andrew; Chong, Nicola; Machovsky Capuska, Gabriel E; Anderson, Michael G; Talaba, Amanda; Lambert, David; Hauber, Mark E

    2012-07-01

    Ultraviolet (UV) light-transmitted signals play a major role in avian foraging and communication, subserving functional roles in feeding, mate choice, egg recognition, and nestling discrimination. Sequencing functionally relevant regions of the short wavelength sensitive type 1 (SWS1) opsin gene that is responsible for modulating the extent of SWS1 UV sensitivity in birds allows predictions to be made about the visual system's UV sensitivity in species where direct physiological or behavioral measures would be impractical or unethical. Here, we present SWS1 segment sequence data from representative species of three avian lineages for which visually based cues for foraging and communication have been investigated to varying extents. We also present a preliminary phylogenetic analysis and ancestral character state reconstructions of key spectral tuning sites along the SWS1 opsin based on our sequence data. The results suggest ubiquitous ultraviolet SWS1 sensitivity (UVS) in both paleognaths, including extinct moa (Emeidae), and parrots, including the nocturnal and flightless kakapo (Strigops habroptilus), and in most, but not all, songbird (oscine) lineages, and confirmed violet sensitivity (VS) in two suboscine families. Passerine hosts of avian brood parasites were included both UVS and VS taxa, but sensitivity did not co-vary with egg rejection behaviors. The results should stimulate future research into the functional parallels between the roles of visual signals and the genetic basis of visual sensitivity in birds and other taxa. PMID:22534772

  16. Optogenetic approaches for investigating neural pathways implicated in schizophrenia and related disorders.

    PubMed

    Cho, Kathleen K A; Sohal, Vikaas S

    2014-09-15

    Optogenetic approaches have been rapidly adopted by neuroscientists in order to control the activity of neurons with high temporal, spatial and genetic specificity. By expressing light-sensitive microbial opsins within a genetically-specified population of neurons, flashes of light can be used to activate these opsins and thereby modulate the targeted cells in a spatially and temporally defined manner. Thus, optogenetics can be used to activate very specific sets of neurons or projections at particular times, either within freely behaving animals, or in reduced preparations such as brain slices. These techniques are ideally suited for dissecting complex interactions within neuronal circuits, and for testing ideas about how changes in these circuits might contribute to abnormal behaviors in the context of neuropsychiatric disorders. Here, we review several studies that have used optogenetics to dissect circuits implicated in schizophrenia, and elucidate the ways in which specific components of these circuits may contribute to normal or abnormal behavior. Specifically, optogenetics can be used to label and excite neurons that express particular genes, in order to study how they interact with other neurons and/or modulate behavior. Optogenetics can also be used to study changes in these interactions or behavioral effects following genetic manipulations. In this way, optogenetics may serve to 'fill in the gaps' between genes, circuits and behavior, in a manner that should help to translate the rapidly growing list of genes associated with neuropsychiatric disorders into specific pathophysiological mechanisms. PMID:24824218

  17. The molecular genetics of red and green color vision in mammals.

    PubMed

    Yokoyama, S; Radlwimmer, F B

    1999-10-01

    To elucidate the molecular mechanisms of red-green color vision in mammals, we have cloned and sequenced the red and green opsin cDNAs of cat (Felis catus), horse (Equus caballus), gray squirrel (Sciurus carolinensis), white-tailed deer (Odocoileus virginianus), and guinea pig (Cavia porcellus). These opsins were expressed in COS1 cells and reconstituted with 11-cis-retinal. The purified visual pigments of the cat, horse, squirrel, deer, and guinea pig have lambdamax values at 553, 545, 532, 531, and 516 nm, respectively, which are precise to within +/-1 nm. We also regenerated the "true" red pigment of goldfish (Carassius auratus), which has a lambdamax value at 559 +/- 4 nm. Multiple linear regression analyses show that S180A, H197Y, Y277F, T285A, and A308S shift the lambdamax values of the red and green pigments in mammals toward blue by 7, 28, 7, 15, and 16 nm, respectively, and the reverse amino acid changes toward red by the same extents. The additive effects of these amino acid changes fully explain the red-green color vision in a wide range of mammalian species, goldfish, American chameleon (Anolis carolinensis), and pigeon (Columba livia). PMID:10511567

  18. Electrophysiological study of Drosophila rhodopsin mutants

    PubMed Central

    1986-01-01

    Electrophysiological investigations were carried out on several independently isolated mutants of the ninaE gene, which encodes opsin in R1-6 photoreceptors, and a mutant of the ninaD gene, which is probably important in the formation of the rhodopsin chromophore. In these mutants, the rhodopsin content in R1-6 photoreceptors is reduced by 10(2)-10(6)-fold. Light-induced bumps recorded from even the most severely affected mutants are physiologically normal. Moreover, a detailed noise analysis shows that photoreceptor responses of both a ninaE mutant and a ninaD mutant follow the adapting bump model. Since any extensive rhodopsin-rhodopsin interactions are not likely in these mutants, the above results suggest that such interactions are not needed for the generation and adaptation of light-induced bumps. Mutant bumps are strikingly larger in amplitude than wild-type bumps. This difference is observed both in ninaD and ninaE mutants, which suggests that it is due to severe depletion of rhodopsin content, rather than to any specific alterations in the opsin protein. Lowering or buffering the intracellular calcium concentration by EGTA injection mimics the effects of the mutations on the bump amplitude, but, unlike the mutations, it also affects the latency and kinetics of light responses. PMID:3097245

  19. Color vision: "OH-site" rule for seeing red and green.

    PubMed

    Sekharan, Sivakumar; Katayama, Kota; Kandori, Hideki; Morokuma, Keiji

    2012-06-27

    Eyes gather information, and color forms an extremely important component of the information, more so in the case of animals to forage and navigate within their immediate environment. By using the ONIOM (QM/MM) (ONIOM = our own N-layer integrated molecular orbital plus molecular mechanics) method, we report a comprehensive theoretical analysis of the structure and molecular mechanism of spectral tuning of monkey red- and green-sensitive visual pigments. We show that interaction of retinal with three hydroxyl-bearing amino acids near the ?-ionone ring part of the retinal in opsin, A164S, F261Y, and A269T, increases the electron delocalization, decreases the bond length alternation, and leads to variation in the wavelength of maximal absorbance of the retinal in the red- and green-sensitive visual pigments. On the basis of the analysis, we propose the "OH-site" rule for seeing red and green. This rule is also shown to account for the spectral shifts obtained from hydroxyl-bearing amino acids near the Schiff base in different visual pigments: at site 292 (A292S, A292Y, and A292T) in bovine and at site 111 (Y111) in squid opsins. Therefore, the OH-site rule is shown to be site-specific and not pigment-specific and thus can be used for tracking spectral shifts in any visual pigment. PMID:22663599

  20. Spectral heterogeneity of honeybee ommatidia

    NASA Astrophysics Data System (ADS)

    Wakakuwa, Motohiro; Kurasawa, Masumi; Giurfa, Martin; Arikawa, Kentaro

    2005-10-01

    The honeybee compound eye is equipped with ultraviolet, blue, and green receptors, which form the physiological basis of a trichromatic color vision system. We studied the distribution of the spectral receptors by localizing the three mRNAs encoding the opsins of the ultraviolet-, blue- and green-absorbing visual pigments. The expression patterns of the three opsin mRNAs demonstrated that three distinct types ommatidia exist, refuting the common assumption that the ommatidia composing the bee compound eye contain identical sets of spectral receptors. We found that type I ommatidia contain one ultraviolet and one blue receptor, type II ommatidia contain two ultraviolet receptors, and type III ommatidia have two blue receptors. All the three ommatidial types contain six green receptors. The ommatidia appear to be distributed rather randomly over the retina. The ratio of type I, II, and III ommatidia was about 44:46:10. Type III ommatidia appeared to be slightly more frequent (18%) in the anterior part of the ventral region of the eye. Retinal heterogeneity and ommatidial randomness, first clearly demonstrated in butterflies, seems to be a common design principle of the eyes of insects.

  1. Structural and Functional Effects of Hemiretinal Endodiathermy Axotomy in Cynomolgus Macaques

    PubMed Central

    Dashek, Ryan J.; Kim, Charlene B. Y.; Rasmussen, Carol A.; Hennes-Beean, Elizabeth A.; VerHoeve, James N.; Nork, T. Michael

    2013-01-01

    Purpose. Outer retinal injury has been well described in glaucoma. To better understand the source of this injury, we wanted to develop a reliable model of partial retinal ganglion cell (RGC) axotomy. Methods. Endodiathermy spots were placed along the inferior 180° adjacent to the optic nerve margin in the right eyes of four cynomolgus monkeys. Fluorescein angiography, spectral domain optical coherence tomography (SD-OCT), and multifocal electroretinography (mfERG) were performed at various intervals. Two animals were sacrificed at 3 months. Two animals were sacrificed at 4 months, at which time they underwent an injection of fluorescent microspheres to measure regional choroidal blood flow. Retinal immunohistochemistry for glial fibrillary acidic protein (GFAP), rhodopsin, S-cone opsin, and M/L-cone opsin were performed, as were axon counts of the optic nerves. Results. At 3 months, there was marked thinning of the inferior nerve fiber layer on SD-OCT. The mfERG waveforms were consistent with inner but not outer retinal injury. Greater than 95% reduction in axons was seen in the inferior optic nerves but no secondary degeneration superiorly. There was marked thinning of the nerve fiber and ganglion cell layers in the inferior retinas. However, the photoreceptor histology was similar in the axotomized and nonaxotomized areas. Regional choroidal blood flow was not affected by the axotomy. Conclusions. Unlike experimental glaucoma, hemiretinal endodiathermy axotomy (HEA) of the RGCs produces no apparent anatomic, functional, or blood flow effects on the outer retina and choroid. PMID:23620427

  2. Evolution of vertebrate retinal photoreception

    PubMed Central

    Lamb, Trevor D.

    2009-01-01

    Recent findings shed light on the steps underlying the evolution of vertebrate photoreceptors and retina. Vertebrate ciliary photoreceptors are not as wholly distinct from invertebrate rhabdomeric photoreceptors as is sometimes thought. Recent information on the phylogenies of ciliary and rhabdomeric opsins has helped in constructing the likely routes followed during evolution. Clues to the factors that led the early vertebrate retina to become invaginated can be obtained by combining recent knowledge about the origin of the pathway for dark re-isomerization of retinoids with knowledge of the inability of ciliary opsins to undergo photoreversal, along with consideration of the constraints imposed under the very low light levels in the deep ocean. Investigation of the origin of cell classes in the vertebrate retina provides support for the notion that cones, rods and bipolar cells all originated from a primordial ciliary photoreceptor, whereas ganglion cells, amacrine cells and horizontal cells all originated from rhabdomeric photoreceptors. Knowledge of the molecular differences between cones and rods, together with knowledge of the scotopic signalling pathway, provides an understanding of the evolution of rods and of the rods' retinal circuitry. Accordingly, it has been possible to propose a plausible scenario for the sequence of evolutionary steps that led to the emergence of vertebrate photoreceptors and retina. PMID:19720653

  3. Shining new light on optogenetics

    NASA Astrophysics Data System (ADS)

    Gu, Ling; Dhakal, Kamal; Li, Ting; Mohanty, Samarendra

    2012-02-01

    Since development of optogenetic stimulation paradigm, there has been several attempts to red shift the excitation maximum of the efficient blue-sensitive opsins. While there has been some success at the cost of altered light-activation kinetics, near-infrared optogenetic probe will be ideal for in-depth cell-specific stimulation of excitable cells in an organ. However, single-photon near-infrared optogenetics based stimulation will still limit precise probing and modulation of in-vivo neural circuits. In contrast, by virtue of non-linear nature of ultrafast light-matter interaction, high spatial precision in optogenetic activation can be achieved in addition to inherent cellular specificity and temporal resolution provided by the opsins. Here, we report use of non-linear optogenetics for stimulation of neurons in-vivo in mouse models. Advantage of using non-linear optogenetics for probing neuronal circuitry is discussed. Further, effectiveness of the non-diffracting optogenetic Bessel beam over classical Gaussian beam in a layered mouse-brain geometry is demonstrated using Monte Carlo (MC) simulation. This is corroborated by electrophysiological measurements in in-vivo mouse models. The large propagation distance, characteristics of Bessel beam is better suited for in-depth single as well as two-photon optogenetic stimulation.

  4. Hearing the light: neural and perceptual encoding of optogenetic stimulation in the central auditory pathway.

    PubMed

    Guo, Wei; Hight, Ariel E; Chen, Jenny X; Klapoetke, Nathan C; Hancock, Kenneth E; Shinn-Cunningham, Barbara G; Boyden, Edward S; Lee, Daniel J; Polley, Daniel B

    2015-01-01

    Optogenetics provides a means to dissect the organization and function of neural circuits. Optogenetics also offers the translational promise of restoring sensation, enabling movement or supplanting abnormal activity patterns in pathological brain circuits. However, the inherent sluggishness of evoked photocurrents in conventional channelrhodopsins has hampered the development of optoprostheses that adequately mimic the rate and timing of natural spike patterning. Here, we explore the feasibility and limitations of a central auditory optoprosthesis by photoactivating mouse auditory midbrain neurons that either express channelrhodopsin-2 (ChR2) or Chronos, a channelrhodopsin with ultra-fast channel kinetics. Chronos-mediated spike fidelity surpassed ChR2 and natural acoustic stimulation to support a superior code for the detection and discrimination of rapid pulse trains. Interestingly, this midbrain coding advantage did not translate to a perceptual advantage, as behavioral detection of midbrain activation was equivalent with both opsins. Auditory cortex recordings revealed that the precisely synchronized midbrain responses had been converted to a simplified rate code that was indistinguishable between opsins and less robust overall than acoustic stimulation. These findings demonstrate the temporal coding benefits that can be realized with next-generation channelrhodopsins, but also highlight the challenge of inducing variegated patterns of forebrain spiking activity that support adaptive perception and behavior. PMID:26000557

  5. Color Vision: The “OH-Site” Rule for Seeing Red and Green

    PubMed Central

    Sekharan, Sivakumar; Katayama, Kota; Kandori, Hideki; Morokuma, Keiji

    2013-01-01

    Eyes gather information and color forms an extremely important component of the information, more so in the case of animals to forage and navigate within their immediate environment. By using the ONIOM (QM/MM) method, we report a comprehensive theoretical analysis of the structure and molecular mechanism of spectral tuning of monkey-red and green-sensitive visual pigments. We show that, interaction of retinal with three hydroxyl-bearing amino acids near the ?-ionone ring part of the retinal in opsin, A164S, F261Y and A269T, increases the electron delocalization, decreases the BLA of the retinal and leads to variation in the wavelength of maximal absorbance in the red- and green-sensitive visual pigments. Based on the analysis, we propose the “OH-site” rule for seeing red and green. This rule is also shown to account for the spectral shifts obtained from hydroxyl-bearing amino acids near the Schiff base in different visual pigments: at site 292 (A292S, A292Y, and A292T) in bovine and at site 111 (Y111) in squid opsins. Therefore, the OH-site rule is shown to be site-specific and not pigment-specific and thus can be used for tracking spectral shifts in any visual pigment. PMID:22663599

  6. Evolution and the origin of the visual retinoid cycle in vertebrates

    PubMed Central

    Kusakabe, Takehiro G.; Takimoto, Noriko; Jin, Minghao; Tsuda, Motoyuki

    2009-01-01

    Absorption of a photon by visual pigments induces isomerization of 11-cis-retinaldehyde (RAL) chromophore to all-trans-RAL. Since the opsins lacking 11-cis-RAL lose light sensitivity, sustained vision requires continuous regeneration of 11-cis-RAL via the process called ‘visual cycle’. Protostomes and vertebrates use essentially different machinery of visual pigment regeneration, and the origin and early evolution of the vertebrate visual cycle is an unsolved mystery. Here we compare visual retinoid cycles between different photoreceptors of vertebrates, including rods, cones and non-visual photoreceptors, as well as between vertebrates and invertebrates. The visual cycle systems in ascidians, the closest living relatives of vertebrates, show an intermediate state between vertebrates and non-chordate invertebrates. The ascidian larva may use retinochrome-like opsin as the major isomerase. The entire process of the visual cycle can occur inside the photoreceptor cells with distinct subcellular compartmentalization, although the visual cycle components are also present in surrounding non-photoreceptor cells. The adult ascidian probably uses RPE65 isomerase, and trans-to-cis isomerization may occur in distinct cellular compartments, which is similar to the vertebrate situation. The complete transition to the sophisticated retinoid cycle of vertebrates may have required acquisition of new genes, such as interphotoreceptor retinoid-binding protein, and functional evolution of the visual cycle genes. PMID:19720652

  7. Optically triggering spatiotemporally confined GPCR activity in a cell and programming neurite initiation and extension

    PubMed Central

    Karunarathne, W. K. Ajith; Giri, Lopamudra; Kalyanaraman, Vani; Gautam, N.

    2013-01-01

    G-protein–coupled receptor (GPCR) activity gradients evoke important cell behavior but there is a dearth of methods to induce such asymmetric signaling in a cell. Here we achieved reversible, rapidly switchable patterns of spatiotemporally restricted GPCR activity in a single cell. We recruited properties of nonrhodopsin opsins—rapid deactivation, distinct spectral tuning, and resistance to bleaching—to activate native Gi, Gq, or Gs signaling in selected regions of a cell. Optical inputs were designed to spatiotemporally control levels of second messengers, IP3, phosphatidylinositol (3,4,5)-triphosphate, and cAMP in a cell. Spectrally selective imaging was accomplished to simultaneously monitor optically evoked molecular and cellular response dynamics. We show that localized optical activation of an opsin-based trigger can induce neurite initiation, phosphatidylinositol (3,4,5)-triphosphate increase, and actin remodeling. Serial optical inputs to neurite tips can refashion early neuron differentiation. Methods here can be widely applied to program GPCR-mediated cell behaviors. PMID:23479634

  8. 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.).

  9. Mass Flows in a Prominence Spine as Observed in EUV

    NASA Astrophysics Data System (ADS)

    Kucera, Therese A.; Gilbert, Holly; Karpen, Judith T.

    2014-06-01

    We analyze a quiescent prominence observed by the Solar Dynamics Observatory's Atmospheric Imaging Assembly with a focus on mass and energy flows in the spine measured using Lyman continuum absorption. This is the first time this sort of analysis has been applied with an emphasis on individual features and flows in a quiescent prominence. The prominence, observed on 2010 Sept. 28, is detectable in most AIA wavebands in absorption and/or emission. Flows along the spine exhibit horizontal bands 5-10 arcsec wide and kinetic energy fluxes consistent with quiet sun coronal heating estimates. For a discrete moving feature we estimate a mass of a few times 10^11 g. We discuss the implications of our derived properties for models of prominence dynamics, in particular the thermal non-equilibrium model. This project was supported by NASA's LWS TR&T program.

  10. 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.

  11. Observational evidence of CMEs interacting in the inner heliosphere as inferred from MHD simulations

    E-print Network

    Lugaz, N; Roussev, I I; Gombosi, T I

    2008-01-01

    The interaction of multiple Coronal Mass Ejections (CMEs) has been observed by LASCO coronagraphs and by near-Earth spacecraft, and it is thought to be an important cause of geo-effective storms, large Solar Energetic Particles events and intense Type II radio bursts. New and future missions such as STEREO, the LWS Sentinels, and the Solar Orbiter will provide additional observations of the interaction of multiple CMEs between the Sun and the Earth. We present the results of simulations of two and more CMEs interacting in the inner heliosphere performed with the Space Weather Modeling Framework (SWMF). Based on those simulations, we discuss the observational evidence of the interaction of multiple CMEs, both in situ and from coronagraphs. The clearest evidence of the interaction of the CMEs are the large temperature in the sheath, due to the shocks merging, and the brightness increase in coronagraphic images, associated with the interaction of the leading edges. The importance of having multiple satellites at...

  12. Laser ultrasound measurement and finite-element simulation on the dispersion behaviors of acoustic waves propagating along wedges with bilinear cross sections.

    PubMed

    Yang, Che-Hua; Tsen, Chun-Zen

    2006-04-01

    In this research, dispersion behaviors of antisymmetric flexural (ASF) modes propagating along the tip of a bilinear wedge (BW) are investigated. A BW has a cross section with two apex angles, as opposed to a linear wedge (LW) whose cross section has a single apex angle. In the literature, many studies regarding the dispersion behaviors of ASF modes have been reported for LWs, but not for BWs. In this study, laser ultrasonic measurements and finite-element numerical simulations are used to investigate the dispersion behavior of BW-ASF modes. It was found that a BW-ASF mode arises as a result of mode coupling between two LW-ASF modes of the same order corresponding to the two apex angles of the BW. PMID:16615579

  13. Cryogenic mechanisms for scanning and interchange of the Fabry-Perot interferometers in the ISO long wavelength spectrometer

    NASA Technical Reports Server (NTRS)

    Davis, G. R.; Furniss, I.; Patrick, T. J.; Sidey, R. C.; Towlson, W. A.

    1991-01-01

    The Infrared Space Observatory (ISO) is an ESA cornerstone mission for infrared astronomy. Schedules for launch in 1993, its four scientific instruments will provide unprecedented sensitivity and spectral resolution at wavelengths which are inaccessible using ground-based techniques. One of these, the Long Wavelength Spectrometer (LWS), will operate in the 45 to 180 micron region (Emery et. al., 1985) and features two Fabry-Perot interferometers mounted on an interchange mechanism. The entire payload module of the spacecraft, comprising the 60 cm telescope and the four focal plane instruments, is maintained at 2 to 4 K by an onboard supply of liquid helium. The mechanical design and testing of the cryogenic interferometer and interchange mechanisms are described.

  14. Spectroscopy of Stellar Jets, Outflows, and Young Stellar Objects with the Infrared Space Observatory

    E-print Network

    Alberto Noriega-Crespo

    2001-01-04

    The Infrared Space Observatory (ISO) was an extremely successful european space mission that gave us an unparallel view of the Universe in the infrared, and provided us with hundreds of observations of star forming regions and bipolar outflows. Three of the instrument teams, in charge of the infrared camera (CAM) and the two spectrometers at short and long wavelengths (SWS and LWS respectively), used a significant fraction of their guarantee time to study YSOs and outflows spectroscopically. In here, I will briefly review some of their main findings, particularly the detection of water, H2 rotational emission lines and the presence of other complex molecules. I will present new spectroscopic results on HH 1-2, HH 7-11 and Cep E, and their sources. And finally, I will discuss some of the general trends derived from these observations and their relevance in understanding the emission from these objects using J and C shock models.

  15. A Survey of 10-Micron Silicate Emission from Dust around Young Sun-Like Stars

    E-print Network

    Eric Gaidos; Christopher Koresko

    2003-07-22

    We obtained low resolution (R = 100) mid-infrared (8-13 micron wavelengths) spectra of 8 nearby young main sequence stars with the Keck 1 telescope and Long-Wavelength Spectrometer (LWS) to search for 10 micron silicate (Si-O stretch) emission from circumstellar dust. No stars exhibited readily apparent emission: Spectra were then analyzed by least-squares fitting of a template based on a spectrum of Comet Hale-Bopp. Using this technique, we were able to constrain the level of silicate emission to a threshold ten times below what was previously possible from space. We found one star, HD 17925, with a spectrum statistically different from its calibrator and consistent with a silicate emission peak of 7% of the photosphere at a wavelength of 10 microns. Excess emission at 60 microns from this star has already been reported.

  16. 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.

  17. The Circumstellar Environment of MWC297: ISO Results and FIRST Expectations

    NASA Astrophysics Data System (ADS)

    Benedettini, M.; Pezzuto, S.; Giannini, T.; Lorenzetti, D.; Nisini, B.; Strafella, F.

    2001-07-01

    The ISO SWS and LWS full grating spectra of the Herbig Be star MWC297 are presented. The spectra are dominated by a strong continuum; in addition, in the SWS range (2.3-45 microns), emission lines from the HI recombination series, PAH emission and absorption by solid CO2, H2O, and silicates have been observed while in the LWS spectrum (43-197 microns) [OI] and [CII] fine structure lines have been detected. The NIR-FIR data have been combined with ground based photometry to derive the spectral energy distribution (SED) from optical to radio wavelengths. The observed SED has been compared with the SED's computed with a spherical dusty envelope model parametrized by a density and temperature law in order to probe if such a circumstellar matter distribution is compatible with the observations, deriving also suitable values for the spectral type, the extinction and the distance. Consistent determination of the extinction and estimates of both the source mass loss rate and the size of the emitting ionized region have been derived by the analysis of the HI recombination lines of the Brackett, Pfund and Humphreys series observed by ISO together with Paschen and Brackett lines observed from the ground. The results are somewhat hampered by the large beam size of the ISO instruments. We show how the Photoconductor Array Camera and Spectrometer (spectral range 60 - 210 microns) on board the FIRST satellite, with its high spatial resolution (9.4 arcsec) will be able to improve our understanding of the physical conditions in the close neighbourhood of MWC297 and, more generally, to shed light on the distribution of the circumstellar matter around the Herbig Ae/Be stars.

  18. 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. [University of Pennsylvania, 209 S. 33rd St, Philadelphia, PA 19104 (United States); Mason, B. S.; Cotton, W. D. [National Radio Astronomy Observatory, Charlottesville, VA 22903 (United States); Compiegne, M.; Martin, P. G. [Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St George St, Toronto, ON M5S 3H8 (Canada); Ade, P. A. R; Tucker, C. [Cardiff University, 5 The Parade, Cardiff, CF24 3YB (United Kingdom); Benford, D. J.; Staguhn, J. G. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Irwin, K. D. [National Institute of Standards and Technology, 325 Broadway, Boulder, CO 80305 (United States); Maddalena, R. J.; McMullin, J. P.; Shepherd, D.S. [National Radio Astronomy Observatory, Green Bank, WV 24944 (United States); Sievers, A. [IRAM, Avenida Divina Pastora, 7, Nucleo Central, E 18012 Granada (Spain)

    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).

  19. 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.

  20. Hot-electron production and suprathermal heat flux scaling with laser intensity from the two-plasmon-decay instability

    SciTech Connect

    Vu, H. X. [University of California, San Diego, La Jolla, California 92093 (United States); DuBois, D. F. [Lodestar Research Corporation, Boulder, Colorado 80301 (United States); Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Myatt, J. F. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Russell, D. A. [Lodestar Research Corporation, Boulder, Colorado 80301 (United States)

    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.

  1. 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 vitreus subjected to simulated tournament conditions (angling,LW confinement,and weigh-in procedures) under controlled laboratory conditions. We tested three acclimation temperatures (12,18,and 24°C),and three LW temperature differentials (?T = ?4,0,and +4°C) were tested at each acclimation temperature. Survival was monitored after 8 h of LW confinement and during a 5-d retention period in 1,700-L tanks. None of the Walleyes that were acclimated to 24°C and subjected to simulated tournament procedures survived the 5-d retention period; for fish subjected only to simulated angling at 24°C,survival during the 5-d retention period was 29%. Five-day survival was generally over 70% at acclimation temperatures of 12°C and 18°C,and we observed a significant interaction between acclimation temperature and ?T; survival was greatest in LWs at ?4°C ?T for fish acclimated to 18°C and in LWs at +4°C ?T for fish acclimated to 12°C. Best survival of Walleyes subjected to the stress of angling and tournament procedures was obtained at temperatures 6–8°C below the optimum temperature for adult Walleyes (i.e.,optimum = 20–22°C). Five-day survival exceeded 70% when LW DO was 5 or 12–15 mg/L (at an acclimation and LW temperature of 18°C),but survival was 0% when DO was 2 mg/L. Anglers may increase survival of Walleyes through careful manipulation of LW temperature and DO when ambient temperature is at or below 18°C,but high mortality of angled and LW-retained Walleyes should be expected when ambient water temperatures are 24°C or greater.

  2. The Far Infrared Lines of OH as Molecular Cloud Diagnostics

    NASA Technical Reports Server (NTRS)

    Smith, Howard A.

    2004-01-01

    Future IR missions should give some priority to high resolution spectroscopic observations of the set of far-IR transitions of OH. There are 15 far-IR lines arising between the lowest eight rotational levels of OH, and ISO detected nine of them. Furthermore, ISO found the OH lines, sometimes in emission and sometimes in absorption, in a wide variety of galactic and extragalactic objects ranging from AGB stars to molecular clouds to active galactic nuclei and ultra-luminous IR galaxies. The ISO/LWS Fabry-Perot resolved the 119 m doublet line in a few of the strong sources. This set of OH lines provides a uniquely important diagnostic for many reasons: the lines span a wide wavelength range (28.9 m to 163.2 m); the transitions have fast radiative rates; the abundance of the species is relatively high; the IR continuum plays an important role as a pump; the contribution from shocks is relatively minor; and, not least, the powerful centimeter-wave radiation from OH allows comparison with radio and VLBI datasets. The problem is that the large number of sensitive free parameters, and the large optical depths of the strongest lines, make modeling the full set a difficult job. The SWAS montecarlo radiative transfer code has been used to analyze the ISO/LWS spectra of a number of objects with good success, including in both the lines and the FIR continuum; the DUSTY radiative transfer code was used to insure a self-consistent continuum. Other far IR lines including those from H2O, CO, and [OI] are also in the code. The OH lines all show features which future FIR spectrometers should be able to resolve, and which will enable further refinements in the details of each cloud's structure. Some examples are given, including the case of S140, for which independent SWAS data found evidence for bulk flows.

  3. Forecasting Coronal Mass Ejections from Magnetograms

    NASA Technical Reports Server (NTRS)

    Falconer, D. A.; Balasubramanian, S.; Moore, R. L.; Gary, G. A.

    2004-01-01

    We report further results from our ongoing assessment of magnetogram-based measures of active-region nonpotentiality (magnetic shear and twist) and size as predictors of coronal mass ejections (CMEs). From a set of 36 vector magnetograms of bipolar active regions (Falconer, Moore, & Gary 2004, ApJ, submitted), we have found that (1) each of our 5 measures of active-region nonpotentiality has a 75-80% success rate in predicting whether an active region will produce a CME within 2 days after the magnetogram, (2) the correlation of each of these measures with CME production in this window is statistically significant (confidence level greater than 95%), (3) our measure of active-region size has a 65% success rate in predicting CMEs in this window, but (4) the correlation between active-region size and CME productivity is not statistically significant (confidence level approximately 80%). As part of the work under our pending 2003 LWS TR&T proposal, we will double our sample to approximately 70 active regions in order to demonstrate a statistically significant correlation between active-region size and CME productivity, and to determine whether this correlation is a byproduct of any Sun-produced correlation between magnetic twist and size of active regions. Since the 2002 LWS Science Workshop, we have found a measure of active-region nonpotentiality (the length of strong-gradient neutral line) that can be measured from a line-of-sight magnetogram, and we have generalized this measure and the corresponding measure from a vector magnetogram (the length of strong-shear neutral line) so that they can be applied to multiple-bipole complex active regions as well as to bipolar active regions. Preliminary results will be presented from application of these two generalized measures to our sample of bipolar active regions and to a new sample of multiple-bipole active regions.

  4. 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.

  5. 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.

  6. Solitary-wave emission fronts, spectral chirping, and coupling to beam acoustic modes in RPIC simulation of SRS backscatter.

    SciTech Connect

    DuBois, D. F. (Donald F.); Yin, L. (Lin); Daughton, W. S. (William S.); Bezzerides, B. (Bandel); Dodd, E. S. (Evan S.); Vu, H. X. (Hoanh 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.

  7. Spectral sensitivities of the human cones

    Microsoft Academic Search

    Andrew Stockman; Donald I. A. MacLeod; Nancy E. Johnson

    1993-01-01

    Transient chromatic adaptation produced by an abrupt change of background color permits an easier and closer approach to cone isolation than does steady-state adaptation. Using this technique, we measured middle-wave- sensitive (M-) cone spectral sensitivities in 11 normals and 2 protanopes and long-wavelength-sensitive (L-) cone spectral sensitivities in 12 normals and 4 deuteranopes. Although there is great individual variation in

  8. Physical model for shock-wave initiation of detonation in pressed fine crystalline xplosives

    Microsoft Academic Search

    K. F. Grebenkin

    1998-01-01

    A physical model is proposed for the reaction kinetics of heterogeneous explosives under shock-wave initiation of detonation.\\u000a The model is based on the assumption that the molecular crystals of the explosive materials have semiconductor properties.\\u000a The model can account for the experimentally observed strong dependence of the shock-wave sensitivity of pressed explosives\\u000a on their initial density and temperature. The proposed

  9. Human cone spectral sensitivities: a progress report

    Microsoft Academic Search

    Andrew Stockman; Lindsay T. Sharpe

    1998-01-01

    The spectral sensitivities of the short (S-), middle (M-) and long (L-) wave-sensitive cones have been measured in normal trichromats and in dichromats and monochromats of known genotype. For the S-cone sensitivities, three blue-cone monochromats and five normals were used; for the M-cone sensitivities, nine protanopes (three with a single L1M2 gene, three with a single L2M3 gene, one with

  10. Topographical characterization of cone photoreceptors and the area centralis of the canine retina

    PubMed Central

    Mowat, Freya M.; Petersen-Jones, Simon M.; Williamson, Helen; Williams, David L.; Luthert, Philip J.; Ali, Robin R.

    2008-01-01

    Purpose The canine is an important large animal model of human retinal genetic disorders. Studies of ganglion cell distribution in the canine retina have identified a visual streak of high density superior to the optic disc with a temporal area of peak density known as the area centralis. The topography of cone photoreceptors in the canine retina has not been characterized in detail, and in contrast to the macula in humans, the position of the area centralis in dogs is not apparent on clinical funduscopic examination. The purpose of this study was to define the location of the area centralis in the dog and to characterize in detail the topography of rod and cone photoreceptors within the area centralis. This will facilitate the investigation and treatment of retinal disease in the canine. Methods We used peanut agglutinin, which labels cone matrix sheaths and antibodies against long/medium wavelength (L/M)- and short wavelength (S)-cone opsins, to stain retinal cryosections and flatmounts from beagle dogs. Retinas were imaged using differential interference contrast imaging, fluorescence, and confocal microscopy. Within the area centralis, rod and cone size and density were quantified, and the proportion of cones expressing each cone opsin subtype was calculated. Using a grid pattern of sampling in 9 retinal flatmounts, we investigated the distribution of cones throughout the retina to predict the location of the area centralis. Results We identified the area centralis as the site of maximal density of rod and cone photoreceptor cells, which have a smaller inner segment cross-sectional area in this region. L/M opsin was expressed by the majority of cones in the retina, both within the area centralis and in the peripheral retina. Using the mean of cone density distribution from 9 retinas, we calculated that the area centralis is likely to be centered at a point 1.5 mm temporal and 0.6 mm superior to the optic disc. For clinical funduscopic examination, this represents 1.2 disc diameters temporal and 0.4 disc diameters superior to the optic disc. Conclusions We have described the distribution of rods and cone subtypes within the canine retina and calculated a predictable location for the area centralis. These findings will facilitate the characterization and treatment of cone photoreceptor dystrophies in the dog. PMID:19112529

  11. Functional characterization of spectral tuning mechanisms in the great bowerbird short-wavelength sensitive visual pigment (SWS1), and the origins of UV/violet vision in passerines and parrots

    PubMed Central

    2013-01-01

    Background One of the most striking features of avian vision is the variation in spectral sensitivity of the short wavelength sensitive (SWS1) opsins, which can be divided into two sub-types: violet- and UV- sensitive (VS & UVS). In birds, UVS has been found in both passerines and parrots, groups that were recently shown to be sister orders. While all parrots are thought to be UVS, recent evidence suggests some passerine lineages may also be VS. The great bowerbird (Chlamydera nuchalis) is a passerine notable for its courtship behaviours in which males build and decorate elaborate bower structures. Results The great bowerbird SWS1 sequence possesses an unusual residue combination at known spectral tuning sites that has not been previously investigated in mutagenesis experiments. In this study, the SWS1 opsin of C. nuchalis was expressed along with a series of spectral tuning mutants and ancestral passerine SWS1 pigments, allowing us to investigate spectral tuning mechanisms and explore the evolution of UV/violet sensitivity in early passerines and parrots. The expressed C. nuchalis SWS1 opsin was found to be a VS pigment, with a ?max of 403 nm. Bowerbird SWS1 mutants C86F, S90C, and C86S/S90C all shifted ?max into the UV, whereas C86S had no effect. Experimentally recreated ancestral passerine and parrot/passerine SWS1 pigments were both found to be VS, indicating that UV sensitivity evolved independently in passerines and parrots from a VS ancestor. Conclusions Our mutagenesis studies indicate that spectral tuning in C. nuchalis is mediated by mechanisms similar to those of other birds. Interestingly, our ancestral sequence reconstructions of SWS1 in landbird evolution suggest multiple transitions from VS to UVS, but no instances of the reverse. Our results not only provide a more precise prediction of where these spectral sensitivity shifts occurred, but also confirm the hypothesis that birds are an unusual exception among vertebrates where some descendants re-evolved UVS from a violet type ancestor. The re-evolution of UVS from a VS type pigment has not previously been predicted elsewhere in the vertebrate phylogeny. PMID:24499383

  12. Crystal Structure of Rhodopsin: A Template for Cone Visual Pigments and Other G Protein-coupled Receptors

    SciTech Connect

    Stenkamp, R. E.

    2002-01-01

    The crystal structure of rhodopsin has provided the first three-dimensional molecular model for a G-protein-coupled receptor (GPCR). Alignment of the molecular model from the crystallographic structure with the helical axes seen in cryo-electron microscopic (cryo-EM) studies provides an opportunity to investigate the properties of the molecule as a function of orientation and location within the membrane. In addition, the structure provides a starting point for modeling and rational experimental approaches of the cone pigments, the GPCRs in cone cells responsible for color vision. Homology models of the cone pigments provide a means of understanding the roles of amino acid sequence differences that shift the absorption maximum of the retinal chromophore in the environments of different opsins.

  13. Independent optical excitation of distinct neural populations.

    PubMed

    Klapoetke, Nathan C; Murata, Yasunobu; Kim, Sung Soo; Pulver, Stefan R; Birdsey-Benson, Amanda; Cho, Yong Ku; Morimoto, Tania K; Chuong, Amy S; Carpenter, Eric J; Tian, Zhijian; Wang, Jun; Xie, Yinlong; Yan, Zhixiang; Zhang, Yong; Chow, Brian Y; Surek, Barbara; Melkonian, Michael; Jayaraman, Vivek; Constantine-Paton, Martha; Wong, Gane Ka-Shu; Boyden, Edward S

    2014-03-01

    Optogenetic tools enable examination of how specific cell types contribute to brain circuit functions. A long-standing question is whether it is possible to independently activate two distinct neural populations in mammalian brain tissue. Such a capability would enable the study of how different synapses or pathways interact to encode information in the brain. Here we describe two channelrhodopsins, Chronos and Chrimson, discovered through sequencing and physiological characterization of opsins from over 100 species of alga. Chrimson's excitation spectrum is red shifted by 45 nm relative to previous channelrhodopsins and can enable experiments in which red light is preferred. We show minimal visual system-mediated behavioral interference when using Chrimson in neurobehavioral studies in Drosophila melanogaster. Chronos has faster kinetics than previous channelrhodopsins yet is effectively more light sensitive. Together these two reagents enable two-color activation of neural spiking and downstream synaptic transmission in independent neural populations without detectable cross-talk in mouse brain slice. PMID:24509633

  14. The absorbance spectrum and photosensitivity of a new synthetic "visual pigment" based on 4-hydroxyretinal.

    PubMed

    Kito, Y; Partridge, J C; Seidou, M; Narita, K; Hamanaka, T; Michinomae, M; Sekiya, N; Yoshihara, K

    1992-01-01

    The firefly squid, Watasenia scintillans, is the only animal known to possess a visual pigment in which the chromophore is 4-hydroxyretinal. This paper describes the absorbance spectrum and some properties of a synthetic "A4" visual pigment generated from bovine opsin and 4-hydroxyretinal. The absorbance spectrum of this pigment is compared with (a) bovine rhodopsin and (b) a rhodopsin template with the same lambda max as the synthetic visual pigment. The A4 pigment is shown to have an absorbance spectrum that is almost identical to that of a rhodopsin template. It is also shown that the photosensitivity and thermal stability of the A4 pigment, dispersed in detergent micelles, is essentially similar to that of rhodopsin. PMID:1386953

  15. On the color-tuning mechanism of Human-Blue visual pigment: SAC-CI and QM/MM study

    NASA Astrophysics Data System (ADS)

    Fujimoto, Kazuhiro; Hasegawa, Jun-ya; Hayashi, Shigehiko; Nakatsuji, Hiroshi

    2006-12-01

    Color-tuning mechanism of Human-Blue pigment, visual color-receptor in the cone cells of the eye, has been investigated. Based on a previous Homology-modeling structure and experimental evidences, a working model was constructed, and the structure has been optimized by QM(B3LYP)/MM(A MBER) method. SAC-CI calculation was performed to obtain photo-absorption energy. The calculated absorption energy reasonably agrees with the experiment. A decomposition analysis was performed and compared with the case of Bovine rhodopsin. The electrostatic effect from the opsin is primarily important for the color-tuning. The electronic interaction (quantum effect) of the counter-residue is indispensable for quantitative calculation of the absorption energy.

  16. Targeting of GFP to newborn rods by Nrl promoter and temporal expression profiling of flow-sorted photoreceptors

    PubMed Central

    Akimoto, Masayuki; Cheng, Hong; Zhu, Dongxiao; Brzezinski, Joseph A.; Khanna, Ritu; Filippova, Elena; Oh, Edwin C. T.; Jing, Yuezhou; Linares, Jose-Luis; Brooks, Matthew; Zareparsi, Sepideh; Mears, Alan J.; Hero, Alfred; Glaser, Tom; Swaroop, Anand

    2006-01-01

    The Maf-family transcription factor Nrl is a key regulator of photoreceptor differentiation in mammals. Ablation of the Nrl gene in mice leads to functional cones at the expense of rods. We show that a 2.5-kb Nrl promoter segment directs the expression of enhanced GFP specifically to rod photoreceptors and the pineal gland of transgenic mice. GFP is detected shortly after terminal cell division, corresponding to the timing of rod genesis revealed by birthdating studies. In Nrl?/? retinas, the GFP+ photoreceptors express S-opsin, consistent with the transformation of rod precursors into cones. We report the gene profiles of freshly isolated flow-sorted GFP+ photoreceptors from wild-type and Nrl?/? retinas at five distinct developmental stages. Our results provide a framework for establishing gene regulatory networks that lead to mature functional photoreceptors from postmitotic precursors. Differentially expressed rod and cone genes are excellent candidates for retinopathies. PMID:16505381

  17. Light as a central modulator of circadian rhythms, sleep and affect

    PubMed Central

    LeGates, T.A.; Fernandez, D.C.; Hattar, S

    2014-01-01

    Light has profoundly influenced the evolution of life on earth. As widely appreciated, light allows us to generate images of our environment. However, light, through the atypical intrinsically photosensitive retinal ganglion cells (ipRGCs; Box 1), also influences behaviors that are essential for our health and quality of life, yet are independent of image formation. These include the synchronization of the circadian clock to the solar day, tracking of seasonal changes, and regulation of sleep. Irregular light environments lead to problems in circadian rhythms and sleep, which eventually cause mood and learning deficits. Recently, it was found that irregular light can also directly impact mood and learning without producing major disruptions in circadian rhythms and sleep. Here, we will discuss the indirect and direct influence of light on mood and learning and provide a model for how light, the circadian clock, and sleep interact to influence mood and cognitive functions. Box 1Intrinsically photosensitive retinal ganglion cells (ipRGCs)Retinal photoreceptors transduce light energy into electrical signals that initiate vision. The classical photoreceptors, rods and cones, possess modified cilia that consist of stacks of membranes in which photopigments (rhodopsin and cone opsins) are concentrated. Rods are exquisitely sensitive and are able to detect even a few photons. Rods are therefore used for night vision. Cones are less sensitive than rods and are used for day and color vision. Color vision is mediated by cone photoreceptors that express cone-opsins with sensitivity peaks at different wavelengths (colors) of light. Humans have three cone types: short, mid and long wavelength sensitive cones (for simplicity, we will refer to these as blue, green and red cones, respectively). Rods and cones relay photic information through multisynaptic pathways to retinal ganglion cells (RGCs), which innervate different areas in the brain for complex visual processing13.A surprising discovery showed that a subpopulation of RGCs is intrinsically photosensitive and express the photopigment melanopsin. These cells were thus termed ipRGCs17–19. The melanopsin gene (Opn4) was originally cloned from Xenopus laevis dermal melanophores, and was shown to have orthologs in many mammalian species, including humans141. Sequence analysis shows that melanopsin shares more homology with invertebrate opsins than with vertebrate opsins, suggesting that melanopsin may use a different mechanism for light signaling than that used by the photopigments present in the rods and cones of vertebrates142. ipRGCs do not have modified membranes in which the photopigment can be concentrated: thus, melanopsin protein is expressed uniformly throughout the soma, dendrites, and the initial segment of the axon143. The lack of membrane specialization makes ipRGCs less sensitive to light than rods and cones. However, ipRGCs are able to incorporate light signals over extended period of time, resulting in an increase in their sensitivity during prolonged light stimulation. ipRGCs are most sensitive to wavelengths of light that are in the blue region of the light spectrum144, 145. As ganglion cells, ipRGCs also convey light information from rods and cones in addition to their intrinsic melanopsin-dependent pathway and can control a variety of light-mediated behaviors30.Originally, ipRGCs were thought to comprise a uniform population, however, recent discoveries revealed that ipRGCs are highly diverse, comprising at least five distinct subtypes (M1-M5) in rodents based on morphological and electrophysiological analyses22–29. The originally identified population is now known as M1 ipRGCs and project predominantly to brain regions involved in non-image forming visual functions, whereas the non-M1 ipRGCs show widespread projections to areas in the brain important for image formation. ipRGC subtypes express varying levels of the melanopsin protein and have different patterns of dendrite stratification in the inner plexiform layer (IPL)27, 28, 146, 147, indicating

  18. Melatonin Signaling Controls Circadian Swimming Behavior in Marine Zooplankton

    PubMed Central

    Tosches, Maria Antonietta; Bucher, Daniel; Vopalensky, Pavel; Arendt, Detlev

    2014-01-01

    Summary Melatonin, the “hormone of darkness,” is a key regulator of vertebrate circadian physiology and behavior. Despite its ubiquitous presence in Metazoa, the function of melatonin signaling outside vertebrates is poorly understood. Here, we investigate the effect of melatonin signaling on circadian swimming behavior in a zooplankton model, the marine annelid Platynereis dumerilii. We find that melatonin is produced in brain photoreceptors with a vertebrate-type opsin-based phototransduction cascade and a light-entrained clock. Melatonin released at night induces rhythmic burst firing of cholinergic neurons that innervate locomotor-ciliated cells. This establishes a nocturnal behavioral state by modulating the length and the frequency of ciliary arrests. Based on our findings, we propose that melatonin signaling plays a role in the circadian control of ciliary swimming to adjust the vertical position of zooplankton in response to ambient light. PMID:25259919

  19. Brains, genes, and primates.

    PubMed

    Izpisua Belmonte, Juan Carlos; Callaway, Edward M; Caddick, Sarah J; Churchland, Patricia; Feng, Guoping; Homanics, Gregg E; Lee, Kuo-Fen; Leopold, David A; Miller, Cory T; Mitchell, Jude F; Mitalipov, Shoukhrat; Moutri, Alysson R; Movshon, J Anthony; Okano, Hideyuki; Reynolds, John H; Ringach, Dario; Sejnowski, Terrence J; Silva, Afonso C; Strick, Peter L; Wu, Jun; Zhang, Feng

    2015-05-01

    One of the great strengths of the mouse model is the wide array of genetic tools that have been developed. Striking examples include methods for directed modification of the genome, and for regulated expression or inactivation of genes. Within neuroscience, it is now routine to express reporter genes, neuronal activity indicators, and opsins in specific neuronal types in the mouse. However, there are considerable anatomical, physiological, cognitive, and behavioral differences between the mouse and the human that, in some areas of inquiry, limit the degree to which insights derived from the mouse can be applied to understanding human neurobiology. Several recent advances have now brought into reach the goal of applying these tools to understanding the primate brain. Here we describe these advances, consider their potential to advance our understanding of the human brain and brain disorders, discuss bioethical considerations, and describe what will be needed to move forward. PMID:25950631

  20. Direct Action of Light in Naturally Pigmented Muscle Fibers

    PubMed Central

    Seliger, Howard H.

    1962-01-01

    Contraction due to light in excised eel irises appears to follow a simple first order law. The action spectrum for contraction has a maximum which agrees with the eel rhodopsin absorption maximum. Inasmuch as rhodopsin is the rod pigment-opsin complex and the iris sphincter pupillae evolves from the pigment epithelium of the retina in the region of the iris, the muscle pigment might be the same as the visual pigment. In the human eye the contraction of the iris sphincter is activated only by light incident on the retina and the pupil diameter varies inversely with the square root of the light intensity. The inverse first power relation observed in the present experiments suggests a more primitive origin for the light reaction in eel irises. Relaxation is a much slower process and can be approximated as the sum of two first order processes. PMID:13992712

  1. Optogenetics. Engineering of a light-gated potassium channel.

    PubMed

    Cosentino, Cristian; Alberio, Laura; Gazzarrini, Sabrina; Aquila, Marco; Romano, Edoardo; Cermenati, Solei; Zuccolini, Paolo; Petersen, Jan; Beltrame, Monica; Van Etten, James L; Christie, John M; Thiel, Gerhard; Moroni, Anna

    2015-05-01

    The present palette of opsin-based optogenetic tools lacks a light-gated potassium (K(+)) channel desirable for silencing of excitable cells. Here, we describe the construction of a blue-light-induced K(+) channel 1 (BLINK1) engineered by fusing the plant LOV2-J? photosensory module to the small viral K(+) channel Kcv. BLINK1 exhibits biophysical features of Kcv, including K(+) selectivity and high single-channel conductance but reversibly photoactivates in blue light. Opening of BLINK1 channels hyperpolarizes the cell to the K(+) equilibrium potential. Ectopic expression of BLINK1 reversibly inhibits the escape response in light-exposed zebrafish larvae. BLINK1 therefore provides a single-component optogenetic tool that can establish prolonged, physiological hyperpolarization of cells at low light intensities. PMID:25954011

  2. Enlightening the brain: Linking deep brain photoreception with behavior and physiology

    PubMed Central

    Fernandes, António M.; Fero, Kandice; Driever, Wolfgang; Burgess, Harold A.

    2014-01-01

    Vertebrates respond to light with more than just their eyes. In this article we speculate on the intriguing possibility that a link remains between non-visual opsins and neurohormonal systems that control neuronal circuit formation and activity in mammals. Historically, the retina and pineal gland were considered the only significant light-sensing tissues in vertebrates. However, over the last century evidence has accumulated arguing that extra-ocular tissues in vertebrates influence behavior through non-image-forming photoreception. One such class of extra-ocular light detectors are the long mysterious deep brain photoreceptors. Here we review recent findings on the cellular identity and the function of deep brain photoreceptors controlling behavior and physiology in zebrafish, and discuss their implications. PMID:23712321

  3. Modeling the spatiotemporal dynamics of light and heat propagation for in vivo optogenetics

    PubMed Central

    Stujenske, Joseph M.; Spellman, Timothy; Gordon, Joshua A.

    2015-01-01

    Summary Despite the increasing use of optogenetics in vivo, the effects of direct light exposure to brain tissue are understudied. Of particular concern is the potential for heat induced by prolonged optical stimulation. We demonstrate that high intensity light, delivered through an optical fiber, is capable of elevating firing rate locally, even in the absence of opsin expression. Predicting the severity and spatial extent of any temperature increase during optogenetic stimulation is therefore of considerable importance. Here we describe a realistic model that simulates light and heat propagation during optogenetic experiments. We validated the model by comparing predicted and measured temperature changes in vivo. We further demonstrate the utility of this model by comparing predictions for various wavelengths of light and fiber sizes, as well as testing methods for reducing heat effects on neural targets in vivo. PMID:26166563

  4. The developing and evolving retina: using time to organize form.

    PubMed

    Finlay, Barbara L

    2008-02-01

    Evolutionary and other functional accounts of the retina and its normal development highlight different aspects of control of its growth and form than genomic and mechanistic accounts. Discussing examples from opsin expression, developmental regulation of the eye's size and optical quality, regulation of eye size with respect to brain and body size, and the development of the fovea, these different aspects of control are contrasted. Contributions of mouse models, particularly with regard to relative timing of events in different species are reviewed, introducing a Web-based utility for exploration of timing issues (www.translatingtime.net). Variation at the individual level, in early experience, and also across species is an essential source of information to understand normal development and its pathologies. PMID:17692298

  5. QM/MM Study of Dehydro and Dihydro ?-Ionone Retinal Analogues in Squid and Bovine Rhodopsins: Implications for Vision in Salamander Rhodopsin

    PubMed Central

    Sekharan, Sivakumar; Altun, Ahmet; Morokuma, Keiji

    2010-01-01

    Visual pigment rhodopsin provides a decisive crossing point for interaction between organisms and environment. Naturally occurring visual pigments contain only PSB11 and 3,4-dehydro-PSB11 as chromophores. Therefore, the ability of visual opsin to discriminate between the retinal geometries is investigated by means of QM/MM incorporation of PSB11, 6-s-cis and 6-s-trans forms of 3,4-dehydro-PSB11, 3,4-dehydro-5,6-dihydro-PSB11, 5,6-dihydro-PSB11 analogues into squid and bovine rhodopsin environments. The analogue-protein interaction reveals the binding site of squid rhodopsin to be malleable and ductile, while that of bovine rhodopsin to be rigid and stiff. On the basis of these studies, a tentative model of salamander rhodopsin binding site is also proposed. PMID:20964383

  6. Melatonin signaling controls circadian swimming behavior in marine zooplankton.

    PubMed

    Tosches, Maria Antonietta; Bucher, Daniel; Vopalensky, Pavel; Arendt, Detlev

    2014-09-25

    Melatonin, the "hormone of darkness," is a key regulator of vertebrate circadian physiology and behavior. Despite its ubiquitous presence in Metazoa, the function of melatonin signaling outside vertebrates is poorly understood. Here, we investigate the effect of melatonin signaling on circadian swimming behavior in a zooplankton model, the marine annelid Platynereis dumerilii. We find that melatonin is produced in brain photoreceptors with a vertebrate-type opsin-based phototransduction cascade and a light-entrained clock. Melatonin released at night induces rhythmic burst firing of cholinergic neurons that innervate locomotor-ciliated cells. This establishes a nocturnal behavioral state by modulating the length and the frequency of ciliary arrests. Based on our findings, we propose that melatonin signaling plays a role in the circadian control of ciliary swimming to adjust the vertical position of zooplankton in response to ambient light. PMID:25259919

  7. Photoreceptor differentiation of isolated retinal precursor cells includes the capacity for photomechanical responses.

    PubMed Central

    Stenkamp, D L; Adler, R

    1993-01-01

    Isolated retinal precursor cells, grown without pigment epithelial or glial cells and in the absence of intercellular contacts, develop a complex set of photoreceptor-specific properties, including polarized structural and molecular organization and opsin immunoreactivity. We report here that these isolated embryonic photoreceptors are also capable of responding to light. Sequential photography showed that 50% of the photoreceptors grown in a light cycle elongate when exposed to light and contract in response to darkness. A smaller population (20%) showed the opposite response. Responses of individual cells could be observed during several sequential light cycles and resemble photomechanical movements in vivo [Ali, M. A. (1971) Vision Res. 11, 1225-1288]. The differentiation program expressed by isolated precursor cells, therefore, includes the capacity for highly complex functional activities that require light sensitivity. These observations raise challenging questions regarding the nature of the chromophore and pigments that mediate light-regulated behaviors of cultured photoreceptors. Images Fig. 1 Fig. 4 PMID:8446618

  8. Fiber-optic two-photon optogenetic stimulation.

    PubMed

    Dhakal, K; Gu, L; Black, B; Mohanty, S K

    2013-06-01

    Optogenetic stimulation of genetically targeted cells is proving to be a powerful tool in the study of cellular systems, both in vitro and in vivo. However, most opsins are activated in the visible spectrum, where significant absorption and scattering of stimulating light occurs, leading to low penetration depth and less precise stimulation. Since we first (to the best of our knowledge) demonstrated two-photon optogenetic stimulation (TPOS), it has gained considerable interest in the probing of cellular circuitry by precise spatial modulation. However, all existing methods use microscope objectives and complex scanning beam geometries. Here, we report a nonscanning method based on multimode fiber to accomplish fiber-optic TPOS of cells. PMID:23722792

  9. Direct visualization of the murine dorsal cochlear nucleus for optogenetic stimulation of the auditory pathway.

    PubMed

    Kozin, Elliott D; Darrow, Keith N; Hight, Ariel E; Lehmann, Ashton E; Kaplan, Alyson B; Brown, M Christian; Lee, Daniel J

    2015-01-01

    Investigation into the use of virus-mediated gene transfer to arrest or reverse hearing loss has largely been relegated to the peripheral auditory system. Few studies have examined gene transfer to the central auditory system. The dorsal cochlear nucleus (DCN) of the brainstem, which contains second order neurons of the auditory pathway, is a potential site for gene transfer. In this protocol, a technique for direct and maximal exposure of the murine DCN via a posterior fossa approach is demonstrated. This approach allows for either acute or survival surgery. Following direct visualization of the DCN, a host of experiments are possible, including injection of opsins into the cochlear nucleus and subsequent stimulation by an optical fiber coupled to a blue light laser. Other neurophysiology experiments, such as electrical stimulation and neural injector tracings are also feasible. The level of visualization and the duration of stimulation achievable make this approach applicable to a wide range of experiments. PMID:25650555

  10. Photochemical activation of TRPA1 channels in neurons and animals

    PubMed Central

    Kokel, David; Cheung, Chung Yan J.; Mills, Robert; Coutinho-Budd, Jaeda; Huang, Liyi; Setola, Vincent; Sprague, Jared; Jin, Shan; Jin, Youngnam N.; Huang, Xi-Ping; Bruni, Giancarlo; Woolf, Clifford; Roth, Bryan L.; Hamblin, Michael R; Zylka, Mark J.; Milan, David J.; Peterson, Randall T.

    2013-01-01

    Optogenetics is a powerful research tool because it enables high-resolution optical control of neuronal activity. However, current optogenetic approaches are limited to transgenic systems expressing microbial opsins and other exogenous photoreceptors. Here, we identify optovin, a small molecule that enables repeated photoactivation of motor behaviors in wild type animals. Surprisingly, optovin's behavioral effects are not visually mediated. Rather, photodetection is performed by sensory neurons expressing the cation channel TRPA1. TRPA1 is both necessary and sufficient for the optovin response. Optovin activates human TRPA1 via structure-dependent photochemical reactions with redox-sensitive cysteine residues. In animals with severed spinal cords, optovin treatment enables control of motor activity in the paralyzed extremities by localized illumination. These studies identify a light-based strategy for controlling endogenous TRPA1 receptors in vivo, with potential clinical and research applications in non-transgenic animals, including humans. PMID:23396078

  11. Independent Optical Excitation of Distinct Neural Populations

    PubMed Central

    Klapoetke, Nathan C; Murata, Yasunobu; Kim, Sung Soo; Pulver, Stefan R.; Birdsey-Benson, Amanda; Cho, Yong Ku; Morimoto, Tania K; Chuong, Amy S; Carpenter, Eric J; Tian, Zhijian; Wang, Jun; Xie, Yinlong; Yan, Zhixiang; Zhang, Yong; Chow, Brian Y; Surek, Barbara; Melkonian, Michael; Jayaraman, Vivek; Constantine-Paton, Martha; Wong, Gane Ka-Shu; Boyden, Edward S

    2014-01-01

    Optogenetic tools enable the causal examination of how specific cell types contribute to brain circuit functions. A long-standing question is whether it is possible to independently activate two distinct neural populations in mammalian brain tissue. Such a capability would enable the examination of how different synapses or pathways interact to support computation. Here we report two new channelrhodopsins, Chronos and Chrimson, obtained through the de novo sequencing and physiological characterization of opsins from over 100 species of algae. Chrimson is 45 nm red-shifted relative to any previous channelrhodopsin, important for scenarios where red light would be preferred; we show minimal visual system mediated behavioral artifact in optogenetically stimulated Drosophila. Chronos has faster kinetics than any previous channelrhodopsin, yet is effectively more light-sensitive. Together, these two reagents enable crosstalk-free two-color activation of neural spiking and downstream synaptic transmission in independent neural populations in mouse brain slice. PMID:24509633

  12. G-Protein Coupled Receptor Kinase 2 Minimally Regulates Melanopsin Activity in Intrinsically Photosensitive Retinal Ganglion Cells

    PubMed Central

    Sexton, Timothy J.; Van Gelder, Russell N.

    2015-01-01

    Phosphorylation is a primary modulator of mammalian G-protein coupled receptor (GPCR) activity. The GPCR melanopsin is the photopigment of intrinsically photosensitive retinal ganglion cells (ipRGCs) in the mammalian retina. Recent evidence from in vitro experiments suggests that the G-protein coupled receptor kinase 2 (GRK2) phosphorylates melanopsin and reduces its activity following light exposure. Using an ipRGC-specific GRK2 loss-of-function mouse, we show that GRK2 loss alters melanopsin response dynamics and termination time in postnatal day 8 (P8) ipRGCs but not in older animals. However, the alterations are small in comparison to the changes reported for other opsins with loss of their cognate GRK. These results suggest GRK2 contributes to melanopsin deactivation, but that other mechanisms account for most of modulation of melanopsin activity in ipRGCs. PMID:26069965

  13. Action spectrum for melatonin regulation in humans: evidence for a novel circadian photoreceptor

    NASA Technical Reports Server (NTRS)

    Brainard, G. C.; Hanifin, J. P.; Greeson, J. M.; Byrne, B.; Glickman, G.; Gerner, E.; Rollag, M. D.

    2001-01-01

    The photopigment in the human eye that transduces light for circadian and neuroendocrine regulation, is unknown. The aim of this study was to establish an action spectrum for light-induced melatonin suppression that could help elucidate the ocular photoreceptor system for regulating the human pineal gland. Subjects (37 females, 35 males, mean age of 24.5 +/- 0.3 years) were healthy and had normal color vision. Full-field, monochromatic light exposures took place between 2:00 and 3:30 A.M. while subjects' pupils were dilated. Blood samples collected before and after light exposures were quantified for melatonin. Each subject was tested with at least seven different irradiances of one wavelength with a minimum of 1 week between each nighttime exposure. Nighttime melatonin suppression tests (n = 627) were completed with wavelengths from 420 to 600 nm. The data were fit to eight univariant, sigmoidal fluence-response curves (R(2) = 0.81-0.95). The action spectrum constructed from these data fit an opsin template (R(2) = 0.91), which identifies 446-477 nm as the most potent wavelength region providing circadian input for regulating melatonin secretion. The results suggest that, in humans, a single photopigment may be primarily responsible for melatonin suppression, and its peak absorbance appears to be distinct from that of rod and cone cell photopigments for vision. The data also suggest that this new photopigment is retinaldehyde based. These findings suggest that there is a novel opsin photopigment in the human eye that mediates circadian photoreception.

  14. Vitamin A activates rhodopsin and sensitizes it to ultraviolet light

    PubMed Central

    Miyazono, Sadaharu; Isayama, Tomoki; Delori, François C.; Makino, Clint L.

    2013-01-01

    The visual pigment, rhodopsin, consists of opsin protein with 11-cis retinal chromophore, covalently bound. Light activates rhodopsin by isomerizing the chromophore to the all-trans conformation. The activated rhodopsin sets in motion a biochemical cascade that evokes an electrical response by the photoreceptor. All-trans retinal is eventually released from the opsin and reduced to vitamin A. Rod and cone photoreceptors contain vast amounts of rhodopsin, so after exposure to bright light, the concentration of vitamin A can reach relatively high levels within their outer segments. Since a retinal analog, ?-ionone, is capable of activating some types of visual pigments, we tested whether vitamin A might produce a similar effect. In single-cell recordings from isolated dark-adapted salamander green-sensitive rods, exogenously applied vitamin A decreased circulating current and flash sensitivity and accelerated flash response kinetics. These changes resembled those produced by exposure of rods to steady light. Microspectrophotometric measurements showed that vitamin A accumulated in the outer segments and binding of vitamin A to rhodopsin was confirmed in in vitro assays. In addition, vitamin A improved the sensitivity of photoreceptors to ultraviolet (UV) light. Apparently, the energy of a UV photon absorbed by vitamin A transferred by a radiationless process to the 11-cis retinal chromophore of rhodopsin, which subsequently isomerized. Therefore, our results suggest that vitamin A binds to rhodopsin at an allosteric binding site distinct from the chromophore binding pocket for 11-cis retinal to activate the rhodopsin, and that it serves as a sensitizing chromophore for UV light. PMID:22192505

  15. Evolution of Mammalian Opn5 as a Specialized UV-absorbing Pigment by a Single Amino Acid Mutation*

    PubMed Central

    Yamashita, Takahiro; Ono, Katsuhiko; Ohuchi, Hideyo; Yumoto, Akane; Gotoh, Hitoshi; Tomonari, Sayuri; Sakai, Kazumi; Fujita, Hirofumi; Imamoto, Yasushi; Noji, Sumihare; Nakamura, Katsuki; Shichida, Yoshinori

    2014-01-01

    Opn5 is one of the recently identified opsin groups that is responsible for nonvisual photoreception in animals. We previously showed that a chicken homolog of mammalian Opn5 (Opn5m) is a Gi-coupled UV sensor having molecular properties typical of bistable pigments. Here we demonstrated that mammalian Opn5m evolved to be a more specialized photosensor by losing one of the characteristics of bistable pigments, direct binding of all-trans-retinal. We first confirmed that Opn5m proteins in zebrafish, Xenopus tropicalis, mouse, and human are also UV-sensitive pigments. Then we found that only mammalian Opn5m proteins lack the ability to directly bind all-trans-retinal. Mutational analysis showed that these characteristics were acquired by a single amino acid replacement at position 168. By comparing the expression patterns of Opn5m between mammals and chicken, we found that, like chicken Opn5m, mammalian Opn5m was localized in the ganglion cell layer and inner nuclear layer of the retina. However, the mouse and primate (common marmoset) opsins were distributed not in the posterior hypothalamus (including the region along the third ventricle) where chicken Opn5m is localized, but in the preoptic hypothalamus. Interestingly, RPE65, an essential enzyme for forming 11-cis-retinal in the visual cycle is expressed near the preoptic hypothalamus of the mouse and common marmoset brain but not near the region of the chicken brain where chicken Opn5m is expressed. Therefore, mammalian Opn5m may work exclusively as a short wavelength sensor in the brain as well as in the retina with the assistance of an 11-cis-retinal-supplying system. PMID:24403072

  16. Investigating local and long-range neuronal network dynamics by simultaneous optogenetics, reverse microdialysis and silicon probe recordings in vivo

    PubMed Central

    Taylor, Hannah; Schmiedt, Joscha T.; Çarçak, Nihan; Onat, Filiz; Di Giovanni, Giuseppe; Lambert, Régis; Leresche, Nathalie; Crunelli, Vincenzo; David, Francois

    2014-01-01

    Background The advent of optogenetics has given neuroscientists the opportunity to excite or inhibit neuronal population activity with high temporal resolution and cellular selectivity. Thus, when combined with recordings of neuronal ensemble activity in freely moving animals optogenetics can provide an unprecedented snapshot of the contribution of neuronal assemblies to (patho)physiological conditions in vivo. Still, the combination of optogenetic and silicone probe (or tetrode) recordings does not allow investigation of the role played by voltage- and transmitter-gated channels of the opsin-transfected neurons and/or other adjacent neurons in controlling neuronal activity. New method and results We demonstrate that optogenetics and silicone probe recordings can be combined with intracerebral reverse microdialysis for the long-term delivery of neuroactive drugs around the optic fiber and silicone probe. In particular, we show the effect of antagonists of T-type Ca2+ channels, hyperpolarization-activated cyclic nucleotide-gated channels and metabotropic glutamate receptors on silicone probe-recorded activity of the local opsin-transfected neurons in the ventrobasal thalamus, and demonstrate the changes that the block of these thalamic channels/receptors brings about in the network dynamics of distant somatotopic cortical neuronal ensembles. Comparison with existing methods This is the first demonstration of successfully combining optogenetics and neuronal ensemble recordings with reverse microdialysis. This combination of techniques overcomes some of the disadvantages that are associated with the use of intracerebral injection of a drug-containing solution at the site of laser activation. Conclusions The combination of reverse microdialysis, silicone probe recordings and optogenetics can unravel the short and long-term effects of specific transmitter- and voltage-gated channels on laser-modulated firing at the site of optogenetic stimulation and the actions that these manipulations exert on distant neuronal populations. PMID:25004203

  17. Mouse model of human RPE65 P25L hypomorph resembles wild type under normal light rearing but is fully resistant to acute light damage.

    PubMed

    Li, Yan; Yu, Shirley; Duncan, Todd; Li, Yichao; Liu, Pinghu; Gene, Erelda; Cortes-Pena, Yoel; Qian, Haohua; Dong, Lijin; Redmond, T Michael

    2015-08-01

    Human RPE65 mutations cause a spectrum of blinding retinal dystrophies from severe early-onset disease to milder manifestations. The RPE65 P25L missense mutation, though having <10% of wild-type (WT) activity, causes relatively mild retinal degeneration. To better understand these mild forms of RPE65-related retinal degeneration, and their effect on cone photoreceptor survival, we generated an Rpe65/P25L knock-in (KI/KI) mouse model. We found that, when subject to the low-light regime (?100 lux) of regular mouse housing, homozygous Rpe65/P25L KI/KI mice are morphologically and functionally very similar to WT siblings. While mutant protein expression is decreased by over 80%, KI/KI mice retinae retain comparable 11-cis-retinal levels with WT. Consistently, the scotopic and photopic electroretinographic (ERG) responses to single-flash stimuli also show no difference between KI/KI and WT mice. However, the recovery of a-wave response following moderate visual pigment bleach is delayed in KI/KI mice. Importantly, KI/KI mice show significantly increased resistance to high-intensity (20 000 lux for 30 min) light-induced retinal damage (LIRD) as compared with WT, indicating impaired rhodopsin regeneration in KI/KI. Taken together, the Rpe65/P25L mutant produces sufficient chromophore under normal conditions to keep opsins replete and thus manifests a minimal phenotype. Only when exposed to intensive light is this hypomorphic mutation manifested physiologically, as its reduced expression and catalytic activity protects against the successive cycles of opsin regeneration underlying LIRD. These data also help define minimal requirements of chromophore for photoreceptor survival in vivo and may be useful in assessing a beneficial therapeutic dose for RPE65 gene therapy in humans. PMID:25972377

  18. Importance of Achromatic Contrast in Short-Range Fruit Foraging of Primates

    PubMed Central

    Hiramatsu, Chihiro; Melin, Amanda D.; Aureli, Filippo; Schaffner, Colleen M.; Vorobyev, Misha; Matsumoto, Yoshifumi; Kawamura, Shoji

    2008-01-01

    Trichromatic primates have a ‘red-green’ chromatic channel in addition to luminance and ‘blue-yellow’ channels. It has been argued that the red-green channel evolved in primates as an adaptation for detecting reddish or yellowish objects, such as ripe fruits, against a background of foliage. However, foraging advantages to trichromatic primates remain unverified by behavioral observation of primates in their natural habitats. New World monkeys (platyrrhines) are an excellent model for this evaluation because of the highly polymorphic nature of their color vision due to allelic variation of the L-M opsin gene on the X chromosome. In this study we carried out field observations of a group of wild, frugivorous black-handed spider monkeys (Ateles geoffroyi frontatus, Gray 1842, Platyrrhini), consisting of both dichromats (n?=?12) and trichromats (n?=?9) in Santa Rosa National Park, Costa Rica. We determined the color vision types of individuals in this group by genotyping their L-M opsin and measured foraging efficiency of each individual for fruits located at a grasping distance. Contrary to the predicted advantage for trichromats, there was no significant difference between dichromats and trichromats in foraging efficiency and we found that the luminance contrast was the main determinant of the variation of foraging efficiency among red-green, blue-yellow and luminance contrasts. Our results suggest that luminance contrast can serve as an important cue in short-range foraging attempts despite other sensory cues that could be available. Additionally, the advantage of red-green color vision in primates may not be as salient as previously thought and needs to be evaluated in further field observations. PMID:18836576

  19. Hsp90 inhibition protects against inherited retinal degeneration

    PubMed Central

    Aguilà, Mònica; Bevilacqua, Dalila; McCulley, Caroline; Schwarz, Nele; Athanasiou, Dimitra; Kanuga, Naheed; Novoselov, Sergey S.; Lange, Clemens A.K.; Ali, Robin R.; Bainbridge, James W.; Gias, Carlos; Coffey, Peter J.; Garriga, Pere; Cheetham, Michael E.

    2014-01-01

    The molecular chaperone Hsp90 is important for the functional maturation of many client proteins, and inhibitors are in clinical trials for multiple indications in cancer. Hsp90 inhibition activates the heat shock response and can improve viability in a cell model of the P23H misfolding mutation in rhodopsin that causes autosomal dominant retinitis pigmentosa (adRP). Here, we show that a single low dose of the Hsp90 inhibitor HSP990 enhanced visual function and delayed photoreceptor degeneration in a P23H transgenic rat model. This was associated with the induction of heat shock protein expression and reduced rhodopsin aggregation. We then investigated the effect of Hsp90 inhibition on a different type of rod opsin mutant, R135L, which is hyperphosphorylated, binds arrestin and disrupts vesicular traffic. Hsp90 inhibition with 17-AAG reduced the intracellular accumulation of R135L and abolished arrestin binding in cells. Hsf-1?/? cells revealed that the effect of 17-AAG on P23H aggregation was dependent on HSF-1, whereas the effect on R135L was HSF-1 independent. Instead, the effect on R135L was mediated by a requirement of Hsp90 for rhodopsin kinase (GRK1) maturation and function. Importantly, Hsp90 inhibition restored R135L rod opsin localization to wild-type (WT) phenotype in vivo in rat retina. Prolonged Hsp90 inhibition with HSP990 in vivo led to a posttranslational reduction in GRK1 and phosphodiesterase (PDE6) protein levels, identifying them as Hsp90 clients. These data suggest that Hsp90 represents a potential therapeutic target for different types of rhodopsin adRP through distinct mechanisms, but also indicate that sustained Hsp90 inhibition might adversely affect visual function. PMID:24301679

  20. Adenovirus vectors targeting distinct cell types in the retina.

    PubMed

    Sweigard, J Harry; Cashman, Siobhan M; Kumar-Singh, Rajendra

    2010-04-01

    Purpose. Gene therapy for a number of retinal diseases necessitates efficient transduction of photoreceptor cells. Whereas adenovirus (Ad) serotype 5 (Ad5) does not transduce photoreceptors efficiently, previous studies have demonstrated improved photoreceptor transduction by Ad5 pseudotyped with Ad35 (Ad5/F35) or Ad37 (Ad5/F37) fiber or by the deletion of the RGD domain in the Ad5 penton base (Ad5DeltaRGD). However, each of these constructs contained a different transgene cassette, preventing the evaluation of the relative performance of these vectors, an important consideration before the use of these vectors in the clinic. The aim of this study was to evaluate these vectors in the retina and to attempt photoreceptor-specific transgene expression. Methods. Three Ad5-based vectors containing the same expression cassette were generated and injected into the subretinal space of adult mice. Eyes were analyzed for green fluorescence protein expression in flat-mounts, cross-sections, quantitative RT-PCR, and a modified stereological technique. A 257-bp fragment derived from the mouse opsin promoter was analyzed in the context of photoreceptor-specific transgene expression. Results. Each virus tested efficiently transduced the retinal pigment epithelium. The authors found no evidence that Ad5/F35 or Ad5/F37 transduced photoreceptors. Instead, they found that Ad5/F37 transduced Müller cells. Robust photoreceptor transduction by Ad5DeltaRGD was detected. Photoreceptor-specific transgene expression from the 257-bp mouse opsin promoter in the context of Ad5DeltaRGD vectors was found. Conclusions. Adenovirus vectors may be designed with tropism to distinct cell populations. Robust photoreceptor-specific transgene expression can be achieved in the context of Ad5DeltaRGD vectors. PMID:19892875

  1. Adaptive evolution of color vision as seen through the eyes of butterflies

    PubMed Central

    Frentiu, Francesca D.; Bernard, Gary D.; Cuevas, Cristina I.; Sison-Mangus, Marilou P.; Prudic, Kathleen L.; Briscoe, Adriana D.

    2007-01-01

    Butterflies and primates are interesting for comparative color vision studies, because both have evolved middle- (M) and long-wavelength- (L) sensitive photopigments with overlapping absorbance spectrum maxima (?max values). Although positive selection is important for the maintenance of spectral variation within the primate pigments, it remains an open question whether it contributes similarly to the diversification of butterfly pigments. To examine this issue, we performed epimicrospectrophotometry on the eyes of five Limenitis butterfly species and found a 31-nm range of variation in the ?max values of the L-sensitive photopigments (514–545 nm). We cloned partial Limenitis L opsin gene sequences and found a significant excess of replacement substitutions relative to polymorphisms among species. Mapping of these L photopigment ?max values onto a phylogeny revealed two instances within Lepidoptera of convergently evolved L photopigment lineages whose ?max values were blue-shifted. A codon-based maximum-likelihood analysis indicated that, associated with the two blue spectral shifts, four amino acid sites (Ile17Met, Ala64Ser, Asn70Ser, and Ser137Ala) have evolved substitutions in parallel and exhibit significant dN/dS >1. Homology modeling of the full-length Limenitis arthemis astyanax L opsin placed all four substitutions within the chromophore-binding pocket. Strikingly, the Ser137Ala substitution is in the same position as a site that in primates is responsible for a 5- to 7-nm blue spectral shift. Our data show that some of the same amino acid sites are under positive selection in the photopigments of both butterflies and primates, spanning an evolutionary distance >500 million years. PMID:17494749

  2. Computational molecular phenotyping of retinal sheet transplants to rats with retinal degeneration

    PubMed Central

    Seiler, M.J.; Jones, B.W.; Aramant, R.B.; Yang, P.B.; Keirstead, H.S.; Marc, R.E.

    2012-01-01

    Retinal progenitor sheet transplants have been shown to extend neuronal processes into a degenerating host retina and to restore visual responses in the brain. The aim of this study was the first attempt to identify cells involved in transplant signals to retinal degenerate hosts using computational molecular phenotyping (CMP). - S334ter line 3 rats received fetal retinal sheet transplants at the age of 24-40d. Donor tissues were incubated with slow-releasing microspheres containing BDNF or GDNF. Up to 265 days after surgery, eyes of selected rats were vibratome sectioned through the transplant area (some slices stained for donor marker hPAP), dehydrated and embedded in Eponate, sectioned into serial ultrathin datasets and probed for rhodopsin, cone opsin, CRALBP, L-glutamate, L-glutamine, glutathione, glycine, taurine, GABA, and DAPI. - In large transplant areas, photoreceptor outer segments in contact with host RPE revealed rod and cone opsin immunoreactivity whereas no such staining was found in the degenerate host retina. Transplant photoreceptor layers contained high taurine levels. Glutamate levels in the transplants were higher than in the host retina whereas GABA levels were similar. The transplant inner nuclear layer showed some loss of neurons, but amacrine cells and horizontal cells were not reduced. In many areas, glial hypertrophy between the host and transplant was absent and host and transplant neuropil appeared to intermingle. CMP data indicate that horizontal cells and both glycinergic and GABAergic amacrine cells are involved in a novel circuit between transplant and host, generating alternative signal pathways between transplant and degenerating host retina. PMID:22594836

  3. Effects of different colors of light on melatonin suppression and expression analysis of Aanat1 and melanopsin in the eye of a tropical damselfish.

    PubMed

    Takeuchi, Yuki; Imamura, Satoshi; Sawada, Yuji; Hur, Sung-Pyo; Takemura, Akihiro

    2014-08-01

    Ocular melatonin production exhibits a daily rhythm with a decrease during photophase and an increase during scotophase (nocturnal pattern) in teleost fish due to day-night changes in the activity of the rate-limiting melatonin synthesizing enzyme arylalkylamine N-acetyltransferase (AANAT). Acute light exposure during scotophase suppresses AANAT activity and melatonin production in the eyes, suggesting that external light signals are a principal regulator of ocular melatonin synthesis. To better understand the photic regulation of ocular melatonin synthesis in teleost fish, this study sought to characterize the effect of light on ocular melatonin synthesis in the sapphire devil Chrysiptera cyanea, which shows a nocturnal pattern and light-induced inhibition of ocular melatonin production during scotophase. Exposure to three different wavelengths of light (half-peak bandwidth=435-475 nm with a peak of 455 nm, 495-565 nm with a peak of 530 nm, and 607-647 nm with a peak of 627 nm for the blue, green, and red LEDs) for 2h during scotophase resulted in the blue wavelength significantly decreasing ocular melatonin content within 30 min after light exposure. This result clearly indicates that the effective range of visible light on ocular melatonin suppression is distributed within the wavelengths of blue light and that a blue light-sensitive opsin is involved in ocular melatonin suppression in the fish. A PCR-based cloning method revealed the expression of melanopsin, a putative blue light-sensitive nonvisual opsin, in the eyes. Furthermore, in situ hybridization using the sapphire devil Aanat1 and melanopsin RNA probes showed mRNA expressions of both genes in the inner nuclear and ganglion cell layer of the fish retina. These results suggest that melanopsin is a possible candidate photoreceptor involved in ocular melatonin suppression by an external light signal in the sapphire devil. PMID:24859252

  4. The Effect of TIMP-1 on the Cone Mosaic in the Retina of the Rat Model of Retinitis Pigmentosa

    PubMed Central

    Ji, Yerina; Yu, Wan-Qing; Eom, Yun Sung; Bruce, Farouk; Craft, Cheryl Mae; Grzywacz, Norberto M.; Lee, Eun-Jin

    2015-01-01

    Purpose. The array of photoreceptors found in normal retinas provides uniform and regular sampling of the visual space. In contrast, cones in retinas of the S334ter-line-3 rat model for RP migrate to form a mosaic of rings, leaving large holes with few or no photoreceptors. Similar mosaics appear in human patients with other forms of retinal dystrophy. In the current study, we aimed to investigate the effect of tissue inhibitor of metalloproteinase-1 (TIMP-1) on the mosaic of cones in S334ter-line-3 rat retinas. We focused on TIMP-1 because it is one of the regulators of the extracellular matrix important for cellular migration. Methods. Immunohistochemistry was performed to reveal M-opsin cone cells (M-cone) and the results were quantified to test statistically whether or not TIMP-1 restores the mosaics to normal. In particular, the tests focused on the Voronoi and nearest-neighbor distance analyses. Results. Our tests indicated that TIMP-1 led to significant disruption of the M-opsin cone rings in S334ter-line-3 rat retinas and resulted in almost complete homogeneous mosaics. In addition, TIMP-1 induced the M-cone spatial distribution to become closer to random with decreased regularity in S334ter-line-3 rat retinas. Conclusions. These findings confirm that TIMP-1 induced M-cone mosaics in S334ter-line-3 to gain homogeneity without reaching the degree of regularity seen in normal retinal mosaics. Even if TIMP-1 fails to promote regularity, the effects of this drug on homogeneity appear to be so dramatic that TIMP-1 may be a potential therapeutic agent. TIMP-1 improves sampling of the visual field simply by causing homogeneity. PMID:25515575

  5. Identification of the 11-cis-specific retinyl-ester synthase in retinal Müller cells as multifunctional O-acyltransferase (MFAT)

    PubMed Central

    Kaylor, Joanna J.; Cook, Jeremy D.; Makshanoff, Jacob; Bischoff, Nicholas; Yong, Jennifer; Travis, Gabriel H.

    2014-01-01

    Absorption of a photon by a rhodopsin or cone-opsin pigment isomerizes its 11-cis-retinaldehyde (11-cis-RAL) chromophore to all-trans-retinaldehyde (all-trans-RAL), which dissociates after a brief period of activation. Light sensitivity is restored to the resulting apo-opsin when it recombines with another 11-cis-RAL. Conversion of all-trans-RAL to 11-cis-RAL is carried out by an enzyme pathway called the visual cycle in cells of the retinal pigment epithelium. A second visual cycle is present in Müller cells of the retina. The retinol isomerase for this noncanonical pathway is dihydroceramide desaturase (DES1), which catalyzes equilibrium isomerization of retinol. Because 11-cis-retinol (11-cis-ROL) constitutes only a small fraction of total retinols in an equilibrium mixture, a subsequent step involving selective removal of 11-cis-ROL is required to drive synthesis of 11-cis-retinoids for production of visual chromophore. Selective esterification of 11-cis-ROL is one possibility. Crude homogenates of chicken retinas rapidly convert all-trans-ROL to 11-cis-retinyl esters (11-cis-REs) with minimal formation of other retinyl-ester isomers. This enzymatic activity implies the existence of an 11-cis-specific retinyl-ester synthase in Müller cells. Here, we evaluated multifunctional O-acyltransferase (MFAT) as a candidate for this 11-cis-RE-synthase. MFAT exhibited much higher catalytic efficiency as a synthase of 11-cis-REs versus other retinyl-ester isomers. Further, we show that MFAT is expressed in Müller cells. Finally, homogenates of cells coexpressing DES1 and MFAT catalyzed the conversion of all-trans-ROL to 11-cis-RP, similar to what we observed with chicken-retina homogenates. MFAT is therefore an excellent candidate for the retinyl-ester synthase that cooperates with DES1 to drive synthesis of 11-cis-retinoids by mass action. PMID:24799687

  6. Suppressing thyroid hormone signaling preserves cone photoreceptors in mouse models of retinal degeneration.

    PubMed

    Ma, Hongwei; Thapa, Arjun; Morris, Lynsie; Redmond, T Michael; Baehr, Wolfgang; Ding, Xi-Qin

    2014-03-01

    Cone phototransduction and survival of cones in the human macula is essential for color vision and for visual acuity. Progressive cone degeneration in age-related macular degeneration, Stargardt disease, and recessive cone dystrophies is a major cause of blindness. Thyroid hormone (TH) signaling, which regulates cell proliferation, differentiation, and apoptosis, plays a central role in cone opsin expression and patterning in the retina. Here, we investigated whether TH signaling affects cone viability in inherited retinal degeneration mouse models. Retinol isomerase RPE65-deficient mice [a model of Leber congenital amaurosis (LCA) with rapid cone loss] and cone photoreceptor function loss type 1 mice (severe recessive achromatopsia) were used to determine whether suppressing TH signaling with antithyroid treatment reduces cone death. Further, cone cyclic nucleotide-gated channel B subunit-deficient mice (moderate achromatopsia) and guanylate cyclase 2e-deficient mice (LCA with slower cone loss) were used to determine whether triiodothyronine (T3) treatment (stimulating TH signaling) causes deterioration of cones. We found that cone density in retinol isomerase RPE65-deficient and cone photoreceptor function loss type 1 mice increased about sixfold following antithyroid treatment. Cone density in cone cyclic nucleotide-gated channel B subunit-deficient and guanylate cyclase 2e-deficient mice decreased about 40% following T3 treatment. The effect of TH signaling on cone viability appears to be independent of its regulation on cone opsin expression. This work demonstrates that suppressing TH signaling in retina dystrophy mouse models is protective of cones, providing insights into cone preservation and therapeutic interventions. PMID:24550448

  7. PDA (Prolonged Depolarizing Afterpotential) - Defective Mutants: The Story of nina's and ina's—pinta and santa maria, Too

    PubMed Central

    Pak, William L.; Shino, Shikoh; Leung, Hung-Tat

    2012-01-01

    Our objective is to present a comprehensive view of the PDA (prolonged depolarizing afterpotential)-defective Drosophila mutants, nina's and ina's, from the discussion of the PDA and the PDA-based mutant screening strategy to summaries of the knowledge gained through the studies of mutants generated using the strategy. The PDA is a component of the light-evoked photoreceptor potential that is generated when a substantial fraction of rhodopsin is photoconverted to its active form, metarhodopsin. The PDA-based mutant screening strategy was adopted to enhance the efficiency and efficacy of ERG (electroretinogram)-based screening for identifying phototransduction-defective mutants. Using this strategy, two classes of PDA-defective mutants were identified and isolated, nina and ina, each comprising multiple complementation groups. The nina mutants are characterized by allele-dependent reduction in the major rhodopsin, Rh1, whereas the ina mutants display defects in some aspects of functions related to the transduction channel, TRP (transient receptor potential). The signaling proteins that have been identified and elucidated through the studies of nina mutants include the Drosophila opsin protein (NINAE), the chaperone protein for nascent opsin (NINAA), and the multifunctional protein, NINAC, required in multiple steps of the Drosophila phototransduction cascade. Also identified by the nina mutants are some of the key enzymes involved in the biogenesis of the rhodopsin chromophore. As for the ina mutants, they led to the discovery of the scaffold protein, INAD, responsible for the nucleation of the supramolecular signaling complex. Also identified by the ina mutants is one of the key members of the signaling complex, INAC (ePKC), and two other proteins that are likely to be important, though their roles in the signaling cascade have not yet been fully elucidated. In most of these cases, the protein identified is the first member of its class to be so recognized. PMID:22283778

  8. Hsp90 inhibition protects against inherited retinal degeneration.

    PubMed

    Aguilà, Mònica; Bevilacqua, Dalila; McCulley, Caroline; Schwarz, Nele; Athanasiou, Dimitra; Kanuga, Naheed; Novoselov, Sergey S; Lange, Clemens A K; Ali, Robin R; Bainbridge, James W; Gias, Carlos; Coffey, Peter J; Garriga, Pere; Cheetham, Michael E

    2014-04-15

    The molecular chaperone Hsp90 is important for the functional maturation of many client proteins, and inhibitors are in clinical trials for multiple indications in cancer. Hsp90 inhibition activates the heat shock response and can improve viability in a cell model of the P23H misfolding mutation in rhodopsin that causes autosomal dominant retinitis pigmentosa (adRP). Here, we show that a single low dose of the Hsp90 inhibitor HSP990 enhanced visual function and delayed photoreceptor degeneration in a P23H transgenic rat model. This was associated with the induction of heat shock protein expression and reduced rhodopsin aggregation. We then investigated the effect of Hsp90 inhibition on a different type of rod opsin mutant, R135L, which is hyperphosphorylated, binds arrestin and disrupts vesicular traffic. Hsp90 inhibition with 17-AAG reduced the intracellular accumulation of R135L and abolished arrestin binding in cells. Hsf-1(-/-) cells revealed that the effect of 17-AAG on P23H aggregation was dependent on HSF-1, whereas the effect on R135L was HSF-1 independent. Instead, the effect on R135L was mediated by a requirement of Hsp90 for rhodopsin kinase (GRK1) maturation and function. Importantly, Hsp90 inhibition restored R135L rod opsin localization to wild-type (WT) phenotype in vivo in rat retina. Prolonged Hsp90 inhibition with HSP990 in vivo led to a posttranslational reduction in GRK1 and phosphodiesterase (PDE6) protein levels, identifying them as Hsp90 clients. These data suggest that Hsp90 represents a potential therapeutic target for different types of rhodopsin adRP through distinct mechanisms, but also indicate that sustained Hsp90 inhibition might adversely affect visual function. PMID:24301679

  9. The heat-shock response co-inducer arimoclomol protects against retinal degeneration in rhodopsin retinitis pigmentosa.

    PubMed

    Parfitt, D A; Aguila, M; McCulley, C H; Bevilacqua, D; Mendes, H F; Athanasiou, D; Novoselov, S S; Kanuga, N; Munro, P M; Coffey, P J; Kalmar, B; Greensmith, L; Cheetham, M E

    2014-01-01

    Retinitis pigmentosa (RP) is a group of inherited diseases that cause blindness due to the progressive death of rod and cone photoreceptors in the retina. There are currently no effective treatments for RP. Inherited mutations in rhodopsin, the light-sensing protein of rod photoreceptor cells, are the most common cause of autosomal-dominant RP. The majority of mutations in rhodopsin, including the common P23H substitution, lead to protein misfolding, which is a feature in many neurodegenerative disorders. Previous studies have shown that upregulating molecular chaperone expression can delay disease progression in models of neurodegeneration. Here, we have explored the potential of the heat-shock protein co-inducer arimoclomol to ameliorate rhodopsin RP. In a cell model of P23H rod opsin RP, arimoclomol reduced P23H rod opsin aggregation and improved viability of mutant rhodopsin-expressing cells. In P23H rhodopsin transgenic rat models, pharmacological potentiation of the stress response with arimoclomol improved electroretinogram responses and prolonged photoreceptor survival, as assessed by measuring outer nuclear layer thickness in the retina. Furthermore, treated animal retinae showed improved photoreceptor outer segment structure and reduced rhodopsin aggregation compared with vehicle-treated controls. The heat-shock response (HSR) was activated in P23H retinae, and this was enhanced with arimoclomol treatment. Furthermore, the unfolded protein response (UPR), which is induced in P23H transgenic rats, was also enhanced in the retinae of arimoclomol-treated animals, suggesting that arimoclomol can potentiate the UPR as well as the HSR. These data suggest that pharmacological enhancement of cellular stress responses may be a potential treatment for rhodopsin RP and that arimoclomol could benefit diseases where ER stress is a factor. PMID:24853414

  10. Evolution of ultraviolet vision in the largest avian radiation - the passerines

    PubMed Central

    2011-01-01

    Background Interspecific variation in avian colour vision falls into two discrete classes: violet sensitive (VS) and ultraviolet sensitive (UVS). They are characterised by the spectral sensitivity of the most shortwave sensitive of the four single cones, the SWS1, which is seemingly under direct control of as little as one amino acid substitution in the cone opsin protein. Changes in spectral sensitivity of the SWS1 are ecologically important, as they affect the abilities of birds to accurately assess potential mates, find food and minimise visibility of social signals to predators. Still, available data have indicated that shifts between classes are rare, with only four to five independent acquisitions of UV sensitivity in avian evolution. Results We have classified a large sample of passeriform species as VS or UVS from genomic DNA and mapped the evolution of this character on a passerine phylogeny inferred from published molecular sequence data. Sequencing a small gene fragment has allowed us to trace the trait changing from one stable state to another through the radiation of the passeriform birds. Their ancestor is hypothesised to be UVS. In the subsequent radiation, colour vision changed between UVS and VS at least eight times. Conclusions The phylogenetic distribution of SWS1 cone opsin types in Passeriformes reveals a much higher degree of complexity in avian colour vision evolution than what was previously indicated from the limited data available. Clades with variation in the colour vision system are nested among clades with a seemingly stable VS or UVS state, providing a rare opportunity to understand how an ecologically important trait under simple genetic control may co-evolve with, and be stabilised by, associated traits in a character complex. PMID:22024316

  11. Violet Light Down-Regulates the Expression of Specific Differentiation Markers through Rhodopsin in Normal Human Epidermal Keratinocytes

    PubMed Central

    Kim, Hyoung-June; Son, Eui Dong; Jung, Ji-Yong; Choi, Hyun; Lee, Tae Ryong; Shin, Dong Wook

    2013-01-01

    Several recent reports have demonstrated that photoreceptors are expressed in human skin. The rod and cone photoreceptor-like proteins are expressed in human skin and rhodopsin, long wavelength-opsin, and short wavelength-opsin are also present in cultured murine melanocytes. Furthermore, the photopigment rhodopsin is expressed in human melanocytes and is involved in ultraviolet A phototransduction which induces early melanin synthesis. In this study, we investigated whether rhodopsin is expressed and plays any physiological roles in the normal human epidermal keratinocytes (NHEKs). We found that rhodopsin was expressed and localized on the plasma membrane in NHEKs, and only violet light among several wavelengths within the visible range significantly increased the expression of rhodopsin mRNA. We further found that rhodopsin over-expression decreased the mRNA expression levels of keratinocyte differentiation markers, such as keratin-1 and keratin-10, and violet light also decreased the mRNA expression levels of keratinocyte differentiation markers and these decreased expression levels were recovered by a rhodopsin-directed siRNA. Moreover, we further demonstrated that violet light significantly decreased the phosphorylation levels of cAMP responsive element-binding protein (CREB) and that it more effectively decreased the phosphorylation of CREB when rhodopsin was over-expressed. In addition, we observed that pertussis toxin, a G?i protein inhibitor, restored the rhodopsin-induced decrease in the differentiation markers in NHEKs. Taken together, these results suggest that rhodopsin down-regulates the expression levels of specific keratinocyte differentiation markers via the G?i signaling pathway in NHEKs. PMID:24069221

  12. Lake Michigan Offshore Wind Feasibility Assessment

    SciTech Connect

    Boezaart, Arnold [GVSU; Edmonson, James [GVSU; Standridge, Charles [GVSU; Pervez, Nahid [GVSU; Desai, Neel [University of Michigan; Williams, Bruce [University of Delaware; Clark, Aaron [GVSU; Zeitler, David [GVSU; Kendall, Scott [GVSU; Biddanda, Bopi [GVSU; Steinman, Alan [GVSU; Klatt, Brian [Michigan State University; Gehring, J. L. [Michigan State University; Walter, K. [Michigan State University; Nordman, Erik E. [GVSU

    2014-06-30

    The purpose of this project was to conduct the first comprehensive offshore wind assessment over Lake Michigan and to advance the body of knowledge needed to support future commercial wind energy development on the Great Lakes. The project involved evaluation and selection of emerging wind measurement technology and the permitting, installation and operation of the first mid-lake wind assessment meteorological (MET) facilities in Michigan’s Great Lakes. In addition, the project provided the first opportunity to deploy and field test floating LIDAR and Laser Wind Sensor (LWS) technology, and important research related equipment key to the sitting and permitting of future offshore wind energy development in accordance with public participation guidelines established by the Michigan Great Lakes Wind Council (GLOW). The project created opportunities for public dialogue and community education about offshore wind resource management and continued the dialogue to foster Great Lake wind resource utilization consistent with the focus of the GLOW Council. The technology proved to be effective, affordable, mobile, and the methods of data measurement accurate. The public benefited from a substantial increase in knowledge of the wind resources over Lake Michigan and gained insights about the potential environmental impacts of offshore wind turbine placements in the future. The unique first ever hub height wind resource assessment using LWS technology over water and development of related research data along with the permitting, sitting, and deployment of the WindSentinel MET buoy has captured public attention and has helped to increase awareness of the potential of future offshore wind energy development on the Great Lakes. Specifically, this project supported the acquisition and operation of a WindSentinel (WS) MET wind assessment buoy, and associated research for 549 days over multiple years at three locations on Lake Michigan. Four research objectives were defined for the project including to: 1) test and validate floating LIDAR technology; 2) collect and access offshore wind data; 3) detect and measure bird and bat activity over Lake Michigan; 4) conduct an over water sound propagation study; 5) prepare and offer a college course on offshore energy, and; 6) collect other environmental, bathometric, and atmospheric data. Desk-top research was performed to select anchorage sites and to secure permits to deploy the buoy. The project also collected and analyzed data essential to wind industry investment decision-making including: deploying highly mobile floating equipment to gather offshore wind data; correlating offshore wind data with conventional on-shore MET tower data; and performing studies that can contribute to the advancement and deployment of offshore wind technologies. Related activities included: • Siting, permitting, and deploying an offshore floating MET facility; • Validating the accuracy of floating LWS using near shoreline cup anemometer MET instruments; • Assessment of laser pulse technology (LIDAR) capability to establish hub height measurement of wind conditions at multiple locations on Lake Michigan; • Utilizing an extended-season (9-10 month) strategy to collect hub height wind data and weather conditions on Lake Michigan; • Investigation of technology best suited for wireless data transmission from distant offshore structures; • Conducting field-validated sound propagation study for a hypothetical offshore wind farm from shoreline locations; • Identifying the presence or absence of bird and bat species near wind assessment facilities; • Identifying the presence or absence of benthic and pelagic species near wind assessment facilities; All proposed project activities were completed with the following major findings: • Floating Laser Wind Sensors are capable of high quality measurement and recordings of wind resources. The WindSentinel presented no significant operational or statistical limitations in recording wind data technology at a at a high confidence level as compared to traditional an

  13. The ISO Long Wavelength Spectrometer line spectrum of VY Canis Majoris and other oxygen-rich evolved stars

    NASA Astrophysics Data System (ADS)

    Polehampton, E. T.; Menten, K. M.; van der Tak, F. F. S.; White, G. J.

    2010-02-01

    Context. The far-infrared spectra of circumstellar envelopes around various oxygen-rich stars were observed using the ISO Long Wavelength Spectrometer (LWS). These have been shown to be spectrally rich, particularly in water lines, indicating a high H2O abundance. Aims: We have examined high signal-to-noise ISO LWS observations of the luminous supergiant star, VY CMa, with the aim of identifying all of the spectral lines. By paying particular attention to water lines, we aim to separate the lines due to other species, in particular, to prepare for forthcoming observations that will cover the same spectral range using Herschel PACS and at higher spectral resolution using Herschel HIFI and SOFIA. Methods: We have developed a fitting method to account for blended water lines using a simple weighting scheme to distribute the flux. We have used this fit to separate lines due to other species which cannot be assigned to water. We have applied this approach to several other stars which we compare with VY CMa. Results: We present line fluxes for the unblended H2O and CO lines, and present detections of several possible ?2=1 vibrationally excited water lines. We also identify blended lines of OH, one unblended and several blended lines of NH3, and one possible detection of H3O+. Conclusions: The spectrum of VY CMa shows a detection of emission from virtually every water line up to 2000 K above the ground state, as well as many additional higher energy and some vibrationally excited lines. A simple rotation diagram analysis shows large scatter (probably due to some optically thick lines). The fit gives a rotational temperature of 670+210-130 K, and lower limit on the water column density of (7.0±1.2) × 1019 cm-2. We estimate a CO column density ~100 times lower, showing that water is the dominant oxygen carrier. The other stars that we examined have similar rotation temperatures, but their H2O column densities are an order of magnitude lower (as are the mass loss rates). 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 United Kingdom) with the participation of ISAS and NASA.Current address: Space Science Department, Rutherford Appleton Laboratory, UK

  14. The Shock Structure of Supernova Remnant IC443

    NASA Technical Reports Server (NTRS)

    Haas, Michael R.; Higdon, S. J. U.; Burton, M. G.; Hollenbach, D. J.; Fonda, Mark (Technical Monitor)

    2003-01-01

    We present and discuss ISO observations of IC443, a supernova remnant interacting with a molecular cloud. An SWS spectrum centered on molecular hydrogen clump R10E (RA(2000) = 6 17 7.6, Decl(2000) = 22 25 34.6) is dominated by strong [SiII] (34 microns) emission and the pure rotational transitions of molecular hydrogen ranging from 0-0 S(1) to 0-0 S(13). Fits to these H$-2$ lines imply a large column (approx. 7E19 cm$ {-2)$) of warm (T approx. 700 K) gas and an ortho/para ratio for hydrogen near 3. LWS Fabry-Perot spectra of [OI] (63 microns) and [CII] (158 microns) at positions R10E and C (RA(2000) = 6 17 42.8, Decl(2000) = 22 21 38.1) find broad (approx. 75 km/s), blue-shifted (-40 km/s) line profiles; their similarity strongly suggests a common, shock-generated origin for these two lines. The surprisingly large [CII]/[OI] ratio (approx. 0.1 to 0.2) confirms previous observations with the Kuiper Airborne Observatory. These [CII] and [OI] line intensities, the [SiII] intensity (above), and LWS grating measurements of OH (119 microns) and [OI] (145 microns) are all readily fit by a single, fast J-shock model. Although the [OI] (63) emission can alternatively be produced by a slow C-shock, this ensemble of lines can not be produced by such a shock and provides strong evidence for the existence of a J-shock. A 24-arcmin strip map shows that this far-infrared line emission is spatially correlated with the H$-2$ 1-0 S(1) emission, which most likely arises in an associated C-shock. In addition to this spatially correlated shock emission, the strip map identifies extended [CII] and [OI] emission with a significantly larger line ratio (approx. 0.6); this 'background' component is compared with current J-shock, C-shock, photo-dissociation region (PDR), and X-ray dissociation region (XDR) models in an effort to explain its origin.

  15. Variation in the action spectrum of erythrolabe among deuteranopes.

    PubMed Central

    Alpern, M; Pugh, E N

    1977-01-01

    1. Eight deuteranopes matched a mixture of a monochromatic light on the long wave side of the neutral point and a violet (450 nm) primary to a fixed white as well as a monochromatic light on the short wave side of the neutral point mixed with a red (650 nm) primary, to the same white. For lambda greater than 530 nm, the former set of matches defined the action spectrum of the long wave sensitive foveal cones, and for lambda less than 480 nm, the latter that of the short wave sensitive cones. 2. Individual differences in the former matches were approximately correlated with the respective ratio of the sensitivities of the wave-length of the anomaloscope primaries, in a way that individual differences of the latter were not. 3. Assuming that eye media differences alone account for the differences in long wave sensitive foveal action spectra, the spectral reflectivity of the foveal fundus was predicted for these deuteranopes. The prediction is inconsistent with measurement. 4. Thirteen deuteranopes matched monochromatic spectral lights with a green (535 nm) and a blue (460 nm) primary. The result were analysed by von Kries' method in which differences in matching due to differences in eye media absorption are obviated. The matches of five differed significantly from one another when so analysed. It was concluded that at least one of two action spectra of the foveal cones of every one of these five differed from that of all of the others. 5. The canon that deuteranopes accept normal colour matches was evaluated by confronting a single normal with five deuternopes in the analytical anomaloscope of Baker & Rushton, set in the mode of each of the five in turn. Obvious differences existed between this normal's matches and those of four of five deuteranopes. 6. Explanations for differences in the spectrum of erythrolabe in different deuteranopes are evaluated. The possibilities that all have the identical visual pigment but (a) in cones with different optical funnelling properties or (b) in different optical densities are considered. Preliminary results are not in agreement with the expectations of either of these ideas. 7. It is suggested that the visual pigment in the foveal long wave sensitive cones of different deuternopes (and of different normals) may have different extinction spectra. The idea is consistent with micro-spectrophotometric measurements of rhodopsin in individual rods from different frogs (Bowmaker, Loew & Leibman, 1975). PMID:301186

  16. The Water Vapor Abundance in Orion KL Outflows

    E-print Network

    J. Cernicharo; J. R. Goicoechea; F. Daniel; M. R. Lerate; M. J. Barlow; B. M. Swinyard; E. van Dishoeck; T. L. Lim; S. Viti; J. Yates

    2006-08-16

    We present the detection and modeling of more than 70 far-IR pure rotational lines of water vapor, including the 18O and 17O isotopologues, towards Orion KL. Observations were performed with the Long Wavelength Spectrometer Fabry-Perot (LWS/FP; R~6800-9700) on board the Infrared Space Observatory (ISO) between ~43 and ~197 um. The water line profiles evolve from P-Cygni type profiles (even for the H2O18 lines) to pure emission at wavelengths above ~100 um. We find that most of the water emission/absorption arises from an extended flow of gas expanding at 25+-5 kms^-1. Non-local radiative transfer models show that much of the water excitation and line profile formation is driven by the dust continuum emission. The derived beam averaged water abundance is 2-3x10^-5. The inferred gas temperature Tk=80-100 K suggests that: (i) water could have been formed in the "plateau" by gas phase neutral-neutral reactions with activation barriers if the gas was previously heated (e.g. by shocks) to >500 K and/or (ii) H2O formation in the outflow is dominated by in-situ evaporation of grain water-ice mantles and/or (iii) H2O was formed in the innermost and warmer regions (e.g. the hot core) and was swept up in ~1000 yr, the dynamical timescale of the outflow.

  17. Technology Development Activities for the Space Environment and its Effects on Spacecraft

    NASA Technical Reports Server (NTRS)

    Kauffman, Billy; Hardage, Donna; Minor, Jody; Barth, Janet; LaBel, Ken

    2003-01-01

    Reducing size and weight of spacecraft, along with demanding increased performance capabilities, introduces many uncertainties in the engineering design community on how emerging microelectronics will perform in space. The engineering design community is forever behind on obtaining and developing new tools and guidelines to mitigate the harmful effects of the space environment. Adding to this complexity is the push to use Commercial-off-the-shelf (COTS) and shrinking microelectronics behind less shielding and the potential usage of unproven technologies such as large solar sail structures and nuclear electric propulsion. In order to drive down these uncertainties, various programs are working together to avoid duplication, save what resources are available in this technical area and possess a focused agenda to insert these new developments into future mission designs. This paper will describe the relationship between the Living With a Star (LWS): Space Environment Testbeds (SET) Project and NASA's Space Environments and Effects (SEE) Program and their technology development activities funded as a result from the recent SEE Program's NASA Research Announcement.

  18. Global-scale Observations of the Limb and Disk (GOLD): Mission Implementation

    NASA Astrophysics Data System (ADS)

    McClintock, W.; Lankton, M.; Estes, R.; Aksens, A.; Anderson, D.; Andersson, L.; Codrescu, M.; Burns, A.; Daniell, R.; Eparvier, F.; Harvey, J.; Krywonos, A.; Lumpe, J.; Prolss, G.; Woods, T.; Richmond, A.; Rusch, D.; Solomon, S.; Strickland, D.

    2006-12-01

    The Global-scale Observations of the Limb and Disk (GOLD) mission of opportunity will fly an ultraviolet imaging spectrograph on a geostationary satellite to measure densities and temperatures in the thermosphere and ionosphere. From this vantage point, GOLD will observe emissions from an entire hemisphere (disk) and the horizon (limb) of the Earth. On the limb stellar occultations will provide information that is not available from the emissions. Analysis of these data will answer four specific science questions: 1. What is the global-scale response of the thermosphere and ionosphere to geomagnetic forcing? 2. What is the global-scale response of the thermosphere and ionosphere to changing EUV radiation? 3. What are the solar & geospace causes of small-scale ionospheric density irregularities? 4. What are the global-scale tidal amplitude and phase variations? Answers to these questions will address the central question of the Living With a Star (LWS) program: What is the global-scale response of the thermosphere and ionosphere to forcing in the integrated Sun-Earth system? This presentation discusses the GOLD measurement approach and describes the GOLD mission implementation, including the instrument design concept, its accommodation to the spacecraft, observation scenarios, and the ground data system.

  19. VizieR Online Data Catalog: Compendium of ISO far-IR extragalactic data (Brauher+, 2008)

    NASA Astrophysics Data System (ADS)

    Brauher, J. R.; Dale, D. A.; Helou, G.

    2009-07-01

    Far-infrared line and continuum fluxes are presented for a sample of 227 galaxies observed with the Long Wavelength Spectrometer on the Infrared Space Observatory (ISO, Kessler et al., 1996A&A...315L..27K). The galaxy sample includes normal star-forming systems, starbursts, and active galactic nuclei covering a wide range of colors and morphologies. The data set spans some 1300 line fluxes, 600 line upper limits, and 800 continuum fluxes. Several fine-structure emission lines are detected that arise in either photodissociation or HII regions: [OIII] 52um, [NIII] 57um, [OI] 63um, [OIII] 88um, [NII] 122um, [OI] 145um, and [CII] 158um. Molecular lines such as OH at 53, 79, 84, 119, and 163um, and H2O at 58, 66, 75, 101, and 108um are also detected in some galaxies. In addition to those lines emitted by the target galaxies, serendipitous detections of Milky Way [CII] 158um and an unidentified line near 74um in NGC 1068 are also reported. Finally, continuum fluxes at 52, 57, 63, 88, 122, 145, 158, and 170um are derived for a subset of galaxies in which the far-infrared emission is contained within the ~75" ISO LWS beam. The statistics of this large database of continuum and line fluxes, including trends in line ratios with the far-infrared color and infrared-to-optical ratio, are explored. (3 data files).

  20. ISAP: ISO Spectral Analysis Package

    NASA Astrophysics Data System (ADS)

    Ali, Babar; Bauer, Otto; Brauher, Jim; Buckley, Mark; Harwood, Andrew; Hur, Min; Khan, Iffat; Li, Jing; Lord, Steve; Lutz, Dieter; Mazzarella, Joe; Molinari, Sergio; Morris, Pat; Narron, Bob; Seidenschwang, Karla; Sidher, Sunil; Sturm, Eckhard; Swinyard, Bruce; Unger, Sarah; Verstraete, Laurent; Vivares, Florence; Wieprecht, Ecki

    2014-03-01

    ISAP, written in IDL, simplifies the process of visualizing, subsetting, shifting, rebinning, masking, combining scans with weighted means or medians, filtering, and smoothing Auto Analysis Results (AARs) from post-pipeline processing of the Infrared Space Observatory's (ISO) Short Wavelength Spectrometer (SWS) and Long Wavelength Spectrometer (LWS) data. It can also be applied to PHOT-S and CAM-CVF data, and data from practically any spectrometer. The result of a typical ISAP session is expected to be a "simple spectrum" (single-valued spectrum which may be resampled to a uniform wavelength separation if desired) that can be further analyzed and measured either with other ISAP functions, native IDL functions, or exported to other analysis package (e.g., IRAF, MIDAS) if desired. ISAP provides many tools for further analysis, line-fitting, and continuum measurements, such as routines for unit conversions, conversions from wavelength space to frequency space, line and continuum fitting, flux measurement, synthetic photometry and models such as a zodiacal light model to predict and subtract the dominant foreground at some wavelengths.

  1. Magnetic Causes of Solar Coronal Mass Ejections: Dominance of the Free Magnetic Energy over Either the Magnetic Twist or Size Alone

    NASA Technical Reports Server (NTRS)

    Falconer, D. A.; Moore, R. L.; Gary, G. A.

    2006-01-01

    We report further results from our ongoing assessment of magnetogram-based measures of active-region nonpotentiality and size as predictors of coronal mass ejections (CMEs). We have devised improved generalized measures of active-region nonpotentiality that apply to active regions of any degree of magnetic complexity, rather than being limited to bipolar active regions as our initial measures were. From a set of approx.50 active-regions, we have found that measures of total nonpotentiality have a 75-80% success rate n predicting whether an active region will produce a CME in 2 days after the magnetogram. This makes measures of total nonpotentiality a better predictor than either active-region size, or active region twist (size-normalized nonpotentiality), which have a approx.65% success rates. We have also found that we can measure from the line-of-sight magnetograms an active region's total nonpotentiality and the size, which allows use to use MDI to evaluate these quantities for 4-5 consecutive days for each active region, and to investigate if there is some combination of size and total nonpotentiality that have a stronger predictive power than does total nonpotentiality. This work was funded by NASA through its LWS TR&T Program and its Solar and Heliospheric Physics SR&T Program, and by NSF through its Solar Terrestrial Research and SHINE programs.

  2. Challenges to modeling the Sun-Earth System: A Workshop Summary

    NASA Technical Reports Server (NTRS)

    Spann, James F.

    2006-01-01

    This special issue of the Journal of' Atmospheric and Solar-Terrestrial Physics is a compilation of 23 papers presented at The 2004 Huntsville Modeling Workshop: Challenges to Modeling thc San-Earth System held in Huntsville, AB on October 18-22, 2004. The title of the workshop appropriately captures the theme of what was presented and discussed by the 120 participants. Currently, end-to-end modeling of the Sun-Earth system is a major goal of the National Space Weather and NASA living with a star (LWS) programs. While profound advances have been made in modeling isolated regions of the Sun-Earth system, minimal progress has been achieved in modeling the end-to-end system. The transfer of mass, energy and momentum through the coupled Sun-Earth system spans a wide range of scales inn time and space. The uncertainty in the underlying physics responsible for coupling contiguous regions of the Sun-Earth system is recognized as a significant barrier to progress

  3. Small-Scale Irregularities in Equatorial Spread-F

    NASA Astrophysics Data System (ADS)

    Dimant, Yakov; Oppenheim, Meers

    2014-10-01

    Equatorial Spread-F is a spectacular plasma phenomenon that reshapes the nighttime ionosphere and disrupts GPS navigation and radio communication. Current computer models simulate the evolution of large-scale spread-F phenomena (1000km-to-kilometer), but they do not explain what causes the meter-scale irregularities observed by radars and space-borne instruments. Our recent particle-in-cell (PIC) simulations of weakly collisional plasma have demonstrated that large-scale plasma density gradients and related electric fields may drive local plasma instabilities, although only for a limited set of parameters. Motivated by these PIC simulations, we have revisited the linear theory of this instability, employing a novel and sophisticated eigenmode analysis. This method identified eigenmode wave structures in regions having strong plasma density gradients. These wave structures are not linearly unstable, but are not damped either. This means that small-scale fluctuations provided by an external source (e.g., by a nonlinear spectral cascade from longer-wavelength spread-F turbulence) can be resonantly amplified and may explain radar observations without invoking linear instability. Work supported by NASA LWS Grant 10-LWSTRT10-0078.

  4. Infrared Spectroscopy of Black Hole Candidates

    NASA Technical Reports Server (NTRS)

    Colgan, Sean W.; Cotera, A. S.; Maloney, P. R.; Hollenbach, D. J.; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    ISO LWS and SWS observations of the approx. solar mass black hole candidates 1E1740.7-2942 and GRS1758-258 are presented. For 1E1740.7-2942, it has been suggested that the luminosity is provided in whole or part by Bondi-Hoyle accretion from a surrounding black hole (Bally & Leventhal 1991, Nat, 353,234). Maloney et al. (1997, ApJ482, L41) have predicted that detectable far-infrared line emission from [0I] (63 microns), [CII] (158 microns), [SiII] (35 microns) and other lines will arise from black holes which are embedded in molecular clouds. No strong line emission associated with either 1E1740.7-2942 or GRS1758-258 was detected, implying either that 1) these sources are not embedded in dense molecular clouds, or 2) that their average X-ray luminosity over the past 100 years is significantly lower than its current value. The measured upper limits to the line fluxes are compared with the models of Maloney et al.to constrain the properties of the ISM in the vicinity of these X-ray sources.

  5. The Infrared Continuum Spectrum of VY CMa

    E-print Network

    Martin Harwit; Koen Malfait; Leen Decin; Christoffel Waelkens; Helmut Feuchtgruber; Gary J. Melnick

    2001-09-10

    We combine spectra of VY CMa obtained with the short- and long-wavelength spectrometers, SWS and LWS, on the Infrared Space Observatory to provide a first detailed continuum spectrum of this highly luminous star. The circumstellar dust cloud through which the star is observed is partially self-absorbing, which makes for complex computational modeling. We review previous work and comment on the range of uncertainties about the physical traits and mineralogical composition of the modeled disk. We show that these uncertainties significantly affect the modeling of the outflow and the estimated mass loss. In particular, we demonstrate that a variety of quite diverse models can produce good fits to the observed spectrum. If the outflow is steady, and the radiative repulsion on the dust cloud dominates the star's gravitational attraction, we show that the total dust mass-loss rate is $\\sim 4\\times 10^{-6}M_{\\odot}$ yr$^{-1}$, assuming that the star is at a distance of 1.5 kpc. Several indications, however, suggest that the outflow from the star may be spasmodic. We discuss this and other problems facing the construction of a physically coherent model of the dust cloud and a realistic mass-loss analysis.

  6. Promoting Scientist Communications Through Graduate Summer School in Heliophysics and Space Physics

    NASA Astrophysics Data System (ADS)

    Gross, N. A.; Schrijver, K.; Bagenal, F.; Sojka, J. J.; Wiltberger, M. J.

    2014-12-01

    edagogical tools that promote student interaction can be applied successfully during graduate workshops to enhance community and communication among the participants and instructors. The NASA/LWS funded Heliophysics Summer School and the NSF funded Space Weather Summer School provide graduate students starting research in the field, and others who are involved in space physics, an opportunity to learn from and interact with leaders in the field and each other. These interactions can happen casually, but there are a number of programatic aspects that foster the interaction so that they can be as fruitful as possible during the short period. These include: specific "ice-breaker" activities, practicing "elevator speeches", embedded lecture questions, question cards, discussion questions, interactive lab activities, structured lab groups, and use of social media. We are continuing to develop new ways to foster profession interaction during these short courses. Along with enhancing their own learning, the inclusion of these strategies provides both the participants and the instructors with models of good pedagogical tools and builds community among the students. Our specific implementation of these strategies and evidence of success will be presented.

  7. Euglycemia in Diabetic Rats Leads to Reduced Liver Weight via Increased Autophagy and Apoptosis through Increased AMPK and Caspase-3 and Decreased mTOR Activities

    PubMed Central

    Lee, Jun-Ho; Choi, Soo-Bong; Jin, Mingli; Lee, Ju-Han; Han, Sang-Don; Bae, Hyemi; Lim, Inja; Noh, Yun-Hee

    2015-01-01

    Euglycemia is the ultimate goal in diabetes care to prevent complications. However, the benefits of euglycemia in type 2 diabetes are controversial because near-euglycemic subjects show higher mortality than moderately hyperglycemic subjects. We previously reported that euglycemic-diabetic rats on calorie-control lose a critical liver weight (LW) compared with hyperglycemic rats. Here, we elucidated the molecular mechanisms underlying the loss of LW in euglycemic-diabetic rats and identified a potential risk in achieving euglycemia by calorie-control. Sprague-Dawley diabetic rats generated by subtotal-pancreatectomy were fed a calorie-controlled diet for 7 weeks to achieve euglycemia using 19 kcal% (19R) or 6 kcal% (6R) protein-containing chow or fed ad libitum (19AL). The diet in both R groups was isocaloric/kg body weight to the sham-operated group (19S). Compared with 19S and hyperglycemic 19AL, both euglycemic R groups showed lower LWs, increased autophagy, and increased AMPK and caspase-3 and decreased mTOR activities. Though degree of insulin deficiency was similar among the diabetic rats, Akt activity was lower, and PTEN activity was higher in both R groups than in 19AL whose signaling patterns were similar to 19S. In conclusion, euglycemia achieved by calorie-control is deleterious in insulin deficiency due to increased autophagy and apoptosis in the liver via AMPK and caspase-3 activation. PMID:26060824

  8. Dynamo-based simulations of solar activity differences between north and south hemispheres and forecasts for cycle 24

    NASA Astrophysics Data System (ADS)

    Dikpati, M.; Gilman, P. A.; de Toma, G.

    2006-12-01

    Recently we (GRL, 2006, vol.33, L05102, doi:10.1029/2005GL025221) built a predictive tool based on a Babcock-Leighton type flux-transport dynamo model of solar cycle. By assimilating the observed surface magnetic source data since cycle 12, we ran the model and showed that the model can correctly simulate the relative peaks of cycles 16 through 23. Extending the simulation into the future we predicted that cycle 24 will be 30-50 percent stronger than current cycle 23, because a strong 'seed' for cycle 24 is being formed, from the combination of latitudinal fields from past three cycles, 21, 22 and 23, in the dynamo layer in our model. We are currently exploring the data assimilation in our model for the N and S hemispheres separately, in order to simulate hemispheric asymmetries in the solar cycle features. Preliminary results show that the model has skill in simulating the N and S hemispheres separately, as well as the difference between the two hemispheres. We will discuss which hemisphere of the Sun should become more active in cycle 24 and which hemisphere should reach cycle peak first. This work is partially supported by NASA's LWS grant NNH05AB521, SR&T grant NNH06AD51I and the NCAR Director's Opportunity Fund. National Center for Atmospheric Research is sponsored by National Science Foundation.

  9. Reconstructing meridional flow speed variation from synthetic magnetic observations by using EnKF data assimilation

    NASA Astrophysics Data System (ADS)

    Dikpati, M.; Anderson, J. L.

    2014-12-01

    Meridional circulation plays an important role ingoverning cycle period and memory of solar dynamo models.Accurate knowledge of time variation in flow speed andprofile is crucial for estimating a solar cycle's amplitude,timing, rise and fall patterns and north-south asymmetry,which are ultimately responsible for causing space climatevariation. However, no consensus has been reached yet aboutthe Sun's meridional circulation pattern from observationsand theories. Therefore, it is necessary to implement dataassimilation approaches, in addition to observations andmodels, to investigate solar interior flow properties. Wepresent here first results from a sequential dataassimilation into a Babcock-Leighton flux-transport solardynamo model to reconstruct time-varying meridionalcirculation speed. We perform several observation systemsimulation experiments (OSSE) by implementing an EnsembleKalman Filter (EnKF) in the framework of the Data AssimilationResearch Testbed (DART). We find that the best reconstructionof time-variation in meridional flow-speed can be obtainedwhen ten or more observations are used with an updatingtime of 15 days and a 10% observational error. Increasingensemble-size from 16 to 160 improves reconstruction, buteven larger ensembles do not lead to further improvement.Comparison of reconstructed flow-speed with "true-state"reveals that EnKF data assimilation is very powerful forreconstructing meridional flow-speeds and suggests that it can be implemented for reconstructing spatio-temporal patterns of meridional circulation. This work is partially supported by NASA's LWS grant NNX08AQ34G. NCAR is sponsoredby the NSF.

  10. Rovibrationally-resolved photodissociation of NH and application to the solar UV opacity

    NASA Astrophysics Data System (ADS)

    Shen, G.; Kuri, A.; Fontenla, J. M.; Stancil, P. C.; Wang, J. G.

    2014-05-01

    Rovibrationally-resolved photodissociation cross sections of NH have been evaluated using a combination of ab initio and experimentally derived potential curves and dipole transition moments. Here we present results for the three electronic transitions: 23?- <-- X3?- , 23 ? <-- X3?- , A3 ? <-- X3?- . Partial cross sections for transitions from all 577 rovibrational levels obtained theoretically for the ground electronic state X3?- , were computed for a wavelength range that extends from 500Å to the dissociation threshold for each particular rovibrational level. Assuming a thermal Boltzmann distribution of the rovibrational levels in X3?- , LTE cross sections are presented for gas temperatures between 500 and 10000 K. For applications to cold interstellar gas, cross sections for X3?- (v = 0 , J = 0) to 23?- and 23 ? dominate, but for the high density and temperature conditions in stellar atmospheres, the LTE cross section to the A3 ? becomes competitive. Explicit application of the cross sections to the solar UV opacity will be presented. In particular, the NH photodissociation opacity is found to affect the non-LTE behavior of some species such as Cr I and V I. The work at UGA was partially supported by NASA grant HST-AR-11776.01-A. The work of JMF was supported by NASA LWS grant NNX09AJ22G. GS acknowledges travel support by the International Cooperation and Exchange Foundation of CAEP.

  11. Rapid Changes in the Structure of the BN Object

    NASA Astrophysics Data System (ADS)

    Danchi, W. C.; Gezari, D. Y.; Greenhill, L. J.; Najita, J.; Monnier, J. D.; Tuthill, P. G.; Wishnow, E. H.

    2001-12-01

    The BN/KL region in Orion is the archetypal region of high-mass star formation, radiating about 105 LSun and displaying promininent bulk mass flows. The Becklin-Neugebauer object (BN) is an early-type massive star that is not visible at optical wavelengths, because of extinction, but is the most prominent source in the region at near-infrared wavelengths We used the LWS instrument on the Keck-I telescope to make 12.5? m and 18.7? m images in December 1999 and October 2000. We have discovered an infrared counterpart to the centermeter-wave radio ``companion'' observed about 1.5 arcsec west of BN. This secondary object (a.k.a. B2) is present at both epochs and does not appear to move, on 0.1 arcsec scales. We also see changes in the shape of BN, which may a consequence of ``bullets'' of material being ejected. These bullets are only detected at 18.7? m. Such changes have not been seen before at infrared wavelengths. Careful inspection of images for BN and a calibrator, obtained within a few minutes of eachother, does not suggest the putative bullets are imaging artifacts. We explore several possible scenarios to explain the changes in the mid-infrared appearance of BN on one year time scales.

  12. Langmuir wave self-focusing versus decay instability

    NASA Astrophysics Data System (ADS)

    Rose, Harvey A.

    2004-11-01

    Electron trapping in Langmuir waves (LWs), leads to one dimensional modulational instability, MI (R. L. Dewar, W. L. Kruer and W. M. Manheimer, PRL vol. 28, 215 (1972)). For small amplitude waves, MI is not possible if k? _D>0.33, but in dimension D>1, trapped electron LW self-focusing is possible until k? _D? 0.46 . Its damping threshold decreases with increasing k? _D, and crosses below LDIÂ's at a transitional value of k? _D? 0.3, depending on details of trapped electron escape rate and ion acoustic wave damping. For values of k? D close to but below the transition, the second LDI daughter wave of a cascade may collectively self-focus with the primary LW, leading to co-existence of LDI and LW self-focusing. For parameters appropriate to recent Trident experiments ( J. L. Kline et al., submitted to PRL 8/2005) threshold LW amplitudes are estimated at e? mathord/ hantom e? Te . kern-?lldelimiterspace T_e? 0.2, and for such amplitudes, MI is not possible in D=1, for k? _D>0.28. Trident data suggests coexistence for k? _D? 0.3, implying the need for multi-dimensional models.

  13. Parallel analysis of volatile fatty acids, indole, skatole, phenol, and trimethylamine from waste-related source environments.

    PubMed

    Rahman, Md Mahmudur; Kim, Ki-Hyun

    2013-11-01

    An experimental technique based on sorbent tube-thermal desorption-gas chromatography (ST-TD-GC) was investigated for the simultaneous determination of a cluster of eight volatile odorants (propionic acid, n-butyric acid, i-valeric acid, n-valeric acid, trimethylamine, phenol, indole, and skatole) and a reference compound (benzene). Calibration was made by direct injection of a liquid working standard (L-WS) into a quartz tube packed with three bed sorbent (Tenax TA, Carbopack B, and Carbopack X). To assess the relative performance between different detector systems, a comparative analysis was made using both mass spectrometry (MS) and a flame ionization detector (FID) with the aid of a TD system. In the TD-GC-MS analysis, calibration results were evaluated in two different modes, namely total ion chromatogram (TIC) and extracted ion chromatogram (EIC). In both FID and MS, the elution order of investigated odorants complied with the retention time index (RTI) values for the polar column with a coefficient of determination (R(2)) at or above 0.99. As a means to validate our detection approach, environmental samples from a bathroom and manhole (vacuum samples) as well as cat stool and wastewater (headspace samples) were also collected. The ST-TD method tested for the concurrent analysis of diverse odorants allowed us to measure a list of offensive odorants from those samples. PMID:24070624

  14. The Living With a Star Program and International Collaboration

    NASA Technical Reports Server (NTRS)

    Thompson, Barbara J.

    2004-01-01

    International cooperation has long been a vital element in the scientific investigation of solar variability and its impact on Earth and the space environment. Recently a new international cooperative initiative in solar-terrestrial physics has been established by the major space agencies of the world, called the International Living With a Star (ILWS) program. ILWS is a follow-on to the highly successful International Solar Terrestrial Physics (ISTP) program, which derived its success from the ,cooperation of a number of international partners. ISTP, with its steady flow of discoveries and new knowledge in solar-terrestrial physics, has laid the foundation for the coordinated study of the Sun-Earth system as a connected stellar-planetary system and as humanity's home. The first step in establishing ILWS was taken in the fall of 2000 when funding was approved for the NASA's LWS program whose 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".

  15. Monitoring of potential cytotoxic and inhibitory effects of titanium dioxide using on-line and non-invasive cell-based impedance spectroscopy.

    PubMed

    Male, Keith B; Hamzeh, Mahsa; Montes, Johnny; Leung, Alfred C W; Luong, John H T

    2013-05-13

    Titanium dioxide (TiO2) nanoparticles (NPs) with different sizes and structures were probed for plausible cytotoxicity using electric cell-substrate impedance sensing (ECIS), a non-invasive and on-line procedure for continuous monitoring of cytotoxicity. For insect cells (Spodoptera frugiperda Sf9), the ECIS50 values, i.e., the concentration required to achieve 50% inhibition of the response, differed depending on the size and shape of the TiO2 nanostructure. The lowest ECIS50 value (158 ppm) was observed for the needle shaped rutile TiO2 (10 nm×40 nm, 15.5 nm nominal particle size), followed by 211 ppm for P-25 (34.1 nm, 80% anatase and 20% rutile), 302 ppm for MTI5 (5.9 nm, 99% anatase) and 417 ppm for Hombitan LW-S bulk TiO2 (169.5 nm, 99% anatase). Exposure of TiO2 NPs to UV light at 254 nm or 365 nm exhibited no significant effect on the ECIS50 value due to the aggregation of TiO2 NPs with diminishing photocatalytic activities. Chinese hamster lung fibroblast V79 cells, exhibited no significant cytotoxicity/inhibition up to 400 ppm with P25, MTI5 and bulk TiO2. However, a noticeable inhibitory effect was observed (ECIS50 value of 251 ppm) with rutile TiO2 as cell spreading on the electrode surface was prevented. PMID:23622968

  16. For whales and seals the ocean is not blue: a visual pigment loss in marine mammals.

    PubMed

    Peichl, L; Behrmann, G; Kröger, R H

    2001-04-01

    Most terrestrial mammals have colour vision based on two spectrally different visual pigments located in two types of retinal cone photoreceptors, i.e. they are cone dichromats with long-to-middle-wave-sensitive (commonly green) L-cones and short-wave-sensitive (commonly blue) S-cones. With visual pigment-specific antibodies, we here demonstrate an absence of S-cones in the retinae of all whales and seals studied. The sample includes seven species of toothed whales (Odontoceti) and five species of marine carnivores (eared and earless seals). These marine mammals have only L-cones (cone monochromacy) and hence are essentially colour-blind. For comparison, the study also includes the wolf, ferret and European river otter (Carnivora) as well as the mouflon and pygmy hippopotamus (Artiodactyla), close terrestrial relatives of the seals and whales, respectively. These have a normal complement of S-cones and L-cones. The S-cone loss in marine species from two distant mammalian orders strongly argues for convergent evolution and an adaptive advantage of that trait in the marine visual environment. To us this suggests that the S-cones may have been lost in all whales and seals. However, as the spectral composition of light in clear ocean waters is increasingly blue-shifted with depth, an S-cone loss would seem particularly disadvantageous. We discuss some hypotheses to explain this paradox. PMID:11328346

  17. Circadian regulation of chick electroretinogram: effects of pinealectomy and exogenous melatonin.

    PubMed

    McGoogan, J M; Cassone, V M

    1999-11-01

    Melatonin is an important component of the avian circadian system. This study investigates the effects of pinealectomy (Pin-X) and melatonin implantation (Mel) on electroretinogram (ERG) rhythms in chicks. Feeding rhythms were monitored to obtain a phase reference for ERG recordings. Pin-X and Mel had little or no effect on feeding rhythms. Sham-operated Pin-X and vehicle implantation had no effect on ERG rhythms in the light-dark (LD) cycle or constant darkness (DD). ERG a- and b-wave amplitudes were higher during the day than during the night. The a- and b-wave implicit times were shorter during the day than during the night. a-Wave sensitivity was higher during the night than during the day, whereas b-wave sensitivity was not rhythmic. Pin-X abolished the circadian rhythm of b-wave amplitude and implicit time in DD but had no effect on a-wave rhythmicity. Mel abolished the rhythm of b-wave amplitude and of a- and b-wave implicit time in DD. Neither treatment affected ERG in LD. These results suggest that the circadian system regulates rhythmic visual function in the retina at least partially through Mel. The role played by the pineal gland and Mel may be specific to some physiological modalities (e.g., vision) while not influencing others (e.g., feeding). PMID:10564215

  18. Extreme retinal remodeling triggered by light damage: implications for age related macular degeneration

    PubMed Central

    Jones, B.W.; Watt, C.B.; Vazquez-Chona, F.; Vaughan, D.K.; Organisciak, D.T.

    2008-01-01

    Purpose Our objective was to comprehensively assess the nature and chronology of neural remodeling in retinal degenerations triggered by light-induced retinal damage (LIRD) in adult albino rodents. Our primary hypothesis is that all complete photoreceptor degenerations devolve to extensive remodeling. An hypothesis emergent from data analysis is that the LIRD model closely mimics late-stage atrophic age relared macular degeneration (AMD). Methods Sprague-Dawley (SD) rats received intense light exposures of varied durations and survival times ranging from 0 to 240 days. Remodeling was visualized by computational molecular phenotyping (CMP) of a small molecule library: 4-aminobutyrate (?), arginine (R), aspartate (D), glutamate (E), glutamine (Q), glutathione (J), glycine (G), and taurine (?). This library was augmented by probes for key proteins such as rod opsin, cone opsin and cellular retinal binding protein (CRALBP). Quantitative CMP was used to profile 160 eyes from 86 animals in over 6,000 sections. Results The onset of remodeling in LIRD retinas is rapid, with immediate signs of metabolic stress in photoreceptors, the retinal pigmented epithelium (RPE), the choriocapillaris, and Müller cells. In particular, anomalous elevated aspartate levels appear to be an early stress marker in photoreceptors. After the stress phase, LIRD progresses to focal photoreceptor degeneration within 14 days and extensive remodeling by 60 days. RPE and choriocapillaris losses parallel Müller cell distal seal formation, with progressive neuronal migration, microneuroma evolution, fluid channel formation, and slow neuronal death. The remaining retina in advanced light damage can be classified as survivor, light damage (LD), or decimated zones where massive Müller cell and neuronal emigration into the choroid leaves a retina depleted of neurons and Müller cells. These zones and their transitions closely resemble human geographic atrophy. Across these zones, Müller cells manifest extreme changes in the definitive Müller cell ?QE signature, as well as CRALBP and arginine signals. Conclusions LIRD retinas manifest remodeling patterns of genetic retinal degeneration models, but involve no developmental complexities, and are ultimately more aggressive, devastating the remaining neural retina. The decimation of the neural retina via cell emigration through the perforated retina-choroid interface is a serious denouement. If focal remodeling in LIRD accurately profiles late stage atrophic age-related macular degenerations, it augurs poorly for simple molecular interventions. Indeed, the LIRD profile in the SD rat manifests more similarities to advanced human atrophic AMD than most genetically or immunologically induced murine models of AMD. PMID:18483561

  19. Impact of duplicate gene copies on phylogenetic analysis and divergence time estimates in butterflies

    PubMed Central

    Pohl, Nélida; Sison-Mangus, Marilou P; Yee, Emily N; Liswi, Saif W; Briscoe, Adriana D

    2009-01-01

    Background The increase in availability of genomic sequences for a wide range of organisms has revealed gene duplication to be a relatively common event. Encounters with duplicate gene copies have consequently become almost inevitable in the context of collecting gene sequences for inferring species trees. Here we examine the effect of incorporating duplicate gene copies evolving at different rates on tree reconstruction and time estimation of recent and deep divergences in butterflies. Results Sequences from ultraviolet-sensitive (UVRh), blue-sensitive (BRh), and long-wavelength sensitive (LWRh) opsins,EF-1? and COI were obtained from 27 taxa representing the five major butterfly families (5535 bp total). Both BRh and LWRh are present in multiple copies in some butterfly lineages and the different copies evolve at different rates. Regardless of the phylogenetic reconstruction method used, we found that analyses of combined data sets using either slower or faster evolving copies of duplicate genes resulted in a single topology in agreement with our current understanding of butterfly family relationships based on morphology and molecules. Interestingly, individual analyses of BRh and LWRh sequences also recovered these family-level relationships. Two different relaxed clock methods resulted in similar divergence time estimates at the shallower nodes in the tree, regardless of whether faster or slower evolving copies were used, with larger discrepancies observed at deeper nodes in the phylogeny. The time of divergence between the monarch butterfly Danaus plexippus and the queen D. gilippus (15.3–35.6 Mya) was found to be much older than the time of divergence between monarch co-mimic Limenitis archippus and red-spotted purple L. arthemis (4.7–13.6 Mya), and overlapping with the time of divergence of the co-mimetic passionflower butterflies Heliconius erato and H. melpomene (13.5–26.1 Mya). Our family-level results are congruent with recent estimates found in the literature and indicate an age of 84–113 million years for the divergence of all butterfly families. Conclusion These results are consistent with diversification of the butterfly families following the radiation of angiosperms and suggest that some classes of opsin genes may be usefully employed for both phylogenetic reconstruction and divergence time estimation. PMID:19439087

  20. Differential Loss of Prolyl Isomerase or Chaperone Activity of Ran-binding Protein 2 (Ranbp2) Unveils Distinct Physiological Roles of Its Cyclophilin Domain in Proteostasis*

    PubMed Central

    Cho, Kyoung-in; Patil, Hemangi; Senda, Eugene; Wang, Jessica; Yi, Haiqing; Qiu, Sunny; Yoon, Dosuk; Yu, Minzhong; Orry, Andrew; Peachey, Neal S.; Ferreira, Paulo A.

    2014-01-01

    The immunophilins, cyclophilins, catalyze peptidyl cis-trans prolyl-isomerization (PPIase), a rate-limiting step in protein folding and a conformational switch in protein function. Cyclophilins are also chaperones. Noncatalytic mutations affecting the only cyclophilins with known but distinct physiological substrates, the Drosophila NinaA and its mammalian homolog, cyclophilin-B, impair opsin biogenesis and cause osteogenesis imperfecta, respectively. However, the physiological roles and substrates of most cyclophilins remain unknown. It is also unclear if PPIase and chaperone activities reflect distinct cyclophilin properties. To elucidate the physiological idiosyncrasy stemming from potential cyclophilin functions, we generated mice lacking endogenous Ran-binding protein-2 (Ranbp2) and expressing bacterial artificial chromosomes of Ranbp2 with impaired C-terminal chaperone and with (Tg-Ranbp2WT-HA) or without PPIase activities (Tg-Ranbp2R2944A-HA). The transgenic lines exhibit unique effects in proteostasis. Either line presents selective deficits in M-opsin biogenesis with its accumulation and aggregation in cone photoreceptors but without proteostatic impairment of two novel Ranbp2 cyclophilin partners, the cytokine-responsive effectors, STAT3/STAT5. Stress-induced STAT3 activation is also unaffected in Tg-Ranbp2R2944A-HA::Ranbp2?/?. Conversely, proteomic analyses found that the multisystem proteinopathy/amyotrophic lateral sclerosis proteins, heterogeneous nuclear ribonucleoproteins A2/B1, are down-regulated post-transcriptionally only in Tg-Ranbp2R2944A-HA::Ranbp2?/?. This is accompanied by the age- and tissue-dependent reductions of diubiquitin and ubiquitylated proteins, increased deubiquitylation activity, and accumulation of the 26 S proteasome subunits S1 and S5b. These manifestations are absent in another line, Tg-Ranbp2CLDm-HA::Ranbp2?/?, harboring SUMO-1 and S1-binding mutations in the Ranbp2 cyclophilin-like domain. These results unveil distinct mechanistic and biological links between PPIase and chaperone activities of Ranbp2 cyclophilin toward proteostasis of selective substrates and with novel therapeutic potential. PMID:24403063

  1. Evolution of Eye Morphology and Rhodopsin Expression in the Drosophila melanogaster Species Subgroup

    PubMed Central

    Hopfen, Corinna; Hilbrant, Maarten; Ramos-Womack, Margarita; Murat, Sophie; Schönauer, Anna; Herbert, Samantha L.; Nunes, Maria D. S.; Arif, Saad; Breuker, Casper J.; Schlötterer, Christian; Mitteroecker, Philipp; McGregor, Alistair P.

    2012-01-01

    A striking diversity of compound eye size and shape has evolved among insects. The number of ommatidia and their size are major determinants of the visual sensitivity and acuity of the compound eye. Each ommatidium is composed of eight photoreceptor cells that facilitate the discrimination of different colours via the expression of various light sensitive Rhodopsin proteins. It follows that variation in eye size, shape, and opsin composition is likely to directly influence vision. We analyzed variation in these three traits in D. melanogaster, D. simulans and D. mauritiana. We show that D. mauritiana generally has larger eyes than its sibling species, which is due to a combination of larger ommatidia and more ommatidia. In addition, intra- and inter-specific differences in eye size among D. simulans and D. melanogaster strains are mainly caused by variation in ommatidia number. By applying a geometric morphometrics approach to assess whether the formation of larger eyes influences other parts of the head capsule, we found that an increase in eye size is associated with a reduction in the adjacent face cuticle. Our shape analysis also demonstrates that D. mauritiana eyes are specifically enlarged in the dorsal region. Intriguingly, this dorsal enlargement is associated with enhanced expression of rhodopsin 3 in D. mauritiana. In summary, our data suggests that the morphology and functional properties of the compound eyes vary considerably within and among these closely related Drosophila species and may be part of coordinated morphological changes affecting the head capsule. PMID:22662147

  2. Zebrafish Lbh-like Is Required for Otx2-mediated Photoreceptor Differentiation

    PubMed Central

    Li, Wen-Hua; Zhou, Li; Li, Zhi; Wang, Yang; Shi, Jian-Tao; Yang, Yan-Jing; Gui, Jian-Fang

    2015-01-01

    The homeobox transcription factor orthodenticle homolog 2 (otx2) is supposed as an organizer that orchestrates a transcription factor network during photoreceptor development. However, its regulation in the process remains unclear. In this study, we have identified a zebrafish limb bud and heart-like gene (lbh-like), which is expressed initially at 30 hours post fertilization (hpf) in the developing brain and eyes. Lbh-like knockdown by morpholinos specifically inhibits expression of multiple photoreceptor-specific genes, such as opsins, gnat1, gnat2 and irbp. Interestingly, otx2 expression in the morphants is not significantly reduced until 32 hpf when lbh-like begins to express, but its expression level in 72 hpf morphants is higher than that in wild type embryos. Co-injection of otx2 and its downstream target neuroD mRNAs can rescue the faults in eyes of Lbh-like morphants. Combined with the results of promoter-reporter assay, we suggest that lbh-like is a new regulator of photoreceptor differentiation directly through affecting otx2 expression in zebrafish. Furthermore, knockdown of lbh-like increases the activity of Notch pathway and perturbs the balance among proliferation, differentiation and survival of photoreceptor precursors. PMID:25999792

  3. A novel function for the pineal organ in the control of swim depth in the Atlantic halibut larva

    NASA Astrophysics Data System (ADS)

    Novales Flamarique, Iñigo

    2002-02-01

    The pineal organ of vertebrates is a photo-sensitive structure that conveys photoperiod information to the brain. This information influences circadian rhythm and related metabolic processes such as thermoregulation, hatching time, body growth, and the timing of reproduction. This study demonstrates extra-ocular light responses that control swim depth in the larva of the Atlantic halibut, Hyppoglosus hyppoglosus. Young larvae without a functional eye (<29 days) swim upwards after an average delay of 5 s following the onset of a downwelling light stimulus, but sink downwards a few seconds later. Older larvae (>=29 days), which possess a functional eye, swim immediately downwards (microsecond delay) following the onset of the light stimulus, but proceed to swim upwards several seconds later. These two response patterns are thus opposite in polarity and have different time kinetics. Because the pineal organ of the Atlantic halibut develops during the embryonic stage, and because it is the only centre in the brain that expresses functional visual pigments (opsins) at early larval stages, it is the only photosensory organ capable of generating the extra-ocular responses observed.

  4. Transgenic expression of a GFP-rhodopsin COOH-terminal fusion protein in zebrafish rod photoreceptors.

    PubMed

    Perkins, Brian D; Kainz, Pamela M; O'Malley, Donald M; Dowling, John E

    2002-01-01

    To facilitate the identification and characterization of mutations affecting the retina and photoreceptors in the zebrafish, a transgene expressing green fluorescent protein (GFP) fused to the C-terminal 44 amino acids of Xenopus rhodopsin (Tam et al., 2000) under the control of the 1.3-kb proximal Xenopus opsin promoter was inserted into the zebrafish genome. GFP expression was easily observed in a ventral patch of retinal cells at 4 days postfertilization (dpf). Between 45-50% of the progeny from the F1, F2, and F3 generations expressed the transgene, consistent with a single integration event following microinjection. Immunohistochemical analysis demonstrated that GFP is expressed exclusively in rod photoreceptors and not in the UV, blue, or red/green double cones. Furthermore, GFP is localized to the rod outer segments with little to no fluorescence in the rod inner segments, rod cell bodies, or rod synapse regions, indicating proper targeting and transport of the GFP fusion protein. Application of exogenous retinoic acid (RA) increased the number of GFP-expressing cells throughout the retina, and possibly the level of expressed rhodopsin. When bred to a zebrafish rod degeneration mutant, fewer GFP-expressing rods were seen in living mutants as compared to wild-type siblings. This transgenic line will facilitate the search for recessive and dominant mutations affecting rod photoreceptor development and survival as well as proper rhodopsin expression, targeting, and transport. PMID:12511087

  5. Transgenic expression of a GFP-rhodopsin COOH-terminal fusion protein in zebrafish rod photoreceptors.

    PubMed

    Perkins, Brian D; Kainz, Pamela M; O'Malley, Donald M; Dowling, John E

    2002-01-01

    To facilitate the identification and characterization of mutations affecting the retina and photoreceptors in the zebrafish, a transgene expressing green fluorescent protein (GFP) fused to the C-terminal 44 amino acids of Xenopus rhodopsin (Tam et al., 2000) under the control of the 1.3-kb proximal Xenopus opsin promoter was inserted into the zebrafish genome. GFP expression was easily observed in a ventral patch of retinal cells at 4 days postfertilization (dpf). Between 45-50% of the progeny from the F1, F2, and F3 generations expressed the transgene, consistent with a single integration event following microinjection. Immunohistochemical analysis demonstrated that GFP is expressed exclusively in rod photoreceptors and not in the UV, blue, or red/green double cones. Furthermore, GFP is localized to the rod outer segments with little to no fluorescence in the rod inner segments, rod cell bodies, or rod synapse regions, indicating proper targeting and transport of the GFP fusion protein. Application of exogenous retinoic acid (RA) increased the number of GFP-expressing cells throughout the retina, and possibly the level of expressed rhodopsin. When bred to a zebrafish rod degeneration mutant, fewer GFP-expressing rods were seen in living mutants as compared to wild-type siblings. This transgenic line will facilitate the search for recessive and dominant mutations affecting rod photoreceptor development and survival as well as proper rhodopsin expression, targeting, and transport. PMID:12392175

  6. Phylogenetic and transcriptomic analyses reveal the evolution of bioluminescence and light detection in marine deep-sea shrimps of the family Oplophoridae (Crustacea: Decapoda).

    PubMed

    Wong, Juliet M; Pérez-Moreno, Jorge L; Chan, Tin-Yam; Frank, Tamara M; Bracken-Grissom, Heather D

    2015-02-01

    Bioluminescence is essential to the survival of many organisms, particularly in the deep sea where light is limited. Shrimp of the family Oplophoridae exhibit a remarkable mechanism of bioluminescence in the form of a secretion used for predatory defense. Three of the ten genera possess an additional mode of bioluminescence in the form of light-emitting organs called photophores. Phylogenetic analyses can be useful for tracing the evolution of bioluminescence, however, the few studies that have attempted to reconcile the relationships within Oplophoridae have generated trees with low-resolution. We present the most comprehensive phylogeny of Oplophoridae to date, with 90% genera coverage using seven genes (mitochondrial and nuclear) across 30 oplophorid species. We use our resulting topology to trace the evolution of bioluminescence within Oplophoridae. Previous studies have suggested that oplophorid visual systems may be tuned to differentiate the separate modes of bioluminescence. While all oplophorid shrimp possess a visual pigment sensitive to blue-green light, only those bearing photophores have an additional pigment sensitive to near-ultraviolet light. We attempt to characterize opsins, visual pigment proteins essential to light detection, in two photophore-bearing species (Systellaspis debilis and Oplophorus gracilirostris) and make inferences regarding their function and evolutionary significance. PMID:25482362

  7. CRALBP supports the mammalian retinal visual cycle and cone vision

    PubMed Central

    Xue, Yunlu; Shen, Susan Q.; Jui, Jonathan; Rupp, Alan C.; Byrne, Leah C.; Hattar, Samer; Flannery, John G.; Corbo, Joseph C.; Kefalov, Vladimir J.

    2015-01-01

    Mutations in the cellular retinaldehyde–binding protein (CRALBP, encoded by RLBP1) can lead to severe cone photoreceptor–mediated vision loss in patients. It is not known how CRALBP supports cone function or how altered CRALBP leads to cone dysfunction. Here, we determined that deletion of Rlbp1 in mice impairs the retinal visual cycle. Mice lacking CRALBP exhibited M-opsin mislocalization, M-cone loss, and impaired cone-driven visual behavior and light responses. Additionally, M-cone dark adaptation was largely suppressed in CRALBP-deficient animals. While rearing CRALBP-deficient mice in the dark prevented the deterioration of cone function, it did not rescue cone dark adaptation. Adeno-associated virus–mediated restoration of CRALBP expression specifically in Müller cells, but not retinal pigment epithelial (RPE) cells, rescued the retinal visual cycle and M-cone sensitivity in knockout mice. Our results identify Müller cell CRALBP as a key component of the retinal visual cycle and demonstrate that this pathway is important for maintaining normal cone–driven vision and accelerating cone dark adaptation. PMID:25607845

  8. T-box Transcription Regulator Tbr2 Is Essential for the Formation and Maintenance of Opn4/Melanopsin-Expressing Intrinsically Photosensitive Retinal Ganglion Cells

    PubMed Central

    Li, Hongyan; Zhang, Zhijing; Kiyama, Takae; Panda, Satchidananda; Hattar, Samer; Ribelayga, Christophe P.; Mills, Stephen L.

    2014-01-01

    Opsin 4 (Opn4)/melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs) play a major role in non-image-forming visual system. Although advances have been made in understanding their morphological features and functions, the molecular mechanisms that regulate their formation and survival remain unknown. Previously, we found that mouse T-box brain 2 (Tbr2) (also known as Eomes), a T-box-containing transcription factor, was expressed in a subset of newborn RGCs, suggesting that it is involved in the formation of specific RGC subtypes. In this in vivo study, we used complex mouse genetics, single-cell dye tracing, and behavioral analyses to determine whether Tbr2 regulates ipRGC formation and survival. Our results show the following: (1) Opn4 is expressed exclusively in Tbr2-positive RGCs; (2) no ipRGCs are detected when Tbr2 is genetically ablated before RGC specification; and (3) most ipRGCs are eliminated when Tbr2 is deleted in established ipRGCs. The few remaining ipRGCs display abnormal dendritic morphological features and functions. In addition, some Tbr2-expressing RGCs can activate Opn4 expression on the loss of native ipRGCs, suggesting that Tbr2-expressing RGCs may serve as a reservoir of ipRGCs to regulate the number of ipRGCs and the expression levels of Opn4. PMID:25253855

  9. The hippocampo-amygdala control of contextual fear expression is affected in a model of intellectual disability.

    PubMed

    Zhang, Chun-Lei; Houbaert, Xander; Lepleux, Marilyn; Deshors, Melissa; Normand, Elisabeth; Gambino, Frédéric; Herzog, Etienne; Humeau, Yann

    2014-08-27

    The process of learning mainly depends on the ability to store new information, while the ability to retrieve this information and express appropriate behaviors are also crucial for the adaptation of individuals to environmental cues. Thereby, all three components contribute to the cognitive fitness of an individual. While a lack of behavioral adaptation is a recurrent trait of intellectually disabled patients, discriminating between memory formation, memory retrieval or behavioral expression deficits is not easy to establish. Here, we report some deficits in contextual fear behavior in knockout mice for the intellectual disability gene Il1rapl1. Functional in vivo experiments revealed that the lack of conditioned response resulted from a local inhibitory to excitatory (I/E) imbalance in basolateral amygdala (BLA) consecutive to a loss of excitatory drive onto BLA principal cells by caudal hippocampus axonal projections. A normalization of the fear behavior was obtained in adult mutant mice following opsin-based in vivo synaptic priming of hippocampo-BLA synapses in adult il1rapl1 knockout mice, indicating that synaptic efficacy at hippocampo-BLA projections is crucial for contextual fear memory expression. Importantly, because this restoration was obtained after the learning phase, our results suggest that some of the genetically encoded cognitive deficits in humans may originate from a lack of restitution of genuinely formed memories rather than an exclusive inability to store new memories. PMID:25158900

  10. Monte Carlo loop refinement and virtual screening of the thyroid-stimulating hormone receptor transmembrane domain

    PubMed Central

    Ali, M. Rejwan; Latif, Rauf; Davies, Terry F.; Mezei, Mihaly

    2015-01-01

    Metropolis Monte Carlo (MMC) loop refinement has been performed on the three extracellular loops (ECLs) of rhodopsin and opsin-based homology models of the thyroid-stimulating hormone receptor transmembrane domain, a class A type G protein-coupled receptor. The Monte Carlo sampling technique, employing torsion angles of amino acid side chains and local moves for the six consecutive backbone torsion angles, has previously reproduced the conformation of several loops with known crystal structures with accuracy consistently less than 2 Å. A grid-based potential map, which includes van der Waals, electrostatics, hydrophobic as well as hydrogen-bond potentials for bulk protein environment and the solvation effect, has been used to significantly reduce the computational cost of energy evaluation. A modified sigmoidal distance-dependent dielectric function has been implemented in conjunction with the desolvation and hydrogen-bonding terms. A long high-temperature simulation with 2 kcal/mol repulsion potential resulted in extensive sampling of the conformational space. The slow annealing leading to the low-energy structures predicted secondary structure by the MMC technique. Molecular docking with the reported agonist reproduced the binding site within 1.5 Å. Virtual screening performed on the three lowest structures showed that the ligand-binding mode in the inter-helical region is dependent on the ECL conformations. PMID:25012978

  11. Transformation of cone precursors to functional rod photoreceptors by bZIP transcription factor NRL

    PubMed Central

    Oh, Edwin C. T.; Khan, Naheed; Novelli, Elena; Khanna, Hemant; Strettoi, Enrica; Swaroop, Anand

    2007-01-01

    Networks of transcriptional regulatory proteins dictate specification of neural lineages from multipotent retinal progenitors. Rod photoreceptor differentiation requires the basic motif–leucine zipper (bZIP) transcription factor NRL, because loss of Nrl in mice (Nrl?/?) results in complete transformation of rods to functional cones. To examine the role of NRL in cell fate determination, we generated transgenic mice that express Nrl under the control of Crx promoter in postmitotic photoreceptor precursors of WT and Nrl?/? retina. We show that NRL expression, in both genetic backgrounds, leads to a functional retina with only rod photoreceptors. The absence of cones does not alter retinal lamination, although cone synaptic circuitry is now recruited by rods. Ectopic expression of NRL in developing cones can also induce rod-like characteristics and partially suppress cone-specific gene expression. We show that NRL is associated with specific promoter sequences in Thrb (encoding TR?2 transcription factor required for M-cone differentiation) and S-opsin and may, therefore, directly participate in transcriptional suppression of cone development. Our studies establish that NRL is not only essential but is sufficient for rod differentiation and that postmitotic photoreceptor precursors are competent to make binary decisions during early retinogenesis. PMID:17242361

  12. CRYPTOCHROME-mediated phototransduction by modulation of the potassium ion channel ?-subunit redox sensor

    PubMed Central

    Fogle, Keri J.; Baik, Lisa S.; Houl, Jerry H.; Tran, Tri T.; Roberts, Logan; Dahm, Nicole A.; Cao, Yu; Zhou, Ming; Holmes, Todd C.

    2015-01-01

    Blue light activation of the photoreceptor CRYPTOCHROME (CRY) evokes rapid depolarization and increased action potential firing in a subset of circadian and arousal neurons in Drosophila melanogaster. Here we show that acute arousal behavioral responses to blue light significantly differ in mutants lacking CRY, as well as mutants with disrupted opsin-based phototransduction. Light-activated CRY couples to membrane depolarization via a well conserved redox sensor of the voltage-gated potassium (K+) channel ?-subunit (Kv?) Hyperkinetic (Hk). The neuronal light response is almost completely absent in hk?/? mutants, but is functionally rescued by genetically targeted neuronal expression of WT Hk, but not by Hk point mutations that disable Hk redox sensor function. Multiple K+ channel ?-subunits that coassemble with Hk, including Shaker, Ether-a-go-go, and Ether-a-go-go–related gene, are ion conducting channels for CRY/Hk-coupled light response. Light activation of CRY is transduced to membrane depolarization, increased firing rate, and acute behavioral responses by the Kv? subunit redox sensor. PMID:25646452

  13. An investigation of scavenger receptor A mediated leukocyte binding to polyanionic and uncharged polymer hydrogels.

    PubMed

    Love, Ryan J; Patenaude, Mathew; Dorrington, Michael; Bowdish, Dawn M E; Hoare, Todd; Jones, Kim S

    2015-05-01

    Cell adhesion to biomaterials can be mediated in part by mechanisms aside from the traditionally recognized opsinization and integrin binding mechanisms. In this study, we investigated the role of scavenger receptor A (SR-A) in leukocyte binding to a series of well-controlled polyanionic and uncharged hydrogels based on a poly(N-isopropylacrylamide) backbone. The hydrogels were injected in the peritoneal cavity of SR-A knockout (KO) and wild-type mice using a minimally invasive procedure and allowed to set in situ. After 24 h, the hydrogels were recovered and analyzed, the peritoneal cavity was lavaged, and cytokine concentrations were assessed by ELISA. The polyanionic hydrogels retrieved from the KO animals were found to be completely devoid of adherent leukocytes, which were present in other materials regardless of the mouse strain in which they were injected. Results from a subsequent in vitro cellular adhesion study with a RAW264.7 cell line failed to yield a similarly definitive role for SR-A in the cellular binding of a polyanionic hydrogel. Taken together, the results of this study show that SR-A mediates leukocyte adhesion to a polyanionic hydrogel in the peritoneal cavity, but other adhesion mechanisms contribute to cellular binding in vitro. PMID:25087871

  14. Computer-assisted counting of retinal cells by automatic segmentation after TV denoising

    PubMed Central

    2013-01-01

    Background Quantitative evaluation of mosaics of photoreceptors and neurons is essential in studies on development, aging and degeneration of the retina. Manual counting of samples is a time consuming procedure while attempts to automatization are subject to various restrictions from biological and preparation variability leading to both over- and underestimation of cell numbers. Here we present an adaptive algorithm to overcome many of these problems. Digital micrographs were obtained from cone photoreceptor mosaics visualized by anti-opsin immuno-cytochemistry in retinal wholemounts from a variety of mammalian species including primates. Segmentation of photoreceptors (from background, debris, blood vessels, other cell types) was performed by a procedure based on Rudin-Osher-Fatemi total variation (TV) denoising. Once 3 parameters are manually adjusted based on a sample, similarly structured images can be batch processed. The module is implemented in MATLAB and fully documented online. Results The object recognition procedure was tested on samples with a typical range of signal and background variations. We obtained results with error ratios of less than 10% in 16 of 18 samples and a mean error of less than 6% compared to manual counts. Conclusions The presented method provides a traceable module for automated acquisition of retinal cell density data. Remaining errors, including addition of background items, splitting or merging of objects might be further reduced by introduction of additional parameters. The module may be integrated into extended environments with features such as 3D-acquisition and recognition. PMID:24138794

  15. Optical suppression of drug-evoked phasic dopamine release

    PubMed Central

    McCutcheon, James E.; Cone, Jackson J.; Sinon, Christopher G.; Fortin, Samantha M.; Kantak, Pranish A.; Witten, Ilana B.; Deisseroth, Karl; Stuber, Garret D.; Roitman, Mitchell F.

    2014-01-01

    Brief fluctuations in dopamine concentration (dopamine transients) play a key role in behavior towards rewards, including drugs of abuse. Drug-evoked dopamine transients may result from actions at both dopamine cell bodies and dopamine terminals. Inhibitory opsins can be targeted to dopamine neurons permitting their firing activity to be suppressed. However, as dopamine transients can become uncoupled from firing, it is unknown whether optogenetic hyperpolarization at the level of the soma is able to suppress dopamine transients. Here, we used in vivo fast-scan cyclic voltammetry to record transients evoked by cocaine and raclopride in nucleus accumbens (NAc) of urethane-anesthetized rats. We targeted halorhodopsin (NpHR) specifically to dopamine cells by injecting Cre-inducible virus into ventral tegmental area (VTA) of transgenic rats that expressed Cre recombinase under control of the tyrosine hydroxylase promoter (TH-Cre+ rats). Consistent with previous work, co-administration of cocaine and raclopride led to the generation of dopamine transients in NAc shell. Illumination of VTA with laser strongly suppressed the frequency of transients in NpHR-expressing rats, but not in control rats. Laser did not have any effect on amplitude of transients. Thus, optogenetics can effectively reduce the occurrence of drug-evoked transients and is therefore a suitable approach for studying the functional role of such transients in drug-associated behavior. PMID:25278845

  16. Optetrode: a multichannel readout for optogenetic control in freely moving mice

    PubMed Central

    Anikeeva, Polina; Andalman, Aaron S; Witten, Ilana; Warden, Melissa; Goshen, Inbal; Grosenick, Logan; Gunaydin, Lisa A; Frank, Loren M; Deisseroth, Karl

    2014-01-01

    Recent advances in optogenetics have improved the precision with which defined circuit elements can be controlled optically in freely moving mammals; in particular, recombinase-dependent opsin viruses, used with a growing pool of transgenic mice expressing recombinases, allow manipulation of specific cell types. However, although optogenetic control has allowed neural circuits to be manipulated in increasingly powerful ways, combining optogenetic stimulation with simultaneous multichannel electrophysiological readout of isolated units in freely moving mice remains a challenge. We designed and validated the optetrode, a device that allows for colocalized multi-tetrode electrophysiological recording and optical stimulation in freely moving mice. Optetrode manufacture employs a unique optical fiber-centric coaxial design approach that yields a lightweight (2 g), compact and robust device that is suitable for behaving mice. This low-cost device is easy to construct (2.5 h to build without specialized equipment). We found that the drive design produced stable high-quality recordings and continued to do so for at least 6 weeks following implantation. We validated the optetrode by quantifying, for the first time, the response of cells in the medial prefrontal cortex to local optical excitation and inhibition, probing multiple different genetically defined classes of cells in the mouse during open field exploration. PMID:22138641

  17. Exploration of genetically encoded voltage indicators based on a chimeric voltage sensing domain

    PubMed Central

    Mishina, Yukiko; Mutoh, Hiroki; Song, Chenchen; Knöpfel, Thomas

    2014-01-01

    Deciphering how the brain generates cognitive function from patterns of electrical signals is one of the ultimate challenges in neuroscience. To this end, it would be highly desirable to monitor the activities of very large numbers of neurons while an animal engages in complex behaviors. Optical imaging of electrical activity using genetically encoded voltage indicators (GEVIs) has the potential to meet this challenge. Currently prevalent GEVIs are based on the voltage-sensitive fluorescent protein (VSFP) prototypical design or on the voltage-dependent state transitions of microbial opsins. We recently introduced a new VSFP design in which the voltage-sensing domain (VSD) is sandwiched between a fluorescence resonance energy transfer pair of fluorescent proteins (termed VSFP-Butterflies) and also demonstrated a series of chimeric VSD in which portions of the VSD of Ciona intestinalis voltage-sensitive phosphatase are substituted by homologous portions of a voltage-gated potassium channel subunit. These chimeric VSD had faster sensing kinetics than that of the native Ci-VSD. Here, we describe a new set of VSFPs that combine chimeric VSD with the Butterfly structure. We show that these chimeric VSFP-Butterflies can report membrane voltage oscillations of up to 200 Hz in cultured cells and report sensory evoked cortical population responses in living mice. This class of GEVIs may be suitable for imaging of brain rhythms in behaving mammalians. PMID:25324718

  18. Lateral and radial growth uncoupled in reaggregated retinospheroids of embryonic avian retina.

    PubMed

    Willbold, E; Mansky, P; Layer, P G

    1996-12-01

    According to an earlier resented model (Layer and Willbold, Int. Rev. Cytol. 146: 1-47, 1993), growth of the retina can be conceived of as an areal increase of an epithelial tissue sheet ("lateralization") plus a concomitant establishment of the layered retina ("radialization"). To provide further support for this model, here we have reaggregated dissociated retinal plus pigmented cells from chick or quail embryos and observed their development into histotypic three-dimensional spheres in rotation culture. These so-called stratospheroids consist of a continuous fully laminated retinal part with a coiled-up pigmented epithelial core. Using BrdU-labeling, we show that radial growth, i.e. the sequential production of cell types in spheroids, is comparable to normal vitreal-scleral retinogenesis. The region next to the pigmented epithelial core represents a "lateral growth zone" (equivalent to an ora serrata in vivo), where mitotic cell numbers are highest, even when in the laminated part proliferation has already ceased. Gradients of lateral differentiation emanate from this growth zone into the retinal tissue, as revealed by immunostaining of the photoreceptor protein opsin and the cell recognition molecule F11. Moreover, we found that stratospheroids derived from older embryos consist only of a hollow monolayered neuroepithelium which develops in the absence of any radial growth. This indicates that cell production is sustained longer in lateral than in radial direction. These differently staged stratospheroids will be excellent models to characterize genes involved in the regulation of lateral and radial growth processes. PMID:9032020

  19. Rax Homeoprotein Regulates Photoreceptor Cell Maturation and Survival in Association with Crx in the Postnatal Mouse Retina.

    PubMed

    Irie, Shoichi; Sanuki, Rikako; Muranishi, Yuki; Kato, Kimiko; Chaya, Taro; Furukawa, Takahisa

    2015-08-01

    The Rax homeobox gene plays essential roles in multiple processes of vertebrate retina development. Many vertebrate species possess Rax and Rax2 genes, and different functions have been suggested. In contrast, mice contain a single Rax gene, and its functional roles in late retinal development are still unclear. To clarify mouse Rax function in postnatal photoreceptor development and maintenance, we generated conditional knockout mice in which Rax in maturing or mature photoreceptor cells was inactivated by tamoxifen treatment (Rax iCKO mice). When Rax was inactivated in postnatal Rax iCKO mice, developing photoreceptor cells showed a significant decrease in the level of the expression of rod and cone photoreceptor genes and mature adult photoreceptors exhibited a specific decrease in cone cell numbers. In luciferase assays, we found that Rax and Crx cooperatively transactivate Rhodopsin and cone opsin promoters and that an optimum Rax expression level to transactivate photoreceptor gene expression exists. Furthermore, Rax and Crx colocalized in maturing photoreceptor cells, and their coimmunoprecipitation was observed in cultured cells. Taken together, these results suggest that Rax plays essential roles in the maturation of both cones and rods and in the survival of cones by regulating photoreceptor gene expression with Crx in the postnatal mouse retina. PMID:25986607

  20. Disruption of intraflagellar protein transport in photoreceptor cilia causes Leber congenital amaurosis in humans and mice

    PubMed Central

    Boldt, Karsten; Mans, Dorus A.; Won, Jungyeon; van Reeuwijk, Jeroen; Vogt, Andreas; Kinkl, Norbert; Letteboer, Stef J.F.; Hicks, Wanda L.; Hurd, Ron E.; Naggert, Jürgen K.; Texier, Yves; den Hollander, Anneke I.; Koenekoop, Robert K.; Bennett, Jean; Cremers, Frans P.M.; Gloeckner, Christian J.; Nishina, Patsy M.; Roepman, Ronald; Ueffing, Marius

    2011-01-01

    The mutations that cause Leber congenital amaurosis (LCA) lead to photoreceptor cell death at an early age, causing childhood blindness. To unravel the molecular basis of LCA, we analyzed how mutations in LCA5 affect the connectivity of the encoded protein lebercilin at the interactome level. In photoreceptors, lebercilin is uniquely localized at the cilium that bridges the inner and outer segments. Using a generally applicable affinity proteomics approach, we showed that lebercilin specifically interacted with the intraflagellar transport (IFT) machinery in HEK293T cells. This interaction disappeared when 2 human LCA-associated lebercilin mutations were introduced, implicating a specific disruption of IFT-dependent protein transport, an evolutionarily conserved basic mechanism found in all cilia. Lca5 inactivation in mice led to partial displacement of opsins and light-induced translocation of arrestin from photoreceptor outer segments. This was consistent with a defect in IFT at the connecting cilium, leading to failure of proper outer segment formation and subsequent photoreceptor degeneration. These data suggest that lebercilin functions as an integral element of selective protein transport through photoreceptor cilia and provide a molecular demonstration that disrupted IFT can lead to LCA. PMID:21606596

  1. AAV-mediated cone rescue in a naturally occurring mouse model of CNGA3-achromatopsia.

    PubMed

    Pang, Ji-jing; Deng, Wen-Tao; Dai, Xufeng; Lei, Bo; Everhart, Drew; Umino, Yumiko; Li, Jie; Zhang, Keqing; Mao, Song; Boye, Sanford L; Liu, Li; Chiodo, Vince A; Liu, Xuan; Shi, Wei; Tao, Ye; Chang, Bo; Hauswirth, William W

    2012-01-01

    Achromatopsia is a rare autosomal recessive disorder which shows color blindness, severely impaired visual acuity, and extreme sensitivity to bright light. Mutations in the alpha subunits of the cone cyclic nucleotide-gated channels (CNGA3) are responsible for about 1/4 of achromatopsia in the U.S. and Europe. Here, we test whether gene replacement therapy using an AAV5 vector could restore cone-mediated function and arrest cone degeneration in the cpfl5 mouse, a naturally occurring mouse model of achromatopsia with a CNGA3 mutation. We show that gene therapy leads to significant rescue of cone-mediated ERGs, normal visual acuities and contrast sensitivities. Normal expression and outer segment localization of both M- and S-opsins were maintained in treated retinas. The therapeutic effect of treatment lasted for at least 5 months post-injection. This study is the first demonstration of substantial, relatively long-term restoration of cone-mediated light responsiveness and visual behavior in a naturally occurring mouse model of CNGA3 achromatopsia. The results provide the foundation for development of an AAV5-based gene therapy trial for human CNGA3 achromatopsia. PMID:22509403

  2. Detection of Optogenetic Stimulation in Somatosensory Cortex by Non-Human Primates - Towards Artificial Tactile Sensation

    PubMed Central

    Brush, Benjamin; Borton, David; Wagner, Fabien; Agha, Naubahar; Sheinberg, David L.; Nurmikko, Arto V.

    2014-01-01

    Neuroprosthesis research aims to enable communication between the brain and external assistive devices while restoring lost functionality such as occurs from stroke, spinal cord injury or neurodegenerative diseases. In future closed-loop sensorimotor prostheses, one approach is to use neuromodulation as direct stimulus to the brain to compensate for a lost sensory function and help the brain to integrate relevant information for commanding external devices via, e.g. movement intention. Current neuromodulation techniques rely mainly of electrical stimulation. Here we focus specifically on the question of eliciting a biomimetically relevant sense of touch by direct stimulus of the somatosensory cortex by introducing optogenetic techniques as an alternative to electrical stimulation. We demonstrate that light activated opsins can be introduced to target neurons in the somatosensory cortex of non-human primates and be optically activated to create a reliably detected sensation which the animal learns to interpret as a tactile sensation localized within the hand. The accomplishment highlighted here shows how optical stimulation of a relatively small group of mostly excitatory somatosensory neurons in the nonhuman primate brain is sufficient for eliciting a useful sensation from data acquired by simultaneous electrophysiology and from behavioral metrics. In this first report to date on optically neuromodulated behavior in the somatosensory cortex of nonhuman primates we do not yet dissect the details of the sensation the animals exerience or contrast it to those evoked by electrical stimulation, issues of considerable future interest. PMID:25541938

  3. Dynamics of the Rhomboid-like Protein RHBDD2 Expression in Mouse Retina and Involvement of Its Human Ortholog in Retinitis Pigmentosa*

    PubMed Central

    Ahmedli, Novruz B.; Gribanova, Yekaterina; Njoku, Collins C.; Naidu, Akash; Young, Alejandra; Mendoza, Emmanuel; Yamashita, Clyde K.; Özgül, Riza Köksal; Johnson, Jerry E.; Fox, Donald A.; Farber, Debora B.

    2013-01-01

    The novel rhomboid-like protein RHBDD2 is distantly related to rhomboid proteins, a group of highly specialized membrane-bound proteases that catalyze regulated intramembrane proteolysis. In retina, RHBDD2 is expressed from embryonic stages to adulthood, and its levels show age-dependent changes. RHBDD2 is distinctly abundant in the perinuclear region of cells, and it localizes to their Golgi. A glycine zipper motif present in one of the transmembrane domains of RHBDD2 is important for its packing into the Golgi membranes. Its deletion causes dislodgment of RHBDD2 from the Golgi. A specific antibody against RHBDD2 recognizes two forms of the protein, one with low (39 kDa; RHBDD2L) and the other with high (117 kDa; RHBDD2H) molecular masses in mouse retinal extracts. RHBDD2L seems to be ubiquitously expressed in all retinal cells. In contrast, RHBDD2H seems to be present only in the outer segments of cone photoreceptors and may correspond to a homotrimer of RHBDD2L. This protein consistently co-localizes with S- and M-types of cone opsins. We identified a homozygous mutation in the human RHBDD2 gene, R85H, that co-segregates with disease in affected members of a family with autosomal recessive retinitis pigmentosa. Our findings suggest that the RHBDD2 protein plays important roles in the development and normal function of the retina. PMID:23386608

  4. The monarch butterfly genome yields insights into long-distance migration.

    PubMed

    Zhan, Shuai; Merlin, Christine; Boore, Jeffrey L; Reppert, Steven M

    2011-11-23

    We present the draft 273 Mb genome of the migratory monarch butterfly (Danaus plexippus) and a set of 16,866 protein-coding genes. Orthology properties suggest that the Lepidoptera are the fastest evolving insect order yet examined. Compared to the silkmoth Bombyx mori, the monarch genome shares prominent similarity in orthology content, microsynteny, and protein family sizes. The monarch genome reveals a vertebrate-like opsin whose existence in insects is widespread; a full repertoire of molecular components for the monarch circadian clockwork; all members of the juvenile hormone biosynthetic pathway whose regulation shows unexpected sexual dimorphism; additional molecular signatures of oriented flight behavior; microRNAs that are differentially expressed between summer and migratory butterflies; monarch-specific expansions of chemoreceptors potentially important for long-distance migration; and a variant of the sodium/potassium pump that underlies a valuable chemical defense mechanism. The monarch genome enhances our ability to better understand the genetic and molecular basis of long-distance migration. PMID:22118469

  5. Mapping Anatomy to Behavior in Thy1:18 ChR2-YFP Transgenic Mice Using Optogenetics.

    PubMed

    Fenno, Lief E; Gunaydin, Lisa A; Deisseroth, Karl

    2015-01-01

    Linking the activity of defined neural populations with behavior is a key goal of neuroscience. In the context of controlling behavior, electrical stimulation affords researchers precision in the temporal domain with gross regional specificity, whereas pharmacology allows for more specific manipulation of cell types, but in the absence of temporal precision. The use of microbial opsins-light activated, genetically encoded ion channels and pumps-to control mammalian neurons now allows researchers to "sensitize" genetically and/or topologically defined populations of neurons to light to induce either depolarization or hyperpolarization in both a cell-type-specific and temporally precise manner not achievable with previous techniques. Here, we describe the use of transgenic mice expressing the blue-light gated cation channel Channelrhodopsin-2 (ChR2) under control of the Thy1 promoter for the purpose of linking neuronal activity to behavior through restricted delivery of light to an anatomic region of interest. The surgical procedure for implanting a fiber-optic light delivery guide into the mouse brain, the process of optically stimulating the brain in a behaving animal, and post hoc evaluation are given, along with necessary reagents and discussion of common technical problems and their solutions. PMID:26034299

  6. Restoration of cone vision in the CNGA3-/- mouse model of congenital complete lack of cone photoreceptor function.

    PubMed

    Michalakis, Stylianos; Mühlfriedel, Regine; Tanimoto, Naoyuki; Krishnamoorthy, Vidhyasankar; Koch, Susanne; Fischer, M Dominik; Becirovic, Elvir; Bai, Lin; Huber, Gesine; Beck, Susanne C; Fahl, Edda; Büning, Hildegard; Paquet-Durand, François; Zong, Xiangang; Gollisch, Tim; Biel, Martin; Seeliger, Mathias W

    2010-12-01

    Congenital absence of cone photoreceptor function is associated with strongly impaired daylight vision and loss of color discrimination in human achromatopsia. Here, we introduce viral gene replacement therapy as a potential treatment for this disease in the CNGA3(-/-) mouse model. We show that such therapy can restore cone-specific visual processing in the central nervous system even if cone photoreceptors had been nonfunctional from birth. The restoration of cone vision was assessed at different stages along the visual pathway. Treated CNGA3(-/-) mice were able to generate cone photoreceptor responses and to transfer these signals to bipolar cells. In support, we found morphologically that treated cones expressed regular cyclic nucleotide-gated (CNG) channel complexes and opsins in outer segments, which previously they did not. Moreover, expression of CNGA3 normalized cyclic guanosine monophosphate (cGMP) levels in cones, delayed cone cell death and reduced the inflammatory response of Müller glia cells that is typical of retinal degenerations. Furthermore, ganglion cells from treated, but not from untreated, CNGA3(-/-) mice displayed cone-driven, light-evoked, spiking activity, indicating that signals generated in the outer retina are transmitted to the brain. Finally, we demonstrate that this newly acquired sensory information was translated into cone-mediated, vision-guided behavior. PMID:20628362

  7. Reverse evolution in RH1 for adaptation of cichlids to water depth in Lake Tanganyika.

    PubMed

    Nagai, Haruka; Terai, Yohey; Sugawara, Tohru; Imai, Hiroo; Nishihara, Hidenori; Hori, Michio; Okada, Norihiro

    2011-06-01

    Reverse evolution is a widespread phenomenon in biology, but the genetic mechanism for the reversal of a genetic change for adaptation to the ancestral state is not known. Here, we report the first case of complete reverse evolution of two amino acids, serine and alanine, at a single position in RH1 opsin pigment for adaptation to water depth. We determined RH1 sequences of cichlid fishes from four tribes of Lake Tanganyika with different habitat depths. Most of the species were divided into two types: RH1 with 292A for species in shallow water or 292S for species in deep water. Both types were adapted to their ambient light environments as indicated by the absorption spectra of the RH1 pigments. Based on the RH1 locus tree and ecological data, we inferred the ancestral amino acids at position 292 and the distribution of the depth ranges (shallow or deep) of ancestral species of each tribe. According to these estimates, we identified two distinct parallel adaptive evolutions: The replacement A292S occurred at least four times for adaptation from shallow to deep water, and the opposite replacement S292A occurred three times for adaptation from deep to shallow water. The latter parallelism represents the complete reverse evolution from the derived to the ancestral state, following back adaptive mutation with reversal of the RH1 pigment function accompanied by reversal of the species habitat shift. PMID:21172834

  8. Molecular analysis of the amphioxus frontal eye unravels the evolutionary origin of the retina and pigment cells of the vertebrate eye

    PubMed Central

    Vopalensky, Pavel; Pergner, Jiri; Liegertova, Michaela; Benito-Gutierrez, Elia; Arendt, Detlev; Kozmik, Zbynek

    2012-01-01

    The origin of vertebrate eyes is still enigmatic. The “frontal eye” of amphioxus, our most primitive chordate relative, has long been recognized as a candidate precursor to the vertebrate eyes. However, the amphioxus frontal eye is composed of simple ciliated cells, unlike vertebrate rods and cones, which display more elaborate, surface-extended cilia. So far, the only evidence that the frontal eye indeed might be sensitive to light has been the presence of a ciliated putative sensory cell in the close vicinity of dark pigment cells. We set out to characterize the cell types of the amphioxus frontal eye molecularly, to test their possible relatedness to the cell types of vertebrate eyes. We show that the cells of the frontal eye specifically coexpress a combination of transcription factors and opsins typical of the vertebrate eye photoreceptors and an inhibitory Gi-type alpha subunit of the G protein, indicating an off-responding phototransductory cascade. Furthermore, the pigmented cells match the retinal pigmented epithelium in melanin content and regulatory signature. Finally, we reveal axonal projections of the frontal eye that resemble the basic photosensory-motor circuit of the vertebrate forebrain. These results support homology of the amphioxus frontal eye and the vertebrate eyes and yield insights into their evolutionary origin. PMID:22949670

  9. Protein Field Effect on the Dark State of 11-cis Retinal in Rhodopsin by Quantum Monte Carlo/Molecular Mechanics

    PubMed Central

    Coccia, Emanuele; Varsano, Daniele; Guidoni, Leonardo

    2014-01-01

    The accurate determination of the geometrical details of the dark state of 11-cis retinal in rhodopsin represents a fundamental step for the rationalization of the protein role in the optical spectral tuning in the vision mechanism. We have calculated geometries of the full retinal protonated Schiff base chromophore in the gas phase and in the protein environment using the correlated variational Monte Carlo method. The bond length alternation of the conjugated carbon chain of the chromophore in the gas phase shows a significant reduction when moving from the ?-ionone ring to the nitrogen, whereas, as expected, the protein environment reduces the electronic conjugation. The proposed dark state structure is fully compatible with solid-state NMR data reported by Carravetta et al. [J. Am. Chem. Soc. 2004, 126, 3948–3953]. TDDFT/B3LYP calculations on such geometries show a blue opsin shift of 0.28 and 0.24 eV induced by the protein for S1 and S2 states, consistently with literature spectroscopic data. The effect of the geometrical distortion alone is a red shift of 0.21 and 0.16 eV with respect to the optimized gas phase chromophore. Our results open new perspectives for the study of the properties of chromophores in their biological environment using correlated methods. PMID:24611033

  10. Morphological changes of short-wavelength cones in the developing S334ter-3 Transgenic rat

    PubMed Central

    Hombrebueno, Jose R.; Tsai, Melody M.; Kim, Hong-Lim; De Juan, Joaquin; Grzywacz, Norberto M.; Lee, Eun-Jin

    2010-01-01

    The S334ter-3 rat is a transgenic model of retinal degeneration (RD) developed to express a rhodopsin mutation similar to that found in human retinitis pigmentosa. Due to this advantage over other models of RD, a few retina transplant studies have been reported on this animal model. Currently, no information is available on cone photoreceptor changes that occur in the S334ter RD model. In this study, we investigated the effect of RD on the morphology, distribution, and synaptic connectivity of short-wavelength cones (S-cones) during development of S334ter-3 rat retinas. At P21 RD retinas, the outer-nuclear layer was significantly narrower, while S-cones showed shortening of their segments and axons compared to control retinas. From P90 onward, S-opsin-immunoreactive cells appeared at the outer margin of the inner-nuclear layer of RD retinas. Double-labelling experiments showed these cells contained recoverin and cone arrestin. Furthermore, ultra-structure study showed that synaptic ribbons are conserved in the S-cone at P180 RD retinas. Although cell density of S-cones significantly dropped after P90, survival rates depended on the retinal region. Overall, the S334ter-3 RD model shows hallmarks of cone remodelling due to photoreceptor degeneration. PMID:20114037

  11. Evolution of optogenetic microdevices.

    PubMed

    Kale, Rajas P; Kouzani, Abbas Z; Walder, Ken; Berk, Michael; Tye, Susannah J

    2015-07-01

    Implementation of optogenetic techniques is a recent addition to the neuroscientists' preclinical research arsenal, helping to expose the intricate connectivity of the brain and allowing for on-demand direct modulation of specific neural pathways. Developing an optogenetic system requires thorough investigation of the optogenetic technique and of previously fabricated devices, which this review accommodates. Many experiments utilize bench-top systems that are bulky, expensive, and necessitate tethering to the animal. However, these bench-top systems can make use of power-demanding technologies, such as concurrent electrical recording. Newer portable microdevices and implantable systems carried by freely moving animals are being fabricated that take advantage of wireless energy harvesting to power a system and allow for natural movements that are vital for behavioral testing and analysis. An investigation of the evolution of tethered, portable, and implantable optogenetic microdevices is presented, and an analysis of benefits and detriments of each system, including optical power output, device dimensions, electrode width, and weight is given. Opsins, light sources, and optical fiber coupling are also discussed to optimize device parameters and maximize efficiency from the light source to the fiber, respectively. These attributes are important considerations when designing and developing improved optogenetic microdevices. PMID:26158015

  12. Zebrafish Lbh-like Is Required for Otx2-mediated Photoreceptor Differentiation.

    PubMed

    Li, Wen-Hua; Zhou, Li; Li, Zhi; Wang, Yang; Shi, Jian-Tao; Yang, Yan-Jing; Gui, Jian-Fang

    2015-01-01

    The homeobox transcription factor orthodenticle homolog 2 (otx2) is supposed as an organizer that orchestrates a transcription factor network during photoreceptor development. However, its regulation in the process remains unclear. In this study, we have identified a zebrafish limb bud and heart-like gene (lbh-like), which is expressed initially at 30 hours post fertilization (hpf) in the developing brain and eyes. Lbh-like knockdown by morpholinos specifically inhibits expression of multiple photoreceptor-specific genes, such as opsins, gnat1, gnat2 and irbp. Interestingly, otx2 expression in the morphants is not significantly reduced until 32 hpf when lbh-like begins to express, but its expression level in 72 hpf morphants is higher than that in wild type embryos. Co-injection of otx2 and its downstream target neuroD mRNAs can rescue the faults in eyes of Lbh-like morphants. Combined with the results of promoter-reporter assay, we suggest that lbh-like is a new regulator of photoreceptor differentiation directly through affecting otx2 expression in zebrafish. Furthermore, knockdown of lbh-like increases the activity of Notch pathway and perturbs the balance among proliferation, differentiation and survival of photoreceptor precursors. PMID:25999792

  13. Kinesin molecular motors: Transport pathways, receptors, and human disease

    NASA Astrophysics Data System (ADS)

    Goldstein, Lawrence S. B.

    2001-06-01

    Kinesin molecular motor proteins are responsible for many of the major microtubule-dependent transport pathways in neuronal and non-neuronal cells. Elucidating the transport pathways mediated by kinesins, the identity of the cargoes moved, and the nature of the proteins that link kinesin motors to cargoes are areas of intense investigation. Kinesin-II recently was found to be required for transport in motile and nonmotile cilia and flagella where it is essential for proper left-right determination in mammalian development, sensory function in ciliated neurons, and opsin transport and viability in photoreceptors. Thus, these pathways and proteins may be prominent contributors to several human diseases including ciliary dyskinesias, situs inversus, and retinitis pigmentosa. Kinesin-I is needed to move many different types of cargoes in neuronal axons. Two candidates for receptor proteins that attach kinesin-I to vesicular cargoes were recently found. One candidate, sunday driver, is proposed to both link kinesin-I to an unknown vesicular cargo and to bind and organize the mitogen-activated protein kinase components of a c-Jun N-terminal kinase signaling module. A second candidate, amyloid precursor protein, is proposed to link kinesin-I to a different, also unknown, class of axonal vesicles. The finding of a possible functional interaction between kinesin-I and amyloid precursor protein may implicate kinesin-I based transport in the development of Alzheimer's disease.

  14. Vitreal delivery of AAV vectored Cnga3 restores cone function in CNGA3-/-/Nrl-/- mice, an all-cone model of CNGA3 achromatopsia†.

    PubMed

    Du, Wei; Tao, Ye; Deng, Wen-Tao; Zhu, Ping; Li, Jie; Dai, Xufeng; Zhang, Yuxin; Shi, Wei; Liu, Xuan; Chiodo, Vince A; Ding, Xi-Qin; Zhao, Chen; Michalakis, Stylianos; Biel, Martin; Zhang, Zuoming; Qu, Jia; Hauswirth, William W; Pang, Ji-Jing

    2015-07-01

    The CNGA3(-/-)/Nrl(-/-) mouse is a cone-dominant model with Cnga3 channel deficiency, which partially mimics the all cone foveal structure of human achromatopsia 2 with CNGA3 mutations. Although subretinal (SR) AAV vector administration can transfect retinal cells efficiently, the injection-induced retinal detachment can cause retinal damage, particularly when SR vector bleb includes the fovea. We therefore explored whether cone function-structure could be rescued in CNGA3(-/-)/Nrl(-/-) mice by intravitreal (IVit) delivery of tyrosine to phenylalanine (Y-F) capsid mutant AAV8. We find that AAV-mediated CNGA3 expression can restore cone function and rescue structure following IVit delivery of AAV8 (Y447, 733F) vector. Rescue was assessed by restoration of the cone-mediated electroretinogram (ERG), optomotor responses, and cone opsin immunohistochemistry. Demonstration of gene therapy in a cone-dominant mouse model by IVit delivery provides a potential alternative vector delivery mode for safely transducing foveal cones in achromatopsia patients and in other human retinal diseases affecting foveal function. PMID:25855802

  15. Nature as the observer: A simplified approach to the measurement problem and related issues

    E-print Network

    Fred H. Thaheld

    2007-03-14

    Several theories have been advanced recently which appear to offer a resolution to that portion of the measurement problem which previously dealt with a possible reduction of the state vector in a subjective fashion by the brain, mind or consciousness. It now appears, based on both biological and mathematical analysis, that collapse of the wave function always takes place in an objective fashion in the retinal rod-rhodopsin molecule, and that only measured information is ever presented to the brain, mind or consciousness for possible subjective analysis. The remaining portion of the measurement problem has to do with the use and legitimacy of such terms as boundary (Heisenberg or von Neumann cut), information, irreversible, measurement, microscopic, macroscopic, observer (apparatus or measuring system), observed (measured system) and wave function collapse. This portion of the measurement problem may be resolved in two ways. First, by adopting Dirac's theory that it is nature that makes the choice of measuremental result. Second, by the insertion of a mesoscopic bridge between the microscopic and macroscopic worlds, in the existing form of the rhodopsin molecule with its retinal and opsin components.

  16. UVS is rare in seabirds.

    PubMed

    Machovsky Capuska, Gabriel E; Huynen, Leon; Lambert, David; Raubenheimer, David

    2011-06-21

    Ultraviolet-sensitive vision (UVS), believed to have evolved from an ancestral state of violet-sensitive vision (VS), is widespread among terrestrial birds, where it is thought to play a role in orientation, foraging, and sexual selection. Less is known, however, about the distribution and significance of UVS in seabirds. To date UVS has been definitively demonstrated only in two families (Laridae and Sternidae), although indirect evidence has been used to argue for a more widespread occurrence. In this study we analyzed short-wavelength sensitive (SWS1) opsin DNA sequences to determine the distribution of ancestral (VS) and derived (UVS) amino acid spectral tuning sites in 16 seabird species representing 8 families with diverse ecological niches. Our results revealed sequences associated with UVS pigments (UVSs) in the Black-backed gull (Larus dominicanus), providing further evidence of its widespread occurrence within the Laridae. The Caspian tern (Hydroprogne caspia) and White-fronted tern (Sterna striata), however, were found to have VSs, suggesting an evolutionary reversion to the ancestral state within Sternidae. VSs were also detected in an additional six families. Our results raise interesting questions about the functions of UV vision in marine environments. PMID:21527267

  17. The monarch butterfly genome yields insights into long-distance migration

    PubMed Central

    Zhan, Shuai; Merlin, Christine; Boore, Jeffrey L.; Reppert, Steven M.

    2011-01-01

    SUMMARY We present the draft 273 Mb genome of the migratory monarch butterfly (Danaus plexippus) and a set of 16, 866 protein-coding genes. Orthology properties suggest that the Lepidoptera are the fastest evolving insect order yet examined. Compared to the silkmoth Bombyx mori, the monarch genome shares prominent similarity in orthology content, microsynteny, and protein family sizes. The monarch genome reveals: a vertebrate-like opsin whose existence in insects is widespread; a full repertoire of molecular components for the monarch circadian clockwork; all members of the juvenile hormone biosynthetic pathway whose regulation shows unexpected sexual dimorphism; additional molecular signatures of oriented flight behavior; microRNAs that are differentially expressed between summer and migratory butterflies; monarch-specific expansions of chemoreceptors potentially important for long-distance migration; and a variant of the sodium/potassium pump that underlies a valuable chemical defense mechanism. The monarch genome enhances our ability to better understand the genetic and molecular basis of long-distance migration. PMID:22118469

  18. The ‘division of labour’ model of eye evolution

    PubMed Central

    Arendt, Detlev; Hausen, Harald; Purschke, Günter

    2009-01-01

    The ‘division of labour’ model of eye evolution is elaborated here. We propose that the evolution of complex, multicellular animal eyes started from a single, multi-functional cell type that existed in metazoan ancestors. This ancient cell type had at least three functions: light detection via a photoreceptive organelle, light shading by means of pigment granules and steering through locomotor cilia. Located around the circumference of swimming ciliated zooplankton larvae, these ancient cells were able to mediate phototaxis in the absence of a nervous system. This precursor then diversified, by cell-type functional segregation, into sister cell types that specialized in different subfunctions, evolving into separate photoreceptor cells, shading pigment cells (SPCs) or ciliated locomotor cells. Photoreceptor sensory cells and ciliated locomotor cells remained interconnected by newly evolving axons, giving rise to an early axonal circuit. In some evolutionary lines, residual functions prevailed in the specialized cell types that mirror the ancient multi-functionality, for instance, SPCs expressing an opsin as well as possessing rhabdomer-like microvilli, vestigial cilia and an axon. Functional segregation of cell types in eye evolution also explains the emergence of more elaborate photosensory–motor axonal circuits, with interneurons relaying the visual information. PMID:19720646

  19. Ultraviolet-sensitive vision in long-lived birds

    PubMed Central

    Carvalho, Livia S.; Knott, Ben; Berg, Mathew L.; Bennett, Andrew T. D.; Hunt, David M.

    2011-01-01

    Long-term exposure to ultraviolet (UV) light generates substantial damage, and in mammals, visual sensitivity to UV is restricted to short-lived diurnal rodents and certain marsupials. In humans, the cornea and lens absorb all UV-A and most of the terrestrial UV-B radiation, preventing the reactive and damaging shorter wavelengths from reaching the retina. This is not the case in certain species of long-lived diurnal birds, which possess UV-sensitive (UVS) visual pigments, maximally sensitive below 400 nm. The Order Psittaciformes contains some of the longest lived bird species, and the two species examined so far have been shown to possess UVS pigments. The objective of this study was to investigate the prevalence of UVS pigments across long-lived parrots, macaws and cockatoos, and therefore assess whether they need to cope with the accumulated effects of exposure to UV-A and UV-B over a long period of time. Sequences from the SWS1 opsin gene revealed that all 14 species investigated possess a key substitution that has been shown to determine a UVS pigment. Furthermore, in vitro regeneration data, and lens transparency, corroborate the molecular findings of UV sensitivity. Our findings thus support the claim that the Psittaciformes are the only avian Order in which UVS pigments are ubiquitous, and indicate that these long-lived birds have UV sensitivity, despite the risks of photodamage. PMID:20667872

  20. CIS-TRANS ISOMERS OF VITAMIN A AND RETINENE IN THE RHODOPSIN SYSTEM

    PubMed Central

    Hubbard, Ruth; Wald, George

    1952-01-01

    Vitamin A and retinene, the carotenoid precursors of rhodopsin, occur in a variety of molecular shapes, cis-trans isomers of one another. For the synthesis of rhodopsin a specific cis isomer of vitamin A is needed. Ordinary crystalline vitamin A, as also the commercial synthetic product, both primarily all-trans, are ineffective. The main site of isomer specificity is the coupling of retinene with opsin. It is this reaction that requires a specific cis isomer of retinene. The oxidation of vitamin A to retinene by the alcohol dehydrogenase-cozymase system displays only a low degree of isomer specificity. Five isomers of retinene have been isolated in crystalline condition: all-trans; three apparently mono-cis forms, neoretinenes a and b and isoretinene a; and one apparently di-cis isomer, isoretinene b. Neoretinenes a and b were first isolated in our laboratory, and isoretinenes a and b in the Organic Research Laboratory of Distillation Products Industries. Each of these substances is converted to an equilibrium mixture of stereoisomers on simple exposure to light. For this reaction, light is required which retinene can absorb; i.e., blue, violet, or ultraviolet light. Yellow, orange, or red light has little effect. The single geometrical isomers of retinene must therefore be protected from low wave length radiation if their isomerization is to be avoided. By incubation with opsin in the dark, the capacity of each of the retinene isomers to synthesize rhodopsin was examined. All-trans retinene and neoretinene a are inactive. Neoretinene b yields rhodopsin indistinguishable from that extracted from the dark-adapted retina (?max· 500 mµ). Isoretinene a yields a similar light-sensitive pigment, isorhodopsin, the absorption spectrum of which is displaced toward shorter wave lengths (?max· 487 mµ). Isoretinene b appears to be inactive, but isomerizes preferentially to isoretinene a, which in the presence of opsin is removed to form isorhodopsin before the isomerization can go further. The synthesis of rhodopsin in solution follows the course of a bimolecular reaction, as though one molecule of neoretinene b combines with one of opsin. The synthesis of isorhodopsin displays similar kinetics. The bleaching of rhodopsin, whether by chemical means or by exposure to yellow or orange (i.e., non-isomerizing) light, yields primarily or exclusively all-trans retinene. The same appears to be true of isorhodopsin. The process of bleaching is therefore intrinsically irreversible. The all-trans retinene which results must be isomerized to active configurations before rhodopsin or isorhodopsin can be regenerated. A cycle of isomerization is therefore an integral part of the rhodopsin system. The all-trans retinene which emerges from the bleaching of rhodopsin must be isomerized to neoretinene b before it can go back; or if first reduced to all-trans vitamin A, this must be isomerized to neovitamin Ab before it can regenerate rhodopsin. The retina obtains new supplies of the neo-b isomer: (a) by the isomerization of all-trans retinene in the eye by blue or violet light; (b) by exchanging all-trans vitamin A for new neovitamin Ab from the blood circulation; and (c) the eye tissues may contain enzymes which catalyze the isomerization of retinene and vitamin A in situ. When the all-trans retinene which results from bleaching rhodopsin in orange or yellow light is exposed to blue or violet light, its isomerization is accompanied by a fall in extinction and a shift of absorption spectrum about 5 mµ toward shorter wave lengths. This is a second photochemical step in the bleaching of rhodopsin. It converts the inactive, all-trans isomer of retinene into a mixture of isomers, from which mixtures of rhodopsin and isorhodopsin can be regenerated. Isorhodopsin, however, is an artefact. There is no evidence that it occurs in the retina; nor has isovitamin Aa or b yet been identified in vivo. In rhodopsin and isorhodopsin, the prosthetic groups appear to retain the cis configurations characteristic of their retinene p

  1. Circulating neutrophils maintain physiological blood pressure by suppressing bacteria and IFN?-dependent iNOS expression in the vasculature of healthy mice

    PubMed Central

    Morton, Jonathan; Coles, Barbara; Wright, Kate; Gallimore, Awen; Morrow, Jason D.; Terry, Erin S.; Anning, Peter B.; Morgan, B. Paul; Dioszeghy, Vincent; Kühn, Hartmut; Chaitidis, Pavlos; Hobbs, Adrian J.; Jones, Simon A.

    2008-01-01

    Whether leukocytes exert an influence on vascular function in vivo is not known. Here, genetic and pharmacologic approaches show that the absence of neutrophils leads to acute blood pressure dysregulation. Following neutrophil depletion, systolic blood pressure falls significantly over 3 days (88.0 ± 3.5 vs 104.0 ± 2.8 mm Hg, day 3 vs day 0, mean ± SEM, P < .001), and aortic rings from neutropenic mice do not constrict properly. The constriction defect is corrected using l-nitroarginine-methyl ester (L-NAME) or the specific inducible nitric oxide synthase (iNOS) inhibitor 1400W, while acetylcholine relaxation is normal. iNOS- or IFN?-deficient mice are protected from neutropenia-induced hypotension, indicating that iNOS-derived nitric oxide (NO) is responsible and that its induction involves IFN?. Oral enrofloxacin partially inhibited hypotension, implicating bacterial products. Roles for cyclooxygenase, complement C5, or endotoxin were excluded, although urinary prostacyclin metabolites were elevated. Neutrophil depletion required complement opsinization, with no evidence for intravascular degranulation. In summary, circulating neutrophils contribute to maintaining physiological tone in the vasculature, at least in part through suppressing early proinflammatory effects of infection. The speed with which hypotension developed provides insight into early changes that occur in the absence of neutrophils and illustrates the importance of constant surveillance of mucosal sites by granulocytes in healthy mice. PMID:18281503

  2. Transcription Coactivators p300 and CBP Are Necessary for Photoreceptor-Specific Chromatin Organization and Gene Expression

    PubMed Central

    Hennig, Anne K.; Peng, Guang-Hua; Chen, Shiming

    2013-01-01

    Rod and cone photoreceptor neurons in the mammalian retina possess specialized cellular architecture and functional features for converting light to a neuronal signal. Establishing and maintaining these characteristics requires appropriate expression of a specific set of genes, which is tightly regulated by a network of photoreceptor transcription factors centered on the cone-rod homeobox protein CRX. CRX recruits transcription coactivators p300 and CBP to acetylate promoter-bound histones and activate transcription of target genes. To further elucidate the role of these two coactivators, we conditionally knocked out Ep300 and/or CrebBP in differentiating rods or cones, using opsin-driven Cre recombinase. Knockout of either factor alone exerted minimal effects, but loss of both factors severely disrupted target cell morphology and function: the unique nuclear chromatin organization seen in mouse rods was reversed, accompanied by redistribution of nuclear territories associated with repressive and active histone marks. Transcription of many genes including CRX targets was severely impaired, correlating with reduced histone H3/H4 acetylation (the products of p300/CBP) on target gene promoters. Interestingly, the presence of a single wild-type allele of either coactivator prevented many of these defects, with Ep300 more effective than Cbp. These results suggest that p300 and CBP play essential roles in maintaining photoreceptor-specific structure, function and gene expression. PMID:23922782

  3. A direct and melanopsin-dependent fetal light response regulates mouse eye development

    PubMed Central

    Rao, Sujata; Chun, Christina; Fan, Jieqing; Kofron, J. Matthew; Yang, Michael B.; Hegde, Rashmi S.; Ferrara, Napoleone; Copenhagen, David R.; Lang, Richard A.

    2013-01-01

    Vascular patterning is critical for organ function. In the eye, there is simultaneous regression of embryonic hyaloid vasculature1 (important to clear the optical path) and formation of the retinal vasculature2 (important for the high metabolic demands of retinal neurons). These events occur postnatally in the mouse. Here we have identified a light-response pathway that regulates both processes. We show that when mice are mutated in the gene (Opn4) for the atypical opsin melanopsin3–5, or are dark-reared from late gestation, the hyaloid vessels are persistent at 8 days post-partum and the retinal vasculature overgrows. We provide evidence that these vascular anomalies are explained by a light-response pathway that suppresses retinal neuron number, limits hypoxia and, as a consequence, holds local expression of vascular endothelial growth factor (VEGFA) in check. We also show that the light response for this pathway occurs in late gestation at about embryonic day 16 and requires the photopigment in the fetus and not the mother. Measurements show that visceral cavity photon flux is probably sufficient to activate melanopsin-expressing retinal ganglion cells in the mouse fetus. These data thus show that light—the stimulus for function of the mature eye—is also critical in preparing the eye for vision by regulating retinal neuron number and initiating a series of events that ultimately pattern the ocular blood vessels. PMID:23334418

  4. Structure and function in rhodopsin: further elucidation of the role of the intradiscal cysteines, Cys-110, -185, and -187, in rhodopsin folding and function.

    PubMed

    Hwa, J; Reeves, P J; Klein-Seetharaman, J; Davidson, F; Khorana, H G

    1999-03-01

    The disulfide bond between Cys-110 and Cys-187 in the intradiscal domain is required for correct folding in vivo and function of mammalian rhodopsin. Misfolding in rhodopsin, characterized by the loss of ability to bind 11-cis-retinal, has been shown to be caused by an intradiscal disulfide bond different from the above native disulfide bond. Further, naturally occurring single mutations of the intradiscal cysteines (C110F, C110Y, and C187Y) are associated with retinitis pigmentosa (RP). To elucidate further the role of every one of the three intradiscal cysteines, mutants containing single-cysteine replacements by alanine residues and the above three RP mutants have been studied. We find that C110A, C110F, and C110Y all form a disulfide bond between C185 and C187 and cause loss of retinal binding. C185A allows the formation of a C110-C187 disulfide bond, with wild-type-like rhodopsin phenotype. C187A forms a disulfide bond between C110 and C185 and binds retinal, and the pigment formed has markedly altered bleaching behavior. However, the opsin from the RP mutant C187Y forms no rhodopsin chromophore. PMID:10051572

  5. Changes in the colour of light cue circadian activity

    PubMed Central

    Kuchenbecker, James A.; Neitz, Maureen

    2012-01-01

    The discovery of melanopsin, the non-visual opsin present in intrinsically photosensitive retinal ganglion cells (ipRGCs), has created great excitement in the field of circadian biology. Now, researchers have emphasized melanopsin as the main photopigment governing circadian activity in vertebrates. Circadian biologists have tested this idea under standard laboratory, 12h Light: 12h Dark, lighting conditions that lack the dramatic daily colour changes of natural skylight. Here we used a stimulus paradigm in which the colour of the illumination changed throughout the day, thus mimicking natural skylight, but luminance, sensed intrinsically by melanopsin containing ganglion cells, was kept constant. We show in two species of cichlid, Aequidens pulcher and Labeotropheus fuelleborni, that changes in light colour, not intensity, are the primary determinants of natural circadian activity. Moreover, opponent-cone photoreceptor inputs to ipRGCs mediate the sensation of wavelength change, and not the intrinsic photopigment, melanopsin. These results have implications for understanding the evolutionary biology of non-visual photosensory pathways and answer long-standing questions about the nature and distribution of photopigments in organisms, including providing a solution to the mystery of why nocturnal animals routinely have mutations that interrupt the function of their short wavelength sensitive photopigment gene. PMID:22639465

  6. Retinal photoreceptor and related gene expression in normal and clinostat-treated fish embryos

    NASA Astrophysics Data System (ADS)

    Nishiwaki, Y.; Ijiri, K.; Satoh, T.; Tokunaga, F.; Morita, T.

    1999-01-01

    Medaka fish had performed mating behavior successfully in space for the first time among vertebrate, and the eggs which were laid in space developed normally, and hatched during the space travel of 15 days aboard the space shuttle in the second International Microgravity Laboratory (IML-2) mission in 1994 (Ijiri 1994). But there has been few studies whether microgravity affects the development of rather complex tissues in this fish. Investigating this problem, we focused on the organogenetic events in the retina in developing Medaka under normal and simulated microgravity conditions (by a three-dimensional clinostat, 3D-clinostat). Our results showed that both normal and 3D-clinostat-treated Medaka embryos developed on almost equal time course. Moreover, we investigated the development of the retina in normal and 3D-clinostat-treated embryos, but there were no differences in organogenesis of their retina. Lamination of retina occurred almost at equal timing and the expressions of opsin genes in the 3D-clinostat-treated group also began almost at the same time as control. Our observations suggest that there were no definite effects of simulated microgravity on the organizations of a complex tissue such as retina in developing fish embryos.

  7. Optical control demonstrates switch-like PIP3 dynamics underlying the initiation of immune cell migration

    PubMed Central

    Karunarathne, W. K. Ajith; Giri, Lopamudra; Patel, Anilkumar K.; Venkatesh, Kareenhalli V.; Gautam, N.

    2013-01-01

    There is a dearth of approaches to experimentally direct cell migration by continuously varying signal input to a single cell, evoking all possible migratory responses and quantitatively monitoring the cellular and molecular response dynamics. Here we used a visual blue opsin to recruit the endogenous G-protein network that mediates immune cell migration. Specific optical inputs to this optical trigger of signaling helped steer migration in all possible directions with precision. Spectrally selective imaging was used to monitor cell-wide phosphatidylinositol (3,4,5)-triphosphate (PIP3), cytoskeletal, and cellular dynamics. A switch-like PIP3 increase at the cell front and a decrease at the back were identified, underlying the decisive migratory response. Migration was initiated at the rapidly increasing switch stage of PIP3 dynamics. This result explains how a migratory cell filters background fluctuations in the intensity of an extracellular signal but responds by initiating directionally sensitive migration to a persistent signal gradient across the cell. A two-compartment computational model incorporating a localized activator that is antagonistic to a diffusible inhibitor was able to simulate the switch-like PIP3 response. It was also able simulate the slow dissipation of PIP3 on signal termination. The ability to independently apply similar signaling inputs to single cells detected two cell populations with distinct thresholds for migration initiation. Overall the optical approach here can be applied to understand G-protein–coupled receptor network control of other cell behaviors. PMID:23569254

  8. Sequence, Structure and Ligand Binding Evolution of Rhodopsin-Like G Protein-Coupled Receptors: A Crystal Structure-Based Phylogenetic Analysis

    PubMed Central

    Wolf, Steffen; Grünewald, Stefan

    2015-01-01

    G protein-coupled receptors (GPCRs) form the largest family of membrane receptors in the human genome. Advances in membrane protein crystallization so far resulted in the determination of 24 receptors available as high-resolution atomic structures. We performed the first phylogenetic analysis of GPCRs based on the available set of GPCR structures. We present a new phylogenetic tree of known human rhodopsin-like GPCR sequences based on this structure set. We can distinguish the three separate classes of small-ligand binding GPCRs, peptide binding GPCRs, and olfactory receptors. Analyzing different structural subdomains, we found that small molecule binding receptors most likely have evolved from peptide receptor precursors, with a rhodopsin/S1PR1 ancestor, most likely an ancestral opsin, forming the link between both classes. A light-activated receptor therefore seems to be the origin of the small molecule hormone receptors of the central nervous system. We find hints for a common evolutionary path of both ligand binding site and central sodium/water binding site. Surprisingly, opioid receptors exhibit both a binding cavity and a central sodium/water binding site similar to the one of biogenic amine receptors instead of peptide receptors, making them seemingly prone to bind small molecule ligands, e.g. opiates. Our results give new insights into the relationship and the pharmacological properties of rhodopsin-like GPCRs. PMID:25881057

  9. Modeling Reconnection-Driven Solar Polar Jets with Gravity and Wind

    NASA Astrophysics Data System (ADS)

    Karpen, Judith T.; DeVore, C. R.; Antiochos, S. K.

    2013-07-01

    Solar polar jets are dynamic, narrow, radially extended structures observed in EUV emission. They have been found to originate within the open magnetic field of coronal holes in “anemone” regions, which are generally accepted to be intrusions of opposite polarity. The associated embedded-dipole topology consists of a spine line emanating from a null point atop a dome-shaped fan surface. Previous work (Pariat et al. 2009, 2010) has validated the idea that magnetic free energy stored on twisted closed field lines within the fan surface can be released explosively by the onset of fast reconnection between the highly stressed closed field inside the null and the unstressed open field outside (Antiochos 1996). The simulations showed that a dense jet comprising a nonlinear, torsional Alfven wave is ejected into the outer corona on the newly reconnected open field lines. While proving the principle of the basic model, those simulations neglected the important effects of gravity, the solar wind, and an expanding spherical geometry. We introduce those additional physical processes in new simulations of reconnection-driven jets, to determine whether the model remains robust in the resulting more realistic setting, and to begin establishing the signatures of the jets in the inner heliosphere for comparison with observations. Initial results demonstrate explosive energy release and a jet in the low corona very much like that in the earlier Cartesian, gravity-free, static-atmosphere runs. We report our analysis of the results, their comparison with previous work, and their implications for observations. This work was supported by NASA’s LWS TR&T program.Abstract (2,250 Maximum Characters): Solar polar jets are dynamic, narrow, radially extended structures observed in EUV emission. They have been found to originate within the open magnetic field of coronal holes in “anemone” regions, which are generally accepted to be intrusions of opposite polarity. The associated embedded-dipole topology consists of a spine line emanating from a null point atop a dome-shaped fan surface. Previous work (Pariat et al. 2009, 2010) has validated the idea that magnetic free energy stored on twisted closed field lines within the fan surface can be released explosively by the onset of fast reconnection between the highly stressed closed field inside the null and the unstressed open field outside (Antiochos 1996). The simulations showed that a dense jet comprising a nonlinear, torsional Alfven wave is ejected into the outer corona on the newly reconnected open field lines. While proving the principle of the basic model, those simulations neglected the important effects of gravity, the solar wind, and an expanding spherical geometry. We introduce those additional physical processes in new simulations of reconnection-driven jets, to determine whether the model remains robust in the resulting more realistic setting, and to begin establishing the signatures of the jets in the inner heliosphere for comparison with observations. Initial results demonstrate explosive energy release and a jet in the low corona very much like that in the earlier Cartesian, gravity-free, static-atmosphere runs. We report our analysis of the results, their comparison with previous work, and their implications for observations. This work was supported by NASA’s LWS TR&T program.

  10. ISO observations of the interacting galaxy Markarian 297. with the powerful supernova remnant 1982aa

    NASA Astrophysics Data System (ADS)

    Metcalfe, L.; O'Halloran, B.; McBreen, B.; Delaney, M.; Burgdorf, M.; Leech, K.; Barr, P.; Clavel, J.; Coia, D.; Hanlon, L.; Gallais, P.; Laureijs, R.; Smith, N.

    2005-12-01

    Markarian (Mkn) 297 is a complex system comprised of two interacting galaxies that has been modelled with a variety of scenarios. Observations of this system were made with the Infrared Space Observatory (ISO) using the ISOCAM, ISOPHOT and LWS instruments. ISOCAM maps at 6.7 ?m, 7.7 ?m, 12 ?m and 14.3 ?m are presented which, together with PHT-S spectrometry of the central interacting region, probe the dust obscured star formation and the properties of the organic dust. The ISOCAM observations reveal that the strongest emission in the four bands is at a location completely unremarkable at visible and near-IR (e.g. 2MASS) wavelengths, and does not coincide with the nuclear region of either colliding galaxy. This striking characteristic has also been observed in the overlap region of the colliding galaxies in the Antennae (NGC 4038/4039), the intragroup region of Stephan's Quintet, and in IC 694 in the interacting system Arp 299, and again underlines the importance of infrared observations in understanding star formation in colliding/merging systems. At 15 ?m, the hidden source in Mkn 297 is, respectively, 14.6 and 3.8 times more luminous than the hidden sources in the Antennae (NGC 4038/4039) and Stephan's Quintet. Numerical simulations of the Mkn 297 system indicate that a co-planar radial penetration between two disk galaxies yielded the observed wing formation in the system about 1.5 × 108 years after the collision. A complex emission pattern with knots and ridges of emission was detected with ISOCAM. The 7.7 ?m map predominantly shows the galaxy in emission from the 7.7 ?m feature attributed to PAHs (Polycyclic Aromatic Hydrocarbons). The 14.3/7.7 ?m ratio is greater than unity over most of the galaxy, implying widespread strong star formation. Strong emission features were detected in the ISOPHOT spectrum, while [O I], [O III] and [C II] emission lines were seen with LWS. Using data from the three instruments, luminosities and masses for two dust components were determined. The total infrared luminosity is approximately 10<(11)> L?, which (marginally) classifies the system as a luminous infrared galaxy (LIRG). A supernova that exploded in 1979 (SN 1982aa) gave rise to one of the most powerful known radio remnants which falls close to the strongest mid-infrared source and is identified with star forming region 14 in the optical. This supernova explosion may have been accompanied by a gamma-ray burst (GRB), consistent with the idea that GRBs are associated with supernovae in star forming regions, and a search for a GRB consistent with the direction to Mkn 297, in satellite data from July to December 1979, is recommended. 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 United Kingdom) with the participation of ISAS and NASA

  11. PREFACE: Eclipse on the Coral Sea: Cycle 24 Ascending

    NASA Astrophysics Data System (ADS)

    Cally, Paul; Erdélyi, Robert; Norton

    2013-06-01

    A total solar eclipse is the most spectacular and awe-inspiring astronomical phenomenon most people will ever see in their lifetimes. Even hardened solar scientists draw inspiration from it. The eclipse with 2 minutes totality in the early morning of 14 November 2012 (local time) drew over 120 solar researchers (and untold thousands of the general public) to the small and picturesque resort town of Palm Cove just north of Cairns in tropical north Queensland, Australia, and they were rewarded when the clouds parted just before totality to reveal a stunning solar display. Eclipse photograph The eclipse was also the catalyst for an unusually broad and exciting conference held in Palm Cove over the week 12--16 November. Eclipse on the Coral Sea: Cycle 24 Ascending served as GONG 2012, LWS/SDO-5, and SOHO 27, indicating how widely it drew on the various sub-communities within solar physics. Indeed, as we neared the end of the ascending phase of the peculiar Solar Cycle 24, it was the perfect time to bring the whole community together to discuss our Sun's errant recent behaviour, especially as Cycle 24 is the first to be fully observed by the Solar Dynamics Observatory (SDO). The whole-Sun perspective was a driving theme of the conference, with the cycle probed from interior (helioseismology), to atmosphere (the various lines observed by the Atmospheric Imaging Assemble (AIA) aboard SDO, the several instruments on Hinode, and other modern observatories), and beyond (CMEs etc). The quality of the presentations was exceptional, and the many speakers are to be commended for pitching their talks to the broad community present. These proceedings draw from the invited and contributed oral presentations and the posters exhibited in Palm Cove. They give an (incomplete) snapshot of the meeting, illustrating its broad vistas. The published contributions are organized along the lines of the conference sessions, as set out in the Contents, leading off with a provocative view of Cycle 24 thus far from Sarbani Basu. Other invited papers presented here include an appreciation of Hinode's view of solar activity as the cycle rises by Toshifumi Shimizu; a first taxonomy of magnetic tornadoes and chromospheric swirls by Sven Wedemeyer {\\it et al}; an analysis of Hinode/EIS observations of transient heating events; a timely re-examination of solar dynamo theory by Paul Charbonneau; an exciting teaser for the solar potential of the Murchison Widefield Array now operating in Western Australia by Steven Tingay {\\it et al}; an overview and critique of the state of nonlinear force-free magnetic field extrapolation theory and practice by Mike Wheatland and Stuart Gilchrist; and a masterful review of atmospheric MHD wave coupling to the Sun's internal p-mode oscillations by Elena Khomenko and Irantzu Calvo Santamaria. The many contributed papers published here are no less exciting. All papers have been refereed to a high standard. The editors thank all the referees, drawn both from conference attendees and the wider community, who have taken their tasks very seriously and provided very detailed and helpful reports. Nearly all contributions have been substantially improved by the process. We must also thank our financial sponsors. Both the Global Oscillations Network Group (GONG) and LWS/SDO were generous in their support, as were the School of Mathematical Sciences and the Monash Centre for Astrophysics (MoCA) at Monash University, Melbourne, and the Centre for Astronomy at James Cook University, Townsville. The Local Organizing Committee and the many students who assisted before and during the conference also deserve high praise for facilitating such a memorable meeting. Paul Cally, Robert Erdélyi and Aimee Norton Conference photograph

  12. Assessing the Space-Radiation Hazard in Ground-Level Enhanced (GLE) Solar Particle Events (Invited)

    NASA Astrophysics Data System (ADS)

    Tylka, A. J.; Dietrich, W. F.; Atwell, W. A.

    2010-12-01

    The most severe transient radiation hazards for human spaceflight in the historical record are solar particle events associated with so-called Ground-Level Enhancements (GLEs), in which processes at the Sun can accelerate protons to GeV energies in minutes. We report on recent efforts to improve the reliability of assessments of these radiation hazards. These efforts are based on a new analysis of the entire historical data base of GLEs from 1956-2006, using the complete ensemble of measurements from riometers, satellites, and neutron-monitors, from ˜10 MeV to ˜10 GeV. Of particular importance is the functional form of the proton spectrum. We have found that the event-integrated integral proton spectrum can generally be well represented by the so-called Band function (Band et al., ApJ 413, 281-292, 1993; a double power law with a smooth rollover) in rigidity. The residuals of these fits with respect to the data typically range from <10% for satellite measurements to <30% for neutron monitor measurements. We present a new catalogue of Band fit parameters for 58 out of the 66 GLEs that have been observed since 1956. We also examine how the dose-depth profiles calculated from these Band fits differ from earlier calculations, based on assumed functional forms derived from more limited datasets. For some of the larger events, we also show hour-by-hour analysis of the accumulated dose. Supported by ONR, NASA/SRAG (IPR NNJ09HC54I), and NASA LWS/TRT (DPR NNH09AL11I).

  13. Solar Polar Jets Driven by Magnetic Reconnection, Gravity, and Wind

    NASA Astrophysics Data System (ADS)

    DeVore, C. Richard; Karpen, Judith T.; Antiochos, Spiro K.

    2014-06-01

    Polar jets are dynamic, narrow, radially extended structures observed in solar EUV emission near the limb. They originate within the open field of coronal holes in “anemone” regions, which are intrusions of opposite magnetic polarity. The key topological feature is a magnetic null point atop a dome-shaped fan surface of field lines. Applied stresses readily distort the null into a current patch, eventually inducing interchange reconnection between the closed and open fields inside and outside the fan surface (Antiochos 1996). Previously, we demonstrated that magnetic free energy stored on twisted closed field lines inside the fan surface is released explosively by the onset of fast reconnection across the current patch (Pariat et al. 2009, 2010). A dense jet comprised of a nonlinear, torsional Alfvén wave is ejected into the outer corona along the newly reconnected open field lines. Now we are extending those exploratory simulations by including the effects of solar gravity, solar wind, and expanding spherical geometry. We find that the model remains robust in the resulting more complex setting, with explosive energy release and dense jet formation occurring in the low corona due to the onset of a kink-like instability, as found in the earlier Cartesian, gravity-free, static-atmosphere cases. The spherical-geometry jet including gravity and wind propagates far more rapidly into the outer corona and inner heliosphere than a comparison jet simulation that excludes those effects. We report detailed analyses of our new results, compare them with previous work, and discuss the implications for understanding remote and in-situ observations of solar polar jets.This work was supported by NASA’s LWS TR&T program.

  14. Epistatic adaptive evolution of human color vision.

    PubMed

    Yokoyama, Shozo; Xing, Jinyi; Liu, Yang; Faggionato, Davide; Altun, Ahmet; Starmer, William T

    2014-12-01

    Establishing genotype-phenotype relationship is the key to understand the molecular mechanism of phenotypic adaptation. This initial step may be untangled by analyzing appropriate ancestral molecules, but it is a daunting task to recapitulate the evolution of non-additive (epistatic) interactions of amino acids and function of a protein separately. To adapt to the ultraviolet (UV)-free retinal environment, the short wavelength-sensitive (SWS1) visual pigment in human (human S1) switched from detecting UV to absorbing blue light during the last 90 million years. Mutagenesis experiments of the UV-sensitive pigment in the Boreoeutherian ancestor show that the blue-sensitivity was achieved by seven mutations. The experimental and quantum chemical analyses show that 4,008 of all 5,040 possible evolutionary trajectories are terminated prematurely by containing a dehydrated nonfunctional pigment. Phylogenetic analysis further suggests that human ancestors achieved the blue-sensitivity gradually and almost exclusively by epistasis. When the final stage of spectral tuning of human S1 was underway 45-30 million years ago, the middle and long wavelength-sensitive (MWS/LWS) pigments appeared and so-called trichromatic color vision was established by interprotein epistasis. The adaptive evolution of human S1 differs dramatically from orthologous pigments with a major mutational effect used in achieving blue-sensitivity in a fish and several mammalian species and in regaining UV vision in birds. These observations imply that the mechanisms of epistatic interactions must be understood by studying various orthologues in different species that have adapted to various ecological and physiological environments. PMID:25522367

  15. A 205 ?m [N II] Map of the Carina Nebula

    NASA Astrophysics Data System (ADS)

    Oberst, T. E.; Parshley, S. C.; Nikola, T.; Stacey, G. J.; Löhr, A.; Lane, A. P.; Stark, A. A.; Kamenetzky, J.

    2011-10-01

    We present the results of a ~250 arcmin2 mapping of the 205 ?m [N II] fine-structure emission over the northern Carina Nebula, including the Car I and Car II H II regions. Spectra were obtained using the South Pole Imaging Fabry-Perot Interferometer (SPIFI) at the Antarctic Submillimeter Telescope and Remote Observatory (AST/RO) at the South Pole. We supplement the 205 ?m data with new reductions of far-IR fine-structure spectra from the Infrared Space Observatory (ISO) Long Wavelength Spectrometer (LWS) in 63 ?m [O I], 122 ?m [N II], 146 ?m [O I], and 158 ?m [C II]; the 146 ?m [O I] data include 90 raster positions which have not been previously published. Morphological comparisons are made with optical, radio continuum, and CO maps. The 122/205 line ratio is used to probe the density of the low-ionization gas, and the 158/205 line ratio is used to probe the fraction of C+ arising from photodissociation regions (PDRs). The [O I] and [C II] lines are used to construct a PDR model of Carina. When the PDR properties are compared with other sources, Carina is found to be more akin to 30 Doradus than galactic star-forming regions such as Orion, M17, or W49; this is consistent with the view of Carina as a more evolved region, where much of the parent molecular cloud has been ionized or swept away. These data constitute the first ground-based detection of the 205 ?m [N II] line, and the third detection overall since those of COBE FIRAS and the Kuiper Airborne Observatory in the early 1990s.

  16. Sound radiation and wing mechanics in stridulating field crickets (Orthoptera: Gryllidae).

    PubMed

    Montealegre-Z, Fernando; Jonsson, Thorin; Robert, Daniel

    2011-06-15

    Male field crickets emit pure-tone mating calls by rubbing their wings together. Acoustic radiation is produced by rapid oscillations of the wings, as the right wing (RW), bearing a file, is swept across the plectrum borne on the left wing (LW). Earlier work found the natural resonant frequency (f(o)) of individual wings to be different, but there is no consensus on the origin of these differences. Previous studies suggested that the frequency along the song pulse is controlled independently by each wing. It has also been argued that the stridulatory file has a variable f(o) and that the frequency modulation observed in most species is associated with this variability. To test these two hypotheses, a method was developed for the non-contact measurement of wing vibrations during singing in actively stridulating Gryllus bimaculatus. Using focal microinjection of the neuroactivator eserine into the cricket's brain to elicit stridulation and micro-scanning laser Doppler vibrometry, we monitored wing vibration in actively singing insects. The results show significantly lower f(o) in LWs compared with RWs, with the LW f(o) being identical to the sound carrier frequency (N=44). But during stridulation, the two wings resonate at one identical frequency, the song carrier frequency, with the LW dominating in amplitude response. These measurements also demonstrate that the stridulatory file is a constant resonator, as no variation was observed in f(o) along the file during sound radiation. Our findings show that, as they engage in stridulation, cricket wings work as coupled oscillators that together control the mechanical oscillations generating the remarkably pure species-specific song. PMID:21613528

  17. A 205 {mu}m [N II] MAP OF THE CARINA NEBULA

    SciTech Connect

    Oberst, T. E.; Parshley, S. C.; Nikola, T.; Stacey, G. J. [Department of Astronomy, Cornell University, Ithaca, NY 14853 (United States); Loehr, A.; Lane, A. P.; Stark, A. A. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Kamenetzky, J., E-mail: oberstte@westminster.edu [Center for Astrophysics and Space Astronomy, University of Colorado, Boulder, CO 80303 (United States)

    2011-10-01

    We present the results of a {approx}250 arcmin{sup 2} mapping of the 205 {mu}m [N II] fine-structure emission over the northern Carina Nebula, including the Car I and Car II H II regions. Spectra were obtained using the South Pole Imaging Fabry-Perot Interferometer (SPIFI) at the Antarctic Submillimeter Telescope and Remote Observatory (AST/RO) at the South Pole. We supplement the 205 {mu}m data with new reductions of far-IR fine-structure spectra from the Infrared Space Observatory (ISO) Long Wavelength Spectrometer (LWS) in 63 {mu}m [O I], 122 {mu}m [N II], 146 {mu}m [O I], and 158 {mu}m [C II]; the 146 {mu}m [O I] data include 90 raster positions which have not been previously published. Morphological comparisons are made with optical, radio continuum, and CO maps. The 122/205 line ratio is used to probe the density of the low-ionization gas, and the 158/205 line ratio is used to probe the fraction of C{sup +} arising from photodissociation regions (PDRs). The [O I] and [C II] lines are used to construct a PDR model of Carina. When the PDR properties are compared with other sources, Carina is found to be more akin to 30 Doradus than galactic star-forming regions such as Orion, M17, or W49; this is consistent with the view of Carina as a more evolved region, where much of the parent molecular cloud has been ionized or swept away. These data constitute the first ground-based detection of the 205 {mu}m [N II] line, and the third detection overall since those of COBE FIRAS and the Kuiper Airborne Observatory in the early 1990s.

  18. Epistatic Adaptive Evolution of Human Color Vision

    PubMed Central

    Yokoyama, Shozo; Xing, Jinyi; Liu, Yang; Faggionato, Davide; Altun, Ahmet; Starmer, William T.

    2014-01-01

    Establishing genotype-phenotype relationship is the key to understand the molecular mechanism of phenotypic adaptation. This initial step may be untangled by analyzing appropriate ancestral molecules, but it is a daunting task to recapitulate the evolution of non-additive (epistatic) interactions of amino acids and function of a protein separately. To adapt to the ultraviolet (UV)-free retinal environment, the short wavelength-sensitive (SWS1) visual pigment in human (human S1) switched from detecting UV to absorbing blue light during the last 90 million years. Mutagenesis experiments of the UV-sensitive pigment in the Boreoeutherian ancestor show that the blue-sensitivity was achieved by seven mutations. The experimental and quantum chemical analyses show that 4,008 of all 5,040 possible evolutionary trajectories are terminated prematurely by containing a dehydrated nonfunctional pigment. Phylogenetic analysis further suggests that human ancestors achieved the blue-sensitivity gradually and almost exclusively by epistasis. When the final stage of spectral tuning of human S1 was underway 45–30 million years ago, the middle and long wavelength-sensitive (MWS/LWS) pigments appeared and so-called trichromatic color vision was established by interprotein epistasis. The adaptive evolution of human S1 differs dramatically from orthologous pigments with a major mutational effect used in achieving blue-sensitivity in a fish and several mammalian species and in regaining UV vision in birds. These observations imply that the mechanisms of epistatic interactions must be understood by studying various orthologues in different species that have adapted to various ecological and physiological environments. PMID:25522367

  19. Magnetic Topology of the Global MHD Configuration on 2010 August 1-2

    NASA Astrophysics Data System (ADS)

    Titov, V. S.; Mikic, Z.; Torok, T.; Linker, J.; Panasenco, O.

    2014-12-01

    It appears that the global magnetic topology of the solar corona predetermines to a large extent the magnetic flux transfer during solar eruptions. We have recently analyzed the global topology for a source-surface model of the background magnetic field at the time of the 2010 August 1-2 sympathetic CMEs (Titov et al. 2012). Now we extend this analysis to a more accurate thermodynamic MHD model of the solar corona. As for the source-surface model, we find a similar triplet of pseudo-streamers in the source regions of the eruptions. The new study confirms that all these pseudo-streamers contain separatrix curtains that fan out from a basic magnetic null point, individual for each of the pseudo-streamers. In combination with the associated separatrix domes, these separatrix curtains fully isolate adjacent coronal holes of the like polarity from each other. However, the size and shape of the coronal holes, as well as their open magnetic fluxes and the fluxes in the lobes of the separatrix domes, are very different for the two models. The definition of the open separator field lines, where the (interchange) reconnection between open and closed magnetic flux takes place, is also modified, since the structurally unstable source-surface null lines do not exist anymore in the MHD model. In spite of all these differences, we reassert our earlier hypothesis that magnetic reconnection at these nulls and the associated separators likely plays a key role in coupling the successive eruptions observed by SDO and STEREO. The results obtained provide further validation of our recent simplified MHD model of sympathetic eruptions (Török et al. 2011). Research supported by NASA's Heliophysics Theory and LWS Programs, and NSF/SHINE and NSF/FESD.

  20. Miniature Filament Eruptions and their Reconnections in X-Ray Jets: Evidence for a New Paradigm

    NASA Technical Reports Server (NTRS)

    Sterling, Alphonse C.; Moore, Ronald L.; Falconer, David A.

    2014-01-01

    We investigate the onset of approximately10 random X-ray jets observed by Hinode/XRT. Each jet was near the limb in a polar coronal hole, and showed a ``bright point'' in an edge of the base of the jet, as is typical for previously-observed X-ray jets. We examined SDO/AIA EUV images of each of the jets over multiple AIA channels, including 304 Ang, which detects chromospheric emissions, and 171, 193, and 211 Ang, which detect cooler-coronal emissions. We find the jets to result from eruptions of miniature (size less than approximately 10 arcsec) filaments from the bases of the jets. Much of the erupting-filament material forms a chromospheric-temperature jet. In the cool-coronal channels, often the filament appears in absorption and the jet in emission. The jet bright point forms at the location from which the miniature filament is ejected, analogous to the formation of a standard solar flare in the wake of the eruption of a typical larger-scale chromospheric filament. Thus these X-ray jets and their bright points are made by miniature filament eruptions. They are evidently produced the same way as an on-disk coronal jet we observed in Adams et al. (2014); that on-disk jet had no obvious emerging magnetic field in its base. We conclude that, for many jets, the standard idea of X-ray jets forming from reconnection between emerging flux and preexisting coronal field is incorrect. ACS and RLM were supported by funding from NASA/LWS, Hinode, and ISSI.

  1. Cold H2O and CO ice and gas toward the Galactic Center

    E-print Network

    Andrea Moneti; Jose Cernicharo; Juan Ramon Pardo

    2000-12-13

    We present observations of CO, 13CO and of H2O in the middle and far-infrared taken with the ISO-SWS and ISO-LWS spectrometers toward two positions in the Galactic Center region (Sgr A* and GCS-3). Both ice and gas phase molecules are detected. The ISO data have been complemented with observations of the J=3-2 and J=7-6 lines of CO carried out at the Caltech Submillimeter Observatory. The ISO and CSO data indicate that the absorbing gas is extremely cold, T_K ~ 10 K, suggesting that it is located in the dark clouds of the different spiral arms that intersect the line of sight towards the Galactic Center. From the analysis of the CO absorption we derive 13CO gas phase column densities of 1.1 and 0.7E17 cm-2 towards Sgr A* and GCS-3, respectively. The H2O gas column density in the direction of Sgr A* is ~ 2E16 cm-2. The derived CO/H2O and gas/solid abundance ratios corresponding to these cold clouds are remarkably similar along the two lines of sight. We find that nearly all the CO is in the gas phase, while the H2O is almost entirely frozen onto the surfaces of cold dust grains. Finally, the N_{gas+ice}(CO)/N_{gas+ice}(H2O) abundance ratio is ~5 implying that H2O formation processes are highly efficient.

  2. Test of the Angle Detecting Inclined Sensor (ADIS) Technique for Measuring Space Radiation

    NASA Astrophysics Data System (ADS)

    Connell, J. J.; Lopate, C.; McLaughlin, K. R.

    2009-12-01

    In February 2008 we exposed an Angle Detecting Inclined Sensor (ADIS) prototype to beams of 150 MeV/u 78Kr and fragments at the National Superconducting Cyclotron Laboratory's (NSCL) Coupled Cyclotron Facility (CCF). ADIS is a highly innovative and uniquely simple detector configuration used to determine the angles of incidence of heavy ions in energetic charged particle instruments. Corrections for angle of incidence are required for good charge and mass separation. An ADIS instrument is under development to fly on the GOES-R series of weather satellites. The prototype tested consisted of three ADIS detectors, two of which were inclined at an angle to the telescope axis, forming the initial detectors in a five-detector telescope stack. By comparing the signals from the ADIS detectors, the angle of incidence may be determined and a pathlength correction applied to charge and mass determinations. Thus, ADIS replaces complex position sensing detectors with a system of simple, reliable and robust Si detectors. Accelerator data were taken at multiple angles to both primary and secondary beams with a spread of energies. This test instrument represents an improvement over the previous ADIS prototype in that it used oval inclined detectors and a much lower-mass support structure, thus reducing the number of events passing through dead material. These data show a charge peak resolution of 0.18 ± 0.01 e at Br (Z = 35), excellent for such a simple instrument. We will present the results of this test. The ADIS instrument development project was partially funded by NASA under the Living With a Star (LWS) Targeted Research and Technology program (grant NAG5-12493).

  3. Visual pigments, oil droplets, lens, and cornea characterization in the whooping crane (Grus americana)

    USGS Publications Warehouse

    Porter, Megan L.; Kingston, Alexandra C. N.; McCready, Robert; Cameron, Evan G.; Hofmann, Christopher M.; Suarez, Lauren; Olsen, Glenn H.; Cronin, Thomas W.; Robinson, Phyllis R.

    2014-01-01

    Vision has been investigated in many species of birds, but few studies have considered the visual systems of large birds and the particular implications of large eyes and long-life spans on visual system capabilities. To address these issues we investigated the visual system of the whooping crane, Grus americana (Gruiformes: Gruidae). G. americana (an endangered species) is one of only two North American crane species and represents a large, long-lived bird where ultraviolet sensitivity may be degraded by chromatic aberrations and entrance of ultraviolet light into the eye could be detrimental to retinal tissues. To investigate the whooping crane visual system we used microspectrophotometry to determine the absorbance spectra of retinal oil droplets and to investigate if the ocular media (i.e., the lens and cornea) absorbs UV light. In vitro expression and reconstitution was used to determine the absorbance spectra of rod and cone visual pigments. The rod visual pigments had wavelengths of peak absorbance (?max) at 500 nm, while the cone visual pigments ?max values were determined to be 404 nm (SWS1), 450 nm (SWS2), 499 nm (RH2), and 561 nm (LWS), similar to other characterized bird visual pigment absorbance values. The oil droplet cutoff wavelength (?cut) values similarly fell within ranges recorded from other avian species: 576 nm (R-type), 522 nm (Y-type), 506 nm (P-type), and 448 nm (C-type). We confirm that G. americana has a violet-sensitive visual system, although based on the ?max of the SWS1 visual pigment (404 nm) may also have some ability for UV sensitivity.

  4. Shock excited far-infrared molecular emission around T Tau

    E-print Network

    L. Spinoglio; T. Giannini; B. Nisini; M. E. van den Ancker; E. Caux; A. M. Di Giorgio; D. Lorenzetti; F. Palla; S. Pezzuto; P. Saraceno; H. A. Smith; G. J. White

    1999-09-29

    The first complete far-infrared spectrum of T Tau has been obtained with the LWS spectrometer on-board the Infrared Space Observatory, which detected strong emission from high-J (J=14-25) CO, para- and ortho-H2O and OH transitions over the wavelength range from 40 to 190 micron. Most of the observed molecular emission can be explained by a single emission region at T~300-900 K and n(H_2)~10^(5-6) cm^(-3),with a diameter of about 2-3 arcsec. This corresponds to a very compact region of 300-400 AU at the distance of 140 pc. An higher temperature component seems to be needed to explain the highest excitation CO and water lines. We derive a water abundance of 1-7x10^(-5) and an OH abundance of ~3x10^(-5) with respect to molecular hydrogen, implying water and OH enhancements by more than a factor of 10 with respect to the expected ambient gas abundance. The observed cooling in the various species amounts to 0.04 L(sun),comparable to the mechanical luminosity of the outflow, indicating that the stellar winds could be responsible of the line excitation through shocks. In order to explain the observed molecular cooling in T Tau in terms of C-type shock models, we hypothesise that the strong far-ultraviolet radiation field photodissociates water in favour of OH. This would explain the large overabundance of OH observed. The estimated relatively high density and compactness of the observed emission suggest that it originates from the shocks taking place at the base of the molecular outflow emission, in the region where the action of the stellar winds from the two stars of the binary system is important.

  5. The Solar Dynamics Observatory: Your Eye On The Sun

    NASA Technical Reports Server (NTRS)

    Pesnell, William Dean

    2008-01-01

    The Sun hiccups and satellites die. That is what NASA's Living With a Star Program is all about. The Solar Dynamics Observatory (SDO) is the first Space Weather Mission in LWS. SDO's main goal is to understand, driving towards a predictive capability, those solar variations that influence life on Earth and humanity's technological systems. The past decade has seen an increasing emphasis on understanding the entire Sun, from the nuclear reactions at the core to the development and loss of magnetic loops in the corona. SDO's three science investigations (HMI, AIA, and EVE) will determine how the Sun's magnetic field is generated and structured, how this stored magnetic energy is released into the heliosphere and geospace as the solar wind, energetic particles, and variations in the solar irradiance. SDO will return full-disk Dopplergrams, full-disk vector magnetograms, full-disk images at nine E/UV wavelengths, and EUV spectral irradiances, all taken at a rapid cadence. This means you can "observe the database" to study events, but we can also move forward in producing quantitative models of what the Sun is doing today. SDO is scheduled to launch in 2008 on an Atlas V rocket from the Kennedy Space Center, Cape Canaveral, Florida. The satellite will fly in a 28 degree inclined geosynchronous orbit about the longitude of New Mexico, where a dedicated Ka-band ground station will receive the 150 Mbps data flow. How SDO data will transform the study of the Sun and its affect on Space Weather studies will be discussed.

  6. A Mid-Infrared Imaging Survey of Embedded Young Stellar Objects in the (rho) Ophiuchi Cloud Core

    NASA Technical Reports Server (NTRS)

    Barsony, Mary; Ressler, Michael E.; Marsh, Kenneth A.

    2005-01-01

    Results of a comprehensive, new, ground-based mid-infrared imaging survey of the young stellar population of the (rho) Ophiuchi cloud are presented. Data were acquired at the Palomar 5m and at the Keck 10m telescopes with the MIRLIN and LWS instruments, at 0'.5 and 0'.25 resolutions, respectively. Of 172 survey objects, 85 were detected. Among the 22 multiple systems observed, 15 were resolved and their individual component fluxes determined. A plot of the frequency distribution of the detected objects with SED spectral slope shows that YSOs spend approx.4 x 10(exp 5) yr in the flat-spectrum phase, clearing out their remnant infall envelopes. Mid-infrared variability is found among a significant fraction of the surveyed objects and is found to occur for all SED classes with optically thick disks. Large-amplitude near-infrared variability, also found for all SED classes with optically thick disks, seems to occur with somewhat higher frequency at the earlier evolutionary stages. Although a general trend of mid-infrared excess and near-infrared veiling exists progressing through SED classes, with Class I objects generally exhibiting r(sub K) >= 1, flat-spectrum objects with r(sub K) >= 0.58, and Class III objects with r(sub K) =0, Class II objects exhibit the widest range of r(sub K) values, ranging from 0 <= r(sub K) <= 4.5. However, the highly variable value of veiling that a single source can exhibit in any of the SED classes in which active disk accretion can take place is striking and is direct observational evidence for highly time-variable accretion activity in disks. Finally, by comparing mid-infrared versus near-infrared excesses in a subsample with well-determined effective temperatures and extinction values, disk-clearing mechanisms are explored. The results are consistent with disk clearing proceeding from the inside out.

  7. Quiescent Giant Molecular Cloud Cores in the Galactic Center

    NASA Technical Reports Server (NTRS)

    Lis, D. C.; Serabyn, E.; Zylka, R.; Li, Y.

    2000-01-01

    We have used the Long Wavelength Spectrometer (LWS) aboard the Infrared Space Observatory (ISO) to map the far-infrared continuum emission (45-175 micrometer) toward several massive Giant Molecular Cloud (GMC) cores located near the Galactic center. The observed far-infrared and submillimeter spectral energy distributions imply low temperatures (approx. 15 - 22 K) for the bulk of the dust in all the sources, consistent with external heating by the diffuse ISRF and suggest that these GMCs do not harbor high- mass star-formation sites, in spite of their large molecular mass. Observations of FIR atomic fine structure lines of C(sub II) and O(sub I) indicate an ISRF enhancement of approx. 10(exp 3) in the region. Through continuum radiative transfer modeling we show that this radiation field strength is in agreement with the observed FIR and submillimeter spectral energy distributions, assuming primarily external heating of the dust with only limited internal luminosity (approx. 2 x 10(exp 5) solar luminosity). Spectroscopic observations of millimeter-wave transitions of H2CO, CS, and C-34S carried out with the Caltech Submillimeter Observatory (CSO) and the Institut de Radio Astronomie Millimetrique (IRAM) 30-meter telescope indicate a gas temperature of approx. 80 K, significantly higher than the dust temperatures, and density of approx. 1 x 10(exp 5)/cc in GCM0.25 + 0.01, the brightest submillimeter source in the region. We suggest that shocks caused by cloud collisions in the turbulent interstellar medium in the Galactic center region are responsible for heating the molecular gas. This conclusion is supported by the presence of wide-spread emission from molecules such as SiO, SO, and CH3OH, which are considered good shock tracers. We also suggest that the GMCs studied here are representative of the "typical", pre-starforming cloud population in the Galactic center.

  8. Discovery of Interstellar Hydrogen Fluoride

    E-print Network

    David A. Neufeld; Jonas Zmuidzinas; Peter Schilke; Thomas G. Phillips

    1997-08-01

    We report the first detection of interstellar hydrogen fluoride. Using the Long Wavelength Spectrometer (LWS) of the Infrared Space Observatory (ISO), we have detected the 121.6973 micron J = 2 - 1 line of HF in absorption toward the far-infrared continuum source Sagittarius B2. The detection is statistically significant at the 13 sigma level. On the basis of our model for the excitation of HF in Sgr B2, the observed line equivalent width of 1.0 nm implies a hydrogen fluoride abundance of 3E-10 relative to H2. If the elemental abundance of fluorine in Sgr B2 is the same as that in the solar system, then HF accounts for ~ 2% of the total number of fluorine nuclei. We expect hydrogen fluoride to be the dominant reservoir of gas-phase fluorine in Sgr B2, because it is formed rapidly in exothermic reactions of atomic fluorine with either water or molecular hydrogen; thus the measured HF abundance suggests a substantial depletion of fluorine onto dust grains. Similar conclusions regarding depletion have previously been reached for the case of chlorine in dense interstellar clouds. We also find evidence at a lower level of statistical significance (~ 5 sigma) for an emission feature at the expected position of the 4(3,2)-4(2,3) 121.7219 micron line of water. The emission line equivalent width of 0.5 nm for the water feature is consistent with the water abundance of 5E-6 relative to H2 that has been inferred previously from observations of the hot core of Sgr B2.

  9. Large Silicon Abundance in Photodissociation Regions

    E-print Network

    Yoko Okada; Takashi Onaka; Takao Nakagawa; Hiroshi Shibai; Daigo Tomono; Yukari Y. Yui

    2005-11-17

    We have made one-dimensional raster-scan observations of the rho Oph and sigma Sco star-forming regions with two spectrometers (SWS and LWS) on board the ISO. In the rho Oph region, [SiII] 35um, [OI] 63um, 146um, [CII] 158um, and the H2 pure rotational transition lines S(0) to S(3) are detected, and the PDR properties are derived as the radiation field scaled by the solar neighborhood value G_0~30-500, the gas density n~250--2500 /cc, and the surface temperature T~100-400 K. The ratio of [SiII] 35um to [OI] 146um indicates that silicon of 10--20% of the solar abundance must be in the gaseous form in the photodissociation region (PDR), suggesting that efficient dust destruction is undergoing even in the PDR and that part of silicon atoms may be contained in volatile forms in dust grains. The [OI] 63um and [CII] 158um emissions are too weak relative to [OI] 146um to be accounted for by standard PDR models. We propose a simple model, in which overlapping PDR clouds along the line of sight absorb the [OI] 63um and [CII] 158um emissions, and show that the proposed model reproduces the observed line intensities fairly well. In the sigma Sco region, we have detected 3 fine-structure lines, [OI] 63um, [NII] 122um, and [CII] 158um, and derived that 30-80% of the [CII] emission comes from the ionized gas. The upper limit of the [SiII] 35um is compatible with the solar abundance relative to nitrogen and no useful constraint on the gaseous Si is obtained for the sigma Sco region.

  10. Design and evaluation of net radiometers

    NASA Astrophysics Data System (ADS)

    Fritschen, Leo J.; Fritschen, Charles L.

    Net radiometer designs were evaluated with respect to long and short wave sensitivities and to the effect of ambient wind on the signal. The design features of the instrument with the best overall performance include: equal sensitivity to long and short wave radiation, a thermal pile which is thermally isolated from the frame, a white guard ring, pathways for internal circulation between the top and bottom hemispheres, and self-supporting windshields. The windshields have O-ring seals, a ball joint is provided for ease of leveling, and ample desiccant is enclosed in the mounting pipe. Under a high radiant load, the net radiometer signal decreased by 2.5, 3.7, and 4.3 percent at wind speeds of 12.5, 4.6, and 7.5 m/s.

  11. Effects of picrotoxin on the turtle's electroretinogram under different background illumination.

    PubMed

    Kupenova, P; Belcheva, S; Vitanova, L; Penchev, A

    1986-01-01

    The effect of 0.4 mM solution of picrotoxin (PT) on the electroretinogram (ERG) of isolated eyecup preparations of turtle (Emys orbicularis) was investigated under two different backgrounds (Ib)--scotopic (0.009 lx) and mesopic (9 lx). The test stimulus intensity was 46 lx. An increase of the amplitudes of all ERG waves was observed after PT application. The relative increase of the d-wave was the most pronounced one and was similar under the two Ib. The relative increase of the b-wave, however, was greater in mesopic than in scotopic conditions. The two subcomponents of the a-wave were differentially influenced by PT. The development of a new steady level of b-wave sensitivity was delayed after PT. PMID:3020874

  12. Combined Wind Vector and Sea State Impact on Ocean Nadir-Viewing Ku- and C-Band Radar Cross-Sections

    PubMed Central

    Tran, Ngan; Chapron, Bertrand

    2006-01-01

    The authors report the first results in studying the polarization anisotropy of the microwave backscatter from nadir observations provided