Two opsins from the compound eye of the crab Hemigrapsus sanguineus

1996 ◽  
Vol 199 (2) ◽  
pp. 441-450 ◽  
Author(s):  
K Sakamoto ◽  
O Hisatomi ◽  
F Tokunaga ◽  
E Eguchi
Keyword(s):  
Photoreceptor Cell ◽  
Compound Eye ◽  
Visual Pigments ◽  
Amino Acid Residues ◽  
Hemigrapsus Sanguineus ◽  
Brachyuran Crab ◽  
Maximal Absorption ◽  
Retinular Cells ◽  
Cdna Nucleotide

The primary structures of two opsins from the brachyuran crab Hemigrapsus sanguineus were deduced from the cDNA nucleotide sequences. Both deduced proteins were composed of 377 amino acid residues and included residues highly conserved in visual pigments of other species, and the proteins were 75 % identical to each other. The distribution of opsin transcripts in the compound eye, determined by in situ hybridization, suggested that the mRNAs of the two opsins were expressed simultaneously in all of the seven retinular cells (R1-R7) forming the main rhabdom in each ommatidium. Two different visual pigments may be present in one photoreceptor cell in this brachyuran crab. The spectral sensitivity of the compound eye was also determined by recording the electroretinogram. The compound eye was maximally sensitive at about 480 nm. These and previous findings suggest that both opsins of this brachyuran crab produce visual pigments with maximal absorption in the blue-green region of the spectrum. Evidence is presented that crustaceans possess multiple pigment systems for vision.

scholarly journals Drosophila R8 photoreceptor cell subtype specification requires Notch and hibris

2018 ◽  
Author(s):  
Hong Tan ◽  
Ruth E. Fulton ◽  
Wen-Hai Chou ◽  
Denise A. Birkholz ◽  
Meridee P. Mannino ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Cell Differentiation ◽  
Photoreceptor Cell ◽  
Compound Eye ◽  
Visual Pigments ◽  
Exact Nature ◽  
Diverse Range ◽  
Developmental Program ◽  
Color Sensitivity ◽  
Different Types

AbstractCell differentiation and cell fate determination in sensory systems are essential for stimulus discrimination and coding of environmental stimuli. Color vision is based on the differential color sensitivity of retinal photoreceptors, however the developmental programs that control photoreceptor cell differentiation and specify color sensitivity are poorly understood. In Drosophila melanogaster, there is evidence that the color sensitivity of different photoreceptors in the compound eye is regulated by inductive signals between cells, but the exact nature of these signals and how they are propagated remains unknown. We conducted a genetic screen to identify additional regulators of this process and identified a novel mutation in the hibris gene. hibris encodes an irre cell recognition module protein (IRM). These immunoglobulin super family cell adhesion molecules include human neph and nephrin (NPHS1). hibris is expressed dynamically in the developing Drosophila melanogaster eye and loss-of-function mutations give rise to a diverse range of mutant phenotypes including disruption of the specification of R8 photoreceptors cell diversity. The specification of blue or green sensitivity in R8 cells is also dependent upon Notch signaling. We demonstrate that hibris is required within the retina, non-cell autonomously for these effects, suggesting an additional layer of complexity in the signaling process that produces paired expression of opsin genes in adjacent R7 and R8 photoreceptor cells.Author SummaryAs humans, our ability to distinguish different colors is dependent upon the presence of three different types of cone cell neurons in the retina of the eye. The cone cells express blue, green or red absorbing visual pigments that detect and discriminate between these colors. The principle of color discrimination by neurons “tuned” to different colors is an evolutionarily conserved specialization that occurs in many different animals. This specialization requires 1) visual pigments that detect different colors and 2) a developmental program that regulates the expression of these pigments in different types of cells. In this study we discovered that the fruit fly (Drosophila melanogaster) gene hibris is required for the developmental program that produces blue sensitive neurons in the fly retina. When we over-expressed hibris throughout the developing retina, extra blue sensitive cells were produced. These results demonstrate that if there is not enough hibris, too few blue sensitive cells form, but if there is too much hibris, too many blue sensitive cells form. Finally, we discovered that the hibris gene does not act in color sensitive neurons of the retina themselves. This surprising discovery suggests that hibris may influence development of the retina in a completely new and different way.

scholarly journals Actin-based vesicular transport in the first 20 min after dusk is crucial for daily rhabdom synthesis in the compound eye of the grapsid crab Hemigrapsus sanguineus.

1997 ◽  
Vol 200 (18) ◽  
pp. 2387-2392
Author(s):  
A Matsushita ◽  
K Arikawa
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Body ◽  
Actin Filaments ◽  
Photoreceptor Cell ◽  
Compound Eye ◽  
Smooth Endoplasmic Reticulum ◽  
Cytochalasin D ◽  
Hemigrapsus Sanguineus ◽  
Grapsid Crab ◽  
Light:Dark Cycle

In the crab Hemigrapsus sanguineus, maintained under a 12 h:12 h light:dark cycle, the amount of vesicular smooth endoplasmic reticulum (vesicular sER) in the photoreceptor cell body increases after the light is turned off. This paper demonstrates that actin filaments in the photoreceptor cell body are involved in the transport of vesicular sER towards the rhabdom. To specify the time of actin contribution to rhabdom synthesis, we disrupted the organization of actin filaments in the cell body with cytochalasin D at various time around dusk. We then measured the rhabdom size and also examined the ultrastructure of the photoreceptor cell body 3 h after extinguishing the light. When cytochalasin D was applied from either 1 h before or immediately after extinguishing the light, the rhabdom size did not increase, whereas vesicular sER accumulated in the cell body. In contrast, cytochalasin D applied to the eyes from 20 min after turning the light off did not inhibit rhabdom synthesis. These results indicate that the first 20 min after the light is turned off is particularly important for the transport of vesicular sER towards the rhabdom by the cell body actin filaments.

Three opsin-encoding cDNAS from the compound eye of Manduca sexta.

1997 ◽  
Vol 200 (18) ◽  
pp. 2469-2478 ◽  
Author(s):  
M R Chase ◽  
R R Bennett ◽  
R H White
Keyword(s):  
Amino Acid ◽  
Manduca Sexta ◽  
Compound Eye ◽  
Visual Pigments ◽  
Phylogenetic Group ◽  
Amino Acid Residues ◽  
Praying Mantis ◽  
Long Wavelength ◽  
Related Group

Three distinct opsin-encoding cDNAs, designated MANOP1, MANOP2 and MANOP3, were isolated from the retina of the sphingid moth Manduca sexta. MANOP1 codes for a protein with 377 amino acid residues. It is similar in sequence to members of a phylogenetic group of long-wavelength-sensitive arthropod photopigments, most closely resembling the opsins of ants, a praying mantis, a locust and the honeybee. MANOP2 and MANOP3 opsins have 377 and 384 residues respectively. They belong to a related group of insect visual pigments that include the ultraviolet-sensitive rhodopsins of flies as well as other insect rhodopsins that are also thought to absorb at short wavelengths. The retina of Manduca sexta contains three rhodopsins, P520, P450 and P357, with absorbance peaks, respectively, at green, blue and ultraviolet wavelengths. There is evidence that MANOP1 encodes the opsin of P520. We suggest that MANOP2 encodes P357 and that MANOP3, representing a class of blue-sensitive insect photopigments, encodes P450.

scholarly journals Two visual pigments in a single photoreceptor cell: identification and histological localization of three mRNAs encoding visual pigment opsins in the retina of the butterfly Papilio xuthus.

1998 ◽  
Vol 201 (9) ◽  
pp. 1255-1261 ◽  
Author(s):  
J Kitamoto ◽  
K Sakamoto ◽  
K Ozaki ◽  
Y Mishina ◽  
K Arikawa
Keyword(s):  
In Situ Hybridization ◽  
Visual Pigment ◽  
Photoreceptor Cell ◽  
Wavelength Region ◽  
Photoreceptor Cells ◽  
Visual Pigments ◽  
Cell Identification ◽  
Papilio Xuthus

This paper describes the localization of newly identified visual pigment opsins in the tiered retina of the Japanese yellow swallowtail Papilio xuthus. We first cloned three cDNAs encoding visual pigment opsins, PxRh1, PxRh2 and PxRh3, and then carried out histological in situ hybridization to localize their mRNAs in the retina. By combining the present data with our previous electrophysiological results, we concluded that both PxRh1 and PxRh2 correspond to visual pigments expressed in photoreceptor cells sensitive in the green wavelength region (green receptors), whereas PxRh3 corresponds to a pigment in red receptors. The in situ hybridization studies showed that some photoreceptor cells express two opsin mRNAs. In the ventral half of the eye, all green receptors in the distal tier were labelled by both PxRh1 and PxRh2 probes. The labelling by the PxRh2 and PxRh3 probes was detected throughout the eye in the proximal tier; in 18 % of ommatidia, the probes labelled the same photoreceptor cell. These results suggest that the possible co-localization of two different visual pigments will broaden the sensitivity spectrum of the photoreceptor cells.

scholarly journals Adiponectin receptor 1 conserves docosahexaenoic acid and promotes photoreceptor cell survival

2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Dennis S. Rice ◽  
Jorgelina M. Calandria ◽  
William C. Gordon ◽  
Bokkyoo Jun ◽  
Yongdong Zhou ◽  
...  
Keyword(s):  
Docosahexaenoic Acid ◽  
Opposite Effect ◽  
Photoreceptor Cell ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Adiponectin Receptor ◽  
Cell Integrity ◽  
Photoreceptor Degeneration ◽  
Adiponectin Receptor 1

Abstract The identification of pathways necessary for photoreceptor and retinal pigment epithelium (RPE) function is critical to uncover therapies for blindness. Here we report the discovery of adiponectin receptor 1 (AdipoR1) as a regulator of these cells’ functions. Docosahexaenoic acid (DHA) is avidly retained in photoreceptors, while mechanisms controlling DHA uptake and retention are unknown. Thus, we demonstrate that AdipoR1 ablation results in DHA reduction. In situ hybridization reveals photoreceptor and RPE cell AdipoR1 expression, blunted in AdipoR1−/− mice. We also find decreased photoreceptor-specific phosphatidylcholine containing very long-chain polyunsaturated fatty acids and severely attenuated electroretinograms. These changes precede progressive photoreceptor degeneration in AdipoR1−/− mice. RPE-rich eyecup cultures from AdipoR1−/− reveal impaired DHA uptake. AdipoR1 overexpression in RPE cells enhances DHA uptake, whereas AdipoR1 silencing has the opposite effect. These results establish AdipoR1 as a regulatory switch of DHA uptake, retention, conservation and elongation in photoreceptors and RPE, thus preserving photoreceptor cell integrity.

scholarly journals The Differences in the Expressions of Visual Pigments and Transducin in Photoreceptor Cell Differentiation.

1996 ◽  
Vol 178 (3) ◽  
pp. 233-240 ◽  
Author(s):  
Hiroshi Ohguro ◽  
Kouichi Kitamura ◽  
Kenji Konari ◽  
Hitoshi Sohma ◽  
Yoshitaka Fukada ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Photoreceptor Cell ◽  
Visual Pigments

Fine structure of the compound eye of the black fly Simulium vittatum (Diptera: Simuliidae)

1987 ◽  
Vol 65 (6) ◽  
pp. 1454-1469 ◽  
Author(s):  
Gail E. O'Grady ◽  
Susan B. McIver
Keyword(s):  
Fine Structure ◽  
Compound Eye ◽  
Sensory Receptor ◽  
Dorsal Region ◽  
Male And Female ◽  
Simulium Vittatum ◽  
Transmission Electron ◽  
Accessory Pigment ◽  
Open Rhabdom ◽  
Retinular Cells

The fine structure of the ommatidia in light- and dark-adapted eyes of male and female Simulium vittatum Zetterstedt was investigated using scanning and transmission electron microscopy. The male eye is divided into distinct dorsal and ventral regions. The facets in the dorsal region are approximately two times larger than those in the ventral one, which are similar in size to the ones in the female eye. All ommatidia of S. vittatum examined consist of two general regions: a distal dioptric apparatus with bordering primary and accessory pigment and Semper cells, and a sensory receptor layer. Each ommatidium in the female eye and ventral eye of the male has eight retinular cells (R cells): six peripheral (R1–6) and two central (R7, R8). R7 occurs distally and R8 basally. Strikingly, the ommatidia in the dorsal eye of the male lack the R7 cell. In all ommatidia, rhabdomeres on the inner surface of the peripheral R cells are separate throughout their length, creating an open rhabdom. A greater diameter of corneal facets, elongated peripheral R cells, and perhaps the lack of the R7 cell are specializations of the dorsal region of the eye that help the male to detect small, rapidly moving females against the skylight as they fly above the swarm of males. Differences observed between light- and dark-adapted eyes of male and female S. vittatum were the same and were associated with the internal components of the peripheral R cells.

scholarly journals How [FeFe]-Hydrogenase Facilitates Bidirectional Proton Transfer

2019 ◽  
Author(s):  
Moritz Senger ◽  
Viktor Eichmann ◽  
Konstantin Laun ◽  
Jifu Duan ◽  
Florian Wittkamp ◽  
...  
Keyword(s):  
Amino Acid ◽  
Proton Transfer ◽  
Active Site ◽  
Molecular Hydrogen ◽  
H2 Production ◽  
Amino Acid Residues ◽  
Difference Spectroscopy ◽  
Dynamic Changes ◽  
In Situ Ir

Hydrogenases are metalloenzymes that catalyse the interconversion of protons and molecular hydrogen, H2. [FeFe]-hydrogenases show particularly high rates of hydrogen turnover and have inspired numerous compounds for biomimetic H2 production. Two decades of research on the active site cofactor of [FeFe]-hydrogenases have put forward multiple models of the catalytic proceedings. In comparison, understanding of the catalytic proton transfer is poor. We were able to identify the amino acid residues forming a proton transfer pathway between active site cofactor and bulk solvent; however, the exact mechanism of catalytic proton transfer remained inconclusive. Here, we employ in situ IR difference spectroscopy on the [FeFe]-hydrogenase from Chlamydomonas reinhardtii evaluating dynamic changes in the hydrogen-bonding network upon catalytic proton transfer. Our analysis allows for a direct, molecular unique assignment to individual amino acid residues. We found that transient protonation changes of arginine and glutamic acid residues facilitate bidirectional proton transfer in [FeFe]-hydrogenases.<br>

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