Extracellular shedding of photoreceptor membrane in the open rhabdom of a tipulid fly

1980 ◽  
Vol 205 (3) ◽  
Author(s):  
DavidS. Williams ◽  
A.D. Blest
Keyword(s):  
Photoreceptor Membrane ◽  
Open Rhabdom

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 Distinct roles of Bazooka and Stardust in the specification of Drosophila photoreceptor membrane architecture

2003 ◽  
Vol 100 (22) ◽  
pp. 12712-12717 ◽  
Author(s):  
Y. Hong ◽  
L. Ackerman ◽  
L. Y. Jan ◽  
Y.-N. Jan
Keyword(s):  
Photoreceptor Membrane ◽  
Drosophila Photoreceptor ◽  
Membrane Architecture

APPEARANCE OF PHOTOINDUCED POTENTIAL ON PHOTORECEPTOR MEMBRANE

1980 ◽  
pp. 433-437 ◽  
Author(s):  
V.I. Bolshakov ◽  
G.R. Kalamkarov ◽  
M.A. Ostrovsky
Keyword(s):  
Photoreceptor Membrane

scholarly journals Dark-adaptation in the eyes of a lake and a sea population of opossum shrimp (Mysis relicta): retinoid isomer dynamics, rhodopsin regeneration, and recovery of light sensitivity

2020 ◽  
Vol 206 (6) ◽  
pp. 871-889
Author(s):  
Tatiana Feldman ◽  
Marina Yakovleva ◽  
Martta Viljanen ◽  
Magnus Lindström ◽  
Kristian Donner ◽  
...  
Keyword(s):  
Dark Adaptation ◽  
Severe Depression ◽  
Light Sensitivity ◽  
Membrane Turnover ◽  
Low Light ◽  
Photoreceptor Membrane ◽  
Mysis Relicta ◽  
Opossum Shrimp ◽  
Exposure Levels ◽  
Photoreceptor Membranes

Abstract We have studied dark-adaptation at three levels in the eyes of the crustacean Mysis relicta over 2–3 weeks after exposing initially dark-adapted animals to strong white light: regeneration of 11-cis retinal through the retinoid cycle (by HPLC), restoration of native rhodopsin in photoreceptor membranes (by MSP), and recovery of eye photosensitivity (by ERG). We compare two model populations (“Sea”, Sp, and “Lake”, Lp) inhabiting, respectively, a low light and an extremely dark environment. 11-cis retinal reached 60–70% of the pre-exposure levels after 2 weeks in darkness in both populations. The only significant Lp/Sp difference in the retinoid cycle was that Lp had much higher levels of retinol, both basal and light-released. In Sp, rhodopsin restoration and eye photoresponse recovery parallelled 11-cis retinal regeneration. In Lp, however, even after 3 weeks only ca. 25% of the rhabdoms studied had incorporated new rhodopsin, and eye photosensitivity showed only incipient recovery from severe depression. The absorbance spectra of the majority of the Lp rhabdoms stayed constant around 490–500 nm, consistent with metarhodopsin II dominance. We conclude that sensitivity recovery of Sp eyes was rate-limited by the regeneration of 11-cis retinal, whilst that of Lp eyes was limited by inertia in photoreceptor membrane turnover.

scholarly journals Renewal of opsin in the photoreceptor cells of the mosquito.

1979 ◽  
Vol 74 (5) ◽  
pp. 565-582 ◽  
Author(s):  
P J Stein ◽  
J D Brammer ◽  
S E Ostroy
Keyword(s):  
Membrane Protein ◽  
Protein Metabolism ◽  
Gel Electrophoresis ◽  
Visual Pigment ◽  
Light Adaptation ◽  
Sodium Dodecyl ◽  
Photoreceptor Cells ◽  
Membrane Turnover ◽  
Photoreceptor Membrane ◽  
Perinuclear Cytoplasm

Mosquito rhodopsin is a digitonin-soluble membrane protein of molecular weight 39,000 daltons, as determined by sodium dodecyl sulfate gel electrophoresis. The rhodopsin undergoes a spectral transition from R515-520 to M480 after orange illumination. The visual pigment apoprotein, opsin, is the major membrane protein in the eye. Protein synthesis in the photoreceptor cells occurs in the perinuclear cytoplasm and the newly made protein is transported to the rhabdom. Light adaptation increases the rate of turnover of this rhabdomal protein. The turnover of electrophoretically isolated opsin is also stimulated by light adaptation. The changes observed in protein metabolism biochemically, are consistent with previous morphological observations of photoreceptor membrane turnover. The results agree with the hypothesis that the newly synthesized rhabdomal protein is opsin.

A possible role of rhodopsin in maintaining bilayer structure in the photoreceptor membrane

1979 ◽  
Vol 558 (3) ◽  
pp. 330-337 ◽  
Author(s):  
W.J. De Grip ◽  
E.H.S. Drenthe ◽  
C.J.A. Van Echteld ◽  
B. De Kruijff ◽  
A.J. Verkleij
Keyword(s):  
Bilayer Structure ◽  
Photoreceptor Membrane

scholarly journals Properties of tetraethylammonium ion-resistant K+ channels in the photoreceptor membrane of the giant barnacle.

1981 ◽  
Vol 77 (6) ◽  
pp. 629-646 ◽  
Author(s):  
D R Edgington ◽  
A E Stuart
Keyword(s):  
Action Potential ◽  
Action Potentials ◽  
Cardiac Glycosides ◽  
Time Course ◽  
Photoreceptor Membrane ◽  
K Channels ◽  
Na Pump ◽  
Tetraethylammonium Ion ◽  
Electrogenic Na Pump ◽  
Time Courses

After the offset of illumination, barnacle photoreceptors undergo a large hyperpolarization that lasts seconds or minutes. We studied the mechanisms that generate this afterpotential by recording afterpotentials intracellularly from the medial photoreceptors of the giant barnacle Balanus nubilus. The afterpotential has two components with different time-courses: (a) an earlier component due to an increase in conductance to K+ that is not blocked by extracellular tetraethylammonium ion (TEA+) or 3-aminopyridine (3-AP) and (b) a later component that is sensitive to cardiac glycosides and that requires extracellular K+, suggesting that it is due to an electrogenic Na+ pump. The K+ conductance component increases in amplitude with increasing CA++ concentration and is inhibited by extracellular Co++; the Co++ inhibition can be overcome by increasing the Ca++ concentration. Thus, the K+ conductance component is Ca++ dependent. An afterpotential similar to that evoked by a brief flash of light is generated by depolarization with current in the dark and by eliciting Ca++ action potentials in the presence of TEA+ in the soma, axon, or terminal regions of the photoreceptor. The action potential undershoot is generated by an increase in conductance to K+ that is resistant to TEA+ and 3-AP and inhibited by Co++. The similarity in time-course and pharmacology of the hyperpolarization afterpotentials elicited by (a) a brief flash of light, (b) depolarization with current, and (c) an action potential indicates that Ca++-dependent K+ channels throughout the photoreceptor membrane are responsible for all three hyperpolarizing events.

Transbilayer distribution of phospholipids in photoreceptor membrane studied with various phospholipases

1980 ◽  
Vol 603 (1) ◽  
pp. 117-129 ◽  
Author(s):  
E.H.S. Drenthe ◽  
S.L. Bonting ◽  
F.J.M. Daemen
Keyword(s):  
Photoreceptor Membrane

Circular dichroism of oriented photoreceptor membrane film

1980 ◽  
Vol 94 (2) ◽  
pp. 618-624 ◽  
Author(s):  
Ta-Lee Hsiao ◽  
Kenneth J. Rothschild
Keyword(s):  
Circular Dichroism ◽  
Photoreceptor Membrane ◽  
Circular Dichroïsm
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