Diplostomum adamsi sp.n.: description, life cycle, and pathogenesis in the retina of Perca flavescens

1977 ◽  
Vol 55 (1) ◽  
pp. 64-73 ◽  
Author(s):  
R. J. G. Lester ◽  
H. W. Huizinga
Keyword(s):  
Gasterosteus Aculeatus ◽  
Pigment Epithelium ◽  
Perca Flavescens ◽  
Photoreceptor Cells ◽  
Salvelinus Namaycush ◽  
Anterior Testis ◽  
Peripheral Retina ◽  
Catostomus Commersoni ◽  
Semotilus Atromaculatus ◽  
Lymnaea Elodes

Forty-two perch eyes (Perca flavescens) infected with metacercariae of Diplostomum adamsi were fed to a herring gull (Larus argentatus). Eighty adults were recovered from the intestine 10 days later. They were characterized by their small size (1.5 to 2.1 mm), asymmetrical anterior testis, and the absence of vitellaria in forebody anterior to the middle of the ventral sucker.Eggs of D. adamsi passed by the gull embryonated in 22 days at 22 °C and hatched when exposed to light. Miracidia penetrated snails of the species Lymnaea elodes and L. stagnalis. Forty days later straight-tailed cercariae with six pairs of caudal bodies were released from both lymnaeids. They penetrated and developed in P. flavescens but not in Salvelinus namaycush, Catostomus commersoni, Semotilus atromaculatus, or Carassius auratus. In P. flavescens, metacercariae were found in clusters in the peripheral retina, in a cavity between the photoreceptor cells and the pigment epithelium. The photoreceptor cells were disorganized but not destroyed, unlike those in the eyes of Gasterosteus aculeatus parasitized by D. scudderi.

The biology of Trypanosoma phaleri n.sp. from bowfin, Amia calva L., in Canada and the United States

1990 ◽  
Vol 68 (9) ◽  
pp. 1956-1961 ◽  
Author(s):  
Simon R. M. Jones ◽  
Patrick T. K. Woo
Keyword(s):  
Carassius Auratus ◽  
Gasterosteus Aculeatus ◽  
Perca Flavescens ◽  
The United States ◽  
Salmo Gairdneri ◽  
Anguilla Rostrata ◽  
Catostomus Commersoni ◽  
Ictalurus Nebulosus ◽  
Amia Calva ◽  
A New Species

Between 1985 and 1989, 133 of 136 (98%) bowfin (Amia calva) collected from Lakes Ontario, Erie and Huron, Ontario, Canada, and from Sugg's Lake, Florida, U.S.A., were infected with a new species of trypanosome. Trypanosoma phaleri n.sp. was pleomorphic, developed to infective metatrypanosomes in the leech Desserobdella phalera, and was transmitted by D. phalera to laboratory-reared bowfin but not to Catostomus commersoni, Anguilla rostrata, Ictalurus nebulosus, Gasterosteus aculeatus, Salmo gairdneri, Perca flavescens, Stizostedion vitreum, or Carassius auratus. Trypanosoma phaleri n.sp. developed poorly in the leech Hemiclepsis marginata.

Survival to hatching of fishes in sulfate-saline waters, Devils Lake, North Dakota

1995 ◽  
Vol 52 (3) ◽  
pp. 464-469 ◽  
Author(s):  
Todd M. Koel ◽  
John J. Peterka
Keyword(s):  
North Dakota ◽  
Sodium Sulfate ◽  
Yellow Perch ◽  
Hatching Success ◽  
Perca Flavescens ◽  
White Sucker ◽  
Catostomus Commersoni ◽  
Devils Lake ◽  
Common Carp Cyprinus Carpio ◽  
Species Survival

Laboratory-based bioassays were conducted to determine concentrations of sodium-sulfate type salinities that limit the hatching success of several fish species. Survival to hatching (SH) was significantly lower (P < 0.05) in sodium-sulfate type waters from Devils Lake, North Dakota, of ≥ 2400 mg/L total dissolved solids (TDS) than in fresh water of 200 mg/L. In waters of 200, 1150, 2400, 4250, and 6350 mg/L TDS, walleye (Stizostedion vitreum) SH was 41, 38, 7, 1, and 0%; northern pike (Esox lucius) SH was 92, 68, 33, 2, and 0%; yellow perch (Perca flavescens) SH was 88, 70, 73, 0, and 0%; white sucker (Catostomus commersoni) SH was 87, 95, 66, 0, and 0%; common carp (Cyprinus carpio) SH was 71, 69, 49, 63, and 25%.

scholarly journals INHERITED RETINAL DYSTROPHY IN THE RAT

1962 ◽  
Vol 14 (1) ◽  
pp. 73-109 ◽  
Author(s):  
John E. Dowling ◽  
Richard L. Sidman
Keyword(s):  
Pigment Epithelium ◽  
Light And Electron Microscopy ◽  
Retinal Dystrophy ◽  
Photoreceptor Cells ◽  
Pigment Cells ◽  
Membrane Thickness ◽  
Outer Segments ◽  
Progressive Loss ◽  
Retinal Rods ◽  
Microscopy Data

Retinal dystrophies, known in man, dog, mouse, and rat, involve progressive loss of photoreceptor cells with onset during or soon after the developmental period. Functional (electroretinogram), chemical (rhodopsin analyses) and morphological (light and electron microscopy) data obtained in the rat indicated two main processes: (a) overproduction of rhodopsin and an associated abnormal lamellar tissue component, (b) progressive loss of photoreceptor cells. The first abnormality recognized was the appearance of swirling sheets or bundles of extracellular lamellae between normally developing retinal rods and pigment epithelium; membrane thickness and spacing resembled that in normal outer segments. Rhodopsin content reached twice normal values, was present in both rods and extracellular lamellae, and was qualitatively normal, judged by absorption maximum and products of bleaching. Photoreceptors attained virtually adult form and ERG function. Then rod inner segments and nuclei began degenerating; the ERG lost sensitivity and showed selective depression of the a-wave at high luminances. Outer segments and lamellae gradually degenerated and rhodopsin content decreased. No phagocytosis was seen, though pigment cells partially dedifferentiated and many migrated through the outer segment-debris zone toward the retina. Eventually photoreceptor cells and the b-wave of the ERG entirely disappeared. Rats kept in darkness retained electrical activity, rhodopsin content, rod structure, and extracellular lamellae longer than litter mates in light.

The effect of extrinsic factors on two distinctive rhodopsin–porphyropsin systems

1977 ◽  
Vol 55 (6) ◽  
pp. 1000-1009 ◽  
Author(s):  
William N. McFarland ◽  
Donald M. Allen
Keyword(s):  
Visual Pigment ◽  
Brook Trout ◽  
Pigment Epithelium ◽  
Cold Treatment ◽  
Continuous Light ◽  
Photoreceptor Cells ◽  
Pigment Composition ◽  
Extrinsic Factors ◽  
Treatment Groups ◽  
Species Groups

The effects of light, temperature, and thyroxine on the proportions of two visual pigments (rhodopsin and porphyropsin) are compared for three species of fishes in which the pigment proportions change oppositely in response to light (rainbow and brook trout vs. common shiners). In rainbow trout and common shiners higher temperatures reduced the proportions of porphyropsin in the retina, independent of photic conditions. The greatest differences between the warm and cold treatment groups, however, were obtained with a photoperiod as contrasted with continuous light or darkness. Capping of one eye in brook trout reduced porphyropsin independently of the uncapped eye. Thyroxine, which favors porphyropsin in both species groups, acted effectively only in the presence of light. It is suggested that a photoperiod, which produces both bleaching and photomechanical movements within the retina, enhances the exchange of vitamin A1 and A2 aldehydes between the photoreceptor cells and the pigment epithelium. Apparently light influences these processes oppositely in the different groups of fishes. A model to explain how photic conditions affect visual pigment composition in tadpoles (Bridges 1975) is extended to account for the opposite responses to light and darkness observed in different fishes.

JAM-C maintains VEGR2 expression to promote retinal pigment epithelium cell survival under oxidative stress

2017 ◽  
Vol 117 (04) ◽  
pp. 750-757
Author(s):  
Xin Jia ◽  
Chen Zhao ◽  
Qishan Chen ◽  
Yuxiang Du ◽  
Lijuan Huang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Retinal Pigment Epithelium ◽  
Cell Survival ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Retinal Pigment Epithelium Cell ◽  
Photoreceptor Cells ◽  
Rpe Cells

SummaryJunctional adhesion molecule-C (JAM-C) has been shown to play critical roles during development and in immune responses. However, its role in adult eyes under oxidative stress remains poorly understood. Here, we report that JAM-C is abundantly expressed in adult mouse retinae and choroids in vivo and in cultured retinal pigment epithelium (RPE) and photoreceptor cells in vitro. Importantly, both JAM-C expression and its membrane localisation are downregulated by H2O2-induced oxidative stress. Under H2O2-induced oxidative stress, JAM-C is critically required for the survival of human RPE cells. Indeed, loss of JAM-C by siRNA knockdown decreased RPE cell survival. Mechanistically, we show that JAM-C is required to maintain VEGFR2 expression in RPE cells, and VEGFR2 plays an important role in keeping the RPE cells viable since overexpression of VEGFR2 partially restored impaired RPE survival caused by JAM-C knockdown and increased RPE survival. We further show that JAM-C regulates VEGFR2 expression and, in turn, modulates p38 phosphorylation. Together, our data demonstrate that JAM-C plays an important role in maintaining VEGR2 expression to promote RPE cell survival under oxidative stress. Given the vital importance of RPE in the eye, approaches that can modulate JAM-C expression may have therapeutic values in treating diseases with impaired RPE survival.

Responses of Walleye (Stizostedion vitreum vitreum) and Yellow Perch (Perca flavescens) Populations to Removal of White Sucker (Catostomus commersoni) from a Minnesota Lake, 1966

1977 ◽  
Vol 34 (10) ◽  
pp. 1633-1642 ◽  
Author(s):  
Fritz H. Johnson
Keyword(s):  
Species Interactions ◽  
Standing Crop ◽  
Yellow Perch ◽  
Perca Flavescens ◽  
Food Competition ◽  
Community Response ◽  
Stizostedion Vitreum ◽  
Catostomus Commersoni ◽  
Young Of The Year ◽  
Fish Species Diversity

In a northeastern Minnesota lake subject only to sportfishing, removal of 85% of the estimated standing crop (34 kg/ha) of adult white suckers, Catostomus commersoni in 1966 was followed by marked changes in community structure and interrelations. During 7 yr alter the removal: catch indices for adult suckers remained far below those before the sucker removal but juvenile suckers increased about 17-fold; yellow perch, Perca flavescens, increased about 15-fold; walleye Stizostedion vitreum vitreum, standing crop increased about one-third; mayflies increased in diet of adult perch and smaller invertebrates decreased; micro-crustaceans increased in diet of young-of-the-year and juvenile perch; young-of-the-year perch increased in diet of adult walleye; walleye angling yield increased from an average of 3.0 kg/ha before the removal to an average of 4.9 kg/ha in 1970–73; the rate of exploitation of adult walleye did not change with increase in angling effort; and the increased walleye harvest consisted mostly of fish recruited to the catch during the fishing season. The average annual harvest of walleye in 1970–73 exceeded estimated potential production for all fish by 81.5% and probably cannot be sustained. Removal of white suckers from lakes with limited fish species diversity appears to benefit percid populations. Key words: Percidae, species interactions, (Stizostedion vitreum vitreum), Perca flavescens, Catostomus commersoni, harvests, community response, community ecology, food, competition

Neural differentiation in the retina of the larval sea lamprey (Petromyzon marinus)

1989 ◽  
Vol 3 (3) ◽  
pp. 241-248 ◽  
Author(s):  
Kalman Rubinson ◽  
Hilary Cain
Keyword(s):  
Ganglion Cells ◽  
Photoreceptor Cells ◽  
Sea Lamprey ◽  
High Ratio ◽  
Bipolar Cells ◽  
Peripheral Retina ◽  
Radial Gradient ◽  
New Development ◽  
Cell Layers ◽  
Relationship Of

AbstractThe peripheral retina of the sea lamprey develops in a 5-year-long process in which only certain neurons differentiate each year. The growth of cell layers, the differentiation of the neurons, and the morphology of their dendrites and axons were studied with normal, HRP, and Golgi preparations. Ganglion cells are differentiated in 3-year-old larvae, amacrine and horizontal cells in 4-year-old larvae, photoreceptor cells in stage I transformers, and bipolar cells in stage III transformers. Each new development is expressed as a radial gradient of differentiation. As a result of this protracted and stepped process, lamprey retinal neurons, particularly ganglion cells, differentiate in the absence of other cells to which they will ultimately be connected and may express their individual genetic programs more fully than in other vertebrate retinas. This could account for the unusual relationship of the ganglion cell, inner plexiform, and optic nerve layers and for the very high ratio of displaced to orthotopic ganglion cells.

Suitability of Vertical Slot and Denil Fishways for Passing North-Temperate, Nonsalmonid Fish

1985 ◽  
Vol 42 (11) ◽  
pp. 1815-1822 ◽  
Author(s):  
Karl Schwalme ◽  
William C. Mackay ◽  
Dieter Lindner
Keyword(s):  
Yellow Perch ◽  
Perca Flavescens ◽  
High Water ◽  
Water Levels ◽  
Coregonus Clupeaformis ◽  
White Sucker ◽  
Catostomus Commersoni ◽  
Vertical Slot ◽  
Vertical Slot Fishway ◽  
Longnose Sucker

A vertical slot fishway and two Denil fishways (of 10 and 20% slope) built into a weir on the Lesser Slave River (55°18′N, 115°45′W) were studied from May 12 to June 25, 1984, to determine how effectively these designs pass north-temperate, nonsalmonid fishes. Thousands of spottail shiner (Notropis hudsonius), substantial numbers (> 100) of northern pike (Esox lucius), longnose sucker (Catostomus catostomus), white sucker (Catostomus commersoni), immature yellow perch (Perca flavescens), and lesser numbers of burbot (Lota lota), adult yellow perch, lake whitefish (Coregonus clupeaformis), and trout-perch (Percopsis omiscomaycus) ascended the fishways. Walleye (Stizostedion vitreum) and goldeye (Hiodon alosoides), although probably moving extensively through the river, did not use the fishways. Although high water levels allowed most fish to surmount the weir, of those that chose the fishway, pike strongly preferred to ascend the Denil fishways and the two sucker species preferred to ascend the vertical slot. Therefore, a combination of several different fishways may be required for the most efficient passage of a wide variety of species. Plasma glucose and lactate measurements on pike revealed that ascending the Denil fishways was only moderately stressful for these fish.

scholarly journals Phagocytosis of Retinal Rod and Cone Photoreceptors

Physiology ◽  
2010 ◽  
Vol 25 (1) ◽  
pp. 8-15 ◽  
Author(s):  
Brian M. Kevany ◽  
Krzysztof Palczewski
Keyword(s):  
Outer Segment ◽  
Photoreceptor Cell ◽  
Current Knowledge ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Photoreceptor Cells ◽  
Constant Length ◽  
Outer Segments ◽  
Retinal Rod ◽  
Rod And Cone Photoreceptors

Photoreceptor cells maintain a roughly constant length by continuously generating new outer segments from their base while simultaneously releasing mature outer segments engulfed by the retinal pigment epithelium (RPE). Thus postmitotic RPE cells phagocytose an immense amount of material over a lifetime, disposing of photoreceptor cell waste while retaining useful content. This review focuses on current knowledge of outer segment phagocytosis, discussing the steps involved along with their critical participants as well as how various perturbations in outer segment (OS) disposal can lead to retinopathies.

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