On the Distribution of Vitamins A1 and A2

Wald, George

doi:10.1085/jgp.22.3.391

Cited by 106 publications

(32 citation statements)

References 17 publications

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“…A similar accumulation may occur naturally in certain fish-eating mammals (Gillam, 1938). The distribution of vitamin A and the 696 m# chromogen in a wide variety of animals and tissues has been reported in the papers cited, by Edisbury, Morton, Simpkins, and Lovern (1938), and by Wald (1938-39).…”

Section: Vitamin a ~ And Raine~mentioning

confidence: 62%

The Porphyropsin Visual System

Wald

1939

Journal of General Physiology

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113

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1. In the rods of fresh-water and some anadromous fishes, rhodopsin is replaced by the purple photolabile pigment porphyropsin. This participates in a retinal cycle identical in form with that of rhodopsin, but in which new carotenoids replace retinene and vitamin A. 2. Porphyropsin possesses a broad absorption maximum at 522 ± 2 mµ, and perhaps a minimum at about 430 mµ. The vitamin A-analogue, vitamin A2, possesses a maximum in chloroform at 355 mµ and yields with antimony trichloride a deep blue color due to a band at 696 mµ. The retinene-analogue, retinene2, absorbs maximally in chloroform at 405 mµ and possesses an antimony chloride maximum at 706 mµ. 3. Its non-diffusibility through a semi-permeable membrane, salting-out properties, and sensitivity to chemical denaturants and to heat, characterize porphyropsin as a conjugated carotenoid-protein. 4. The porphyropsin cycle may be formulated: porphyropsin See PDF for Structure. retinene2-protein (2)→ vitamin A2-protein (3)→ porphyropsin. Isolation of the retina cuts this cycle at (3); denaturation procedures or extraction of porphyropsin into aqueous solution eliminate in addition (1) and (2). 5. The primary difference between the rhodopsin and porphyropsin systems appears to be the possession by the latter of an added ethylenic group in the polyene chain.

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Section: Vitamin a ~ And Raine~mentioning

confidence: 62%

The Porphyropsin Visual System

Wald

1939

Journal of General Physiology

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113

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“…That seasonal shifts in A 1 /A 2 VP ratio are found in such a diverse range of species suggests that vitamin A 1 /A 2 VP ratio is not linked directly to migration and metamorphic events as was previously thought (Crescitelli, 1958;Crescitelli, 1991;Munz and Beatty, 1965;Wald, 1939;Wald, 1941;Wald, 1960), particularly when the seasonal timing of these events is taken into consideration.…”

Section: Rodsmentioning

confidence: 86%

Ontogenetic changes in photoreceptor opsin gene expression in coho salmon(Oncorhynchus kisutch, Walbaum)

Temple

Veldhoen

Phelan

et al. 2008

Journal of Experimental Biology

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SUMMARYPacific salmonids start life in fresh water then migrate to the sea, after a metamorphic event called smoltification, later returning to their natal freshwater streams to spawn and die. To accommodate changes in visual environments throughout life history, salmon may adjust their spectral sensitivity. We investigated this possibility by examining ontogenetic and thyroid hormone (TH)-induced changes in visual pigments in coho salmon (Oncorhynchus kisutch, Walbaum). Using microspectrophotometry, we measured the spectral absorbance (quantified by λ max ) of rods, and middle and long wavelength-sensitive (MWS and LWS) cones in three age classes of coho, representing both freshwater and marine phases. The λ max of MWS and LWS cones differed among freshwater (alevin and parr) and ocean (smolt) phases. The λ max of rods, on the other hand, did not vary, which is evidence that vitamin A 1 /A 2 visual pigment chromophore ratios were similar among freshwater and ocean phases when sampled at the same time of year. Exogenous TH treatment long wavelength shifted the λ max of rods, consistent with an increase in A 2 . However, shifts in cones were greater than predicted for a change in chromophore ratio. Real-time quantitative RT-PCR demonstrated that at least two RH2 opsin subtypes were expressed in MWS cones, and these were differentially expressed among alevin, parr and THtreated alevin groups. Combined with changes in A 1 /A 2 ratio, differential expression of opsin subtypes allows coho to alter the spectral absorbance of their MWS and LWS cones by as much as 60 and 90 nm, respectively. To our knowledge, this is the largest spectral shift reported in a vertebrate photoreceptor.

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“…Although the photopic spectral sensitivity of alewives has been previously investigated (Wald 1939), this study is the first to report the absorbance characteristics of the rod visual pigments of alewife. A single Vitamin A 1 -based rod visual pigment was found with a wavelength of maximum absorbance, l max , at 505 nm.…”

Section: Discussionmentioning

confidence: 98%

Light effects on alewife‐mysid interactions in Lake Ontario: A combined sensory physiology, behavioral, and spatial approach

Boscarino

Rudstam

Tirabassi

et al. 2010

Limnology & Oceanography

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An understanding of the effect of light on predator-prey interactions in aquatic systems requires the integration of sensory physiology, behavioral ecology, and spatial distributions of predator and prey in the field. Here, we present such an integrative approach to a study on the interactions between the alewife, Alosa pseudoharengus, and the mysid shrimp, Mysis diluviana, (formerly M. relicta) in Lake Ontario at night, when it is unknown whether visual feeding is possible. Visual pigment analyses of alewife rod photoreceptors were used to derive an alewife-specific unit of brightness-the 'alelux' (wavelength of maximum absorbance, l max 5 505 nm)-which formed the basic unit of light intensity in alewife feeding-rate experiments and field applications. At light levels of 10 27 alelux (, 10 24.1 lux) and greater in the laboratory, alewives engaged in visual search and strike behaviors and fed at rates that were significantly higher than those under completely dark conditions. Field observations from Lake Ontario showed that light levels at the upper edge of the mysid distribution were within the range of those required for visual feeding in the laboratory on a full moon night, but not on a new moon night. These increased light levels translated into feeding rates that were . 30 times higher on the full moon night, despite a larger degree of spatial separation of the two trophic levels. We hypothesize that observed increased water clarity in Lake Ontario in recent years has led to increased consumption of mysids by alewife at night and associated food-web changes.

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On the Distribution of Vitamins A1 and A2

Cited by 106 publications

References 17 publications

The Porphyropsin Visual System

The Porphyropsin Visual System

Ontogenetic changes in photoreceptor opsin gene expression in coho salmon(Oncorhynchus kisutch, Walbaum)

Light effects on alewife‐mysid interactions in Lake Ontario: A combined sensory physiology, behavioral, and spatial approach

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