Direct Effects of UV-B Radiation on the Freshwater Heterotrophic Nanoflagellate<i>Paraphysomonas</i>sp

The influences of intensity and repeated exposure to ultraviolet-B radiation (UVB), photoreactivating repair radiation (PRR), and temperature on the scuticociliate Parauronema acutum were explored under laboratory conditions. Population growth was negatively affected after exposure to the equivalent of one sunny summer day of ambient UVB, especially in the absence of PRR. Repeated daily exposure to UVB severely compromised ciliate survival. UVB-exposed treatments without PRR recovered slower and reached lower final abundances than treatments receiving PRR. Reducing the daily UVB exposure approximately 25% improved ciliate recovery after exposure. In the single exposure treatments, temperature effects were not consistent, except that growth was slowest for control and treatments at the lowest temperature (15 °C). These data suggest that dark repair and/or photoprotection are present in P. acutum, but photoenzymatic repair was the more effective mechanism in reversing UVB damage. Repeated exposure treatments without PRR had zero or declining growth at all temperatures (15, 20 and 25 °C), as did those with PRR at 15 °C. Significant temperature/dose differences were identified in the repeated exposure treatments; ciliates subjected to the higher UVB intensity with PRR survived only at 25 °C, while ciliate populations under reduced UVB increased at 20 and 25 °C.

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“…), a heterotrophic flagellate (Macaluso et al. ), zooplankton (Connelly et al. ), various marine and freshwater fish (Malloy et al.…”

Section: Discussionmentioning

confidence: 99%

“…Other protists and zooplankton exposed to PRR also showed increased survival with decreasing UVB intensity (Macaluso et al. ; Sanders et al. ; Williamson et al.…”

Section: Discussionmentioning

confidence: 99%

Effects of Temperature and Photorepair Radiation on a Marine Ciliate Exposed to UVB Radiation

Hamsher

Sung

Sanders

2018

J Eukaryotic Microbiology

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“…That is, PER appeared to work better at lower temperatures in some species compared to others. PER was also examined in the nanoflagellate Paraphysomonas (125). Parallel to marine studies Scott et al.…”

Section: Environmental Photobiologymentioning

confidence: 99%

Antibodies and DNA Photoproducts: Applications, Milestones and Reference Guide

Mitchell¹,

Brooks

2010

Photochem & Photobiology

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Polyclonal and monoclonal antibodies recognizing the primary DNA photoproducts induced by ultraviolet radiation (UVR) have proven to be essential tools in the study of photochemical and photobiological phenomena. As specific ''DNA damage binding proteins'' these reagents have been used to develop a diverse array of technical procedures applied to a plethora of important problems in DNA photochemistry and the biological effects of UVR at the molecular, developmental, organism and population levels. This survey attempts to cover this science from an historical perspective and to reveal the great breadth of discovery and contribution associated with the development and application of DNA damage antibodies to the current body of science.Three papers published in the 1960s were seminal to the development of immunoassays for the study of photochemical and photobiological phenomena. In 1960 Rosalyn Yalow and Solomon Berson published a paper in the Journal of Clinical Investigation entitled ''Immunoassay of endogenous plasma insulin in man'' (1), which described the development of a sensitive radioimmunoassay (RIA) to measure minute quantities of hormones in blood samples. This technique played a seminal role in the exponential expansion of research in medicine and the biological sciences over the past half century. In 1977 Dr. Yalow was awarded the Nobel Prize in Medicine for her work. In 1964 Otto Plescia and colleagues published a paper in the Proceedings of the National Academy of Sciences entitled ''Production of antibodies to denatured deoxyribonucleic acid (DNA)'' (2). Using a technique whereby singlestranded DNA was electrostatically coupled to methylated bovine serum albumin they were able to elicit an immune response in rabbits. In the wake of this paper it was not long before a group led by Lawrence Levine and Helen van Vanukis published an article in Science in 1966 entitled ''Antibodies to photoproducts of deoxyribonucleic acids irradiated with ultraviolet light'' (3). Using the technique established by Plescia, this group was able to produce a rabbit antiserum using DNA irradiated with 270 nm light with antigenic determinants that were reversible by 235 nm light and responsive to UV-irradiated thymidine nucleotides. It appeared that antibodies had been created in response to thymine dimers.Over the course of the following two decades a number of polyclonal and monoclonal antibodies to various UV-induced DNA lesions were produced and characterized. The technology that developed blossomed and has been applied to a broad spectrum of problems in photochemistry, the biological response to UV radiation (UVR), photomedicine and environmental photobiology. Early immunoassays generated DNA repair curves showing rapid removal of most antibody binding sites leaving behind a significant remnant (4,5). These results were not consistent with the known repair kinetics using biochemical and enzymatic techniques. Subsequently, it was discovered that polyclonal antisera raised against heavily UVirradiated DNA contai...

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“…Such applications include, for example, the manufacturing of crucibles used to produce solar grade silicon [Minami et al, 2011, Kodama et al, 2010, Yamahara et al, 2000 and the production of transparent bulbs for UV light-induced water purification [Macaluso et al, 2009, Barkhudarov et al, 2008. However, in order to be employed in such applications, silica glass needs to have adequate properties, such chemical purity, optical transparency and radiation resistance.…”

Section: Introductionmentioning

confidence: 98%

Processing of quartz lumps rejected by silicon industry to obtain a raw material for silica glass

Santos

Fujiwara

Schenkel

et al. 2015

International Journal of Mineral Processing

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Direct Effects of UV-B Radiation on the Freshwater Heterotrophic NanoflagellateParaphysomonassp

Cited by 19 publications

References 38 publications

Effects of Temperature and Photorepair Radiation on a Marine Ciliate Exposed to UVB Radiation

Effects of Temperature and Photorepair Radiation on a Marine Ciliate Exposed to UVB Radiation

Antibodies and DNA Photoproducts: Applications, Milestones and Reference Guide

Processing of quartz lumps rejected by silicon industry to obtain a raw material for silica glass

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