MONITORING ULTRAVIOLET‐B‐INDUCED DNA DAMAGE IN INDIVIDUAL DIATOM CELLS BY IMMUNOFLUORESCENT THYMINE DIMER DETECTION 1 | Semantic Scholar (2024)

A quantitative method was developed to determine the frequency of thymine dimers in aquatic primary producers such as cyanobacteria, phytoplankton and macroalgae to study the effects of UV radiation.

There are a number of strategies such as PCR (polymerase chain reaction), comet, halo, TUNEL (Terminal deoxyribonucleotidyltransferase-mediated deoxyuridine triphosphate nick end labeling), FISH (Fluorescence in situ hybridization), FCM (Flow cytometry), annexin V labeling, immunological assays, that are commonly used to detect DNA damage in various organisms.

This review deals with UV-induced DNA damage and the associated repair mechanisms as well as methods of detectingDNA damage and its future perspectives.

The results show that plankton cells present in the clear waters off Curacao undergo UVBR stress despite the fact that they are subjected to vertical mixing.

The results indicate that UVBR vulnerability is size dependent, and the low CPD levels observed in these field communities may be explained by the low mean biologically effective doses received by the cells as a result of wind-induced mixing.

Repair of DNA damage induced by ultraviolet-B radiation (UVBR) was investigated in the sublittoral red alga Rhodymenia pseudopalmata at different temperatures, using immunofluorescent detection of thymine dimers and it was concluded that R. pseudopal mata is able to repair DNA damageinduced by high UVBR doses efficiently.

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The efficient formation of both types of damage in the shorter UV region, as well as at 260 nm, which had been believed to be the most efficient wavelength for the formation of UV lesions, is detected.

An immunoslot blot assay was developed to detect pyrimidine dimers induced in DNA by sublethal doses of UV radiation, and this immunological approach utilizing irradiated DNA immobilized to nitrocellulose should allow the direct quantitation of dimers following very low levels of irradiation in small biological samples and isolated gene fragments.

Flow cytometric analysis showed that FL treatment did not affect the distribution of cell cycle phase at the time of UV‐irradiation (8 h after FL treatment), and pyrimidine dimers induced by UV were measured by the use of UV endonuclease of Micrococcus luteus and alkaline agarose gel electrophoresis.

Comparison of cellular responses associated with photoenhanced repair and nucleotide excision (“dark”) repair indicated that light‐mediated correction of UV damage was an important factor in cell survival, and a general dependence of photoproduct induction and D37 values on cell size and shape was indicated.

Results of pyrimidine dimer induction in DNA by solar UV accurately predicted UV doses to the phage DNA show the sensitivity of both the biochemical (dimers) and biological (phage plaques) DNA dosimeters.

From the rapid effect of dimer removal by PHR on UDS it can be deduced that the excision of dimers up to the repair synthesis step takes considerably less than 30 min, which supports the idea that in these XP cells preferential repair of nondimer lesions does occur, but at a much lower rate.

A modified assay for T <> T based on flow cytometry that allows a quick assessment of UV damage levels in 10,000s of cells and makes immunofluorescence of DNA damage more accessible to other research groups.

Monoclonal antibodies produced by this hybridoma were characterized by testing the effect of various inhibitors in a competitive enzyme‐linked immunosorbent assay (ELISA) and have a high specificity for thymine dimers in single‐stranded DNA or poly(dT), but do not bind UV‐irradiated d(TpC)5.

The first report of the simultaneous establishment of monoclonal antibodies against the two different types of photolesions from the same mouse is reported, which indicated that the epitope of 64M antibodies was the (6‐4)photoproduct in DNA.

The various types of DNA alteration known to be induced in this region will be summarized together with a description of the various repair systems that can act to ameliorate this damage in procaryotic and eucaryotic cells.

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