Detekcija genotoksičnosti s pomoću biljnih biotestova - molekularno-citogenetički pristup

It is important for the prevention of DNA changes caused by environment to understand the biological consequences of DNA damages and their molecular modes of action that lead to repair or alterations of the genetic material. Numerous genotoxicity assay systems have been developed to identify DNA reactive compounds. The available data show that plant bioassays are important tests in the detection of genotoxic contamination in the environment and the establishment of controlling systems. Plant system can detect a wide range of genetic damage, including gene mutations and chromosome aberrations. Recently introduced molecular cytogenetic methods allow analysis of genotoxicity, both at the chromosomal and DNA level. FISH gives a new possibility of the detection and analysis of chromosomal rearrangements in a great detail. DNA fragmentation can be estimated using the TUNEL test and the single cell gel electrophoresis (Comet assay).Za prevenciju oštećivanja molekule DNA zbog onečišćenja okoliša nužno je razumijevanje bioloških posljedica nastalih oštećenjem DNA i molekularnih mehanizama djelovanja genotoksikanata koji vode ili popravku ili promjenama genskog materijala. Do danas je usavršen niz testova za detekciju genotoksičnog djelovanja koji omogućuju identifikaciju supstancija koje reagiraju s molekulom DNA. Raspoloživi podaci pokazuju da su biljni biotestovi vrlo važni u detekciji genotoksičnog onečišćenja okoliša, kao i za uspostavljanje nadzornih sustava u okolišu. Biljni test-sustav može otkriti široki raspon genskog oštećenja uključujući mutacije gena i kromosomske aberacije. Nove molekularno-citogenetičke metode omogućuju analizu genotoksičnog djelovanja na razini kromosoma i molekule DNA. Metoda FISH-a ("fluorescent in situ hybridization") pruža nove mogućnosti za detekciju i analizu kromosomskih preraspodjela. Lomovi u molekuli DNA mogu se uspješno detektirati s pomoću metode TUNEL i gel-elektroforeze pojedinačnih stanica (komet test)

Detekcija genotoksičnosti s pomoću biljnih biotestova - molekularno-citogenetički pristup

It is important for the prevention of DNA changes caused by environment to understand the biological consequences of DNA damages and their molecular modes of action that lead to repair or alterations of the genetic material. Numerous genotoxicity assay systems have been developed to identify DNA reactive compounds. The available data show that plant bioassays are important tests in the detection of genotoxic contamination in the environment and the establishment of controlling systems. Plant system can detect a wide range of genetic damage, including gene mutations and chromosome aberrations. Recently introduced molecular cytogenetic methods allow analysis of genotoxicity, both at the chromosomal and DNA level. FISH gives a new possibility of the detection and analysis of chromosomal rearrangements in a great detail. DNA fragmentation can be estimated using the TUNEL test and the single cell gel electrophoresis (Comet assay).Za prevenciju oštećivanja molekule DNA zbog onečišćenja okoliša nužno je razumijevanje bioloških posljedica nastalih oštećenjem DNA i molekularnih mehanizama djelovanja genotoksikanata koji vode ili popravku ili promjenama genskog materijala. Do danas je usavršen niz testova za detekciju genotoksičnog djelovanja koji omogućuju identifikaciju supstancija koje reagiraju s molekulom DNA. Raspoloživi podaci pokazuju da su biljni biotestovi vrlo važni u detekciji genotoksičnog onečišćenja okoliša, kao i za uspostavljanje nadzornih sustava u okolišu. Biljni test-sustav može otkriti široki raspon genskog oštećenja uključujući mutacije gena i kromosomske aberacije. Nove molekularno-citogenetičke metode omogućuju analizu genotoksičnog djelovanja na razini kromosoma i molekule DNA. Metoda FISH-a ("fluorescent in situ hybridization") pruža nove mogućnosti za detekciju i analizu kromosomskih preraspodjela. Lomovi u molekuli DNA mogu se uspješno detektirati s pomoću metode TUNEL i gel-elektroforeze pojedinačnih stanica (komet test)

DNA damage induced by mutagens in plant and human cell nuclei in acellular comet assay.

Higher plant cells have a long tradition of use in the studies on environmental mutagenesis in situ, especially in relation to human health risk determination. The studies on the response of plant and human cells to physical and chemical mutagens showed differences in their sensitivity. The differences in the presence of cell components in plants and humans could influence such response. Additionally, the level of the organization of the employed material could influence DNA-damaging effect: leukocytes are isolated cells and plant--an intact organism. To preclude these obstacles, the effects of direct treatment of isolated nuclei with genotoxic agents were determined to compare the sensitivity of plant and human cells. In the present study, we have determined the DNA-damaging effects of two chemical mutagens: maleic acid hydrazide (MH) and N-methyl-N-nitroso-urea (MNU) applied to isolated nuclei of both plant and human cells. In order to compare the sensitivity of the nuclei of Nicotiana tabacum var. xanthi and the nuclei of leukocytes, the acellular Comet assay was carried out. The results showed higher sensitivity of the nuclei of leukocytes as compared to the nuclei of plant cells to mutagenic treatment with the applied doses of MH and MNU

DNA damage induced by mutagens in plant and human cell nuclei in acellular comet assay

Higher plant cells have a long tradition of use in the studies on environmental mutagenesis in situ, especially in relation to human health risk determination. The studies on the response of plant and human cells to physical and chemical mutagens showed differences in their sensitivity. The differences in the presence of cell components in plants and humans could influence such response. Additionally, the level of the organization of the employed material could influence DNA-damaging effect: leukocytes are isolated cells and plant - an intact organism. To preclude these obstacles, the effects of direct treatment of isolated nuclei with genotoxic agents were determined to compare the sensitivity of plant and human cells. In the present study, we have determined the DNA-damaging effects of two chemical mutagens: maleic acid hydrazide (MH) and N-methyl-N-nitroso-urea (MNU) applied to isolated nuclei of both plant and human cells. In order to compare the sensitivity of the nuclei of Nicotiana tabacum var. xanthi and the nuclei of leukocytes, the acellular Comet assay was carried out. The results showed higher sensitivity of the nuclei of leukocytes as compared to the nuclei of plant cells to mutagenic treatment with the applied doses of MH and MNU

Państwo bez stosów. Czy z doświadczeń polskich w zakresie tolerancji religijnej i kulturowej może czerpać współczesna Europa?

Praca wyróżniona w konkursie, zorganizowanym przez Studenckie Koło Naukowe Historyków oraz Instytut Historii i Stosunków Międzynarodowych UPH w Siedlcach; kl. III d, Liceum Ogólnokształcące im. gen. Władysława Sikorskiego w Międzyrzecu Podlaskim, Opiekun: p. Bożena Lesiu

Candida albicans; exploring glycosylation pathway in the search of targets for antimicrobial agents and yeast to hyphae transition

Microbial cell wall is mostly synthesized by the glycosylated proteins with the distinct enzymatic activity. In this review we have concentrated on the description of the certain steps of glycosylation and their effect on the cell wall integrity and yeast to hyphae transition, the process enhancing the pathogenic properties of C.albicans. The glycoproteins play an invaluable role in C. albicans virulence and they modulate adhesive, invasive, morphogenetic and immune stimulating properties of the pathogen as well as its susceptibility to the antifungal agents. Therefore, understanding of C. albicans glycobiology might let us expand the arsenal in the war against fungal enemies. The early stages of N-, O-glycans and GPI-anchor synthesis requires dolichol - the lipid carrier of sugar residues. Diminished supply of dolichol causes series of defects in C. albicans cells, among which aberrant protein glycosylation is the most evident. Furthermore, the relations between the cell wall composition and integrity, resistance to some antifungal and cell wall disturbing agents and dolichol dependent glycosylation are observed. Moreover relevance of these reactions for the morphological differentiation of C.albicans is described

FISH in analysis of gamma ray-induced micronuclei formation in barley

A micronucleus test in combination with fluorescent in situ hybridization (FISH) using telomere-, centromere-specific probes and 5S and 25S rDNA was used for a detailed analysis of the effects of gamma ray irradiation on the root tip meristem cells of barley, Hordeum vulgare (2n = 14). FISH with four DNA probes was used to examine the involvement of specific chromosomes or chromosome fragments in gamma ray-induced micronuclei formation and then to explain their origin. Additionally, a comparison of the possible origin of the micronuclei induced by physical and chemical treatment: maleic hydrazide (MH) and N-nitroso-N-methylurea (MNU) was done. The micronuclei induced by gamma ray could originate from acentric fragments after chromosome breakage or from whole lagging chromosomes as a result of a dysfunction of the mitotic apparatus. No micronuclei containing only centromeric signals were found. An application of rDNA as probes allowed it to be stated that 5S rDNA–bearing chromosomes are involved in micronuclei formation more often than NOR chromosomes. This work allowed the origin of physically- and chemically-induced micronuclei in barley cells to be compared: the origin of micronuclei was most often from terminal fragments. FISH confirmed its usefulness in the characterization of micronuclei content, as well as in understanding and comparing the mechanisms of the actions of mutagens applied in plant genotoxicity

Comet-FISH for the evaluation of plant DNA damage after mutagenic treatments

The aim of this study was to perform a comparative investigation of the actions of three mutagens that are widely used in plant mutagenesis using the comet-FISH technique. The comet-FISH technique was used for the analysis of DNA damage and the kinetics of repair within specific DNA sequences. FISH with rDNA and telomeric/centromeric DNA probes was applied to comets that were obtained from an alkaline/neutral comet assay. Migration within specific DNA sequences was analysed after treatment with two chemical mutagens-maleic hydrazide (MH) and N-nitroso-N-methylurea (MNU), and γ-rays. Barley was used as a model plant in this study. The possible utility of specific DNA sequences in a comparative assessment of the distribution of DNA damage within a plant genome was evaluated. This study proved that the comet-FISH technique is suitable for a detailed quantification of DNA damage and repair within specific DNA sequences in plant mutagenesis. The analysis of FISH signals demonstrated that the involvement of specific DNA sequences in DNA damage was different and was dependent on the mutagen used. We showed that 5S rDNA and telomeric DNA sequences are more sensitive to mutagenic treatment, which was expressed by a stronger fragmentation and migration in comparison to the other probes used in the study. We found that 5S rDNA and telomeric DNA probes are more suitable for testing the genotoxicity of environmental factors. A comparison of the involvement of specific chromosome domains in direct DNA breakage/repair and in chromosome aberration formation after mutagen treatment indicates the compatibility of the results

Impact of Yeast Glycosylation Pathway on Cell Integrity and Morphology, Glycosylation, Stefana Petrescu (Ed.), ISBN: 978-953-51-0771-2, InTech, Available from: http://www.intechopen.com/books/glycosylation/impact-of-yeast-glycosylation-pathway-on-cell-integrity-and-morphology

Protein glycosylation is a multi step reaction, well conserved in the eukaryotic cells. In N-glycosylation reactions dolichyl phosphate (DolP) serves as a lipid acceptor of sugar residues forming DolPPGlcNAc2Man9Glc3. Dolichyl phosphate mannose (DolPMan) is also a substrate for protein O-glycosylation, where it serves as a donor of the first mannose to be attached to hydroxyl groups of serine or treonine. DolPMan is also involved in the synthesis of the sugar part of glycosylphosphatidyl inositol anchor in yeast and other eukaryotes. Its remnant structure is responsible for the attachment of a large group of glycoproteins to the glucan polymers of the cell wall . Thus, a functional link could be predicted between the dolichol biosynthetic (mevalonate) pathway and subsequent N-glycosylation and O-mannosylation, cell wall assembly and/or fungus–host interaction. Moreover, on the basis of the data presented in this chapter, it can be assumed that the glycosylation pathway in yeast and fungi offers many levels of regulation, which might influence the final quality and quantity of cell wall glycoproteins and consequently cell surface immunogenicity. In this work we concentrate on early glycosylation defects, resulting from the impaired synthesis of dolichol (Dol) and dolichyl phosphate (DolP) or DolPP oligosaccharide (DolPPGlcNAc2Man9Glc3) assembly, and their effect on the cell integrity and morphology