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| Registros recuperados: 31 | |
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| Movahedzadeh,Farahnaz; Frita,Rosangela; Gutka,Hiten J.. |
| The sequence of Mycobacterium tuberculosis, completed in 1998, facilitated both the development of genomic tools, and the creation of a number of mycobacterial mutants. These mutants have a wide range of phenotypes, from attenuated to hypervirulent strains. These phenotypes must be confirmed, to rule out possible secondary mutations that may arise during the generation of mutant strains. This may occur during the amplification of target genes or during the generation of the mutation, thus constructing a complementation strain, which expresses the wild-type copy of the gene in the mutant strain, becomes necessary. In this study we have introduced a two-step strategy to construct complementation strains using the Ag85 promoter. We have constitutively... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Tuberculosis; Mutagenesis; Constitutive expression; Complementation. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572011000200020 |
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| Palermo,A.M; Mudry,M.D. |
| Acetaldehyde (AAld) is a ubiquitous compound in the environment. Exposure may occur in its manufacture or use, in the consumption of alcoholic beverages and through cigarette smoke. It causes distant target effects, including DNA damage, glutathione depletion, enzyme inactivation and cell death. In the present work, its potential teratogenic, mutagenic and recombinagenic effects in somatic cells of D. melanogaster were analyzed. The white/white+ (w/w+) eye mosaic test (Somatic Mutation And Recombination Test, SMART) was applied by mating w/w females with y/Y males. Larvae of 48 ± 4 h were transferred to media with 0.01 %, 0.02 %, 0.05 % and 0.10 % AAld for 12 hs and then moved to regular media until pupation. The emerging w/w+ females were evaluated for... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ethanol; Teratogenesis; Mutagenesis; Loss of heterozygosity; Eye-spot test. |
| Ano: 2015 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1852-62332015000300007 |
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| Santa Maria,Sergio R.; Arana,Margarita; Ramirez,Oswaldo. |
| We analyzed the frequency of chromosomal aberrations in peripheral lymphocytes from underground miners from the Casapalca (n = 8, mean age = 45 y, range = 36 y to 55 y) and Bellavista (n = 8, mean age = 28 y, range 23 y to 34 y) high-altitude mining camps in the Peruvian Andes. This population was occupationally exposed to heavy metals such as lead and zinc as well as diesel emission particles, organic solvents and mine dust. The control groups consisted of individuals from a high altitude farming community in the Peruvian village of Tinco (n = 8, mean age = 37 y, range = 25 y to 52 y) and the sea level city of Lima (n = 14, mean age = 26 y, range = 20 y to 35 y). All individuals were male native Peruvians. A significantly higher incidence (1.88%, p <... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chromosomal aberrations; High altitude; Mutagenesis; Peruvian Andes; Underground miners. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572007000600017 |
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| Melo-Silva, Merieli; Oliveira, Felipe Rafael; Rosa, Jonathan; Gemelli, Emanuelli; Santos, Lilian; Bueno-Krawczyk, Ana Carolina de Deus. |
| Most changes in water bodies are result of human activities that have the potential to undermine the environmental integrity of aquatic ecosystems. Changes in genetic material can be evidenced by the frequency of nuclear abnormalities in fish blood cells, in response to genotoxic agents even at low concentrations. Thus, we aimed at comparing the frequencies of nuclear abnormalities of fish kept in acclimation, with fish collected in Timbó river (Santa Cruz do Timbó, Santa Catarina State), under low anthropogenic interference, and fish collected in Iguaçu river (União da Vitória, Paraná State), a polluted river. The highest frequency of changes in nuclear morphology of fish erythrocytes was found in the urbanized area around the Iguaçu river, while, the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Micronucleus; Ecotoxicology; Mutagenesis; Pollution. Mutagênese. |
| Ano: 2018 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciBiolSci/article/view/40669 |
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| Sun,Jia-Long; Zou,Xiao; Liu,Ai-Ying; Xiao,Tang-Fu. |
| In China, Monascus spp., a traditional fungus used in fermentation, is used as a natural food additive. Monascus spp. can produce a secondary metabolite, monacolin K namely, which is proven to be a cholesterol-lowering and hypotensive agent. Hence, recently, many researchers have begun focusing on how to increase the production of monacolin K by Monascus purpureus. In the present study, we investigated the effect of the fungal elicitor and the mutagenesis of UV & LiCl on the amount of monacolin K produced by Monascus purpureus. The fugal elicitor, Sporobolomyces huaxiensis, was isolated from tea leaves and its filtrate was added into the culture filtrate of Monascus purpureus during growth to induct the production of monacolin K. The results showed... |
| Tipo: Journal article |
Palavras-chave: Monascus spp.; Monacolin K; Fungal elicitor; Mutagenesis. |
| Ano: 2011 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602011000400010 |
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| Zhang,Yu; Li,Zhen-Hua; Zheng,Wei; Tang,Zhen-Xing; Zhang,Zhi-Liang; Shi,Lu-E. |
| Background: To identify the critical amino acid residues that contribute to the high enzyme activity and good thermostability of Yersinia enterocolitica subsp. palearctica (Y. NSN), 15 mutants of Y. NSN were obtained by site-directed mutagenesis in this study. And their enzyme activity and thermostability were assayed. Effect of several factors on the enzyme activity and thermostability of Y. NSN, was also investigated. Results: The results showed that the I203F and D264E mutants retained approximately 75% and 70% enzyme activity, respectively, compared to the wild-type enzyme. In addition to the I203F and D264E mutants, the mutant E202A had an obvious influence on the thermostability of Y. NSN. According to the analysis of enzyme activity and... |
| Tipo: Journal article |
Palavras-chave: Factors affecting enzyme activity; Nuclease; Mutation; Mutagenesis; Nucleases without sequence specificity. |
| Ano: 2016 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582016000600005 |
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| Cestari,Marta Margarete; Lemos,Priscilla Maria M.; Ribeiro,Ciro Alberto de Oliveira; Costa,João Ricardo M. Alves; Pelletier,Emilien; Ferraro,Marcos V.M.; Mantovani,Mário Sérgio; Fenocchio,Alberto Sergio. |
| The effects of clastogenic or mutagenic agents have rarely been studied in neotropical fish species exposed to contaminated water. In this study, the genetic damage caused by lead in the widely distributed South American fish, Hoplias malabaricus, was assessed using the comet (SCGE) assay and by testing for chromosomal aberrations. Eighteen specimens were acclimatized to laboratory conditions and then chronically exposed to contaminated food by feeding prey (Cyprinus sp.) injected intraperitoneally with doses of inorganic lead adjusted to give a contamination level of 21 mg of Pb2+.g-1 net weight of H. malabaricus. Three fish were sampled for chromosomal analysis after four doses (18 days) and another three after eight doses (41 days) of lead and the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chromosomal aberrations; Comet assay; Genotoxicity; Hoplias malabaricus; Lead; Mutagenesis. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572004000200023 |
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| Rahmani, Alexandra; Delavat, François; Lambert, Christophe; Le Goic, Nelly; Dabas, Eric; Paillard, Christine; Pichereau, Vianney. |
| Vibrio tapetis is a Gram-negative bacterium that causes infections of mollusk bivalves and fish. The Brown Ring Disease (BRD) is an infection caused by V. tapetis that primarily affects the Manila clam Ruditapes philippinarum. Recent studies have shown that a type IV secretion system (T4SS) gene cluster is exclusively found in strains of V. tapetis pathogenic to clams. However, whether the T4SS is implicated or not during the infection process remains unknown. The aim of this study was to create and characterize a V. tapetis T4SS null mutant, obtained by a near-complete deletion of the virB4 gene, in order to determine the role of T4SS in the development of BRD. This study demonstrated that the T4SS is neither responsible for the loss of hemocyte adhesion... |
| Tipo: Text |
Palavras-chave: Brown Ring Disease; Vibrio tapetis; Ruditapes philippinarum; Hemocytes; Type four secretion system; Rounding phenotype; Colonization; Mutagenesis. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00692/80383/83507.pdf |
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| Ferreira,Maria Izildinha; Rodrigues,Geraldo Stachetti; Domingos,Marisa; Saldiva,Paulo Hilário do N.. |
| The Tradescantia stamen hair mutation assay (Trad-SHM) was employed for assessing the environmental mutagenesis in two areas of São Paulo City. The study sites were defined as follows: 1) Celso Garcia Avenue, an industrial area on the outskirts of the urban center (Belém neighborhood), with an average daily traffic volume of 8,750 vehicles; 2) Doutor Arnaldo Avenue, in downtown area (Pinheiros neighborhood), with a mostly residential and business offices occupation, with an average daily traffic volume of 46,125 vehicles. The negative control (background) site is located in the city of Jaguariúna, 138 km from São Paulo, in an area of low atmospheric pollution. The mutation frequency observed for Belém was similar to the background for clone 4430, whereas... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Pollution; Mutagenesis; Bioassay; Tradescantia. |
| Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132003000200017 |
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| Massironi,S.M.G.; Reis,B.L.F.S.; Carneiro,J.G.; Barbosa,L.B.S.; Ariza,C.B.; Santos,G.C.; Guénet,J.L.; Godard,A.L.B.. |
| When compared to other model organisms whose genome is sequenced, the number of mutations identified in the mouse appears extremely reduced and this situation seriously hampers our understanding of mammalian gene function(s). Another important consequence of this shortage is that a majority of human genetic diseases still await an animal model. To improve the situation, two strategies are currently used: the first makes use of embryonic stem cells, in which one can induce knockout mutations almost at will; the second consists of a genome-wide random chemical mutagenesis, followed by screening for mutant phenotypes and subsequent identification of the genetic alteration(s). Several projects are now in progress making use of one or the other of these... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Mouse; Ethylnitrosourea; Mutation; Co-isogenic mutations; Mutagenesis. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2006000900009 |
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| Registros recuperados: 31 | |
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