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DEVELOPMENT OF A NOVEL SET OF MICROSATELLITE MARKERS FOR CASTOR BEAN, RICINUS COMMUNIS (EUPHORBIACEAE)

BAJAY, Miklos Maximiliano; ZUCCHI, Maria Imaculada; KIIHL, Tammy Aparecida Manabe; BATISTA, Carlos Eduardo Araujo; MONTEIRO, Mariza; PINHEIRO, Jose Baldin
Fonte: BOTANICAL SOC AMER INC Publicador: BOTANICAL SOC AMER INC
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.77%
Premise of study: Microsatellite primers were developed for castor bean (Ricinus communis L.) to investigate genetic diversity and population structure, and to provide support to germplasm management. Methods and Results: Eleven microsatellite loci were isolated using an enrichment cloning protocol and used to characterize castor bean germplasm from the collection at the Instituto Agronomico de Campinas (IAC). In a survey of 76 castor bean accessions, the investigated loci displayed polymorphism ranging from two to five alleles. Conclusions: The information derived from microsatellite markers led to significant gains in conserved allelic richness and provides support to the implementation of several molecular breeding strategies for castor bean.

Microsatellite loci for the carpenter bee Xylocopa frontalis (Apidae, Xylocopini)

Augusto, Solange Cristina; Pereira Goncalves, Paulo Henrique; Francisco, Flavio de Oliveira; Santiago, Leandro Rodrigues; Francoso, Elaine Aparecida; Suzuki, Karen Mayumi; Sofia, Silvia Helena; Paulino Simoes, Zila Luz; Arias, Maria Cristina
Fonte: SPRINGER; DORDRECHT Publicador: SPRINGER; DORDRECHT
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.77%
In the present study, a microsatellite-enriched genomic library was constructed and primers for 14 microsatellite loci were designed for Xylocopa frontalis. Twenty unrelated individuals were screened. All loci were polymorphic and the number of alleles per locus ranged from 6 to 17 (x = 10.43). Observed (H-o) and expected (H-e) heterozygosities ranged from 0.350 to 0.950 and 0.674 to 0.898, respectively. All loci were in Hardy-Weinberg equilibrium, except one. The microsatellite loci described in this study will contribute towards general biology studies of X. frontalis, intranidal genetic relationships and nest management for the pollination of passion fruit.; Coordenadoria de Aperfeicoamento de Pessoal de Nivel Superior (CAPES); Coordenadoria de Aperfeicoamento de Pessoal de Nivel Superior (CAPES); Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) [Proc. 10/50597-5]; Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP); Fundacao de Amparo a Pesquisa de Minas Gerais (FAPEMIG); Fundacao de Amparo a Pesquisa de Minas Gerais (FAPEMIG)

Estrutura genética e fluxo gênico em populações naturais de tucumã-do-Amazonas por meio de microssatélites visando o manejo e conservação da espécie; Genetic structure and gene flow in natural populations of tucum palm by microsatellite aiming at the management and conservation of the species

Ramos, Santiago Linorio Ferreyra
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 16/07/2014 PT
Relevância na Pesquisa
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O tucumã-do-Amazonas (Astrocaryum aculeatum), da família Arecaceae, é uma espécie com ocorrência na Amazônia Ocidental e Central brasileira. Seu fruto é muito apreciado na região amazônica que consome a polpa na forma fresca. Sua produção é feita pelos agricultores extrativistas. Não existem informações dos parâmetros de diversidade e estrutura genética das populações naturais desta espécie, fundamental para o estabelecimento de estratégias adequadas no uso deste recurso genético, e para aumentar a eficiência da domesticação e seleção para um programa de melhoramento genético. Não é conhecido também como este extrativismo pode estar influenciando a diversidade entre estas populações ao nível dos genitores e progênies, o fluxo gênico e a estrutura genética espacial. Assim, o objetivo desta pesquisa foi caracterizar a estrutura e a diversidade genética de populações de A. aculeatum no Estado do Amazonas, utilizando marcadores microssatélites. Como objetivos específicos o estudo visou desenvolver iniciadores de microssatélites para A. aculeatum; avaliar a diversidade e a estrutura genética; determinar o fluxo gênico, bem como o grau de parentesco, a estrutura genética espacial (EGE) e o coeficiente de coancestria numa população. Os iniciadores de microssatélites foram isolados a partir de uma biblioteca genômica enriquecida e caracterizados usando 40 amostras provenientes de duas populações selvagens. Foram identificados 14 iniciadores de microssatélites...

Polymorphic variation of mononucleotide microsatellites in healthy humans and its implications for microsatellite instability screening; Variação polimórfica de microssatélites mononucleotídicos em indivíduos normais e sua implicação no rastreamento de instabilidade de microssatélites

Cossio, Silvia Liliana; Coura, Renata dos Santos; Bortolini, Maria Cátira; Giugliani, Roberto; Prolla, Patrícia Ashton; Prolla, João Carlos
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Artigo de Revista Científica Formato: application/pdf
ENG
Relevância na Pesquisa
36.83%
Racional - No Brasil, o câncer colorretal é o sexto tumor em freqüência e o quinto em mortalidade. Marcadores moleculares têm sido associados com o prognóstico da doença, especialmente em relação à resposta terapêutica e taxa de sobrevida. Dentre eles, a instabilidade de microssatélites tem sido amplamente estudada. O estado de instabilidade de microssatélites é usualmente determinado pela comparação entre tecido tumoral e tecido normal correspondente de um mesmo paciente e a instabilidade se caracteriza pela diferença no perfi l do produto de amplifi cação por PCR destes tecidos em um determinado locus. Usualmente, é utilizado um painel de cinco marcadores para este propósito. Dois deles (BAT-25 e BAT-26) são considerados monomórfi cos em populações de origem européia. Objetivo - Analisar a freqüência de variação constitutiva nos loci BAT-25 e BAT-26 em amostra de indivíduos do sul do Brasil. Métodos - Duzentos e dezesseis indivíduos saudáveis e não relacionados foram analisados para determinar a freqüência de variação alélica nestes loci. O rastreamento de variantes alélicas foi feito por “polymerase chain reaction – single strand conformation polymorphism” (PCR-SSCP). Resultados - Observou-se possível variação alélica constitutiva em 7% e 6% dos pacientes nos loci BAT-25 e BAT-26...

Genetic diversity of microsatellite loci in Leopardus pardalis, Leopardus wiedii and Leopardus tigrinus

Grisolia, A. B.; Moreno, F.; Campagnari, V. R.; Milazzotto, M. P.; Garcia, J. F.; Adania, C. H.; Souza, E. B.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 382-389
ENG
Relevância na Pesquisa
36.87%
The microsatellite loci FCA045, FCA077, FCA008, and FCA096 are highly variable molecular markers which were used to determine the genetic diversity in 148 captive Leopardus sp. The PCR-amplified products of microsatellite loci were characterized in ABI Prism 310 Genetic Analyzer. Allele numbers, heterozygosity, polymorphism information content, exclusive allele number, and shared alleles were calculated. Sixty-five alleles were found and their sizes ranged from 116 to 216 bp in four microsatellite loci. The heterozygosity ranged from 0.36 to 0.81 in Leopardus pardalis, 0.57 to 0.67 in L. tigrinus and 0.80 to 0.92 in L. wiedii. The polymorphism information content was from 0.80 to 0.88 in L. pardalis, 0.76 to 0.88 in L. tigrinus and 0.77 to 0.90 in L. wiedii. The margay (L. wiedii) showed the highest index of polymorphism among the three species in this study. These results imply that microsatellite DNA markers can help in the study of the genetic diversity of Leopardus specimens. ©FUNPEC-RP.

Polymorphic variation of mononucleotide microsatellites in healthy humans and its implication for microsatellite instability screening

Cossio,Silvia Liliana; Coura,Renata dos Santos; Bortolini,Maria Cátira; Giugliani,Roberto; Ashton-Prolla,Patricia; Prolla,João Carlos
Fonte: Instituto Brasileiro de Estudos e Pesquisas de Gastroenterologia - IBEPEGE ; Colégio Brasileiro de Cirurgia Digestiva - CBCD ; Sociedade Brasileira de Motilidade Digestiva - SBMD ; Federação Brasileira de Gastroenterologia - FBG; Sociedade Brasileira de Hepatologia - SBH; Sociedade Brasileira de Endoscopia Digestiva - SOBED Publicador: Instituto Brasileiro de Estudos e Pesquisas de Gastroenterologia - IBEPEGE ; Colégio Brasileiro de Cirurgia Digestiva - CBCD ; Sociedade Brasileira de Motilidade Digestiva - SBMD ; Federação Brasileira de Gastroenterologia - FBG; Sociedade Brasileira de Hepatologia - SBH; Sociedade Brasileira de Endoscopia Digestiva - SOBED
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2007 EN
Relevância na Pesquisa
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BACKGROUND: Colorectal cancer is the sixth most common tumor and the fifth in mortality in Brazil. Molecular markers have been associated with disease prognosis, especially in relation to therapeutic response and overall survival rates. Among these, microsatellite instability has been extensively studied. Microsatellite stability status is usually determined by comparison of normal and tumoral tissues from the same patient and instability is characterized by the difference in the PCR-amplification profile of these tissues at a given locus. Usually, a panel of five markers is used for this purpose. Two of them (BAT-25 and BAT-26) are considered monomorphic in populations of European origin. AIM: To analyse the frequency of constitutive polymorphic variation at BAT-25 and BAT-26 loci in a sample of individuals from Southern Brazil. METHODS: Two-hundred and sixteen healthy and unrelated individuals were analised to assess the frequency of allelic variation at the BAT-25 and BAT-26 loci in DNA extracted from peripheral blood. Analysis was done by polymerase chain reaction - single strand conformation polymorphism (PCR-SSCP). RESULTS: From the sample of patients studied, 7% and 6% of the patients had possible constitutive allelic variation at the BAT-25 and BAT-26 loci...

Characterization of new Schistosoma mansoni microsatellite loci in sequences obtained from public DNA databases and microsatellite enriched genomic libraries

Rodrigues,NB; LoVerde,PT; Romanha,AJ; Oliveira,G
Fonte: Instituto Oswaldo Cruz, Ministério da Saúde Publicador: Instituto Oswaldo Cruz, Ministério da Saúde
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2002 EN
Relevância na Pesquisa
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In the last decade microsatellites have become one of the most useful genetic markers used in a large number of organisms due to their abundance and high level of polymorphism. Microsatellites have been used for individual identification, paternity tests, forensic studies and population genetics. Data on microsatellite abundance comes preferentially from microsatellite enriched libraries and DNA sequence databases. We have conducted a search in GenBank of more than 16,000 Schistosoma mansoni ESTs and 42,000 BAC sequences. In addition, we obtained 300 sequences from CA and AT microsatellite enriched genomic libraries. The sequences were searched for simple repeats using the RepeatMasker software. Of 16,022 ESTs, we detected 481 (3%) sequences that contained 622 microsatellites (434 perfect, 164 imperfect and 24 compounds). Of the 481 ESTs, 194 were grouped in 63 clusters containing 2 to 15 ESTs per cluster. Polymorphisms were observed in 16 clusters. The 287 remaining ESTs were orphan sequences. Of the 42,017 BAC end sequences, 1,598 (3.8%) contained microsatellites (2,335 perfect, 287 imperfect and 79 compounds). The 1,598 BAC end sequences 80 were grouped into 17 clusters containing 3 to 17 BAC end sequences per cluster. Microsatellites were present in 67 out of 300 sequences from microsatellite enriched libraries (55 perfect...

Genetic diversity and phylogenetic relationships in the rye genus Secale L. (rye) based on Secale cereale microsatellite markers

Shang,Hai-Ying; Wei,Yu-Ming; Wang,Xiao-Rong; Zheng,You-Liang
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2006 EN
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36.83%
The genetic diversity and phylogenetic relationships in the genus Secale L. (rye) was evaluated using 24 Secale cereale microsatellite (SCM) markers. The average polymorphism information content (PIC) value of each microsatellite locus in 30 Secale accessions evaluated was higher than that in 47 cultivated ryes (Secale cereale ssp. cereale). The mean genetic similarity (GS) index in Secale was lower than that in cultivated rye. The highest within-species GS index was observed for S. sylvestre and the lowest for S. strictum, whereas the highest between-species GS index was found between S. cereale and S. vavilovii and the lowest between S. sylvestre and S. cereale. There was no obvious difference in GS levels in the cultivated rye accessions from Asia, Europe, North America or South America. Cluster analysis indicated that all the Secale accessions could be distinguished by the 24 microsatellite loci. We also found that the S. sylvestre accessions were obviously divergent from the accessions of other species and that the S. vavilovii accessions were closely related to the S. cereale accessions. Our results also showed that S. strictum was heterogeneous and showed great within-species differences. The microsatellite-derived dendrogram faithfully reflected the phylogenetic relationships between Secale species but did not indicate a possible domestication process of the cultivated rye based on the geographical sources of the accessions.

Application of a double-enrichment procedure for microsatellite isolation and the use of tailed primers for high throughput genotyping

Diniz,Fábio Mendonça; Iyengar,Arati; Lima,Paulo Sarmanho da Costa; Maclean,Norman; Bentzen,Paul
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2007 EN
Relevância na Pesquisa
36.87%
The number of microsatellite loci and their allelic diversity contribute to increase accuracy and informativity of genetic estimates, however, the isolation of microsatellite loci is not only laborious but also quite expensive. We used (GATA)n and (GACA)n tetranucleotide probes and single- and double-enrichment hybridization to construct and screen a genomic library with an increased proportion of DNA fragments containing repeat motifs. Repeats were found using both types of hybridization but the double-enrichment procedure recovered sequences of which 100% contained (GATA)n and (GACA)n motifs. Microsatellite loci primers were then designed with an M13R-tail or CAG-tag to produce scorable PCR products with minimal stutter. The approach used in this study suggests that double-enrichment is a worthwhile strategy when isolating repeat motifs from eukaryotic genomes. Moreover, the use of tailed microsatellite primers provides increased resolution for compound microsatellite loci, with a significant decrease in costs.

Genetic diversity analysis of Cuban traditional rice (Oryza sativa L.) varieties based on microsatellite markers

Alvarez,Alba; Fuentes,Jorge Luis; Puldón,Violeta; Gómez,Pedro Julio; Mora,Leonor; Duque,Miriam C.; Gallego,Gerardo; Tohme,Joe M.
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2007 EN
Relevância na Pesquisa
36.91%
Microsatellite polymorphism was studied in a sample of 39 traditional rice (Oryza sativa L.) varieties and 11 improved varieties widely planted in Cuba. The study was aimed at assessing the extent of genetic variation in traditional and improved varieties and to establish their genetic relationship for breeding purposes. Heterozygosity was analyzed at each microsatellite loci and for each genotype using 10 microsatellite primer pairs. Between varieties genetic relationship was estimated. The number of alleles per microsatellite loci was 4 to 8, averaging 6.6 alleles per locus. Higher heterozygosity (H) was found in traditional varieties (H TV = 0.72) than in improved varieties (H IV = 0.42), and 68% of the total microsatellite alleles were found exclusively in the traditional varieties. Genetic diversity, represented by cluster analysis, indicated three different genetic groups based on their origin. Genetic relationship estimates based on the proportion of microsatellite loci with shared alleles indicated that the majority of traditional varieties were poorly related to the improved varieties. We also discuss the more efficient use of the available genetic diversity in future programs involving genetic crosses.

PCR-mediated recombination in development of microsatellite markers: mechanism and implications

Roratto,Paula A.; Buchmann,Darine; Santos,Sandro; Bartholomei-Santos,Marlise L.
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2008 EN
Relevância na Pesquisa
36.91%
Protocols for microsatellite-enrichment libraries have been widely applied to several species in order to supply the most informative molecular markers for population and inbreeding studies. One drawback of these protocols is the ratio of designed primer pairs that fail to amplify the expected fragment, even after exhaustive optimization attempts. A possible cause of unsuccessful microsatellite primers may be that such loci are artifacts resulting from chimeric PCR products, instead of real genomic sequences. The microsatellite-enriched library constructed for Aegla longirostri (Crustacea, Decapoda, Anomura) showed that 29% of sequenced clones were chimeric products because these sequences shared one of the flanking regions around the same repeat motif but not the other. PCR-mediated recombination is a well-known event described for several procedures in which related sequences are used as a template. We have associated this phenomenon with microsatellite marker development. This study explained the high ratio of recombinant sequences generated in the A. longirostri microsatellite-enriched library. We discuss the mechanism and implications of PCR chimeric-product formation during microsatellite isolation.

Microsatellite primers for Australian and New Guinean pythons isolated with an efficient marker development method for related species

Jordan, P.; Goodman, A.; Donnellan, S.
Fonte: Blackwell Publishing Ltd Publicador: Blackwell Publishing Ltd
Tipo: Artigo de Revista Científica
Publicado em //2002 EN
Relevância na Pesquisa
36.87%
Microsatellites are powerful molecular genetic markers for many evolutionary and biotechnological investigations, however, development of sufficient microsatellite markers is time-consuming and expensive especially considering the vast numbers of species for which they could be used. In light of the conservative nature of microsatellite loci between related species we describe an alternative approach to microsatellite development. A single round of microsatellite isolation enabled the characterization of sufficient loci for a large number of related python species. From 21 loci isolated in the focal species, an average of 86.2% were conserved within the other species while an average of 60.5% were polymorphic in all 13 python species analysed. Our approach will decrease significantly the expense and time required for microsatellite development for large numbers of related species.; Philip W. Jordan, Amanda E. Goodman and Stephen Donnellan

Construction of a microsatellite based genetic linkage map of almond.

Tavassolian, Iraj
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2008
Relevância na Pesquisa
36.99%
Almond (Prunus dulcis) is the most important nut crop in terms of world production. Due to its health benefit and high nutritional value the consumption and world supply of almond is increasing. To remain competitive in the world market, the Australian almond breeding program was established to produce cultivars with better adaptation to Australian conditions. As part of this program an almond mapping population consisting of 93 F₁ progeny derived from a cross between the American cultivar ‘Nonpareil’ (NP) and the European self-compatible cultivar ‘Lauranne’ (LA) was produced to construct the genetic linkage maps. The first almond linkage map developed prior to the commencement of this project failed to produce the eight linkage groups similar to the basic chromosome number of almond (x = 8) and many large gaps were also observed on the linkage groups. Therefore, more markers were needed to saturate the maps. Microsatellite markers are considered one of the best choices for mapping studies. 195 microsatellite markers isolated from Prunus species were obtained from published papers or by personal communication. Polymorphism was revealed by three different methods, and in general, polyacrylamide gel electrophoresis (PAGE) compared to the fluorescent labelled marker detection using an automated DNA sequencer or agarose gel electrophoresis...

Rise of the machines - recommendations for ecologists when using next generation sequencing for microsatellite development

Gardner, M.; Fitch, A.; Bertozzi, T.; Lowe, A.
Fonte: Blackwell Publishing Ltd Publicador: Blackwell Publishing Ltd
Tipo: Artigo de Revista Científica
Publicado em //2011 EN
Relevância na Pesquisa
36.83%
Next generation sequencing is revolutionizing molecular ecology by simplifying the development of molecular genetic markers, including microsatellites. Here, we summarize the results of the large-scale development of microsatellites for 54 nonmodel species using next generation sequencing and show that there are clear differences amongst plants, invertebrates and vertebrates for the number and proportion of motif types recovered that are able to be utilized as markers. We highlight that the heterogeneity within each group is very large. Despite this variation, we provide an indication of what number of sequences and consequent proportion of a 454 run are required for the development of 40 designable, unique microsatellite loci for a typical molecular ecological study. Finally, to address the challenges of choosing loci from the vast array of microsatellite loci typically available from partial genome runs (average for this study, 2341 loci), we provide a microsatellite development flowchart as a procedural guide for application once the results of a partial genome run are obtained.; Michael G. Gardner, Alison J. Fitch, Terry Bertozzi and Andrew J. Lowe

Allelic size standards and reference genotypes to unify international cocoa (Theobroma cacao L.) microsatellite data

Cryer, N.; Fenn, M.; Turnbull, C.; Wilkinson, M.
Fonte: Kluwer Academic Publ Publicador: Kluwer Academic Publ
Tipo: Artigo de Revista Científica
Publicado em //2006 EN
Relevância na Pesquisa
36.83%
Standardisation of microsatellite allele profiles between laboratories is of fundamental importance to the transferability of genetic fingerprint data and the identification of clonal individuals held at multiple sites. Here we describe two methods of standardisation applied to the microsatellite fingerprinting of 429 Theobroma cacao L. trees representing 345 accessions held in the worlds largest Cocoa Intermediate Quarantine facility: the use of a partial allelic ladder through the production of 46 cloned and sequenced allelic standards (AJ748464 to AJ48509), and the use of standard genotypes selected to display a diverse allelic range. Until now a lack of accurate and transferable identification information has impeded efforts to genetically improve the cocoa crop. To address this need, a global initiative to fingerprint all international cocoa germplasm collections using a common set of 15 microsatellite markers is in progress. Data reported here have been deposited with the International Cocoa Germplasm Database and form the basis of a searchable resource for clonal identification. To our knowledge, this is the first quarantine facility to be completely genotyped using microsatellite markers for the purpose of quality control and clonal identification. Implications of the results for retrospective tracking of labelling errors are briefly explored.; N.C. Cryer...

Breakdown of phylogenetic signal: a survey of microsatellite densities in 454 shotgun sequences from 154 non model Eukaryote species

Meglecz, E.; Neve, G.; Biffin, E.; Gardner, M.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em //2012 EN
Relevância na Pesquisa
36.87%
Microsatellites are ubiquitous in Eukaryotic genomes. A more complete understanding of their origin and spread can be gained from a comparison of their distribution within a phylogenetic context. Although information for model species is accumulating rapidly, it is insufficient due to a lack of species depth, thus intragroup variation is necessarily ignored. As such, apparent differences between groups may be overinflated and generalizations cannot be inferred until an analysis of the variation that exists within groups has been conducted. In this study, we examined microsatellite coverage and motif patterns from 454 shotgun sequences of 154 Eukaryote species from eight distantly related phyla (Cnidaria, Arthropoda, Onychophora, Bryozoa, Mollusca, Echinodermata, Chordata and Streptophyta) to test if a consistent phylogenetic pattern emerges from the microsatellite composition of these species. It is clear from our results that data from model species provide incomplete information regarding the existing microsatellite variability within the Eukaryotes. A very strong heterogeneity of microsatellite composition was found within most phyla, classes and even orders. Autocorrelation analyses indicated that while microsatellite contents of species within clades more recent than 200 Mya tend to be similar...

Microsatellite instability markers in breast cancer: A review and study showing MSI was not detected at 'BAT 25' and 'BAT 26' microsatellite markers in early-onset breast cancer

Siah, S.; Quinn, D.; Bennet, G.; Casey, G.; Flower, R.; Suthers, G.; Rudzki, Z.
Fonte: Kluwer Academic Publ Publicador: Kluwer Academic Publ
Tipo: Artigo de Revista Científica
Publicado em //2000 EN
Relevância na Pesquisa
36.96%
Microsatellite markers may provide evidence of faulty DNA mismatch repair (MMR) via the detection of microsatellite instability (MSI). The choice of microsatellite markers may impact on the MSI detection rate. In hereditary non-polyposis colon cancer (HNPCC), several informative microsatellite markers have been recommended. Two of these, BAT 25 and BAT 26, are quasi-homozygous, enabling analysis of tumour DNA in the absence of paired normal DNA. Sixty-six breast cancer patients under 45 years of age at diagnosis were examined for MSI at BAT 25 and BAT 26. Tumour DNA was extracted from paraffin-embedded tissue. No MSI was detected at the BAT 25 or BAT 26 loci. An additional five microsatellite markers, known to be informative for HNPCC, were examined for MSI in these patients. Apparently-normal profiles were achieved. A tabulated survey of 306 microsatellite markers used to detect MSI in breast cancer revealed that only 35.5% of markers detected MSI at an average rate of 2.9%. The MSI detection rate at the specific HNPCC markers varied from 0% to 10% in breast cancer, with D175250 and TP53 being the HNPCC markers most suitable for analysis of breast cancer. The size of the microsatellite marker's repeat unit did not impact on MSI detection rates. Compiled data from large studies (n > 100) revealed D115988 as the marker with the highest MSI detection rate. Genomic instability pathways of carcinogenesis...

Microsatellite instability in solitary and sporadic gastric cancer

Perez,Rodrigo Oliva; Jacob,Carlos Eduardo; D'Ottaviano,Fabricio L'ofreddo; Alvarenga,Conrado; Ribeiro,Adriana Safatle; Ribeiro Jr.,Ulysses; Bresciani,Cláudio José Caldas; Zilberstein,Bruno; Krieger,José Eduardo; Habr-Gama,Angelita; Gama-Rodrigues,Joaqu
Fonte: Faculdade de Medicina / Universidade de São Paulo - FM/USP Publicador: Faculdade de Medicina / Universidade de São Paulo - FM/USP
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2004 EN
Relevância na Pesquisa
36.87%
Recently, the presence of microsatellite instability (MSI) has been reported in gastric cancer and associated with older age of presentation, distal tumor location, early disease staging, and better overall prognosis. Different characteristics in presentation and in tumor behavior may be explained by different genetic alterations during carcinogenesis of gastric cancer. Identification of specific genetic pathways in gastric cancer may have direct impact on prognosis and selection of treatment strategies. PATIENTS AND METHODS: All 24 patients were treated by radical surgery. Fragments of normal and tumor tissues were extracted from the specimen and stored at -80ºC before DNA purification and extraction. PCR amplification utilizing microsatellite markers was performed. Tumors presenting PCR products of abnormal sizes were considered positive for microsatellite instability (MSI+). RESULTS: Five patients (21%) had tumors that were MSI+ in at least 1 marker. In the group of patients with Lauren's intestinal-type gastric carcinoma, 3 had tumors that were MSI+ (23%), while in the group of diffuse-type gastric cancer, 2 patients had tumors that were MSI+ (19%). The mean age of presentation and the male:female ratio was similar in both groups. Tumors that were MSI+ were more frequently located in proximal portion of the stomach compared to microsatellite-stable (MSS) tumors (40% vs. 16%). Although there was a trend of patients with MSI+ tumors towards a proximal gastric tumor location...

Towards a genus-wide reference linkage map for Eucalyptus based exclusively on highly informative microsatellite markers

Brondani, Rosana Pereira Vianello; Brondani, Claudio; Grattapaglia, Dario
Fonte: Universidade Católica de Brasília Publicador: Universidade Católica de Brasília
Tipo: Artigo de Revista Científica Formato: Texto
EN
Relevância na Pesquisa
36.91%
A novel set of 50 highly polymorphic microsatellite markers were developed and mapped on existing RAPD framework maps of Eucalyptus grandis and E. urophylla. Together with the twenty previously developed microsatellite markers, these were used to align the existing maps for the two most commercially important Eucalyptus species in the tropics. Sixty-three microsatellite markers were placed on the E. grandis map in 11 linkage groups, and 53 on the E. urophylla map distributed in 10 linkage groups. Approximately 66% of the microsatellite markers segregated in a fully informative fashion, allowing the establishment of colinear syntenic linkage groups between the two maps. The 50 new microsatellite markers were highly informative, withan average of 14 alleles per locus, and average expected heterozygosity between 0.82 and 0.87. Furthermore, within the subgenus Symphyomyrtus, to which the vast majority of commercially important Eucalyptus species belong, these markers display on average 90% transportability. This set of 70 mapped microsatellite markers represents a significant step toward the development of a genus-wide reference linkage map for Eucalyptus. These highly multiallelic and transportable markers constitute a powerful tool for QTL discovery and validation...

Instabilidade de microsatelites no cancer gástrico solitário e esporádico; Microsatellite instability in solitary and sporadic gastric cancer

Perez, Rodrigo Oliva; Jacob, Carlos Eduardo; D'Ottaviano, Fabricio L'ofreddo; Alvarenga, Conrado; Ribeiro, Adriana Safatle; Ribeiro Jr., Ulysses; Bresciani, Cláudio José Caldas; Zilberstein, Bruno; Krieger, José Eduardo; Habr-Gama, Angelita; Gama-Rodri
Fonte: Universidade de São Paulo. Faculdade de Medicina Publicador: Universidade de São Paulo. Faculdade de Medicina
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; ; ; Formato: application/pdf
Publicado em 01/01/2004 ENG
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A presença de Instabilidade de microsatellites (IMS) tem sido relatada no cancer gastrico e associada a pacientes com idade mais avançada, localização mais distal do tumor, estadios mais precoces e melhor prognostico. Relatamos neste prospectivo estudo envolvendo 24 pacientes com cancer gastrico solitario e esporadico, a incidencia de IMS, sua correlação com parametros epidemiologicos, clinicos e anatomo patológicos e o seu impacto sobre a sobrevida geral e livre de doença. PACIENTES E MÉTODOS: Todos os pacientes haviam sido tratados com cirurgia radical. Fragmentos de tecido normal e tumoral eram extraidos das peças e armazenados a -80ºC antes da extração e purificação DNA. Realizava-se então a amplificação com PCR utilizando marcadores específicos de microsatelites. Os tumores que apresentavam produtos de amplificação anormais foram considerados positivos para IMS. RESULTADOS: Cinco pacientes (21%) apresentaram Instabilidade de microsatelites (IMS+) com pelo menos um marcador (primer) No grupo de pacientes com adenocarcinomas gástricos do tipo histológico de Lauren, três apresentavam IMS (23%) enquanto no grupo portador de cancar gástrico difuso, dois pacientes mostraram IMS (19%).. Embora haja uma tendência dos pacientes IMS+ apresentarem tumores de localização mais proximal...