Navegando por Assunto "Marcadores moleculares"

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Acesso aberto (Open Access)
Alterações genômicas quantitativas com potencial clínico no adenocarcinoma gástrico
(Universidade Federal do Pará, 2016-05-31) ARAÚJO, Taíssa Maíra Thomaz; KHAYAT, André Salim; http://lattes.cnpq.br/6305099258051586
Gastric cancer is the fifth most frequent type of cancer and the third cause of cancer mortality worldwide. Despite progression in treatment of advanced gastric cancer, the prognosis of patients remains poor, in part due to the low rate of diagnosis during its early stages. This paradigm implies the necessity to search and identify molecular biomarkers for early gastric cancer diagnosis, as well as for disease monitoring, thus contributing to the development of new therapeutic approaches. Therefore, this study aimed at investigating copy number variations in gastric adenocarcnoma through array Comparative Genomic Hybridization (aCGH) technique and selecting genes for validation in a larger sample size by using real-time PCR, in order to find potential molecular biomarkers for this tumor type. The aCGH results demonstrated 22 gene alterations never described before as correlated with gastric carinogenesis, as well as several alterations significantly associated with serosal extravasation and patients aged less than or equal 50 years. Given that most of the genes had never been described in gastric cancer, we selected for validation four gene alterations that showed some consistency with studies published in the literature for other types of cancer. Thus, we investigated by real-time PCR the amplifications of RTEL1, B4GALT5, TRPV2 and ABCA13 genes. The results showed a high frequency of amplification of these genes, but the statistical associations with clinicopathological data of TRPV2 gene with younger patients and ABCA13, with serosal extravasation, observed by aCGH, were not confirmed. Moreover, new significant associations were demonstrated, including RTEL1 recurrent amplification associated with advanced age and intestinal type of gastric adenocarcinoma; B4GALT5 recurrent amplification associated with intestinal type of gastric adenocarcinoma; TRPV2 recurrent amplification associated with lymph node metastasis; ABCA13 recurrent amplification associated with lymph node metastasis and male patients and co-amplification of RTEL1 and ABCA13 associated with advanced staging. Therefore, the aCGH proved to be a useful tool for the investigating new genes associated with carcinogenesis. Additionally, recurrent amplification of RTEL1, B4GALT5, TRPV2 and ABCA13 seem to have an important role in the development and progression of gastric cancer and can be considered as potential biomarkers for this disease.
Acesso aberto (Open Access)
Análises populacionais em Lutjanus purpureus (Poey, 1866) da costa atlântica ocidental a partir de marcadores moleculares
(Universidade Federal do Pará, 2015-03-02) SILVA, Raimundo Darley Figueiredo da; GOMES, Grazielle Fernanda Evangelista; http://lattes.cnpq.br/5740656339448561; SCHNEIDER, Horacio; http://lattes.cnpq.br/3621033429800270
Marine organisms with wide distribution are excellent models for the understanding of historical genetic connectivity patterns. Lutjanus purpureus, or Caribbean snapper, as the species is popularly known, is a marine Teleost belonging to the Family Lutjanidae. The species distribution is from Cuba to the Northeast of Brazil, being often found on rocky and sandy bottoms. It has high economic importance, however there are few studies available on the genetic architecture of the species. Of major goals of this study, the first deals with the development and characterization of the EPIC primers, for population approaches in L. purpureus, and others marine teleosts. The characterization of genomic regions with sufficient polymorphism to population analysis is fundamental for genetic studies with multiple unlinked regions. Were obtained eight primers, and the majority has high levels of genetic variation. EPIC primers have the advantage of being applicable on a wide taxonomic level, thereby these primers were tested and amplified in other taxonomic groups of organisms, so that an indication can be useful in various approaches to intraspecific groups of marine fish. The second main objective was to evaluate issues of genetic diversity, demographics and historical genetic connectivity for L. purpureus using multiple loci (mitochondrial and nuclear DNA). It was found high levels of genetic diversity, probably related to a high effective size presented by species. The Caribbean snapper apparently shows high levels of genetic homogeneity along of the study area, which is consistent with biological traits of species such as spawning in offshore and larval pelagic development. In relation to aspects of historical demography, a population growth scenario is presented, whose beginning is dated about 170,000 years, this period being congruent with a period of glacial maximum to the region of the western Atlantic.
Acesso aberto (Open Access)
Caracterização de polimorfismos nos genes DGAT1 E GH em búfalas (Bubalus bubalis)
(Universidade Federal do Pará, 2014-03-11) SILVA, Caio Santos; MARQUES, José Ribamar Felipe; http://lattes.cnpq.br/0104908318773676
The Buffaloes are domestic animals belonging to Bubalus genus, Bovidae family and Artiodactyla order. Provide meat, milk and workforce. Are quite adapted to the climatic conditions of the state of Pará, producing well in those conditions. However, producers still need tested animals for production characteristics. There were used the technique of SSCP (single-strand conformation polymorphism) and SNP markers (single nucleotideo polymorphism), in order to characterize the 83 buffaloes from murrah and Mediterranean breeds. For the DGAT1, occured allelic frequency of 0.741 for the allele A, 0.253 for the allele B and 0.01 for the allele C. The genotypic frequencies were 0.54 for the AA genotype, 0.39 for the AB genotype, 0.06 for the BB genotype and 0.01 for the AC genotype. For the GH gene was found only one genotype. The DGAT1 gene showed considerable genetic variation and detects the presence of SNPs.
Acesso aberto (Open Access)
Caracterização genética de avestruzes (Struthio camelus) usando marcadores RAPD
(Universidade Federal do Pará, 2007-04-02) FERREIRA, Silvaney Fonseca; MARQUES, José Ribamar Felipe; http://lattes.cnpq.br/0104908318773676
The objective of this work was to evaluate the genetic variability of ostrich populations (Struthio camelus) through RAPD markers (Random Amplified Polymorphic DNA). 121 samples of individuals were used from Pará, Maranhão, Tocantins and Minas Gerais States. The genomic DNA was extracted from total blood. Fifteen primers were selected among the 60. The products of the PCR were visualized in agarose gel 1.5% and, a binary matrix was generated considering the presence (1) of a amplified fragment and its absence (0). The ideal number of polymorphic bands was estimated through the bootstrap analysis using the GQMOL software. The genetic similarity was estimated through the Jaccard coefficient using the NTSYS-PC (Numerical Taxonomy and Multivariate Analysis System) software, version 2.02. The origin of the genetic diversity was quantified by the analysis of molecular variance (AMOVA) using the Arlequin 2,0 software. The 15 primers generated a total of 109 polymorphic bands and the bootstrap analysis showed that at least 100 bands is the ideal number for sampling the genetic diversity, as determined by the high value of correlation (r=0,99), the low value of the squared deviation sum (1,25), and the low stress (0,05). The results suggest that the studied populations are from the same origin. Management measures must be adopted in these breeding, even using other molecular markers in the way to amplify the genetic variability and the conservation of this important genetic resource. RAPD.The bootstrap analysis showed that from 100 bands the work already becomes more trustworthy, a time that the magnitude of the correlation was well next to the maximum value (r=0,99), as also the addition of squares of shunting lines (SQd) reached low value 1,25 and the value of it estresse (e) was of 0,05. In the analysis between pairs of groups, it was verified that the greater and minor similarity are in lathe, respectively, of 0,86 and 0,00. In that it says respect to the distribution of frequency of the similarities gotten between the 5,644 pairs formed in the genetic matrix, it can be verified that 32,69 % of the pairs had been enclosed in the classrooms with similarities varying of 0,01 the 0,10. One notices that the biggest percentage (85,59%) of the pairs was distributed in the three first classrooms of the extremities and that the minority of them (14,41%) presented similarities varying of 0,21 the 1,00. The test of Mantel showed correlation of 0,81 and the dendrograma generated 67 groups delimited for the Sm that was of 0,49. The biggest 0,86 similarity was of and the minor of 0,06. The relative data to the analysis of molecular variance had shown that the percentage of genetic variation between origins was low and significant (24,03%, p < 0,0001), evidencing that great part of the variation meets inside of the populations (75,97 %). markers RAPD they had been efficient in the characterization of the genetic similarity.
Acesso aberto (Open Access)
Identification of duplicates of cassava accessions sampled on the North Region of Brazil using microsatellite markers
(Instituto Nacional de Pesquisas da Amazônia, 2013-12) MOURA, Elisa Ferreira; FARIAS NETO, João Tomé de; SAMPAIO, José Edson; SILVA, Diehgo Tuloza da; RAMALHO, Girena Fernandes
Duplicates are common in germplasm banks and their identification is needed to facilitate germplasm bank management and to reduce maintenance costs. The aim of this work was to identify duplicates of cassava from a germplasm bank in Eastern Amazon, which had been previously characterized both morphological and agronomically. In order to be genotyped with 15 microsatellite loci, 36 accessions were selected. These accessions were classified into 13 groups of similar morpho-agronomical characteristics. All loci were polymorphic, and 75 alleles were identified, with an average of five alleles per loci and HE = 0.66. There were determined 34 pairs of genotypes with identical multiloci profiles and the probability of genetic identity was 1.1x10-12 with probability of exclusion of 99.9999%. Among these duplicates, there are accessions sampled on different years and places, but with different names and accessions with the same name sampled in different places and years. The study identified genotypes that are grown in different places and that have been maintained over the years by local farmers.