Navegando por Assunto "DNA"

Agora exibindo 1 - 11 de 11

Acesso aberto (Open Access)
Allele frequency distributions of six hypervariable loci (D1S80, APOB, D4S43, vW1, F13A and DYS19) in two African-Brazilian communities from the Amazon region
(2003) VALLINOTO, Izaura Maria Vieira Cayres; VALLINOTO, Antonio Carlos Rosário; VALENTE, Cristina Maria Duarte; GUERREIRO, João Farias
The allele frequency distributions of three VNTR (D1S80, APOB and D4S43) and three STR (vW1, F13A1 and DYS19) loci were investigated in two Afro-Brazilian populations from the Amazon: Curiau and Pacoval. Exact tests for population differentiation revealed significant differences in allele frequency between populations only for the D1S80 and APOB loci. A statistically significant deviation from the Hardy-Weinberg equilibrium was observed only in the D1S80 locus of the Pacoval sample. A neighbor-joining tree was constructed based on DA genetic distances of allele frequencies in four Afro-Brazilian populations from the Amazon (Pacoval, Curiau, Trombetas, and Cametá), along with those from Congo, Cameroon, Brazilian Amerindians, and Europeans. This analysis revealed the usefulness of these Amp-FLPs for population studies - African and African-derived populations were closely grouped, and clearly separated from Amerindians and Europeans. Estimates of admixture components based on the gene identity method revealed the prevalence of the African component in both populations studied, amounting to 51% in Pacoval, and to 43% in Curiau. The Amerindian component was also important in both populations (37% in Pacoval, and 24% in Curiau). The European component reached 33% in Curiau.
Acesso aberto (Open Access)
Application of the comet assay in erythrocytes of Oreochromis niloticus (Pisces): a methodological comparison
(2009) CHRISTOFOLETTI, Cintya Aparecida; DAVID, José Augusto de Oliveira; FONTANETTI, Carmem Silvia
The present study applied the comet assay to erythrocytes of Oreochromis niloticus with the aim of improving protocols to detect DNA damage in these cells, by using two distinct pHs (pH = 12.1 and pH > 13) and evaluating whether there is a correspondence between silver and ethidium bromide staining. Comets were visually examined and, the frequency of cells with and without damage was obtained, as well as the distribution of classes and scores. By using the Kruskal-Wallis test, our results revealed that pH 12.1 is more effective, although both pHs can be used. Our findings also suggest that silver staining can substitute ethidium bromide, an expensive and highly toxic stain that requires specific equipment for examination.
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)
Cytogenetic studies in six species of Scinax (Anura, Hylidae) clade Scinax ruber from northern and northeastern Brazil
(2015-06) SILVA, Lídia Nogueira; ZANONI, Juliani Bruna; SOLÉ, Mirco; AFFONSO, Paulo Roberto Antunes de Mello; SIQUEIRA, Sérgio; SAMPAIO, Maria Iracilda da Cunha
Scinax species are still underrepresented in cytogenetic studies, mainly with respect to populations from northeastern and northern Brazil. In this study, we provide new chromosomal information on Scinax boesemani, S. camposseabrai, S. garbei, S. pachycrus, S. trilineatus and S. x-signatus, all belonging to clade S. ruber. They were collected at two locations in the Caatinga biome (northeastern Brazil) and at one in the Amazon (northern Brazil) biomes. Chromosomes were analyzed by conventional staining, C-banding, Ag-NOR staining, and fluorochrome staining. All species shared a modal diploid value of 2n = 24 and fundamental arm number (FN) of 48. Moreover, both chromosomal size and morphology were similar to other species in this Scinax clade. C-banding revealed centromeric heterochromatin in all species, along with terminal species-specific C-bands in some species. Active nucleolar organizer regions (Ag-NORs) were identified at 11q in most species, except for S. boesemani and S. garbei (Ag-NORs at interstitial region of 8q). Differing from most anurans, GC-rich regions were not restricted to NORs, but also coincident with some centromeric and terminal C-bands. These data contribute to the cytotaxonomy of Scinax by providing chromosomal markers and demonstrating the occurrence of microstructural rearrangements and inversions on chromosomal evolution of Scinax.
Acesso aberto (Open Access)
Detecção de Brucella abortus em linfonodos de búfalas (Bubalus bubalis) em diferentes fases da gestação
(Universidade Federal do Pará, 2015-12) SOUSA, Melina Garcia Saraiva de; BRITO, Marilene de Farias; UBIALI, Daniel Guimarães; FONSECA JÚNIOR, Antônio Augusto; SILVA, Jenevaldo Barbosa da; REIS, Alessandra dos Santos Belo; OLIVEIRA, Carlos Magno Chaves; BARBOSA NETO, José Diomedes
The objective of this study was to detect Brucella abortus in lymph nodes of buffaloes as well as to describe the lesions caused. Nineteen buffalo cows in various stages of pregnancy, serologically positive for brucellosis and subjected to culling were used. Fetal age was determined by ultrasound examination and the size of fetuses was measured at necropsy. Fragments of lymph nodes were collected for histopathology and qPCR. The detection of B. abortus DNA in the lymph nodes was checked from the fourth month of pregnancy in seven buffaloes and in a post-calving buffalo. Acute to chronic lymphadenitis was histologically diagnosed. B. abortus DNA was detected in all evaluated groups of lymph nodes; the mammary lymph nodes were the most affected.
Acesso aberto (Open Access)
Espectrometria Raman, UV, DOS e Circular Dicroísmo de alcalóides do cigarro
(Universidade Federal do Pará, 2011-02-28) GUEDES, Alberto Monteiro; CHAVES NETO, Antonio Maia de Jesus; http://lattes.cnpq.br/3507474637884699
This work is about spectroscopic analysis of some molecular structures present in tobacco (Nicotiana glauca), the base for cigarette, and their interactions with the DNA molecule. According to its importance, among the variety present in the cigarette, the molecules studied were derived from nicotinic acid, nicotinic acid (niacin / vitamin B3), nicotinamide, trigonelline, nicotine, nornicotine and anabasine. The optimizations of these structures were initially obtained in the Hyperchem 7.5 computational software based on the theory of molecular mechanics. Then, they were optimized using the method Density Functional Theory, on the basis B3LYP/ 6-311 + + G (d, p), simulated in software Gaussian 03. Once the optimized structures, we obtained the UV absorption, Raman, Infrared, Circular Dichroism and Density of States spectra using Time-Dependent Density Functional Theory also simulated the in the same software. At the end of this process was also simulated, via molecular mechanics, the interactions of these structures with the DNA molecule in order to verify the potential carcinogenic or not these substances.
Acesso aberto (Open Access)
Human aging and somatic point mutations in mtDNA: a comparative study of generational differences (grandparents and grandchildren)
(2011) MARINHO, Anderson Nonato do Rosario; MORAES, Milene Raiol de; SANTOS, Sidney Emanuel Batista dos; SANTOS, Ândrea Kely Campos Ribeiro dos
The accumulation of somatic mutations in mtDNA is correlated with aging. In this work, we sought to identify somatic mutations in the HVS-1 region (D-loop) of mtDNA that might be associated with aging. For this, we compared 31 grandmothers (mean age: 63 ± 2.3 years) and their 62 grandchildren (mean age: 15 ± 4.1 years), the offspring of their daughters. Direct DNA sequencing showed that mutations absent in the grandchildren were detected in a presumably homoplasmic state in three grandmothers and in a heteroplasmic state in an additional 13 grandmothers; no mutations were detected in the remaining 15 grandmothers. However, cloning followed by DNA sequencing in 12 grandmothers confirmed homoplasia in only one of the three mutations previously considered to be homoplasmic and did not confirm heteroplasmy in three out of nine grandmothers found to be heteroplasmic by direct sequencing. Thus, of 12 grandmothers in whom mtDNA was analyzed by cloning, eight were heteroplasmic for mutations not detected in their grandchildren. In this study, the use of genetically related subjects allowed us to demonstrate the occurrence of age-related (> 60 years old) mutations (homoplasia and heteroplasmy). It is possible that both of these situations (homoplasia and heteroplasmy) were a long-term consequence of mitochondrial oxidative phosphorylation that can lead to the accumulation of mtDNA mutations throughout life.
Acesso aberto (Open Access)
Karyotypic evolution of ribosomal sites in buffalo subspecies and their crossbreed
(2014-06) DEGRANDI, Tiago Marafiga; PITA, Sebastian; PANZERA, Yanina; OLIVEIRA, Edivaldo Herculano Correa de; MARQUES, José Ribamar Felipe; FIGUEIRÓ, Marivaldo Rodrigues; MARQUES, Larissa Coelho; VINADE, Lucia Helena do Canto; GUNSKI, Ricardo José; DEL VALLE GARNERO, Analía
Domestic buffaloes are divided into two group based on cytogenetic characteristics and habitats: the “river buffaloes” with 2n = 50 and the “swamp buffaloes”, 2n = 48. Nevertheless, their hybrids are viable, fertile and identified by a 2n = 49. In order to have a better characterization of these different cytotypes of buffaloes, and considering that NOR-bearing chromosomes are involved in the rearrangements responsible for the karyotypic differences, we applied silver staining (Ag-NOR) and performed fluorescent in situ hybridization (FISH) experiments using 18S rDNA as probe. Metaphases were obtained through blood lymphocyte culture of 21 individuals, including river, swamp and hybrid cytotypes. Ag-NOR staining revealed active NORs on six chromosome pairs (3p, 4p, 6, 21, 23, 24) in the river buffaloes, whereas the swamp buffaloes presented only five NOR-bearing pairs (4p, 6, 20, 22, 23). The F1 crossbreed had 11 chromosomes with active NORs, indicating expression of both parental chromosomes. FISH analysis confirmed the numerical divergence identified with Ag-NOR. This result is explained by the loss of the NOR located on chromosome 4p in the river buffalo, which is involved in the tandem fusion with chromosome 9 in this subspecies. A comparison with the ancestral cattle karyotype suggests that the NOR found on the 3p of the river buffalo may have originated from a duplication of ribosomal genes, resulting in the formation of new NOR sites in this subspecies.
Acesso aberto (Open Access)
Molecular detection of Trypanosoma evansi (Kinetoplastida: Trypanosomatidae) in procyonids (Carnivora: Procyonidae) in Eastern Amazon, Brazil
(Universidade Federal do Pará, 2016-04) MATOS, Paulo Cesar Magalhães; SANTOS, Rafaelle Cunha dos; SOUZA, Paulo Geovani Silva; SAMPAIO JUNIOR, Francisco Dantas; MOURÃO, Fábio Rodrigo Paixão; OLIVEIRA, Wanessa Batista Lima; GABRIEL, Áurea Martins; GONZALEZ MONTEIRO, Silvia; CAVALCANTE, Gustavo Góes; SCOFIELD, Alessandra; BARROS, Flávia de Nazaré Leite
The present study aimed to diagnose the natural infection of captive and free-living procyonids with Trypanosoma evansi in the states of Amapá and Pará, Brazil. From February 2012 to August 2013, whole blood samples and blood smears were obtained from 45 free-living procyonids and from nine procyonids kept in captivity in wild life refuges and zoobotanical parks in the states of Amapá and Pará. Whole blood samples were collected and kept at -20ºC for the detection of T. evansi DNA by PCR using the RoTat 1.2 forward and RoTat 1.2 reverse primers. In addition, the blood smears were processed and examined for the presence of trypomastigote forms of T. evansi. T. evansi DNA was detected in 18.52% (10/54) of the procyonids, namely, in captive crab-eating raccoons and captive and free-living coatis in Pará State. No trypomastigote forms were observed in the blood smears. DNA from T. evansi was detected in P. cancrivorus and N. nasua in Pará State, being this the first such report in P. cancrivorus.
Acesso aberto (Open Access)
Paleogenetic and taphonomic analysis of human bones from Moa, Beirada, and Zé Espinho Sambaquis, Rio de Janeiro, Brazil
(2006-12) MARINHO, Anderson Nonato do Rosario; MIRANDA, Newton Cardoso; BRAZ, Valéria Silva; SANTOS, Ândrea Kely Campos Ribeiro dos; SOUZA, Sheila Maria Ferraz Mendonça de
The present paper discusses mtDNA and taphonomy of human remains from Moa, Beirada, and Zé Espinho sambaquis of Saquarema, state of Rio de Janeiro, Brazil. New human bone dating by 14C-AMS for Moa archeological site (3810+50 BP - GX-31826-AMS) is included. Preservation of microscopic lamellae and DNA is not related to the macroscopic integrity of the bones. Results here suggest that the preservation of amplifiable DNA fragments may have relation to the preservation of the lamellar arrangement as indicated by optical microscopic examination (polarized light). In 13 human bone fragments from Moa, Beirada, and Zé Espinho it was possible to sequence mtDNA from the 3 individuals of Moa, and from 1 of 4 individuals of Beirada, whose bones also show extensive areas with preserved lamellar structures. The 6 human bone fragments of Zé Espinho and 3 of the 4 fragments of Beirada showed extensive destruction of cortical microstructure represented by cavities, intrusive minerals, and agglomerated microscopic bodies of fungi and bacteria; it was not possible to extract mtDNA from these samples. The results support the hypothesis that the preservation of the microscopic osteon organization is a good predictor for DNA preservation. It was also confirmed the C haplogroup antiquity in Brazil.