Navegando por Assunto "Diversidade genética"

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Acesso aberto (Open Access)
“Citomegalovírus: diversidade genética e pesquisa de resistência antiviral em pacientes imunodeficientes da cidade de Belém”
(Universidade Federal do Pará, 2015-07-17) SILVA, Dorotéa de Fátima Lobato da; SOUSA, Rita Catarina Medeiros; http://lattes.cnpq.br/3560941703812539
Cytomegalovirus (CMV) is one of the most common cause of morbidity and mortality in immunocompromised patients because its latency and reactivation mechanism that commonly occurs in immunodeficiencies. Genetic analysis showed that the virulence of the strains may be related to genotypic diversity. The main objective of this paper was to describe the seroepidemiology profile and genetic diversity of CMV by detecting mutations that confer viral resistance to ganciclovir in immunodeficient patients from Belém city.A total of 671 samples were analyzed: 243 HIV/AIDS, 257 neoplastic patients, 112 kidney transplant and 60 people with SLE. The seroprevalence of antibodies was 96.1% and active infection and levels of 2.4% (n = 16) lower than that observed by qPCR method which corresponded to 15.63%. Differences in infection rates due to low sensitivity (5.71%) of the serological method demonstrated in screening test. The mutation research was made in 82 samples for pyrosequencing method, a 741pb segment of the UL97 gene was amplified, between 1087-1828 nucleotides. It was observed that 100% (n = 82) of samples had two mutations in amino acid in codon 596 (E596K) and another one in codon 604 (S604F). The S604F mutation was not found in other viral sequences from GenBank. Ten other mutations occurred between codons 377 and 594 in eight samples, including the A594V mutation in a renal transplant patient who ended up dying.It was concluded that the prevalence of antibodies and the epidemiological profile of the group were similar to those observed in populations of developing countries; the viral infection rates are related to viral reactivation, being underestimated by serology; sequence analysis revealed significant genetic diversity in the samples examined; detection of A594V mutation suggests circulating strains with resistance mutation.
Acesso aberto (Open Access)
Diversidade de maçãs (Malus Domestica Borkh.) nas feiras de produtores de Nova Iorque
(2013-06) GUERRA, Gutemberg Armando Diniz; MING, Lin Chau; MENEZES, Maria de Nazaré Angelo
Visiting local growers fairs of New York City during a year, ranging from June, 2008 to May, 2009, a significative number of apple varieties was verified, demonstrating one particular aspect of plant diversity. Offered in Summer with great availability, is in Autumn and Winter that intraspecific diversity can be observed, crossing all seasonal periods. More than four hundred of plant species were verified in the market, choosing apple as one of more evident to analysis of diversity, once it is offered in 65 cultivars in fairs of the State to which the fruit gives the nickname. They represent a kind of diversity that goes beyond the concept of speciali7ation which is usually attributed to agriculture in developed country. The aim of this article is to demonstrate the genetic diversity and use of apples that are expressed in commercial activities in the streets and squares of New York City.
Acesso aberto (Open Access)
Genes that encodes NAGT, MIF1 and MIF2 are not virulence factors for kala-azar caused by Leishmania infantum
(Universidade Federal do Pará, 2014-10) AGUIAR, Bruno Guedes Alcoforado; COELHO, Daniela Lemos; COSTA, Dorcas Lamounier; DRUMOND, Betânia Paiva; COELHO, Luiz Felipe Leomil; FIGUEIREDO, Lívio Carvalho; ZACARIAS, Danielle Alves; SILVA, Jailthon Carlos da; ALONSO, Diego Peres; RIBOLLA, Paulo Eduardo Martins; ISHIKAWA, Edna Aoba Yassui; GAÍDO, Samara Belchior; COSTA, Carlos Henrique Nery
Introduction: Kala-azar is a disease resulting from infection by Leishmania donovani and Leishmania infantum. Most patients with the disease exhibit prolonged fever, wasting, anemia and hepatosplenomegaly without complications. However, some patients develop severe disease with hemorrhagic manifestations, bacterial infections, jaundice, and edema dyspnea, among other symptoms, followed by death. Among the parasite molecules that might influence the disease severity are the macrophage migration inhibitory factor-like proteins (MIF1 and MIF2) and N-acetylglucosamine-1-phosphotransferase (NAGT), which act in the first step of protein N-glycosylation. This study aimed to determine whether MIF1, MIF2 and NAGT are virulence factors for severe kala-azar. Methods: To determine the parasite genotype in kala-azar patients from Northeastern Brazil, we sequenced the NAGT genes of L. infantum from 68 patients as well as the MIF1 and MIF2 genes from 76 different subjects with diverse clinical manifestations. After polymerase chain reaction (PCR), the fragments were sequenced, followed by polymorphism identification. Results: The nucleotide sequencing of the 144 amplicons revealed the absence of genetic variability of the NAGT, MIF1 and MIF2 genes between the isolates. The conservation of these genes suggests that the clinical variability of kala-azar does not depend upon these genes. Additionally, this conservation suggests that these genes may be critical for parasite survival. Conclusions: NAGT, MIF1 and MIF2 do not alter the severity of kala-azar. NAGT, MIF1 and MIF2 are highly conserved among different isolates of identical species and exhibit potential for use in phylogenetic inferences or molecular diagnosis.
Acesso aberto (Open Access)
Genetic relationships among native americans based on beta-globin gene cluster haplotype frequencies
(2003) RIBEIRO, Rita de Cassia Mousinho; SOUSA, Gabriella Pante de; SANTOS, Eduardo José Melo dos; GUERREIRO, João Farias
The distribution of b-globin gene haplotypes was studied in 209 Amerindians from eight tribes of the Brazilian Amazon: Asurini from Xingú, Awá-Guajá, Parakanã, Urubú-Kaapór, Zoé, Kayapó (Xikrin from the Bacajá village), Katuena, and Tiriyó. Nine different haplotypes were found, two of which (n. 11 and 13) had not been previously identified in Brazilian indigenous populations. Haplotype 2 (+ - - - -) was the most common in all groups studied, with frequencies varying from 70% to 100%, followed by haplotype 6 (- + + - +), with frequencies between 7% and 18%. The frequency distribution of the b-globin gene haplotypes in the eighteen Brazilian Amerindian populations studied to date is characterized by a reduced number of haplotypes (average of 3.5) and low levels of heterozygosity and intrapopulational differentiation, with a single clearly predominant haplotype in most tribes (haplotype 2). The Parakanã, Urubú-Kaapór, Tiriyó and Xavante tribes constitute exceptions, presenting at least four haplotypes with relatively high frequencies. The closest genetic relationships were observed between the Brazilian and the Colombian Amerindians (Wayuu, Kamsa and Inga), and, to a lesser extent, with the Huichol of Mexico. North-American Amerindians are more differentiated and clearly separated from all other tribes, except the Xavante, from Brazil, and the Mapuche, from Argentina. A restricted pool of ancestral haplotypes may explain the low diversity observed among most present-day Brazilian and Colombian Amerindian groups, while interethnic admixture could be the most important factor to explain the high number of haplotypes and high levels of diversity observed in some South-American and most North-American tribes.
Acesso aberto (Open Access)
Genética de populações de pirarucus (Arapaima gigas) da Reserva Mamirauá e considerações sobre estrutura genética para a espécie
(Universidade Federal do Pará, 2008-10-24) SILVA, Juliana Araripe Gomes da; SCHNEIDER, Horacio; http://lattes.cnpq.br/3621033429800270
The pirarucu (Arapaima gigas) is an important fishing resource in the Amazon which has been exploited since the XIXth century. There are indications of a decrease in population size in some parts of its distribution. Management is one of the strategies adopted to maintain fishing activity associated to the conservation of the species. We evaluate aspects of pirarucu populations in two places in the Mamirauá Reserve (Jarauá and Maraã), and compare these populations with those of Santarém and Tucuruí, analyzing their genetic variability and structure. In order to achieve this, seven microsatellite loci were genotyped for 463 pirarucus from Mamirauá Reserve collected along five years. Our results show a greater genetic diversity for this population in comparison to populations from Santarém and Tucuruí. Analyses indicate that management has been ecologically efficient, since there were no significant change in genetic diversity over the five years of study. Lateral migration, associated with a possible standardized return to lakes without spacial fidelity seems to have great importance for local genetic admixture. However, this admixture is limited in space, with a small degree of genetic differentiation seem between pirarucus from Jarauá and Maraã. When including more distant localities to the analysis, the differentiation is greater though geographic distance cannot explain all of this. We believe that a population decline in intermediate localities, probably caused by overexploiting is influencing the connectivity among the localities studied.
Acesso aberto (Open Access)
Molecular characterization of progenies of bacurizeiro (Platonia insignis) from Marajó Island, northeastern Amazon
(Instituto Nacional de Pesquisas da Amazônia, 2017-12) PONTES, Lígia Cristine Gonçalves; MOURA, Elisa Ferreira; MOURA, Mônika Fecury; RODRIGUES, Simone de Miranda; OLIVEIRA, Maria do Socorro Padilha de; CARVALHO, José Edmar Urano de; THERRIER, Josette
The bacurizeiro (Platonia insignis Mart.) is a tree native to the Amazon whose fruit is much used in the gastronomy in the North and Northeast regions of Brazil. Due to its great economic potential for these regions, the species is being conserved in germplasm banks to support genetic breeding programs. The aim of this work was the molecular characterization of P. insignis accessions belonging to the germplasm bank of the Embrapa Eastern Amazon research unit using ISSR (Inter Simple Sequence Repeat) markers. Seventy-eight accessions of P. insignis belonging to 16 progenies were sampled in two different localities on Marajó Island, state of Pará, Brazil. Among the 16 progenies, seven were collected in Soure and nine in Salvaterra. The 78 accessions were genotyped with 23 pre-selected primers. We obtained 121 amplified products, of which 54 were polymorphic. The most polymorphic primers were UBC 834, UBC 899 and UBC 900. Primers UBC810 and UBC884 did not amplify polymorphic bands. Forty-nine markers out of 54 were selected for genetic analyses. AMOVA within and among progenies showed low genetic differentiation (ΦPT = 0.064, P<0.001) with higher diversity within progenies (96%), low genetic differentiation among sampling localities (ΦPT = 0.025, P<0.013), and higher diversity within (98%) than among localities. Clustering by UPGMA based on Jaccard similarities among pairs of accessions did not separate genotypes according to progeny or sampling localitiy. We recommend that new germplasm surveys consider a greater sampling effort within sampling localitites.