548 research outputs found
Unraveling the variability and genetic structure of barker frog Physalaemus Cuvieri(Leiuperinae) populations from different regions of Brazil
FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORThe barker frog Physalaemus cuvieri is widely distributed in South America and is found in all regions of Brazil. Significant intraspecific morphological variation in this species has been reported. To determine the genetic structure of the natural Brazilian populations of P. cuvieri, 10 different populations geographically separated by 99.41 to 2936.75 km were evaluated using 10 polymorphic microsatellite loci. In addition, mitochondrial DNA data were analyzed to determine genetic distance between the populations. The genetic variation was found to be significant in most of the populations (HE ranged from 0.40 to 0.59, and allelic richness ranged from 2.07 to 3.54). An FST value of 0.27 indicated that high genetic structure was present among the P. cuvieri populations. STRUCTURE analyses grouped the 10 populations into nine clusters and indicated that only two of the populations were not genetically differentiated. The genetic distance calculated from the mitochondrial DNA data showed values <0.03 for seven of the populations.The barker frog Physalaemus cuvieriis widely distributed in South America and is found in all regions of Brazil. Significant intraspecific morphological variation in this species has been reported. To determine the genetic structure of the natural Brazili13380558065FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR06/59697-7sem informaçã
Study Of Closely Related Species Within The Physalaemus Cuvieri Group (anura): Contribution Of Microsatellite Markers.
Various species of the Physalaemus cuvieri group of frogs are difficult to distinguish morphologically, making molecular analysis an attractive alternative for indentifying members of this group, which is considered to be at risk because of loss of habitat. The genetic structure of natural populations of P. ephippifer and P. albonotatus species was investigated and analyzed, together with that of five previously studied populations of P. cuvieri. Nine microsatellite loci were used in the analyses. The overall G(ST) value (0.46) revealed high genetic variation among the populations, as expected for different species. Bayesian analysis implemented by the STRUCTURE software clustered the seven populations into seven groups (K = 7). All the P. albonotatus and P. ephippifer specimens were grouped into a single cluster, both species showing clear differentiation from P. cuvieri. The different grouping based on these microsatellites of some P. cuvieri individuals from Porto Nacional and from Passo Fundo suggests that they could be a new species, indicating a necessity for taxonomic reevaluation. Despite the intrinsic difficulties in analyzing closely related species, the nine microsatellite loci were found to be adequate for distinguishing these three species of the P. cuvieri group and their populations.101434-4
Variabilidade genética em populações de Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae) nas regiões produtoras de soja no Brasil.
Com o uso de ferramentas moleculares é possível sequenciar genes e caracterizar populações de insetos. Assim, este trabalho teve por objetivo estudar a variabilidade genética entre subpopulações de Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae) nas principais regiões produtoras de soja, utilizando sequências de genes mitocondriais. Foram coletadas populações de A. gemmatalis nas localidades de: Santa Helena de Goiás (GO), Luis Eduardo Magalhães (BA); Mauá da Serra (PR), Coxilha (RS) e Campo Verde (MT), seu DNA foi extraído para amplificação e sequenciamento. A Análise de Variância Molecular (AMOVA) foi aplicada para estimar a estrutura genética utilizando três fragmentos do mtDNA, o gene da subunidade de citocromo oxidase I (COI), citocromo oxidase II (COII) e citocromo B (CytB). A distribuição e frequência de haplótipos foi determinada pelo programa TCS. Foi sequenciado um total de 71 indivíduos de A. gemmatalis. A subpopulação de MT apresentou a menor variação na frequência dos haplótipos para todas as regiões estudadas. O haplótipo mais representativo foi o h2, sendo encontrado em indivíduos da Bahia (9), Paraná (1) e Rio Grande do Sul (1). A maior frequência haplotípica foi observada em MT, PR e RS. Na análise das sequencias de A. gemmatalis foi possível observar que há potencial para identificar possíveis haplótipos que possam caracterizar uma determinada subpopulação. Para isso seria necessário à utilização de outras ferramentas, como por exemplo, estudos de PCR-RFLP e análise de outras regiões gênicas, que possam contribuir na identificação de haplótipos nas subpopulações de A. gemmatalis no Brasil
Variabilidade genética do umbuzeiro no Semi-Árido brasileiro, por meio de marcadores AFLP.
O objetivo deste trabalho foi avaliar a distribuição da variabilidade genética do umbuzeiro (Spondias tuberosa), no Semi-Árido brasileiro, por meio de marcadores AFLP, para subsidiar estratégias de prospecção e conservação da espécie. Foram analisados 68 indivíduos de umbuzeiro de 15 ecorregiões, pelo dendrograma UPGMA e pela dispersão em escala multidimensional (MDS), com o coeficiente de Jaccard de 141 bandas polimórficas de AFLP. A análise da variância molecular foi realizada pela decomposição total entre e dentro das regiões ecogeográficas. O dendrograma apresentou valor cofenético de 0,96, e o gráfico MDS apresentou 0,25 para a falta de ajustamento. A variabilidade genética do umbuzeiro foi estimada em 0,3138, o que indica grande variação entre os grupos de indivíduos. Agrupamentos específicos foram observados em seis regiões ecogeográficas, enquanto nas demais regiões observaram-se pares entre alguns indivíduos, sem formação de agrupamentos específi cos por local de amostragem, o que indica que a variabilidade genética do umbuzeiro não está uniformemente distribuída no Semi-Árido. Sugerem-se estratégias para o estabelecimento de maior número de áreas para conservação in situ ou amostragens de menor número de indivíduos, em várias unidades de paisagens, para conservação ex situ da variabilidade genética do umbuzeiro
Variabilidade genética em populações de Pseudoplusia includens (Walker) (Lepidoptera: Noctuidae) nas regiões produtoras de soja no Brasil.
Pseudoplusia includens (Walker) (Lepidoptera: Noctuidae) é uma importante praga, de difícil controle, na cultura da soja no Brasil. Informações sobre a distribuição da variabilidade de suas subpopulações no Brasil ainda são restritas, embora os conhecimentos da estrutura genética populacional e do fluxo gênico dessa espécie possam contribuir no delineamento do manejo da resistência a inseticidas e toxinas. Assim, este trabalho teve por objetivo estudar a variabilidade genética de P. includens nas principais regiões produtoras de soja, utilizando sequências de genes mitocondriais (mtDNA). Foram coletadas populações de P. includens nas localidades de Campo Verde (MT), Tasso Fragoso (MA), Bela Vista do Paraíso (PR), Santa Helena de Goiás (GO) e Coxilha (RS), totalizando 67 espécimes. O DNA total foi extraído individualmente, e as regiões do mtDNA, citocromo oxidase I (COI), citocromo oxidase II (COII) e citocromo B (CytB) foram amplificadas, purificadas e sequenciadas. A distribuição da variabilidade genética entre e dentro de cada subpopulação foi determinada por meio da Análise de Variância Molecular (AMOVA), usando o programa Arlequin e a frequência de haplótipos foi determinada no programa TCS. As subpopulações dos estados de Goiás e Maranhão foram as que apresentaram a maior diversidade haplotípica. O índice de fixação (ϕST) obtido pela AMOVA indicou que não existe estruturação nas subpopulações estudadas de P. includens. A ausência de agrupamento na análise da rede de haplótipos das sequências de mtDNA evidenciou a reduzida diferenciação entre as subpopulações
Genetic diversity analysis among pigeonpea genotypes adapted to South American regions based on microsatellite markers.
The pigeonpea [Cajanus cajan (L) Millspaugh] is one of the most important perennial legume crops utilized in the food, fodder, soil conservation, crop-livestock integrated systems, reclaiming of degraded pastures and symbiotic nitrogen fixation. Microsatellite markers were used to estimate the genetic diversity of 77 pigeonpea genotypes selected from the germplasm collections at Embrapa Cattle-Southeast and, to evaluate their transferability to Phaseolus vulgaris and Vigna unguiculata species. The number of alleles per locus ranged from 2 to12, with an average of 5.1 alleles. The PIC values ranged from 0.11 to 0.80 (average 0.49) and the D values from 0.23 to 0.91 (average 0.58). The averages of observed and expected heterozygosity were 0.25 and 0.47, respectively, showing a deficit in heterozygosity. A model-based Bayesian approach implemented in the software STRUCTURE was used to assign genotypes into clusters. A dendrogram was constructed based on the modified Roger's genetic distances using a neighbor-joining method (NJ). A total of four clusters were assembled by STRUCTURE and a strong tendency of correspondence between the Bayesian clusters in the NJ tree was observed. The genetic distance ranged from 0.09 to 0.62 (average 0.37), showing a low genetic diversity in the pigeonpea genotypes. Transferability of pigeonpea-specific microsatellites revealed a cross-amplification and the presence of polymorphic alleles in P. vulgaris and V. unguiculata
Genetic variability of garlic accessions as revealed by agro-morphological traits evaluated under different environments.
The cultivated garlic (Allium sativum L.) displays a wide phenotypic diversity, which is derived from natural mutations and phenotypic plasticity, due to dependence on soil type, moisture, latitude, altitude and cultural practices, leading to a large number of cultivars. This study aimed to evaluate the genetic variability shown by 63 garlic accessions belonging to Instituto Agronômico de Campinas and the Escola Superior de Agricultura ?Luiz de Queiroz? germplasm collections. We evaluated ten quantitative characters in experimental trials conducted under two localities of the State of São Paulo: Monte Alegre do Sul and Piracicaba, during the agricultural year of 2007, in a randomized blocks design with five replications. The Mahalanobis distance was used to measure genetic dissimilarities. The UPGMA method and Tocher?s method were used as clustering procedures. Results indicated significant variation among accessions (P < 0.01) for all evaluated characters, except for the percentage of secondary bulb growth in MAS, indicating the existence of genetic variation for bulb production, and germplasm evaluation considering different environments is more reliable for the characterization of the genotypic variability among garlic accessions, since it diminishes the environmental effects in the clustering of genotypes
High genetic diversity within and among bitter cassava cultivated in three soil types in Central Amazonia.
Bitter cassava is an important food crop that was domesticated in Amazonia. Although it is exclusively propagated by stem cuttings, cassava retained its ability of sexual reproduction. The occurrence and incorporation of sexual plants into the stock of clonal varieties contributes to the high genetic diversity observed within the crop. Despite being well adapted to nutrient deprived soils of Amazonia, ethnobotanical observations showed that communities of smallholder farmers along the middle Madeira River, in Central Amazonia, also cultivate cassava in the highly fertile soils of the floodplains and Amazonian dark earths (ADE). These farmers grow different sets of varieties in each soil type, which may also contribute to the maintenance of high levels of genetic diversity within the crop. We evaluated with 10 nuclear microsatellite markers the genetic diversity within and among some of the most commonly cultivated bitter cassava varieties grown on ADE, floodplain and Oxisols soils in the middle Madeira region. High levels of genetic diversity within varieties were observed (HO ranging from 0.495 to 0.707, and HE ranging from 0.250 to 0.460). Additionally, varieties were generally highly differentiated from each other. Although high levels of genetic diversity were previously observed in studies carried out in regions of low soil fertility in other parts of Amazonia, we identified that management of different soil types is important to the maintenance of genetically distinct stocks of varieties, which also contributes to the maintenance of the genetic diversity within the crop
The TBX3 gene, mutated in Ulnar-Mammary syndrome, promotes growth of mammary epithelial cells independently of ARF and p53.
Young Onset Alzheimer’s Disease Associated with C9ORF72 Hexanucleotide Expansion: Further Evidence for a Still Unsolved Association
Frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) are recognized as part of a disease continuum (FTD-ALS spectrum), in which the most common genetic cause is chromosome 9 open reading frame 72 (C9ORF72) gene hexanucleotide repeat expansion. The clinical phenotype of patients carrying this expansion varies widely and includes diseases beyond the FTD-ALS spectrum. Although a few cases of patients with C9ORF72 expansion and a clinical or biomarker-supported diagnosis of Alzheimer’s disease (AD) have been described, they have been considered too sparse to establish a definite association between the C9ORF72 expansion and AD pathology. Here, we describe a C9ORF72 family with pleomorphic phenotypical expressions: a 54-year-old woman showing cognitive impairment and behavioral disturbances with both neuroimaging and cerebrospinal fluid (CSF) biomarkers consistent with AD pathology, her 49-year-old brother with typical FTD-ALS, and their 63-year-old mother with the behavioral variant of FTD and CSF biomarkers suggestive of AD pathology. The young onset of disease in all three family members and their different phenotypes and biomarker profiles make the simple co-occurrence of different diseases an extremely unlikely explanation. Our report adds to previous findings and may contribute to further expanding the spectrum of diseases associated with C9ORF72 expansion
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