871 resultados para INTERNAL TRANSCRIBED SPACER


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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Nine strains of a novel yeast species were isolated from rotting wood, tree bark, ant nests or living as endophytes in leaves of Vellozia gigantea. Analysis of the sequences of the internal transcribed spacer (ITS) region and the D1/D2 domains of the large subunit rRNA gene showed that this species is related to Candida insectorum in the Yamadazyma clade. The new species differs from its closely related species by 10 and 11 substitutions in the ITS region and the D1/D2 domains of the large subunit of the rRNA gene, respectively. The species is heterothallic and forms asci with one to two hat-shaped ascospores. The name Yamadazyma riverae sp. nov. is proposed. The type strain of Yamadazyma riverae sp. nov. is UFMG-CM-Y444T (= CBS 14121) and the allotype strain is TT12 (= CBS 14098 = UFMG-CM-Y577). The Mycobank number is MB 813221.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Background and aims South America and Oceania possess numerous floristic similarities, often confirmed by morphological and molecular data. The carnivorous Drosera meristocaulis (Droseraceae), endemic to the Neblina highlands of northern South America, was known to share morphological characters with the pygmy sundews of Drosera sect. Bryastrum, which are endemic to Australia and New Zealand. The inclusion of D. meristocaulis in a molecular phylogenetic analysis may clarify its systematic position and offer an opportunity to investigate character evolution in Droseraceae and phylogeographic patterns between South America and Oceania. Methods Drosera meristocaulis was included in a molecular phylogenetic analysis of Droseraceae, using nuclear internal transcribed spacer (ITS) and plastid rbcL and rps16 sequence data. Pollen of D. meristocaulis was studied using light microscopy and scanning electron microscopy techniques, and the karyotype was inferred from root tip meristem. Key Results The phylogenetic inferences (maximum parsimony, maximum likelihood and Bayesian approaches) substantiate with high statistical support the inclusion of sect. Meristocaulis and its single species, D. meristocaulis, within the Australian Drosera clade, sister to a group comprising species of sect. Bryastrum. A chromosome number of 2n = approx. 32–36 supports the phylogenetic position within the Australian clade. The undivided styles, conspicuous large setuous stipules, a cryptocotylar (hypogaeous) germination pattern and pollen tetrads with aperture of intermediate type 7–8 are key morphological traits shared between D. meristocaulis and pygmy sundews of sect. Bryastrum from Australia and New Zealand. Conclusions The multidisciplinary approach adopted in this study (using morphological, palynological, cytotaxonomic and molecular phylogenetic data) enabled us to elucidate the relationships of the thus far unplaced taxon D. meristocaulis. Long-distance dispersal between southwestern Oceania and northern South America is the most likely scenario to explain the phylogeographic pattern revealed.

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Homalometron elongatum is reexamined using heat-killed material that was not subjected to pressure during fixation from Gerres cinereus collected from San Juan Harbor, Puerto Rico, U.S.A. The new material is compared with some paratype specimens and differs by having a much less variable forebody length, and a median rather than submedian genital pore. Tegumental spines reportedly cover the anterior end of the body but we observed tegumental spines covering the entire body surface in both the paratype and new material. Homalometron lesliorum n. sp. is described from Eucinostomus currani from the Pacific coasts of Costa Rica and Nicaragua. The new species has three pairs of oral papillae surrounding the mouth and thus resembles three other congeners: H. elongatum, Homalometron carapevae, and Homalometron papilliferum. Homalometron lesliorum n. sp. is distinguished from the three species by having the anterior extent of the vitelline follicles at or above the base of the ventral sucker, compared with posterior to the ventral sucker at the level of the seminal vesicle (H. elongatum) or further posterior at the posterior margin of the ovary (H. carapevae and H. papilliferum). The four species are further differentiated from one another by sucker width ratio, tegumental spine size and distribution, egg size, host preference, and biogeography. Comparison of nuclear ribosomal DNA (3' end of 18S, internal transcribed spacer [ITS]1, ITS2, and 5' end of 28S) between H. elongatum and H. lesliorum n. sp. revealed one variable base (n = 162) at the 3' end of 18S, 12 variable bases (n = 476) at ITS1, 10 variable bases (n = 310) at ITS2, and 11 variable bases (n = 1,325) at the 5' end fragment of 28S. Nuclear ribosomal DNA from Homalometron pallidum and Homalometron armatum are included for further comparison with H. elongatum and H. lesliorum n. sp.

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Endophytic fungi are considered a rich source of active compounds resulting from their secondary metabolism. Fungi from marine environment grow in a habitat with unique conditions that can contribute to the activation of metabolic pathways of synthesis of different unknown molecules. The production of these compounds may support the adaptation and survival of the fungi in the marine ecosystem. Mangroves are ecosystems situated between land and sea. They are frequently found in tropical and subtropical areas and enclose approximately 18.1 million hectares of the planet. The great biodiversity found in these ecosystems shows the importance of researching them, including studies regarding new compounds derived from the endophytic fungi that inhabit these ecosystems. 3-hydroxypropionic acid (3-HPA) has been isolated from the mangrove endophytic fungus Diaporthe phaseolorum, which was obtained from branches of Laguncularia racemosa. The structure of this compound was elucidated by spectroscopic methods, mainly 1D and 2D NMR. In bioassays, 3-HPA showed antimicrobial activities against both Staphylococcus aureus and Salmonella typhi. The structure of this antibiotic was modified by the chemical reaction of Fischer-Speier esterification to evaluate the biologic activity of its chemical analog. The esterified product, 3-hydroxypropanoic ethyl ester, did not exhibit antibiotic activity, suggesting that the free carboxylic acid group is important to the pharmacological activity. The antibiotic-producing strain was identified with internal transcribed spacer sequence data. To the best of our knowledge, this is the first report of antibacterial activity by 3-HPA against the growth of medically important pathogens.

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Two new records of Anopheles homunculus in the eastern part of the Atlantic Forest are reported. This species was found for the first time in Barra do Ouro district, Maquine municipality, Rio Grande do Sul state, located in the southern limit of the Atlantic Forest. The 2nd new record was in the Serra Bonita Reserve, Camacan municipality, southeast Bahia state. These records extend the geographical distribution of An. homunculus, suggesting that the species may be widely distributed in coastal areas of the Atlantic Forest. It is hypothesized that the disjunct distribution of the species may be caused by inadequate sampling, and also difficulties in species identification based only on female external characteristics. Species identification was based on morphological characters of the male, larva, and pupa, and corroborated by DNA sequence analyses, employing data from both 2nd internal transcribed spacer of nuclear ribosomal DNA and of mitochondrial cytochrome c oxidase subunit I.

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Mangrove ecosystems are tropical environments that are characterized by the interaction between the land and the sea. As such, this ecosystem is vulnerable to oil spills. Here, we show a culture-independent survey of fungal communities that are found in the sediments of the following two mangroves that are located on the coast of Sao Paulo State (Brazil): (1) an oil-spill-affected mangrove and (2) a nearby unaffected mangrove. Samples were collected from each mangrove forest at three distinct locations (transect from sea to land), and the samples were analyzed by quantitative PCR and internal transcribed spacer (ITS)-based PCR-DGGE analysis. The abundance of fungi was found to be higher in the oil-affected mangrove. Visual observation and correspondence analysis (CA) of the ITS-based PCR-DGGE profiles revealed differences in the fungal communities between the sampled areas. Remarkably, the oil-spilled area was quite distinct from the unaffected sampling areas. On the basis of the ITS sequences, fungi that are associated with the Basidiomycota and Ascomycota taxa were most common and belonged primarily to the genera Epicoccum, Nigrospora, and Cladosporium. Moreover, the Nigrospora fungal species were shown to be sensitive to oil, whereas a group that was described as "uncultured Basidiomycota" was found more frequently in oil-contaminated areas. Our results showed an increase in fungal abundance in the oil-polluted mangrove regions, and these data indicated potential fungal candidates for remediation of the oil-affected mangroves.

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South America and Oceania possess numerous floristic similarities, often confirmed by morphological and molecular data. The carnivorous Drosera meristocaulis (Droseraceae), endemic to the Neblina highlands of northern South America, was known to share morphological characters with the pygmy sundews of Drosera sect. Bryastrum, which are endemic to Australia and New Zealand. The inclusion of D. meristocaulis in a molecular phylogenetic analysis may clarify its systematic position and offer an opportunity to investigate character evolution in Droseraceae and phylogeographic patterns between South America and Oceania. was included in a molecular phylogenetic analysis of Droseraceae, using nuclear internal transcribed spacer (ITS) and plastid rbcL and rps16 sequence data. Pollen of D. meristocaulis was studied using light microscopy and scanning electron microscopy techniques, and the karyotype was inferred from root tip meristem. The phylogenetic inferences (maximum parsimony, maximum likelihood and Bayesian approaches) substantiate with high statistical support the inclusion of sect. Meristocaulis and its single species, D. meristocaulis, within the Australian Drosera clade, sister to a group comprising species of sect. Bryastrum. A chromosome number of 2n approx. 3236 supports the phylogenetic position within the Australian clade. The undivided styles, conspicuous large setuous stipules, a cryptocotylar (hypogaeous) germination pattern and pollen tetrads with aperture of intermediate type 78 are key morphological traits shared between D. meristocaulis and pygmy sundews of sect. Bryastrum from Australia and New Zealand. The multidisciplinary approach adopted in this study (using morphological, palynological, cytotaxonomic and molecular phylogenetic data) enabled us to elucidate the relationships of the thus far unplaced taxon D. meristocaulis. Long-distance dispersal between southwestern Oceania and northern South America is the most likely scenario to explain the phylogeographic pattern revealed.

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Since the beginning of the HIV epidemic, there has been a significant increase in the number of histoplasmosis cases in Ceara, a state in north-east Brazil. The lack of epidemiological data on the genotypes circulating in the north-east region shows the importance of more detailed studies on the molecular epidemiology of Histoplasma capsulatum var. capsulatum in this region. Different molecular techniques have been used to better characterize the genetic profile of H. capsulatum var. capsulatum strains. The aim of this study was to analyse the genetic diversity of H. capsulatum var. capsulatum isolates in Fortaleza, the capital of Ceara, through the sequencing of the internal transcribed spacer (ITS)1-5.8S-ITS2 region, and establish the molecular profile of these isolates, along with strains from south-east Brazil, by RAPD analysis, featuring the different clusters in those regions. The isolates were grouped into two clusters. Cluster 1 included strains from the south-east and north-east regions with separation of isolates into three distinct subgroups (subgroups 1a, 1 b and 1 c). Cluster 2 included only samples from north-east Brazil. Sequencing of the ITS1 -5.8S-ITS2 region allowed the detection of two major clades, which showed geographical correlation between them and their subgroups. Therefore, it can be concluded that the H. capsulatum var. capsulatum isolates from Ceara have a high degree of genetic polymorphism. The molecular data also confirm that populations of this fungus are composed of different genotypes in Brazil and worldwide.

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Trypanosoma (Megatrypanum) melophagium is a parasite of sheep transmitted by sheep keds, the sheep-restricted ectoparasite Melophagus ovinus (Diptera: Hippoboscidae). Sheep keds were 100% prevalent in sheep from five organic farms in Croatia, Southeastern Europe, whereas trypanosomes morphologically compatible with T. melophagium were 86% prevalent in the guts of the sheep keds. Multilocus phylogenetic analyses using sequences of small subunit rRNA, glycosomal glyceraldehyde-3-phosphate dehydrogenase, spliced leader, and internal transcribed spacer 1 of the rDNA distinguished T. melophagium from all allied trypanosomes from other ruminant species and placed the trypanosome in the subgenus Megatrypanum. Trypanosomes from sheep keds from Croatia and Scotland, the only available isolates for comparison, shared identical sequences. All biologic and phylogenetic inferences support the restriction of T. melophagium to sheep and, especially, to the sheep keds. The comparison of trypanosomes from sheep, cattle, and deer from the same country, which was never achieved before this work, strongly supported the host-restricted specificity of trypanosomes of the subgenus Megatrypanum. Our findings indicate that with the expansion of organic farms, both sheep keds and T. melophagium may re-emerge as parasitic infections of sheep.