157 resultados para HAPLOTYPES


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Background: The chemokine receptor 1 CXCR-1 (or IL8R-alpha) is a specific receptor for the interleukin 8 (IL-8), which is chemoattractant for neutrophils and has an important role in the inflammatory response. The polymorphism rs2234671 at position Ex2+860G > C of the CXCR1 gene causes a conservative amino acid substitution (S276T). This single nucleotide polymorphism (SNP) seemed to be functional as it was associated with decreased lung cancer risk. Previous studies of our group found association of haplotypes in the IL8 and in the CXCR2 genes with the multifactorial disease chronic periodontitis. In this study we investigated the polymorphism rs2234671 in 395 Brazilian subjects with and without chronic periodontitis. Findings. Similar distribution of the allelic and genotypic frequencies were observed between the groups (p > 0.05). Conclusions: The polymorphism rs2234671 in the CXCR1 gene was not associated with the susceptibility to chronic periodontitis in the studied Brazilian population. © 2011 Scarel-Caminaga et al; licensee BioMed Central Ltd.

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Fetal hemoglobin (Hb F), formed by two alpha globin chains (α) and two gamma chains (γ) (α2 γ2), has reduced expression in adults, ranging from 0 to 1% of total hemoglobin. Increased levels of Hb F are due to mutations in the β-globin family, which cause hereditary persistence of fetal hemoglobin (HPFH) and delta-beta thalassemia (δβ-thalassemia).The control of the production takes place by the regulatory region and regions outside the β-globin family, among them 2q16, 6q23, 8q, and Xp22.2.The aims of this study were to determine the presence and frequency of two mutations for δβ-thalassemia, the XmnI polymorphism and β-globin haplotypes in healthy individuals with increased Hb F in the State of São Paulo. We analyzed 60 samples of peripheral blood of healthy adults, without complaints of anemia. The samples were separated into two groups according to Hb F level: group I - 34 samples with Hb F ranging from 2 to 15% and group II - 26 samples with Hb F over 15%. In relation to the polymorphisms examined, we found three heterozygous individuals (5%) for Spanish δβ-thalassemia, belonging to group I, whose Hb F levels were within the normal range.The Sicilian δβ-thalassemia mutation was not found, indicating the need to study other polymorphisms related to the increase of Hb F in adult life.The frequency of XmnI polymorphism was 33.3% and the mean Hb F levels were 15.48 ± 11.69%.The frequency observed in our study for this polymorphic site is higher than that found in the literature for healthy subjects.This polymorphism was more prevalent in individuals with Hb F levels below 15%. For four samples positive for this polymorphism, the Hb F levels were explained by the presence of HPFH and Spanish δβ-thalassemia mutations, so that the presence of the XmnI polymorphic site was not a determinant in the overexpression of γ-globin genes. Regarding β-globin haplotypes, 18 alleles and 27 distinct genotypic patterns were found.The pattern Atp1/Atp2 was the mostfrequent genotype (13.72%).Of the 18 alleles, 13 showed atypical patterns.The results show that the haplotype V was the most frequent (27.45%), followed by atypical Atp2 (13.72%) and Atp1 (11.76%), and that there was a higher correlation with the presence of HPFH and XmnI polymorphism.The high frequency of haplotype V in our samples and high frequency of atypical haplotypes may reflect a high rate of miscegenation in this population, suggesting an ethnic characteristic for the Brazilian population, requiring the evaluation of population genetic markers to corroborate this hypothesis. © FUNPEC-RP.

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Fire ants are aggressive Neotropical ants that are extensively similar in general biology and morphology, making species identification difficult. Some fire ant species are top-rated pests spreading throughout the world by trade vessels. Many researchers attempted to sort between invasive and native species by using chemical characters, including patterns of venom alkaloids. The present study is the first to report intraspecific variation in some chemical characters, namely, cuticular hydrocarbons and venom alkaloids, within the Brazilian fire ant species Solenopsis saevissima and also reports on within-nest variations among members of different castes. Two different haplotypes (cryptic species) of S. saevissima were clearly identified, one presenting a predominant combination of the venom alkaloids cis- and trans-2-methyl-6-undecylpiperidine with the cuticular hydrocarbons C23, 3-Me-C23, 10-C 25:1, C25, and 3-Me-C25, and the other a predominant combination of cis- and trans-2-methyl-6-tridecenylpiperidine with predominance of 12-C25:1, C25, 11-Me-C25, 3-Me-C25, 13-C27:1, C27, and 13-Me-C 27. Intranest variations revealed that the proportions among these compounds varied sensibly among workers of different sizes, gynes, and males (no alkaloids were detected in the latter). Larva contained vestiges of the same compounds. The recorded chemical profiles are quite different from previous reports with S. saevissima samples from So Paulo. The finds thus support other recent claims that S. saevissima includes cryptic species; the study, moreover, adds the find that they can occur in the same geographical location. © 2012 Eduardo Gonalves Paterson Fox et al.

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In order to investigate the intraspecific variability in Hannaella kunmingensis, 11 isolates, including the type strain, were analyzed for their morphological and biochemical traits. The combined internal transcribed spacer region (ITS), D1/D2 domains of the large subunit rDNA (LSU), and cytochrome b gene were examined using phylogenetic and parsimony network analyses. Our investigations revealed differences in colony morphology as well as differences in 31 out of 64 phenotypic characteristics examined, including growth in lactose, vitamin free medium, xylitol, L-arabinitol, and nitrite. Growth in the presence of 0. 1 % cycloheximide was also highlighted in H. kunmingensis. All the 11 strains were conspecific in the LSU; however, variations of about 2. 5 % were found in the ITS while isolate CBS 8356 exhibited a 27. 3 % divergence from the other strains in the cytochrome b gene. Parsimony network analysis revealed the existence of three haplotypes among the H. kunmingensis strains studied but excluded CBS 8356 from the network connecting these haplotypes. This study contributes to the knowledge of the intraspecific diversity of H. kunmingensis. To accommodate such intraspecific variations, an emendation of the species diagnosis is proposed. © 2012 German Mycological Society and Springer.

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Intense selective pressures applied over short evolutionary time have resulted in homogeneity within, but substantial variation among, horse breeds. Utilizing this population structure, 744 individuals from 33 breeds, and a 54,000 SNP genotyping array, breed-specific targets of selection were identified using an FST-based statistic calculated in 500-kb windows across the genome. A 5.5-Mb region of ECA18, in which the myostatin (MSTN) gene was centered, contained the highest signature of selection in both the Paint and Quarter Horse. Gene sequencing and histological analysis of gluteal muscle biopsies showed a promoter variant and intronic SNP of MSTN were each significantly associated with higher Type 2B and lower Type 1 muscle fiber proportions in the Quarter Horse, demonstrating a functional consequence of selection at this locus. Signatures of selection on ECA23 in all gaited breeds in the sample led to the identification of a shared, 186-kb haplotype including two doublesex related mab transcription factor genes (DMRT2 and 3). The recent identification of a DMRT3 mutation within this haplotype, which appears necessary for the ability to perform alternative gaits, provides further evidence for selection at this locus. Finally, putative loci for the determination of size were identified in the draft breeds and the Miniature horse on ECA11, as well as when signatures of selection surrounding candidate genes at other loci were examined. This work provides further evidence of the importance of MSTN in racing breeds, provides strong evidence for selection upon gait and size, and illustrates the potential for population-based techniques to find genomic regions driving important phenotypes in the modern horse. © 2013 Petersen et al.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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In the past, the focus of broiler breeding programs on yield and carcass traits improvement led to problems related to meat quality. Awareness of public concern for quality resulted in inclusion of meat quality traits in the evaluation process. Nevertheless, few genes associated with meat quality attributes are known. Previous studies mapped quantitative trait loci for weight at 35 and 42 days in a region of GGA4 flanked by the microsatellite markers, MCW0240 and LEI0063. In this region, there are 2 fibroblast growth factor binding protein (FGFBP) genes that play an important role in embryogenesis, cellulardifferentiation, and proliferation in chickens. The objective of this study was to identify and associate single nucleotide polymorphisms (SNPs) in FGFBP1 and FGFBP2 with performance, carcass, and meat quality in experimental and commercial chicken populations. In the commercial population, SNP g.2014G>A in FGFBP1 was associated with decreased carcass weight (P < 0.05), and SNP g.651G>A in FGFBP2 was associated with thawing loss and meat redness content (P < 0.05). Four haplotypes were constructed based on 2 SNPs and were associated with breast weight, thawing loss, and meat redness content. The diplotypes were associated with thawing loss, lightness, and redness content. The SNPs evaluated in the present study may be used as markers in poultry breeding programs to aid in improving growth and meat quality traits. © FUNPEC-RP.

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Mitochondrial DNA (mtDNA) analysis is usually a last resort in routine forensic DNA casework. However, it has become a powerful tool for the analysis of highly degraded samples or samples containing too little or no nuclear DNA, such as old bones and hair shafts. The gold standard methodology still constitutes the direct sequencing of polymerase chain reaction (PCR) products or cloned amplicons from the HVS-1 and HVS-2 (hypervariable segment) control region segments. Identifications using mtDNA are time consuming, expensive and can be very complex, depending on the amount and nature of the material being tested. The main goal of this work is to develop a less labour-intensive and less expensive screening method for mtDNA analysis, in order to aid in the exclusion of non-matching samples and as a presumptive test prior to final confirmatory DNA sequencing. We have selected 14 highly discriminatory single nucleotide polymorphisms (SNPs) based on simulations performed by Salas and Amigo (2010) [1] to be typed using SNaPShotTM (Applied Biosystems, Foster City, CA, USA). The assay was validated by typing more than 100 HVS-1/HVS-2 sequenced samples. No differences were observed between the SNP typing and DNA sequencing when results were compared, with the exception of allelic dropouts observed in a few haplotypes. Haplotype diversity simulations were performed using 172 mtDNA sequences representative of the Brazilian population and a score of 0.9794 was obtained when the 14 SNPs were used, showing that the theoretical prediction approach for the selection of highly discriminatory SNPs suggested by Salas and Amigo (2010) [1] was confirmed in the population studied. As the main goal of the work is to develop a screening assay to skip the sequencing of all samples in a particular case, a pair-wise comparison of the sequences was done using the selected SNPs. When both HVS-1/HVS-2 SNPs were used for simulations, at least two differences were observed in 93.2% of the comparisons performed. The assay was validated with casework samples. Results show that the method is straightforward and can be used for exclusionary purposes, saving time and laboratory resources. The assay confirms the theoretic prediction suggested by Salas and Amigo (2010) [1]. All forensic advantages, such as high sensitivity and power of discrimination, as also the disadvantages, such as the occurrence of allele dropouts, are discussed throughout the article. © 2013 Elsevier B.V.

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Twenty-five specimens of the freshwater red alga Compsopogon were collected from locations in North America, South America, Europe, Asia, Australasia and Oceania, and from an aquarium, with the goal of determining genetic diversity among specimens and ascertaining the number of phylogenetic species. Specimens were morphologically identified as having either the 'caeruleus' morphology, with regular polyhedral cortical cells, or the 'leptoclados' morphology, with irregular cortical cells with rhizoidal outgrowths. The 'leptoclados' morphology has been used by some researchers to distinguish the genus Compsopogonopsis from Compsopogon, or at least to distinguish C. leptoclados from other Compsopogon species. Sequence data for the rbcL gene and cox1 barcoding region were obtained for most specimens. In addition, SSU and partial LSU (barcode) rDNA were explored for a few specimens, but all sequences were identical. For the 25 newly generated and eight previously published rbcL gene data, there were seven unique haplotypes, but the sequence divergence was very low (≤7 bp, ≤ 0.7%). One haplotype was widespread, represented by 21 specimens from diverse locations in all regions sampled. Likewise, the 22 new and one previously published cox1 barcode region sequences yielded seven unique haplotypes with little sequence divergence (≤13 bp, ≤ 2.0%). One haplotype was widespread, being shared among 16 specimens from all regions. The combined molecular and morphological data showed no genetic differentiation between the 'caeruleus' and 'leptoclados' morphologies. The ubiquitous distribution of Compsopogon in tropical/subtropical regions and its low genetic variation are probably facilitated by the alga's ability to tolerate a wide range of stream conditions and its propagation via asexual spores. Given the findings of previous culture-based studies, morphometric research and field observations, coupled with the results of our study, we conclude there is only a single monospecific genus worldwide and that the species is correctly called C. caeruleus, since this is the oldest validly published name; all other previously described species of Compsopogon and Compsopogonopsis are synonyms. © 2013 British Phycological Society.

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We provide initial information regarding the population structure and genetic diversity of Stenella frontalis from the Caribbean and southeastern Brazil from analyses of mitochondrial control region sequences and sequences from the first intron of the α-lactalbumin gene. Comparisons with previously described S. frontalis sequences showed a high number of haplotypes shared between populations throughout their distribution range. High diversity was found for southeastern Brazil and Caribbean samples, and population structure analyses indicate significant differentiation among population units at the FST level, but not at the ΦST level. Significant differentiation at the FST level was found between the Caribbean population unit and all other populations units. These results suggest historical or present connectivity between the Azores and Madeira and the southeastern Brazil groups and population differentiation between the Caribbean and southeastern Brazil, supporting the notion of two separate stocks in the waters around the Atlantic coast of South America. © 2013 Elsevier Ltd.

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Adiponectin is a hormone involved in energy homeostasis by regulating glucose and lipid metabolism. In addition, the adiponectin gene (ADIPOQ) has polymorphisms that can modulate the circulating concentration of adiponectin. Abnormal adiponectin levels have been associated with pre-eclampsia (PE); however, the influence of genetic polymorphisms on the development of hypertensive disorders of pregnancy is unclear. The aim of this study was to examine whether ADIPOQ polymorphisms are associated with gestational hypertension (GH) and/or PE. We studied 401 pregnant women: 161 healthy pregnant (HP), 113 pregnant with GH and 127 pregnant with PE. ADIPOQ polymorphisms -11391G>A (rs17300539), -11377C>G (rs266729), 45T>G (rs2241766) and 276G>T (rs1501299) were genotyped by allelic discrimination assays using real-time PCR. Haplotypes were inferred using the PHASE 2.1 program. We observed that the genotypic frequencies of the -11377C>G polymorphism were different in PE compared with HP (P<0.0125), with the CT genotype being more commonly found in PE patients than in HP women (P<0.0125). However, allelic frequencies of this single-nucleotide polymorphism were similar between PE and HP (P>0.0125). No difference was observed when GH and HP groups were compared (both P>0.0125). In addition, we found no difference in genotype or allele distributions for the -11391G>A, 45T>G and 276G>T polymorphisms when we compared GH or PE with HP (all P>0.0125). In conclusion, we found a modest association between the CG genotype of the -11377C>G polymorphism and PE.Journal of Human Hypertension advance online publication, 27 June 2013; doi:10.1038/jhh.2013.53.

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Fungi constitute an important part of the soil ecosystem, playing key roles in decomposition, cycling processes, and biotic interactions. Molecular methods have been used to assess fungal communities giving a more realistic view of their diversity. For this purpose, total DNA was extracted from bulk soils cultivated with tomato (STC), vegetables (SHC), and native forest (SMS) from three sites of the Taquara Branca river basin in Sumaré County, São Paulo State, Brazil. This metagenomic DNA was used as a template to amplify fungal 18S rDNA sequences, and libraries were constructed in Escherichia coli by cloning PCR products. The plasmid inserts were sequenced and compared to known rDNA sequences in the GenBank database. Of the sequenced clones, 22 were obtained from the SMS sample, 18 from the SHC sample, and 6 from the STC sample. Although most of the clone sequences did not match the sequences present in the database, individual amplified sequences matched with Glomeromycota (SMS), Fungi incertae sedis (SMS), and Neocallimastigomycota (SHC). Most of the sequences from the amplified taxa represent uncultured fungi. The molecular analysis of variance (AMOVA) indicated that fluctuations observed of haplotypes in the composition may be related to herbicide application. © 2013 Silvana Pompéia Val-Moraes et al.

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HLA-G has an important role in the modulation of the maternal immune system during pregnancy, and evidence that balancing selection acts in the promoter and 3′UTR regions has been previously reported. To determine whether selection acts on the HLA-G coding region in the Amazon Rainforest, exons 2, 3 and 4 were analyzed in a sample of 142 Amerindians from nine villages of five isolated tribes that inhabit the Central Amazon. Six previously described single-nucleotide polymorphisms (SNPs) were identified and the Expectation-Maximization (EM) and PHASE algorithms were used to computationally reconstruct SNP haplotypes (HLA-G alleles). A new HLA-G allele, which originated in Amerindian populations by a crossing-over event between two widespread HLA-G alleles, was identified in 18 individuals. Neutrality tests evidenced that natural selection has a complex part in the HLA-G coding region. Although balancing selection is the type of selection that shapes variability at a local level (Native American populations), we have also shown that purifying selection may occur on a worldwide scale. Moreover, the balancing selection does not seem to act on the coding region as strongly as it acts on the flanking regulatory regions, and such coding signature may actually reflect a hitchhiking effect.Genes and Immunity advance online publication, 3 October 2013; doi:10.1038/gene.2013.47.