761 resultados para HAPLOTYPES


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The South American sea lion, Otaria flavescens, is widely distributed along the Pacific and Atlantic coasts of South America. However, along the Brazilian coast, there are only two nonbreeding sites for the species (Refúgio de Vida Silvestre da Ilha dos Lobos and Refúgio de Vida Silvestre do Molhe Leste da Barra do Rio Grande), both in Southern Brazil. In this region, the species is continuously under the effect of anthropic activities, mainly those related to environmental contamination with organic and inorganic chemicals and fishery interactions. This paper reports, for the first time, the genetic diversity of O. flavescens found along the Southern Brazilian coast. A 287-bp fragment of the mitochondrial DNA control region (D-loop) was analyzed. Seven novel haplotypes were found in 56 individuals (OFA1-OFA7), with OFA1 being the most frequent (47.54%). Nucleotide diversity was moderate (π = 0.62%) and haplotype diversity was relatively low (67%). Furthermore, the median joining network analysis indicated that Brazilian haplotypes formed a reciprocal monophyletic clade when compared to the haplotypes from the Peruvian population on the Pacific coast. These two populations do not share haplotypes and may have become isolated some time back. Further genetic studies covering the entire species distribution are necessary to better understand the biological implications of the results reported here for the management and conservation of South American sea lions.

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The barley β-amylase I (Bmy1) locus encodes a starch breakdown enzyme whose kinetic properties and thermostability are critical during malt production. Studies of allelic variation at the Bmy1 locus have shown that the encoded enzyme can be commonly found in at least three distinct thermostability classes and demonstrated the nucleotide sequence variations responsible for such phenotypic differences. In order to explore the extent of sequence diversity at the Bmy1 locus in cultivated European barley, 464 varieties representing a cross-section of popular varieties grown in western Europe over the past 60 years, were genotyped for three single nucleotide polymorphisms chosen to tag the four common alleles found in the collection. One of these haplotypes, which has not been explicitly recognised in the literature as a distinct allele, was found in 95% of winter varieties in the sample. When release dates of the varieties were considered, the lowest thermostability allele (Bmy1-Sd2L) appeared to decrease in abundance over time, while the highest thermostability allele (Bmy1-Sd2H) was the rarest allele at 5.4% of the sample and was virtually confined to two-row spring varieties. Pedigree analysis was used to track transmission of particular alleles over time and highlighted issues of genetic stratification of the sample.

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TNF microsatellite and HLA class II polymorphisms were studied in 28 recently diagnosed Brazilian patients presenting type 1 diabetes mellitus (T1DM) and in 120 healthy controls. TNFa-e and HLA-DRB1/DQB1 alleles were identified using sets of sequence-specific primers. Compared to controls, the DRB1* 03 and DQBI*02 allele groups, TNFa1 allele, and the TNFa4-b5-c1-d4-e3 and TNFa10-b5-c1-d4-e3 haplotypes were overrepresented in patients. TNF microsatellite together with HLA polymorphisms is associated with type 1 diabetes in Brazilian patients, corroborating the participation of the MHC genes in disease susceptibility.

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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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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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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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Chronic periodontitis (CP) is considered to be a multifactorial disease influenced by microbial and genetic factors. The aim of the present study was to investigate whether the genetic susceptibility to CP in individuals with the IL8 ATC/TTC haplotype is associated with subgingival levels of periodontopathogens. Sixty-five individuals, grouped according to the presence (n = 28) or absence (n = 37) of the IL8 haplotype, were evaluated. After clinical periodontal evaluation, each group was subdivided according to the presence (CP) or absence (H) of periodontitis. Four subgingival samples were obtained from CP and two samples per subject from H patients. The levels and proportions of Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola were analyzed using quantitative real-time polymerase chain reaction (q-PCR). No differences were found in the proportion of periodontopathogenic bacteria between groups with the presence or absence of the IL8 haplotype. However, in the CP groups, the levels of periodontopathogens were significantly higher in the individuals without the IL8 haplotype than in the individuals with the IL8 haplotype. These results suggest that periodontal destruction may occur in patients who are considered to be genetically susceptible to CP with a lower microbial challenge because of the presence of the IL8 ATC/TTC haplotype than in patients without this haplotype. © 2013 Springer-Verlag Berlin Heidelberg.

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Different IL4 haplotypes were associated to susceptibility to/or protection against chronic periodontitis (CP). The aim of this study was to investigate if individuals carrying different haplotypes would present differences in clinical periodontal parameters and in the IL-4 levels at baseline, 45 and 90 days after non-surgical periodontal therapy. 62 patients were subdivided: genetically protected without CP (PH), genetically protected with CP (PCP), genetically susceptible with CP (SCP), genetically susceptible without CP (healthy) (SH). Clinical examination and gingival crevicular fluid (GCF) collection were performed for all patients, and IL-4 levels were measured by ELISA. At baseline, higher values for plaque index (PI, p = 0.013), gingival index (GI, p = 0.005) were observed for the SCP group in comparison to the PCP group but not after the completion of periodontal therapy. 45 and 90 days after the non-surgical therapy, PCP demonstrated significantly higher IL-4 levels than the SCP (p = 0.000002). Correlation analysis showed different results between clinical parameters and IL-4 production or GCF volume for groups with different genetic loads. The IL4 gene which was previously associated with susceptibility to CP was related with differences in the IL-4 protein levels in the GCF. However, independent of genetic carriage, individuals responded similarly to this therapy. © 2013 American Society for Histocompatibility and Immunogenetics.

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Angiostrongylus cantonensis is the etiologic agent of eosinophilic meningoencephalitis in humans. Cases have been recorded in many parts of the world, including Brazil. The aim of this study was to compare the differences in the biology and morphology of two different Brazilian haplotypes of A. : ac8 and ac9. A significantly larger number of L1 larvae eliminated in the faeces of rodents at the beginning of the patent period was observed for ac9 haplotype and compared to the total of L1 larvae eliminated, there was a significant difference between the two haplotypes. The ac9 haplotype showed a significant difference in the proportion of female and male specimens (0.6:1), but the same was not observed for ac8 (1.2:1). The morphometric analysis showed that male and female specimens isolated from ac8 haplotype were significantly larger with respect to body length, oesophagus length, spicule length (male) and distance from the anus to the rear end (female) compared to specimens from ac9. The morphological analysis by light microscopy showed little variation in the level of bifurcations at the lateral rays in the right lobe of the copulatory bursa between the two haplotypes. The biological, morphological and morphometric variations observed between the two haplotypes agree with the observed variation at the molecular level using the cytochrome oxidase subunit I marker and reinforce the possible influence of geographical isolation on the development of these haplotypes.