Apolipoprotein E genotype is related to nitric oxide production in platelets

The presence of the, 4 allele of apolipoprotein E (APOE) is considered a risk factor for sporadic Alzheimer`s disease (AD). Our recent data demonstrated that the systemic modulation of oxidative stress in platelets and erythrocytes is disrupted in aging and AD. In this study, the relationship between APOE genotype and oxidative stress markers, both in AD patients and controls, was evaluated. The AD group showed an increase in the content of thiobarbituric acid-reactive substances (TBARS) and in the activities of nitric oxide synthase (NOS) and Na, K-ATPase, when compared to controls. Both groups had a similar cGMP content and superoxide dismutase activity. APOE epsilon 4 allele carriers showed higher NOS activity than non-carriers. These results suggest a possible influence of APOE genotype on nitric oxide (NO) production that might enhance the effects of age-related specific factor(s) associated with neurodegenerative disorders. Copyright (C) 2008 John Wiley & Sons, Ltd.

Isolation and genotype analysis of rubella virus from a case of Guillain-Barre syndrome

Rubella virus (RV) infection has sporadically been linked to Guillain-Barre syndrome (GBS), but the association with RV has been based only on clinical and/or serological backgrounds. In the present case it was possible to isolate RV (genotype 1a) from cerebrospinal fluid and peripheral blood mononuclear cells of an 18-year-old woman diagnosed with GBS after clinical manifestations of rubella. This report contributes to confirm RV as one of the triggering pathogens of this peripheral nervous system disease. (C) 2008 Elsevier B.V. All rights reserved.

Evolutionary history of Dengue virus type 4: Insights into genotype phylodynamics

Dengue virus type 4 (DENV-4) circulates in tropical and subtropical countries from Asia and the Americas. Despite the importance of dengue virus distribution, little is known about the worldwide viral spread. Following a Bayesian phylogenetic approach we inferred the evolutionary history of 310 isolates sampled from 37 countries during the time period 1956-2008 and the spreading dynamics for genotypes I and II. The region (tropical rainforest biome) comprised by Malaysia-Thailand was the most likely ancestral area from which the serotype has originated and spread. Interestingly, cross-correlation analysis on demographic time series with the Asian sequences showed a statistically significant negative correlation that could be suggestive of competition among genotypes within the same serotype. (C) 2011 Elsevier B.V. All rights reserved.

Phylogenetic analysis of a near-full-length sequence of an erythrovirus genotype 3 strain isolated in Brazil

Human parvovirus B19 is the only member of the genus Erythrovirus that causes human disease. Recent findings of several strains with considerable sequence divergence from B19 have suggested a new classification for parvovirus genotypes as 1 (B19), 2 (A-6 and LaLi) and 3 (V9). In their overall DNA sequence, the three genotypes differ by similar to 10%. Here, we report the isolation of a genotype-3-related strain named BR543 during a prospective study conducted in Sao Paulo, Brazil. Analysis of the nearly full-length genome sequence of BR543 indicates that this B19 variant sequence clusters with Gh2768, a strain from Ghana belonging to subtype 3b, and showed mostly synonymous substitutions.

A new genotype of Trypanosoma cruzi associated with bats evidenced by phylogenetic analyses using SSU rDNA, cytochrome b and Histone H2B genes and genotyping based on ITS1 rDNA

We characterized 15 Trypanosoma cruzi isolates from bats captured in the Amazon, Central and Southeast Brazilian regions. Phylogenetic relationships among T. cruzi lineages using SSU rDNA, cytochrome b, and Histone H2B genes positioned all Amazonian isolates into T. cruzi I (TCI). However, bat isolates from the other regions, which had been genotyped as T. cruzi II (TC II) by the traditional genotyping method based on mini-exon gene employed in this study, Were not nested within any of the previously defined TCII sublineages, constituting a new genotype designated as TCbat. Phylogenetic analyses demonstrated that TCbat indeed belongs to T. cruzi and not to other closely related bat trypanosomes of the subgenus Schizotrypanum, and that although separated by large genetic distances TO-tat is closest to lineage TCI. A genotyping method targeting ITS1 rDNA distinguished TCbat from established T. cruzi lineages, and from other Schizotrypanum species. In experimentally infected mice, TCbat lacked virulence and yielded loss parasitaemias. Isolates of TCbat presented distinctive morphological features and behaviour in triatomines. To date, TCbat genotype wall found only in bats from anthropic environments of Central and Southeast Brazil. Our findings indicate that the complexity of T. cruzi is larger than currently known, and confirmed bats as important reservoirs and potential source of T. cruzi infections to humans.

Phylogenetic analysis of Trypanosoma vivax supports the separation of South American/West African from East African isolates and a new T-vivax-like genotype infecting a nyala antelope from Mozambique

In this study, we addressed the phylogenetic and taxonomic relationships of Trypanosoma vivax and related trypanosomes nested in the subgenus Duttonella through combined morphological and phylogeographical analyses. We previously demonstrated that the clade T. vivax harbours a homogeneous clade comprising West African/South American isolates and the heterogeneous East African isolates. Herein we characterized a trypanosome isolated from a nyala antelope (Tragelaphus angasi) wild-caught in Mozambique (East Africa) and diagnosed as T. vivax-like based on biological, morphological and molecular data. Phylogenetic relationships, phylogeographical patterns and estimates of genetic divergence were based on SSU and ITS rDNA sequences of T. vivax from Brazil and Venezuela (South America), Nigeria (West Africa), and from T. vivax-like trypanosomes from Mozambique, Kenya and Tanzania (East Africa). Despite being well-supported within the T. vivax clade, the nyala trypanosome was highly divergent from all other T. vivax and T. vivax-like trypanosomes, even those from East Africa. Considering its host origin, morphological features, behaviour in experimentally infected goats, phylogenetic placement, and genetic divergence this isolate represents a new genotype of trypanosome closely phylogenetically related to T. vivax. This study corroborated the high complexity and the existence of distinct genotypes yet undescribed within the subgenus Duttonella.

GENOTYPE CHARACTERIZATION OF THE Haematobia irritans (DIPTERA: MUSCIDAE) FROM BRAZIL, DOMINICAN REPUBLIC AND COLOMBIA BASED ON RANDOMLY AMPLIFIED POLYMORPHIC DNA (RAPD) ANALYSIS

Blood-sucking flies are important parasites in animal production systems, especially regarding confinement conditions. Haematobia irritans, the horn fly, is one of the most troublesome species within bovine production systems, due to the intense stress imposed to the animals. H. irritans is one of the parasites of cattle that cause significant economic losses in many parts of the world, including South America. In the present work, Brazilian, Colombian and Dominican Republic populations of this species were studied by Random Amplified Polymorphic DNA(RAPD) to assess basically genetic variability between populations. Fifteen different decamer random primers were employed in the genomic DNA amplification, yielding 196 fragments in the three H. irritans populations. Among h. irritans samples, that from Colombia produced the smallest numbers of polymorphic hands. This high genetic homogeneity may be ascribed to its geographic origin, which causes high isolation, low gene flow, unlike the other American populations, from Brazil and Dominican Republic. Molecular marker fragments, which its produced exclusive bands, detected in every sample enabled the population origin to be characterized, but they are also potentially useful for further approaches such as the putative origin of Brazilian, Colombian and Dominican Republic populations of horn fly from South America. Similarity indices produced by chemo metric analysis showed the closest relationships between flies from Brazil and Dominican Republic, while flies from Colombia showed the greatest genotypic differentiation relative to the others populations.

Genotype-environment interaction for post-weaning traits in Nellore beef cattle

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Mitochondrial genotype segregation and effects during mammalian development: Applications to biotechnology

Mitochondria are endosymbiotic organelles responsible for energy production in practically every eukaryotic cell. Their uniparental fashion of inheritance, maternally inherited in mammals, and the homogeneity of mitochondrial DNA (mtDNA) within individuals and matrilineages, are biological phenomena that remain unexplained. This paper reviews some of the recent findings on mitochondrial influences on the manner in which embryos develop and how their genotypes are inherited in mammals, with particular emphasis on the genetic bottleneck effect. Animal models carrying a mix of mtDNAs (heteroplasmic) have been produced by karyoplast and cytoplast transplantation to analyze the segregation patterns at different stages during embryogenesis, in fetuses and offspring. Comparisons performed between murine and bovine reveal interesting changes in segregation and replication of transplanted mtDNAs. We have recently obtained Bos indicus and Bos taurus fetuses and calves from embryos reconstructed using enucleated polymorphic oocytes of Bos taurus origin. These and other findings on mitochondrial biology will have important implications in determining the cytoplasmic genotype of clones and in the preservation of endangered breeds and species. (C) 1999 by Elsevier B.V.

Effects of age at slaughter and sire genotype on fatness, muscularity, and the quality of meat from ram lambs born to Romney ewes

Ram lambs (n = 356) born to Romney ewes and sired by a range of straightbred or crossbred sires were evaluated for carcass composition and, for a subsample (n = 236), some meat quality characteristics over a period of 4 years. Within each year, 2 to 4 sire genotypes, including Romney controls, were evaluated at 2 slaughter ages (5-9 months and 10-11 months). Weight-adjusted carcass length was greater for lambs with some East Friesian or Finn genes, but no differences were found in dressing-out percent. At a constant carcass weight, carcass fatness (fat depths and leg dissectible fat) was lower in lambs with East Friesian, Texel, or Finn genes. Meat yield at a constant weight tended to be greatest in sire groups that were least fat, and M:B ratio in the femur region was highest in lambs with Texel genes and, to a lesser extent, those with Poll Dorset genes. Leg muscularity in the femur region generally paralleled differences in M:B, except in a comparison of East Friesian-cross and Romney lambs where the former had lower muscularity but slightly better M:B. Lambs slaughtered at the older age for each year had longer and leaner carcasses at the same weight, possibly because they had been taken part way through a winter or because of slower growth rates leading up to slaughter. Meat quality characteristics differed little between the genotype groups, but for 2 of 3 years, meat from the semimembranosus muscle of lambs in the older slaughter lot was significantly tougher.

Genotype by environment interaction in Nelore cattle from five Brazilian states

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

Genotype by environment interaction for birth and weaning weights of composite beef cattle in different regions of Brazil

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

Effects of sex and age on genotype x environment interaction for beef cattle body weight studied using reaction norm models

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Population dynamics of DENV-1 genotype V in Brazil is characterized by co-circulation and strain/lineage replacement

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)