Endophytic colonisation of tobacco,corn, wheat and soybeans by the fungal entomopathogen Beauveria bassiana (Ascomycota,Hypocreales)

We demonstrate the effectiveness of three inoculation methods (foliar spray, seed immersion and root immersion) in establishing fungal the entomopathogen Beauveria bassiana as an endophyte in tobacco, corn, wheat and soybean. Colonisation of leaves by B. bassiana was assessed 7, 14, 21 and 28 days post-inoculation. There were significant differences (p < 0.001) in endophytic colonisation among the different inoculation techniques.     

Genetic characterization of Uruguayan Pampa Rocha pigs with microsatellite markers

In this study, we genetically characterized the Uruguayan pig breed Pampa Rocha. Genetic variability was assessed by analyzing a panel of 25 microsatellite markers from a sample of 39 individuals. Pampa Rocha pigs showed high genetic variability with observed and expected heterozygosities of 0.583 and 0.603, respectively. The mean number of alleles was 5.72. Twenty-four markers were polymorphic, with 95.8% of them in Hardy Weinberg equilibrium. The level of endogamy was low (F_IS = 0.0475). A factorial analysis of correspondence was used to assess the genetic differences between Pampa Rocha and other pig breeds; genetic distances were calculated, and a tree was designed to reflect the distance matrix. Individuals were also allocated into clusters. This analysis showed that the Pampa Rocha breed was separated from the other breeds along the first and second axes. The neighbour-joining tree generated by the genetic distances D_A showed clustering of Pampa Rocha with the Meishan breed. The allocation of individuals to clusters showed a clear separation of Pampa Rocha pigs. These results provide insights into the genetic variability of Pampa Rocha pigs and indicate that this breed is a well-defined genetic entity.     

Plant-type dependent changes in arbuscular mycorrhizal communities as soil quality indicator in semi-arid Brazil

A large remaining of dry deciduous forest (woody Caatinga) in semi-arid Brazil has been reached by successive fires and exploratory actions what leads to the invasion of low load trees and shrub mesh, called “Carrasco vegetation”. As it restrains the sprouting of woody species, land recuperation was performed using a mixed plantation of native and Eucalyptus species to both preservation and to supply the demand for wood. In order to evaluate the recuperation, a study of microbial communities was proposed. In addition to the highest soil phosphorus content found in the Carrasco area, the greatest spore density of arbuscular mycorrhizal fungi (AMF) communities occurred in the rhizosphere of the both pioneer species: Carrasco and Eucalyptus. In contrast to the DGGE bacteria profile, it was possible to group AMF species of the preserved and experimental sites which were not clustered with Carrasco species through the DGGE of Glomales DNA and also by the principal component analysis (PCA) based on diversity index. Glomus and Acaulospora were the dominant genera at both the preserved site and Carrasco. Nevertheless, Gigaspora species were preferentially found in Dry Forest, while Scutellospora were absent. In contrast, Carrasco favoured the genus Scutellospora and the species Acaulospora scrobiculata. Our results allow one to conclude that vegetation type modifies the AMF communities, which may be used as good indicator of soil quality. Based on AMF communities as soil quality indicator, the mixed forest plantation appears to be underway towards the preserved site two years after transplantation.     

Molecular analysis of 23 exons of the CFTR gene in Brazilian patients leads to the finding of rare cystic fibrosis mutations

To define mutations present in 23 exons and flanking intronic sequences of the cystic fibrosis transmembrane conductance regulator (CFTR) gene in 95 patients from Rio de Janeiro, Brazil, we carried out single-strand conformation polymorphism analysis and automated direct sequencing. Mutation detection was achieved in 45% of the alleles presented, and complete genotyping (two mutated alleles) was accomplished in 34.7% of the patients. Twenty patients (21.1%) were found to carry only one mutation, whereas mutated alleles could not be observed in 42 patients (44.2%). Eleven mutations were found, of which four were characterized as rare mutations: P205S (1.05%), Y1092X (0.53%), S549R (0.53%), and S4X (0.53%). The DF508 mutation in this population sample showed a frequency of 28.42%. The low number of individuals (10 of 95; 10.5%) with compound heterozygous (DF508/non-DF508) genotypes could indicate the presence of another severe mutation leading to the premature death of these individuals. In 4 of the aforementioned 10 individuals with compound heterozygous genotypes, the D-7-2-1-2 (XV2c-KM19-IVS6a-TUB9-M470-T854) haplotype was defined.     

Evidence for selection on synonymous mutations affecting stability of mRNA secondary structure in mammals

Background  

In mammals, contrary to what is usually assumed, recent evidence suggests that synonymous mutations may not be selectively neutral. This position has proven contentious, not least because of the absence of a viable mechanism. Here we test whether synonymous mutations might be under selection owing to their effects on the thermodynamic stability of mRNA, mediated by changes in secondary structure.     

Personalized diagnosis by cached solutions with hypertension as a study model

Statistical modeling of links between genetic profiles with environmental and clinical data to aid in medical diagnosis is a challenge. Here, we present a computational approach for rapidly selecting important clinical data to assist in medical decisions based on personalized genetic profiles. What could take hours or days of computing is available on-the-fly, making this strategy feasible to implement as a routine without demanding great computing power. The key to rapidly obtaining an optimal/nearly optimal mathematical function that can evaluate the "disease stage" by combining information of genetic profiles with personal clinical data is done by querying a precomputed solution database. The database is previously generated by a new hybrid feature selection method that makes use of support vector machines, recursive feature elimination and random sub-space search. Here, to evaluate the method, data from polymorphisms in the renin-angiotensin-aldosterone system genes together with clinical data were obtained from patients with hypertension and control subjects. The disease "risk" was determined by classifying the patients' data with a support vector machine model based on the optimized feature; then measuring the Euclidean distance to the hyperplane decision function. Our results showed the association of renin-angiotensin-aldosterone system gene haplotypes with hypertension. The association of polymorphism patterns with different ethnic groups was also tracked by the feature selection process. A demonstration of this method is also available online on the project's web site.