The SAUR gene family in coffee: genome-wide identification and gene expression analysis during somatic embryogenesis

Molecular Biology Reports - Small auxin-up RNA (SAUR) genes form a wide family supposedly involved in different physiological and developmental processes in plants such as leaf senescence, auxin...     

Selected anthropometric variables and aerobic fitness as predictors of cardiovascular disease risk in children

The aim of this study was to assess the suitability of body mass index, waist circumference, waist-to-height ratio and aerobic fitness as predictors of cardiovascular risk factor clustering in children. A cross-sectional study was conducted with 290 school boys and girls from 6 to 10 years old, randomly selected. Blood was collected after a 12-hour fasting period. Blood pressure, waist circumference (WC), height and weight were evaluated according to international standards. Aerobic fitness (AF) was assessed by the 20-metre shuttle-run test. Clustering was considered when three of these factors were present: high systolic or diastolic blood pressure, high low-density lipoprotein (LDL) cholesterol, high triglycerides, high plasma glucose, high insulin concentrations and low high-density lipoprotein (HDL) cholesterol. A ROC curve identified the cut-off points of body mass index (BMI), WC, waist-to-height ratio (WHtR) and AF as predictors of risk factor clustering. BMI, WC and WHR resulted in significant areas under the ROC curves, which was not observed for AF. The anthropometric variables were good predictors of cardiovascular risk factor clustering in both sexes, whereas aerobic fitness should not be used to identify cardiovascular risk factor clustering in these children.     

Sugarcane (Saccharum X officinarum): A Reference Study for the Regulation of Genetically Modified Cultivars in Brazil

Global interest in sugarcane has increased significantly in recent years due to its economic impact on sustainable energy production. Sugarcane breeding and better agronomic practices have contributed to a huge increase in sugarcane yield in the last 30?years. Additional increases in sugarcane yield are expected to result from the use of biotechnology tools in the near future. Genetically modified (GM) sugarcane that incorporates genes to increase resistance to biotic and abiotic stresses could play a major role in achieving this goal. However, to bring GM sugarcane to the market, it is necessary to follow a regulatory process that will evaluate the environmental and health impacts of this crop. The regulatory review process is usually accomplished through a comparison of the biology and composition of the GM cultivar and a non-GM counterpart. This review intends to provide information on non-GM sugarcane biology, genetics, breeding, agronomic management, processing, products and byproducts, as well as the current technologies used to develop GM sugarcane, with the aim of assisting regulators in the decision-making process regarding the commercial release of GM sugarcane cultivars.     

Reproductive condition of Akodon montensis Thomas and Bolomys lasiurus (Lund) (Rodentia, Muridae) based on histological and histometric analyses of testes and external characteristics of gonads

The reproductive activity of two species of wild rodents was studied in the Serra do Rola‐Moça State Park (PERM), in the state of Minas Gerais, Brazil. From October 1998 to October 1999 specimens of Akodon montensis (Thomas 1913) were captured in an area of seasonal semi‐deciduous forest, while specimens of Bolomys lasiurus (Lund 1840) were captured in a cerrado area (a savannah‐like grassland). The determination of the reproductive condition was based on histological and histometric analyses of testes and external characteristics of gonads. The volume of the testes, diameter of the seminiferous tubules and depth of the seminiferous epithelium were measured. Akodon montensis showed a seasonal annual reproductive cycle divided into four stages (recrudescence, activity or proliferation, regression and rest) with the reproductive activity mainly occurring during the rainy season. In contrast, B. lasiurus presented reproductive activity during almost the whole year. For both species the volume of the testes was an effective indicator of their reproductive condition. We suggest that the histological and histometric analysis of the gonads of males, together with the observations of external characteristics of gonads of males and females, may assist in identifying the reproductive condition of these animals.     

Nodule development induced by Mesorhizobium loti mutant strains affected in polysaccharide synthesis

The role of Mesorhizobium loti surface polysaccharides on the nodulation process is not yet fully understood. In this article, we describe the nodulation phenotype of mutants affected in the synthesis of lipopolysaccharide (LPS) and beta(1,2) cyclic glucan. M. loti lpsbeta2 mutant produces LPS with reduced amount of O-antigen, whereas M. loti lpsbeta1 mutant produces LPS totally devoid of O-antigen. Both genes are clustered in the chromosome. Based on amino acid sequence homology, LPS sugar composition, and enzymatic activity, we concluded that lpsbeta2 codes for an enzyme involved in the transformation of dTDP-glucose into dTDP-rhamnose, the sugar donor of rhamnose for the synthesis of O-antigen. On the other hand, lpsbeta1 codes for a glucosyltransferase involved in the biosynthesis of the O-antigen. Although LPS mutants elicited normal nodules, both show reduced competitiveness compared with the wild type. M. loti beta(1-2) cyclic glucan synthase (cgs) mutant induces white, empty, ineffective pseudonodules in Lotus tenuis. Cgs mutant induces normal root hair curling but is unable to induce the formation of infection threads. M. loti cgs mutant was more sensitive to deoxycholate and displayed motility impairment compared with the wild-type strain. This pleiotropic effect depends on calcium concentration and temperature.     

Structural analysis of the N-glycans of the major cysteine proteinase of Trypanosoma cruzi. Identification of sulfated high-mannose type oligosaccharides

Trypanosoma cruzi, the parasitic protozoan that causes Chagas disease, contains a major cysteine proteinase, cruzipain. This lysosomal enzyme bears an unusual C-terminal extension that contains a number of post-translational modifications, and most antibodies in natural and experimental infections are directed against it. In this report we took advantage of UV-MALDI-TOF mass spectrometry in conjunction with peptide N-glycosidase F deglycosylation and high performance anion exchange chromatography analysis to address the structure of the N-linked oligosaccharides present in this domain. The UV-MALDI-TOF MS analysis in the negative-ion mode, using nor-harmane as matrix, allowed us to determine a new striking feature in cruzipain: sulfated high-mannose type oligosaccharides. Sulfated GlcNAc2Man3 to GlcNAc2Man9 species were identified. In accordance, after chemical or enzymatic desulfation, the corresponding signals disappeared. In addition, by UV-MALDI-TOF MS analysis (a) a main population of high-mannose type oligosaccharides was shown in the positive-ion mode, (b) lactosaminic glycans were also identified, among them, structures corresponding to monosialylated species were detected, and (c) as an interesting fact a fucosylated oligosaccharide was also detected. The presence of the deoxy sugar was further confirmed by high performance anion exchange chromatography. In conclusion, the total number of oligosaccharides occurring in cruzipain was shown to be much higher than previous estimates. This constitutes the first report on the presence of sulfated glycoproteins in Trypanosomatids.     

Diet of wild boar Sus scrofa L. and crop damage in an intensive agroecosystem

The Middle Ebro Valley (MEV) is a semiarid area in northeast Iberia where the original riparian ecosystems are almost extinct and were replaced by intensive irrigated agricultural lands. To minimize crop damages and to understand the impact of wild boar on relict riparian ecosystems, a culling program was undertaken from 1994 until 2004. To assess the impact of wild boars, we analyzed stomach contents and surveyed crop damage. In the MEV, wild boars feed mainly on crops, particularly, maize. Other elements of the diet that are of agricultural origin include wheat, barley, and alfalfa, which are the alternatives to maize in the period between harvest and seeding, which is the basis of seasonal changes in diet. Results indicate that wild boar actively selected maize crops and consumed wheat in proportion to its abundance; barley and alfalfa fields were damaged less than expected based on their abundance. In the MEV, the wild boar population is limited by the availability of shelter areas found in the scarce riparian ecosystems, which do not provide important food items for this population. We conclude that in the region of this study, wild boars are not a significant threat to the flora and fauna of riparian ecosystems, although as these habitats are restored and areas are protected, the carrying capacity for wild boars might increase.     

Laccase activity from the fungus Trametes hirsuta using an air-lift bioreactor

AIM: To produce high laccase activities from the white-rot fungus Trametes hirsuta in an in-house air-lift bioreactor (ALB). METHODS AND RESULTS: Trametes hirsuta was grown in a 6-l ALB. A fed-batch strategy with glycerol as an addition resulted in maximum laccase activity of 19,400 U l(-1), which was the highest reported from the fungus. CONCLUSION: The ALB configuration with additional glycerol resulted in high laccase activities. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides useful information on how to produce high concentrations of laccase.     

Contribution of efflux to the emergence of isoniazid and multidrug resistance in Mycobacterium tuberculosis

Multidrug resistant (MDR) tuberculosis is caused by Mycobacterium tuberculosis resistant to isoniazid and rifampicin, the two most effective drugs used in tuberculosis therapy. Here, we investigated the mechanism by which resistance towards isoniazid develops and how overexpression of efflux pumps favors accumulation of mutations in isoniazid targets, thus establishing a MDR phenotype. The study was based on the in vitro induction of an isoniazid resistant phenotype by prolonged serial exposure of M. tuberculosis strains to the critical concentration of isoniazid employed for determination of drug susceptibility testing in clinical isolates. Results show that susceptible and rifampicin monoresistant strains exposed to this concentration become resistant to isoniazid after three weeks; and that resistance observed for the majority of these strains could be reduced by means of efflux pumps inhibitors. RT-qPCR assessment of efflux pump genes expression showed overexpression of all tested genes. Enhanced real-time efflux of ethidium bromide, a common efflux pump substrate, was also observed, showing a clear relation between overexpression of the genes and increased efflux pump function. Further exposure to isoniazid resulted in the selection and stabilization of spontaneous mutations and deletions in the katG gene along with sustained increased efflux activity. Together, results demonstrate the relevance of efflux pumps as one of the factors of isoniazid resistance in M. tuberculosis. These results support the hypothesis that activity of efflux pumps allows the maintenance of an isoniazid resistant population in a sub-optimally treated patient from which isoniazid genetically resistant mutants emerge. Therefore, the use of inhibitors of efflux should be considered in the development of new therapeutic strategies for preventing the emergence of MDR-TB during treatment.