Depletion of UDP-D-apiose/UDP-D-xylose synthases results in rhamnogalacturonan-II deficiency, cell wall thickening, and cell death in higher plants

D-apiose serves as the binding site for borate cross-linking of rhamnogalacturonan II (RG-II) in the plant cell wall, and biosynthesis of D-apiose involves UDP-D-apiose/UDP-D-xylose synthase catalyzing the conversion of UDP-D-glucuronate to a mixture of UDP-D-apiose and UDP-D-xylose. In this study we have analyzed the cellular effects of depletion of UDP-D-apiose/UDP-D-xylose synthases in plants by using virus-induced gene silencing (VIGS) of NbAXS1 in Nicotiana benthamiana. The recombinant NbAXS1 protein exhibited UDP-D-apiose/UDP-D-xylose synthase activity in vitro. The NbAXS1 gene was expressed in all major plant organs, and an NbAXS1-green fluorescent protein fusion protein was mostly localized in the cytosol. VIGS of NbAXS1 resulted in growth arrest and leaf yellowing. Microscopic studies of the leaf cells of the NbAXS1 VIGS lines revealed cell death symptoms including cell lysis and disintegration of cellular organelles and compartments. The cell death was accompanied by excessive formation of reactive oxygen species and by induction of various protease genes. Furthermore, abnormal wall structure of the affected cells was evident including excessive cell wall thickening and wall gaps. The mutant cell walls contained significantly reduced levels of D-apiose as well as 2-O-methyl-L-fucose and 2-O-methyl-D-xylose, which serve as markers for the RG-II side chains B and A, respectively. These results suggest that VIGS of NbAXS1 caused a severe deficiency in the major side chains of RG-II and that the growth defect and cell death was likely caused by structural alterations in RG-II due to a D-apiose deficiency.     

Assessing Genetic Differentiation in Geographic Populations of Labeo calbasu Using Allozyme Markers

The population structure of Labeo calbasu from 11 rivers belonging to the Indus, Ganges, Bhima, Mahanadi, and Godavari basins was investigated using allozyme marker systems. Seven out of 20 allozyme loci (35%) were polymorphic (P < 0.99). Both probability and score tests indicated significant deviation of genotype proportions from Hardy–Weinberg expectations at two loci, XDH* (Mahanadi, Bhima, and Godavari) and G6PDH* (Mahanadi). A pairwise genetic homogeneity test and F _ST values indicated a low-to-moderate level (0.0515) of genetic structuring in the wild population of L. calbasu. AMOVA analysis also indicated moderate differentiation among the samples from different river basins. Analysis for genetic bottleneck was performed under the infinite allele model. The study revealed nine genetic stocks of L. calbasu from the natural population across Indian rivers. Evidence of genetic bottlenecks in some rivers was also revealed.     

Identification of hub proteins from sequence

Identification of hub proteins from sequence is a challenge in molecular biology. Therefore, it is of interest to predict protein hubs in networks. We describe the prediction of protein "hub" using physiochemical, thermodynamic and conformational properties of amino acid residues in sequence. We have used twenty sequence based features to identify hub behaviour. Linear discriminant analysis and normalised Bayesian approach were utilized for identifying hub proteins solely using these sequence features in E. coli/H. sapiens datasets with accuracies of 99.5/98.6, 87.8/89.6 and 90.1/92.6, respectively.     

Bone and soft connective tissue alterations result from loss of fibrillin-2 expression

Fibrillins 1, 2 and 3 make up a family of genes that encode large, cysteine-rich extracellular matrix glycoproteins found in connective tissues, lung, blood vessels and other extensible tissues. Fibrillins 1 and 2 have both overlapping as well as separate distributions in human embryonic and adult tissues. Fibrillin-containing microfibrils are known to modulate morphogenetic events by proper targeting of growth factors to the extracellular matrix. Mutation of the fibrillin-2 gene causes a genetic disorder, congenital contractural arachnodactyly (CCA), that results in flexion contractures. Previously, we have shown a distinct fibrillin-2 distribution in the pericellular matrix of interior tenocytes and later demonstrated a unique fibrillin-2 containing structure that runs along the tendon cell arrays in the canine flexor tendon. We hypothesized that loss of these fibrillin-2 containing structures might affect normal tendon development. To test our hypothesis, connective tissues from mice null for fibrillin-2 gene expression were studied. Murine flexor digitorum longus tendons were evaluated for total collagen content, and the intermolecular collagen cross-links hydroxylysyl and lysyl pyridinoline. The results show decreased collagen cross-links in fibrillin-2 null mice, however total collagen content remained the same when compared to wild type. Bone morphology was studied using micro computed tomography (CT). Fibrillin-2 null mice display a focal area of decreased bone length in the extremities as compared to wild type mice. Together, these results demonstrate a role for fibrillin-2 in bone and soft connective tissue morphological and biochemical processes.     

Association of educational, occupational and socioeconomic status with cardiovascular risk factors in asian indians: a cross-sectional study

Background

To determine correlation of multiple parameters of socioeconomic status with cardiovascular risk factors in India.

Methods

The study was performed at eleven cities using cluster sampling. Subjects (n = 6198, men 3426, women 2772) were evaluated for socioeconomic, demographic, biophysical and biochemical factors. They were classified into low, medium and high socioeconomic groups based on educational level (<10, 10–15 and >15 yr formal education), occupational class and socioeconomic scale. Risk factor differences were evaluated using multivariate logistic regression.

Results

Age-adjusted prevalence (%) of risk factors in men and women was overweight or obesity in 41.1 and 45.2, obesity 8.3 and 15.8, high waist circumference 35.7 and 57.5, high waist-hip ratio 69.0 and 83.8, hypertension 32.5 and 30.4, hypercholesterolemia 24.8 and 25.3, low HDL cholesterol 34.1 and 35.1, high triglycerides 41.2 and 31.5, diabetes 16.7 and 14.4 and metabolic syndrome in 32.2 and 40.4 percent. Lifestyle factors were smoking 12.0 and 0.5, other tobacco use 12.7 and 6.3, high fat intake 51.2 and 48.2, low fruits/vegetables intake 25.3 and 28.9, and physical inactivity in 38.8 and 46.1%. Prevalence of > = 3 risk factors was significantly greater in low (28.0%) vs. middle (23.9%) or high (22.1%) educational groups (p<0.01). In low vs. high educational groups there was greater prevalence of high waist-hip ratio (odds ratio 2.18, confidence interval 1.65–2.71), low HDL cholesterol (1.51, 1.27–1.80), hypertriglyceridemia (1.16, 0.99–1.37), smoking/tobacco use (3.27, 2.66–4.01), and low physical activity (1.15, 0.97–1.37); and lower prevalence of high fat diet (0.47, 0.38–0.57),overweight/obesity (0.68, 0.58–0.80) and hypercholesterolemia (0.79, 0.66–0.94). Similar associations were observed with occupational and socioeconomic status.

Conclusions

Low educational, occupational and socioeconomic status Asian Indians have greater prevalence of truncal obesity, low HDL cholesterol, hypertriglyceridemia, smoking or tobacco use and low physical activity and clustering of > = 3 major cardiovascular risk factors.     

Cardiac matrix metalloproteinase-2 expression independently induces marked ventricular remodeling and systolic dysfunction

Although enhanced cardiac matrix metalloproteinase (MMP)-2 synthesis has been associated with ventricular remodeling and failure, whether MMP-2 expression is a direct mediator of this process is unknown. We generated transgenic mice expressing active MMP-2 driven by the alpha-myosin heavy chain promoter. At 4 mo MMP-2 transgenic hearts demonstrated expression of the MMP-2 transgene, myocyte hypertrophy, breakdown of Z-band registration, lysis of myofilaments, disruption of sarcomere and mitochondrial architecture, and cardiac fibroblast proliferation. Hearts from 8-mo-old transgenic mice displayed extensive myocyte disorganization and dropout with replacement fibrosis and perivascular fibrosis. Older transgenic mice also exhibited a massive increase in cardiac MMP-2 expression, representing recruitment of endogenous MMP-2 synthesis, with associated expression of MMP-9 and membrane type 1 MMP. Increases in diastolic [control (C) 33 +/- 3 vs. MMP 51 +/- 12 microl; P = 0.003] and systolic (C 7 +/- 2 vs. MMP 28 +/- 14 microl; P = 0.003) left ventricular (LV) volumes and relatively preserved stroke volume (C 26 +/- 4 vs. MMP 23 +/- 3 microl; P = 0.16) resulted in markedly decreased LV ejection fraction (C 78 +/- 7% vs. MMP 48 +/- 16%; P = 0.0006). Markedly impaired systolic function in the MMP transgenic mice was demonstrated in the reduced preload-adjusted maximal power (C 240 +/- 84 vs. MMP 78 +/- 49 mW/microl(2); P = 0.0003) and decreased end-systolic pressure-volume relation (C 7.5 +/- 1.5 vs. MMP 4.7 +/- 2.0; P = 0.016). Expression of active MMP-2 is sufficient to induce severe ventricular remodeling and systolic dysfunction in the absence of superimposed injury.     

Development of MFC using sulphonated polyether ether ketone (SPEEK) membrane for electricity generation from waste water

Polyether ether ketone was sulphonated polyether ether ketone (SPEEK) and utilized as a proton exchange membrane (PEM) in a single chamber MFC (SCMFC). The SPEEK was compared with Nafion? 117 in the SCMFC using Escherichia coli. The MFC with the SPEEK membrane produced 55.2% higher power density than Nafion? 117. The oxygen mass transfer coefficient (K(O)) for SPEEK and Nafion? 117 was estimated to be 2.4 × 10(-6)cm/s and 1.6 × 10(-5)cm/s, respectively resulting in reduced substrate loss and increased columbic efficiency (CE) in the case of SPEEK. When the dairy and domestic waste water was treated in SPEEK-SCMFC, fitted with a membrane electrode assembly (MEA), a higher maximum power density was obtained for dairy waste water (5.7 W/m(3)). The results of this study indicate that SPEEK membrane has the potential to greatly enhance the efficiency of MFCs.     

Agricultural biotechnology for crop improvement in a variable climate: hope or hype?

Developing crops that are better adapted to abiotic stresses is important for food production in many parts of the world today. Anticipated changes in climate and its variability, particularly extreme temperatures and changes in rainfall, are expected to make crop improvement even more crucial for food production. Here, we review two key biotechnology approaches, molecular breeding and genetic engineering, and their integration with conventional breeding to develop crops that are more tolerant of abiotic stresses. In addition to a multidisciplinary approach, we also examine some constraints that need to be overcome to realize the full potential of agricultural biotechnology for sustainable crop production to meet the demands of a projected world population of nine billion in 2050.