440 research outputs found
Plant growth promoting microbial consortia mediated classical biocontrol of sunflower necrosis virus disease
ABSTRACT Biological control is gaining momentum in the management of sunflower necrosis virus disease (SNVD) as no other effective method is available. In glasshouse experiment-I, six different plant growth promoting microbes (PGPM): Streptomyces sp. PM5, Trichothecium roseum MML005, Bacillus licheniformis MML2501, Streptomyces fradiae MML1042, Pseudomonas aeruginosa MML2212 and Bacillus sp. MML2551 and 2% Morinda pubescens fruit extract applied individually (seed + foliar applications) along with sunflower necrosis virus (SNV) were evaluated in sunflower. Among the treatments, B. licheniformis (Bl), Bacillus sp. (Bsp), P. aeruginosa (Pa), S. fradiae (Sf) effectively increased the plant growth and significantly increased the reduction of virus titre, it ranging from 32.5% to 52.5%. In experiment-II, the above four effective PGPM (Bl, Bsp, Pa and Sf) were developed as consortia in all possible combination in this study and were applied along with SNV against SNVD. All the consortial treatments significantly reduced SNVD in virus titre with disease reduction and concomitant increase in growth promotion when compared to control. In experiment-III, the best PGPM consortia (PGPMC) were applied as seed + soil inoculations along with SNV to study the induction of systemic resistance enzymes. The four culture consortium significantly reduced the SNVD symptoms and virus titer with a concomitant increase in plant growth promotion and ISR enzymes compared to control. In experiment-IV, based on biocontrol efficacy and ISR against SNVD from the experiments I to III, the two more dominant PGPMC treatments were selected and evaluated against SNVD under field conditions. From these results, Bl + Bsp + Pa + Sf effectively reduced the SNVD and improved the plant growth and yield parameters with additional seed yield with income and benefit cost ratio when compared to farmer's practice. In conclusion, PGPM (Bl, Bsp, Pa and Sf) was found to be very effective against SNVD under glasshouse and field conditions
DESIGNING OF ENERGY EFFICIENT CLUSTER BASED SCALABLE KEY MANAGEMENT TECHNIQUE TO IMPROVE THE LIFETIME OF WIRELESS SENSOR NETWORK
In the recent times, the demands of Wireless Sensor Networks (WSN) increase the challenges in terms of scalability and energy efficiency. Research has made a significant progress recently in the area of key management for protecting data during communication plays a prominent role in wireless sensor networks. A good key management strategy ensures secure sharing of information among the group. To achieve data confidentiality, scalability and improving lifetime of the sensor, static and movable mobile sinks are deployed. Here, movable sinks are used to receive sensed data from the sensor where it is located. The static mobile sinks act as a trusted third party for computing and distributing keys between sensor nodes and the clusters. It is not necessary to chose new cluster head often because of trusted third party sink, it performs all the computations of cluster head. The energy is retained when computation is reduced in cluster head thereby increases the life time of the particular cluster. The experimental result shows that the lifetime of the network is improved and computational overhead reduced are proved
Characterization of Knitted Coils for e-Textiles
Inductor coils are integrated in many wearable
garments for EM wave screening, heating and health monitoring.
This paper presents a critical evaluation of the inductor
characteristics of circular weft knitted coils for applications in etextiles. Inductors are knitted using circular needles with thin
insulated metal wire and yarn knitted together. The resulting
helical coils are characterized as a function of number of turns,
coil diameter, needle size and insulated metal wire material. The
results are compared to wound coils. Simulations of the knitted
and wound coils show close agreement with the experimental
results and confirm a higher inductance for the knits compared
to the wound coils with the same pitch between turns. The
parasitic coil capacitance is higher in the knit due to the vertical
legs of the stitches, absent in wound coils. Knits with thin Cu and
Litz wires result in flexible and wearable textile coils
Structure, Dynamics, and Branch Migration of a DNA Holliday Junction: A Single-Molecule Fluorescence and Modeling Study
AbstractThe Holliday junction (HJ) is a central intermediate of various genetic processes, including homologous and site-specific DNA recombination and DNA replication. Elucidating the structure and dynamics of HJs provides the basis for understanding the molecular mechanisms of these genetic processes. Our previous single-molecule fluorescence studies led to a model according to which branch migration is a stepwise process consisting of consecutive migration and folding steps. These data led us to the conclusion that one hop can be more than 1 basepair (bp); moreover, we hypothesized that continuous runs over the entire sequence homology (5 bp) can occur. Direct measurements of the dependence of the fluorescence resonance energy transfer (FRET) value on the donor-acceptor (D-A) distance are required to justify this model and are the major goal of this article. To accomplish this goal, we performed single-molecule FRET experiments with a set of six immobile HJ molecules with varying numbers of bps between fluorescent dyes placed on opposite arms. The designs were made in such a way that the distances between the donor and acceptor were equal to the distances between the dyes formed upon 1-bp migration hops of a HJ having 10-bp homology. Using these designs, we confirmed our previous hypothesis that the migration of the junction can be measured with bp accuracy. Moreover, the FRET values determined for each acceptor-donor separation corresponded very well to the values for the steps on the FRET time trajectories, suggesting that each step corresponds to the migration of the branch at a defined depth. We used the dependence of the FRET value on the D-A distance to measure directly the size for each step on the FRET time trajectories. These data showed that one hop is not necessarily 1 bp. The junction is able to migrate over several bps, detected as one hop and confirming our model. The D-A distances extracted from the FRET properties of the immobile junctions formed the basis for modeling the HJ structures. The composite data fit a partially opened, side-by-side model with adjacent double-helical arms slightly kinked at the four-way junction and the junction as a whole adopting a global X-shaped form that mimics the coaxially stacked-X structure implicated in previous solution studies
Distinct RNA profiles in subpopulations of extracellular vesicles: apoptotic bodies, microvesicles and exosomes
Introduction: In recent years, there has been an exponential increase in the number of studies aiming to understand the biology of exosomes, as well as other extracellular vesicles. However, classification of membrane vesicles and the appropriate protocols for their isolation are still under intense discussion and investigation. When isolating vesicles, it is crucial to use systems that are able to separate them, to avoid cross-contamination. Method: EVs released from three different kinds of cell lines: HMC-1, TF-1 and BV-2 were isolated using two centrifugation-based protocols. In protocol 1, apoptotic bodies were collected at 2,000×g, followed by filtering the supernatant through 0.8 µm pores and pelleting of microvesicles at 12,200×g. In protocol 2, apoptotic bodies and microvesicles were collected together at 16,500×g, followed by filtering of the supernatant through 0.2 µm pores and pelleting of exosomes at 120,000×g. Extracellular vesicles were analyzed by transmission electron microscopy, flow cytometry and the RNA profiles were investigated using a Bioanalyzer®. Results: RNA profiles showed that ribosomal RNA was primary detectable in apoptotic bodies and smaller RNAs without prominent ribosomal RNA peaks in exosomes. In contrast, microvesicles contained little or no RNA except for microvesicles collected from TF-1 cell cultures. The different vesicle pellets showed highly different distribution of size, shape and electron density with typical apoptotic body, microvesicle and exosome characteristics when analyzed by transmission electron microscopy. Flow cytometry revealed the presence of CD63 and CD81 in all vesicles investigated, as well as CD9 except in the TF-1-derived vesicles, as these cells do not express CD9. Conclusions: Our results demonstrate that centrifugation-based protocols are simple and fast systems to distinguish subpopulations of extracellular vesicles. Different vesicles show different RNA profiles and morphological characteristics, but they are indistinguishable using CD63-coated beads for flow cytometry analysis
Microguards and micromessengers of the genome
The regulation of gene expression is of fundamental importance to maintain organismal function and integrity and requires a multifaceted and highly ordered sequence of events. The cyclic nature of gene expression is known as ‘transcription dynamics’. Disruption or perturbation of these dynamics can result in significant fitness costs arising from genome instability, accelerated ageing and disease. We review recent research that supports the idea that an important new role for small RNAs, particularly microRNAs (miRNAs), is in protecting the genome against short-term transcriptional fluctuations, in a process we term ‘microguarding’. An additional emerging role for miRNAs is as ‘micromessengers’—through alteration of gene expression in target cells to which they are trafficked within microvesicles. We describe the scant but emerging evidence that miRNAs can be moved between different cells, individuals and even species, to exert biologically significant responses. With these two new roles, miRNAs have the potential to protect against deleterious gene expression variation from perturbation and to themselves perturb the expression of genes in target cells. These interactions between cells will frequently be subject to conflicts of interest when they occur between unrelated cells that lack a coincidence of fitness interests. Hence, there is the potential for miRNAs to represent both a means to resolve conflicts of interest, as well as instigate them. We conclude by exploring this conflict hypothesis, by describing some of the initial evidence consistent with it and proposing new ideas for future research into this exciting topic
An approach for the identification of targets specific to bone metastasis using cancer genes interactome and gene ontology analysis
Metastasis is one of the most enigmatic aspects of cancer pathogenesis and is
a major cause of cancer-associated mortality. Secondary bone cancer (SBC) is a
complex disease caused by metastasis of tumor cells from their primary site and
is characterized by intricate interplay of molecular interactions.
Identification of targets for multifactorial diseases such as SBC, the most
frequent complication of breast and prostate cancers, is a challenge. Towards
achieving our aim of identification of targets specific to SBC, we constructed
a 'Cancer Genes Network', a representative protein interactome of cancer genes.
Using graph theoretical methods, we obtained a set of key genes that are
relevant for generic mechanisms of cancers and have a role in biological
essentiality. We also compiled a curated dataset of 391 SBC genes from
published literature which serves as a basis of ontological correlates of
secondary bone cancer. Building on these results, we implement a strategy based
on generic cancer genes, SBC genes and gene ontology enrichment method, to
obtain a set of targets that are specific to bone metastasis. Through this
study, we present an approach for probing one of the major complications in
cancers, namely, metastasis. The results on genes that play generic roles in
cancer phenotype, obtained by network analysis of 'Cancer Genes Network', have
broader implications in understanding the role of molecular regulators in
mechanisms of cancers. Specifically, our study provides a set of potential
targets that are of ontological and regulatory relevance to secondary bone
cancer.Comment: 54 pages (19 pages main text; 11 Figures; 26 pages of supplementary
information). Revised after critical reviews. Accepted for Publication in
PLoS ON
Breast Cancer Exosome-like Microvesicles and Salivary Gland Cells Interplay Alters Salivary Gland Cell-Derived Exosome-like Microvesicles In Vitro
Saliva is a useful biofluid for the early detection of disease, but how distal tumors communicate with the oral cavity and create disease-specific salivary biomarkers remains unclear. Using an in vitro breast cancer model, we demonstrated that breast cancer-derived exosome-like microvesicles are capable of interacting with salivary gland cells, altering the composition of their secreted exosome-like microvesicles. We found that the salivary gland cells secreted exosome-like microvesicles encapsulating both protein and mRNA. We also showed that the interaction with breast cancer-derived exosome-like microvesicles communicated and activated the transcriptional machinery of the salivary gland cells. Thus, the interaction altered the composition of the salivary gland cell-derived exosome-like microvesicles on both the transcriptomically and proteomically
Growth factor stimulation of cardiomyocytes induces changes in the transcriptional contents of secreted exosomes
Exosomes are nano-sized extracellular vesicles, released from various cells, which can stimulate or repress responses in targets cells. We recently reported that cultured cardiomyocytes are able to release exosomes and that they, in turn, are involved in facilitating events in target cells by alteration of gene expression. We investigated whether external stimuli of the cardiomyocyte might influence the transcriptional content of the released exosomes.Exosomes were isolated from media collected from cultured cardiomyocytes (HL-1) with or without growth factor treatment (TGF-β2 and PDGF-BB), with a series of differential centrifugations, including preparative ultracentrifugation and separation with a sucrose gradient. The exosomes were characterized with dynamic light scattering (DLS), electron microscopy (EM) and Western blot and analyzed with Illumina whole genome microarray gene expression.The exosomes were rounded in shape and had an average size of 50–90 nm in diameter with no difference between treatment groups. Analysis of the mRNA content in repeated experiments conclusively revealed 505 transcripts in the control group, 562 in the TGF-β2-treated group and 300 in the PDGF-BB-treated group. Common transcripts (217) were found in all 3 groups.We show that the mode of stimulation of parental cells affects the characteristics of exosomes released. Hence, there is a difference in mRNA content between exosomes derived from cultured cardiomyocytes stimulated, or not stimulated, with growth factors. We also conclude that all exosomes contain a basic package consisting of ribosomal transcripts and mRNAs coding for proteins with functions within the energy supply system. To access the supplementary material to this article, please see Supplementary files under Article Tools online
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