RNA interference (RNAi)-based host-induced gene silencing (HIGS) is emerging as a novel, efficient and target-specific tool to combat phytonematode infection in crop plants. Mi-msp-1, an effector gene expressed in the subventral pharyngeal gland cells of Meloidogyne incognita plays an important role in the parasitic process. Mi-msp-1 effector is conserved in few of the species of root-knot nematodes (RKNs) and does not share considerable homology with the other phytonematodes, thereby making it a suitable target for HIGS with minimal off-target effects. Six putative eggplant transformants harbouring a single copy RNAi transgene of Mi-msp-1 was generated. Stable expression of the transgene was detected in T1, T2 and T3 transgenic lines for which a detrimental effect on RKN penetration, development and reproduction was documented upon challenge infection with nematode juveniles. The post-parasitic nematode stages extracted from the transgenic plants showed long-term RNAi effect in terms of targeted downregulation of Mi-msp-1. These findings suggest that HIGS of Mi-msp-1 enhances nematode resistance in eggplant and protect the plant against RKN parasitism at very early stage.
Santalum album L. is an economically important tropical tree species. Owing to extensive logging, changes in land-use patterns and poor
natural regeneration, the natural sandal populations are rapidly dwindling. It is feared that such threats could easily undermine
the genetic diversity of sandal populations. Effective measures to prevent such loss are prerequisite. We have developed baseline
data on the levels of genetic diversity and its distribution on a geographic scale for sandal in India. Based on Geographic
Information System, distribution map of sandal was developed and found that the populations were geographically more concentrated
in the Deccan plateau. It was found that, for past 53 years, there was a monotonic decrease in the extraction of sandal in
the state of Karnataka, India. Using allozyme markers, the genetic diversity of 19 sandal populations in peninsular India
were determined and over all observed heterzygosity (Ho) was found to be 31%. The percent Ho was positively correlated with the density of the sandal populations (r = 0.44) and with increasing longitude it was found to be negatively correlated (r = −0.51). The dendrogram analysis indicated a clear clustering of sandal populations based on their geographic occurrence.
The Deccan plateau populations were found to be genetically the most diverse and seemed to represent the ‘hot-spot’ of sandal
genetic resources in peninsular India. Our results have important implications for the conservation strategies for sandal
populations in peninsular India and can be applied for the conservation of other taxa as well. 相似文献
Leukemoid reaction like leukemia indicates noticeable increased count of WBCs (White Blood Cells) but the cause of it is due to severe inflammation or infections in other body regions. In automatic diagnosis in classifying leukemia and leukemoid reactions, ALL IDB2 (Acute Lymphoblastic Leukemia-Image Data Base) dataset has been used which comprises 110 training images of blast cells and healthy cells. This paper aimed at an automatic process to distinguish leukemia and leukemoid reactions from blood smear images using Machine Learning. Initially, automatic detection and counting of WBC is done to identify leukocytosis and then an automatic detection of WBC blasts is performed to support classification of leukemia and leukemoid reactions. Leukocytosis is commonly observed both in leukemia and leukemoid hence physicians may have chance of wrong diagnosis of malignant leukemia for the patients with leukemoid reactions. BCCD (blood cell count detection) Dataset has been used which has 364 blood smear images of which 349 are of single WBC type. The Image segmentation algorithm of Hue Saturation Value color based on watershed has been applied. VGG16 (Visual Geometric Group) CNN (Convolution Neural Network) architecture based deep learning technique is being incorporated for classification and counting WBC type from segmented images. The VGG16 architecture based CNN used for classification and segmented images obtained from first part were tested to identify WBC blasts. 相似文献
Metformin, a first line anti type 2 diabetes drug, has recently been shown to extend lifespan in various species, and therefore, became the first antiaging drug in clinical trial. Oxidative stress due to excess reactive oxygen species (ROS) is considered to be an important factor in aging and related disease, such as Alzheimer's disease (AD). However, the antioxidative effects of metformin and its underlying mechanisms in neuronal cells is not known. In the present study, we showed that metformin, in clinically relevant concentrations, protected neuronal PC12 cells from H2O2-induced cell death. Metformin significantly ameliorated cell death due to H2O2 insult by restoring abnormal changes in nuclear morphology, intracellular ROS, lactate dehydrogenase, and mitochondrial membrane potential induced by H2O2. Hoechst staining assay and flow cytometry analysis revealed that metformin significantly reduced the apoptosis in PC12 cells exposed to H2O2. Western blot analysis further demonstrated that metformin stimulated the phosphorylation and activation of AMP-activated protein kinase (AMPK) in PC12 cells, while application of AMPK inhibitor compound C, or knockdown of the expression of AMPK by specific small interfering RNA or short hairpin RNA blocked the protective effect of metformin. Similar results were obtained in primary cultured hippocampal neurons. Taken together, these results indicated that metformin is able to protect neuronal cells from oxidative injury, at least in part, via the activation of AMPK. As metformin is comparatively cheaper with much less side effects in clinic, our findings support its potential to be a drug for prevention and treatment of aging and aging-related diseases. 相似文献
Extending the storage life of legumes by protecting it from the Callosobruchus maculatus infestation is a major concern for the producers, processors and exporters. Legume processing industry requires “greener” alternatives to the conventional fumigants. Gaseous ozone has a great potential as an insect management strategy that is suited for this niche. Nevertheless, the efficacy of ozone against C. maculatus is yet unknown. A laboratory study was conducted to test the insecticidal effect of ozone in controlling the infestation of C. maculatus in green gram. We have determined the concentration of ozone exposure time–mortality relationship for all the stages of C. maculatus that were exposed to 500–1,500 ppmv ozone. The percentages of mortality for different stages of C. maculatus increased with the increase in ozone concentration and exposure time. It was documented that adult stage is least tolerant to ozone (500 ppmv for 274.40 min exposure required to kill 90%), whereas the most tolerant stage is pupa (500 ppmv for 1816.54 min is required to kill 90%). The results indicate that gaseous ozone is the attractive alternative to the synthetic fumigants. 相似文献
Two multisubunit protein complexes for membrane protein insertion were recently identified in the endoplasmic reticulum (ER): the guided entry of tail anchor proteins (GET) complex and ER membrane complex (EMC). The structures of both of their hydrophobic core subunits, which are required for the insertion reaction, revealed an overall similarity to the YidC/Oxa1/Alb3 family members found in bacteria, mitochondria, and chloroplasts. This suggests that these membrane insertion machineries all share a common ancestry. To test whether these ER proteins can functionally replace Oxa1 in yeast mitochondria, we generated strains that express mitochondria-targeted Get2–Get1 and Emc6–Emc3 fusion proteins in Oxa1 deletion mutants. Interestingly, the Emc6–Emc3 fusion was able to complement an Δoxa1 mutant and restored its respiratory competence. The Emc6–Emc3 fusion promoted the insertion of the mitochondrially encoded protein Cox2, as well as of nuclear encoded inner membrane proteins, although was not able to facilitate the assembly of the Atp9 ring. Our observations indicate that protein insertion into the ER is functionally conserved to the insertion mechanism in bacteria and mitochondria and adheres to similar topological principles.Redirecting the core subunits of the protein membrane insertion complex EMC into mitochondria rescues cells deficient for the mitochondrial Oxa1 system; this supports the hypothesis that the machinery for protein insertion into the ER membrane is functionally analogous to the YidC/Oxa1/Alb3 family of bacteria, mitochondria and chloroplasts. 相似文献
The glycosylation pattern of chCE7, an antineuroblastoma chimeric IgG1, was engineered in Chinese hamster ovary cells with tetracycline-regulated expression of beta(1,4)-N-acetylglucosaminyltransferase III (GnTIII), a glycosyltransferase catalyzing formation of bisected oligosaccharides that have been implicated in antibody-dependent cellular cytotoxicity (ADCC). Measurement of the ADCC activity of chCE7 produced at different tetracycline levels showed an optimal range of GnTIII expression for maximal chCE7 in vitro ADCC activity, and this activity correlated with the level of constant region-associated, bisected complex oligosaccharides determined by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The new optimized variants of chCE7 exhibit substantial ADCC activity and, hence, may be useful for treatment of neuroblastoma. The strategy presented here should be applicable to optimize the ADCC activity of other therapeutic IgGs. 相似文献
ClC chloride channels possess a homodimeric structure in which each monomer contains an independent chloride ion pathway. ClC channel gating is regulated by chloride ion concentration, pH and voltage. Based on structural and physiological evidence, it has been proposed that a glutamate residue on the extracellular end of the selectivity filter acts as a fast gate. We utilized a new search algorithm that incorporates electrostatic information to explore the ion transit pathways through wild-type and mutant bacterial ClC channels. Examination of the chloride ion permeation pathways supports the importance of the glutamate residue in gating. An external chloride binding site previously postulated in physiological experiments is located near a conserved basic residue adjacent to the gate. In addition, access pathways are found for proton migration to the gate, enabling pH control at hyperpolarized membrane potentials. A chloride ion in the selectivity filter is required for the pH-dependent gating mechanism. 相似文献