226 research outputs found

    Assessment of genomic relationship between Oryza sativa and Oryza australinesis

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    The genomic relationship between Oryza sativa (2n = 24 AA) and Oryza australinesis (2n = 24 EE) has not been established. Genomic relationship between these two species was assessed by using three strategies: genomic in situ hybridization (GISH), meiotic chromosome pairing, pollen and spikelet sterility. The hybrid was produced between these two species at the International Rice Research Institute using embryo rescue technique. The chromosome pairing was examined in pollen mother cellsof O. australinesis, O. sativa and the hybrid between O. sativa and O. australinesis. The hybrid was highly sterile with pollen stain ability being 0.05%. Both parents showed regular meiosis with normal chromosome pairing. The F1 hybrid exhibited limited chromosome pairing. On an average, 0 - 4 bivalents and 16 - 24 univalents were recorded at metaphase-1. The most frequent configuration was two bivalent and twenty univalent. The chromosomes of O. australiensis appeared larger and darkly stained. For genomic in situ hybridization, genomic DNA from O. australiensis was used as probe for the mitotic and meiotic chromosomes of the hybrid between O. sativa and O. australiensis. GISH revealed unequivocal discrimination of O. australiensis chromosomes that appeared yellow due to hybridization signal from O. sativa chromosomes that fluoresced red due to counterstaining with propidium iodide (PI). No cross hybridization was examined between the labeled genomic DNA of O.australiensis and the chromosomes of O. sativa. The paired chromosomes were discriminated as autosyndetic and allosyndetic pairing. Meiotic and mitotic chromosomes of the O. australiensis and O. sativa, in the hybrid were discriminated by GISH for the first time. Results showed that both genomes were highly divergent

    valuation of rapeseed genotypes for yield and oil quality under rainfed conditions of district Mansehra

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    Five rapeseed genotypes were evaluated for agronomic parameters, yield, oil quantity and quality. Significant differences were observed for all the parameters except oil and protein percentage. The genotype Siren outperformed the rest of genotypes in yield potential (1104 kg/ha), followed by MRS-1 (866.67 kg/ha). For yield contributing characters like length of inflorescence and pods per plant, genotype Siren again showed good results that are, 51.3 cm and 136.5 pods/plant, respectively. The genotype Siren also showed low glucosinolate (44.82 ìmol/g), erucic acid (23.67 ìmol/g) and higher amounts of oleic acid (59.01%). Due to its high yield and oil quality, the genotype Siren is recommended for general cultivation in the area and further use in breeding programmes for Brassica napus

    Genomic affinity between Oryza sativa and Oryza brachyantha as revealed by in situ hybridization and chromosome pairing

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    Genomic affinity between Oryza sativa (2n = 24 AA), and Oryza brachyantha (2n = 24 FF) was assessed by using three strategies: genomic in situ hybridization (GISH), meiotic chromosome pairing, pollen andspikelet sterility. The chromosome pairing was examined in pollen mother cells of O. brachyantha, O.sativa and the hybrid between O. sativa and O. brachyantha. The hybrid was highly sterile with no pollen stain ability. Both parents showed regular meiosis with normal chromosome pairing. The F1hybrid exhibited limited chromosome pairing. On an average, 0-2 bivalents and 20-24 univalents were recorded at metaphase-1 and 0 - 1 univalent at diakinesis. The most frequent configuration was twobivalents and twenty univalent. The meiosis was highly irregular showing unequal distribution of chromosomes at anaphase, formation of multipolar bodies and variation in the cell cycle of both genomes. GISH revealed unequivocal discrimination of O. brachyantha chromosomes as appeared red from O. sativa chromosomes that fluoresced yellow. No cross hybridization was examined between the labeled genomic DNA of O. brachyantha and the chromosomes of O. sativa. Mitotic chromosomes of O. brachyantha and O. sativa, in the hybrid, were discriminated by GISH. High sterility in this hybrid could be due to abnormal meiosis and lack of pairing

    Historical perspective of in situ hybridization for the analysis of genomic constitution of plants

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    In situ hybridization involves hybridization of DNA or RNA probes to the cytological preparations. The technique originally used auto-radiographic labeling to map both repetitive and low copy DNA sequences. The problem associated with this technique was its short half life, lack of safety and long exposure time which hindered its widespread use in DNA hybridization. To overcome these problems, non isotopic in situ hybridization was developed for use in animal and plant species. In the last decade, the development of haptens and fluorochromes enabled simultaneous multicolored detection of differentially labeled probes. Characterization of parental genomes in interspecific hybrids, restructured chromosomes, gene mapping, detecting nature of chromosome pairing, establishing phylogenetic relationship among the species and localizing introgressed segment have been successfully achieved by fluorescence in situ hybridization. Keywords: In situ hybridization, phylogenetic relationship, homoeologous pairin

    Production and molecular characterization of wide cross derivatives in rice

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    The reduced genetic variability of modern rice varieties (Oryza sativa L.) is of great concern because it reduces the possibilities of genetic gain in breeding programs. Introgression lines (ILs) containing genetic fragment from wild rice can be used to obtain new improved cultivars. The objective of the present study was to develop ILs from the cross between O. sativa x O. longistminata aiming to be used in rice breeding program. In the present study, 12 ILs were produced. Among them, three ILs were highly resistant to all the isolates of bacterial blight from North West Frontier Province (NWFP) of Pakistan. A 900 bp DNA fragment linked to Xa21 was raised in these introgression lines and in O. longistminata by a pair of primers confirming the presence of Xa21 gene in these lines. Results indicated that Xa21 has broad spectrum of resistance to bacterial blight and wild species are the useful source for resistance

    Localizing introgression on the chromosome of rice by genomic in situ hybridization (GISH)

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    Genomic in situ hybridization was used to detect introgressed segment from Oryza australinesis onto the chromosomes of introgression line derived from the hybrid O. sativa x O. australinesis. Genomic DNA from Oryza australinesis was labeled with biotin and hybridized to the homologous sequences on the O. sativa chromosomes. The probe hybridization fluoresced green and non labeled O. sativa chromosomes appeared red or blue due to counterstaining with propidium iodide (PI) or 4,6-diamidino-2-phenylindole (DAPI). This differential painting of chromosomes unequivocally detected the introgressedsegment. Among the 200 cells analyzed, 6.5% of the cells showed  hybridization signal. Signal appeared on one chromosome in 5%, on two homologous chromosomes in 1% and on sister chromatids in 0.5%of the cells. Hybridization was seen on the short arm of the chromosome 12 of the introgression line

    Newtonian Heating Effects of Oldroyd-B Liquid Flow with Cross-Diffusion and Second Order Slip

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    The current study highlights the Newtonian heating and second-order slip velocity with cross-diffusion effects on Oldroyd-B liquid flow. The modified Fourier heat flux is included in the energy equation system. The present problem is modeled with the physical governing system. The complexity of the governing system was reduced to a nonlinear ordinary system with the help of suitable transformations. A homotopy algorithm was used to validate the nonlinear system. This algorithm was solved via MATHEMATICA software. Their substantial aspects are further studied and reported in detail. We noticed that the influence of slip velocity order two is lower than the slip velocity order one

    Efficacy of Avicennia marina (Forsk.) Vierh. leaves extracts against some atmospheric fungi

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    Crude ethanolic extract of Avicennia marina leaves was tested against seven allergenic fungi viz., Alternaria alternata, Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Cladosporium herbarum, Penicillium notatum and Saccharomyces cerevisiae using five different solvents: dimethyl sulphoxide (DMSO), distilled water (DW), chloroform, ethanol and acetone at 2000, 4000 and 6000 ppm doses. Dose dependent tendency in the increase or decrease in the growth of fungi was observed. Two synthetic drugs miconazole and amphotericin-B were used as positive control. Miconazole was 100% effective against A. alternata, C. herbatum, P. notatum and S. cerevisiae with the concentrations of 95.00 ± 1.62, 78.00 ± 4.99, 100.00 ± 0.69 and 110.00 ± 2.33 (μg/ml of SDA medium), respectively. Amphotericin-B completely controlled the growth of A. flavus, A. fumigatus and A. niger in the concentration of 24.00 ± 17.00, 30.00 ± 15.66 and 18.00 ± 18.34 (μg/ml of SDA medium), respectively. Distilled water and DMSO were considered to be the most effective solvents preventing 83.00 ± 4.73% growth of A. niger, 80.33 ± 5.60% A. flavus, 78.58 ± 3.18% A. alternata, 72.91 ± 7.96% P. notatum, 65.25 ± 3.55% C. herbarum, 63.25 ± 4.52% A. fumigatus and 48.5 ± 7.89% S. cerevisiae. Statistically, the results were compared with negative control and found to be highly significant (p<0.01).Key words: Allergenic fungi, inhibition, dose dependent, growth control, synthetic drugs

    Mechanistic Observation of Interactions between Macrophages and Inorganic Particles with Different Densities

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    Many different types of inorganic materials are processed into nano/microparticles for medical utilization. The impact of selected key characteristics of these particles, including size, shape, and surface chemistries, on biological systems, is frequently studied in clinical contexts. However, one of the most important basic characteristics of these particles, their density, is yet to be investigated. When the particles are designed for drug delivery, highly mobile macrophages are the major participants in cellular levels that process them in vivo. As such, it is essential to understand the impact of particles’ densities on the mobility of macrophages. Here, inorganic particles with different densities are applied, and their interactions with macrophages studied. A set of these particles are incubated with the macrophages and the outcomes are explored by optical microscopy. This microscopic view provides the understanding of the mechanistic interactions between particles of different densities and macrophages to conclude that the particles’ density can affect the migratory behaviors of macrophages: the higher the density of particles engulfed inside the macrophages, the less mobile the macrophages become. This work is a strong reminder that the density of particles cannot be neglected when they are designed to be utilized in biological applications

    Invasive fungal disease in PICU: epidemiology and risk factors

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    Candida and Aspergillus spp. are the most common agents responsible for invasive fungal infections in children. They are associated with a high mortality and morbidity rate as well as high health care costs. An important increase in their incidence has been observed during the past two decades. In infants and children, invasive candidiasis is five times more frequent than invasive aspergillosis. Candida sp. represents the third most common agent found in healthcare-associated bloodstream infections in children. Invasive aspergillosis is more often associated with hematological malignancies and solid tumors. Recommendations concerning prophylactic treatment for invasive aspergillosis have been recently published by the Infectious Diseases Society of America. Candida albicans is the main Candida sp. associated with invasive candidiasis in children, even if a strong trend toward the emergence of Candida non-albicans has been observed. The epidemiology and the risk factors for invasive fungal infections are quite different if considering previously healthy children hospitalized in the pediatric intensive care unit, or children with a malignancy or a severe hematological disease (leukemia). In children, the mortality rate for invasive aspergillosis is 2.5 to 3.5 higher than for invasive candidiasis (respectively 70% vs. 20% and 30%)
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