67 research outputs found

    The inactive X chromosome in the human female is enriched in 5-methylcytosine to an unusual degree and appears to contain more of this modified nucleotide than the remainder of the genome

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    By employing a procedure that combines ELISA and photoacoustic spectroscopy, we have examined the content of 5-methylcytosine (m5C) in DNA of individuals who differed from one another in the number of X chromosomes in their genomes. The results show that the human inactive X chromosome (Xi) contains very high amounts of this modified nucleotide. We estimate that in the 46,XX female there is more m5C in Xi (~3.6 × 107) than in all the remaining chromosomes put together (~2.1 × 107). Our results also suggest that nearly one-fifth of all cytosines in Xi are methylated and that, in addition to CpG methylation, there is extensive non-CpG methylation as well

    Intranasal Mice Model to Study the role of Bordetella pertussis antigens in Immunity

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    699-702Pertussis known as whooping cough is a highly contagious disease. Whole cell pertussis vaccine is the most economical and effective strategy for preventing and controlling pertussis. The efficacy of whole cell vaccine is ascertained most commonly by intracerebral challenge assay, but it does not reflect the true efficacy of vaccine as Pertussis essentially is a respiratory disease. Therefore, in order to mimic the natural infection, intranasal challenge model in mice was developed. In intranasal challenge assay mice were immunized with vaccine and challenged through intranasal route. Mice lungs were dissected and examined for bacterial count. The degree of count was related to efficacy of vaccine, higher count indicated low efficacy and low count pointed to better efficacy

    Characterisation of Inactivation Domains and Evolutionary Strata in Human X Chromosome through Markov Segmentation

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    Markov segmentation is a method of identifying compositionally different subsequences in a given symbolic sequence. We have applied this technique to the DNA sequence of the human X chromosome to analyze its compositional structure. The human X chromosome is known to have acquired DNA through distinct evolutionary events and is believed to be composed of five evolutionary strata. In addition, in female mammals all copies of X chromosome in excess of one are transcriptionally inactivated. The location of a gene is correlated with its ability to undergo inactivation, but correlations between evolutionary strata and inactivation domains are less clear. Our analysis provides an accurate estimate of the location of stratum boundaries and gives a high–resolution map of compositionally different regions on the X chromosome. This leads to the identification of a novel stratum, as well as segments wherein a group of genes either undergo inactivation or escape inactivation in toto. We identify oligomers that appear to be unique to inactivation domains alone

    The Pan-University Network for Global Health: framework for collaboration and review of global health needs

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    In the current United Nations efforts to plan for post 2015-Millennium Development Goals, global partnership to address non-communicable diseases (NCDs) has become a critical goal to effectively respond to the complex global challenges of which inequity in health remains a persistent challenge. Building capacity in terms of wellequipped local researchers and service providers is a key to bridging the inequity in global health. Launched by Penn State University in 2014, the Pan University Network for Global Health responds to this need by bridging researchers at more than 10 universities across the globe. In this paper we outline our framework for international and interdisciplinary collaboration, as well the rationale for our research areas, including a review of these two themes. After its initial meeting, the network has established two central thematic priorities: 1) urbanization and health and 2) the intersection of infectious diseases and NCDs. The urban population in the global south will nearly double in 25 years (approx. 2 billion today to over 3.5 billion by 2040). Urban population growth will have a direct impact on global health, and this growth will be burdened with uneven development and the persistence of urban spatial inequality, including health disparities. The NCD burden, which includes conditions such as hypertension, stroke, and diabetes, is outstripping infectious disease in countries in the global south that are considered to be disproportionately burdened by infectious diseases. Addressing these two priorities demands an interdisciplinary and multi-institutional model to stimulate innovation and synergy that will influence the overall framing of research questions as well as the integration and coordination of research

    The Genome of the Stick Insect Medauroidea extradentata Is Strongly Methylated within Genes and Repetitive DNA

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    BACKGROUND: Cytosine DNA methylation has been detected in many eukaryotic organisms and has been shown to play an important role in development and disease of vertebrates including humans. Molecularly, DNA methylation appears to be involved in the suppression of initiation or of elongation of transcription. Resulting organismal functions are suggested to be the regulation of gene silencing, the suppression of transposon activity and the suppression of initiation of transcription within genes. However, some data concerning the distribution of methylcytosine in insect species appear to contradict such roles. PRINCIPAL FINDINGS: By comparison of MspI and HpaII restriction patterns in genomic DNA of several insects we show that stick insects (Phasmatodea) have highly methylated genomes. We isolated methylated DNA fragments from the Vietnamese Walking Stick Medauroidea extradentata (formerly known as Baculum extradentatum) and demonstrated that most of the corresponding sequences are repetitive. Bisulfite sequencing of one of these fragments and of parts of conserved protein-coding genes revealed a methylcytosine content of 12.6%, mostly found at CpG, but also at CpT and CpA dinucleotides. Corresponding depletions of CpG and enrichments of TpG and CpA dinucleotides in some highly conserved protein-coding genes of Medauroidea reach a similar degree as in vertebrates and show that CpG methylation has occurred in the germline of these insects. CONCLUSIONS: Using four different methods, we demonstrate that the genome of Medauroidea extradentata is strongly methylated. Both repetitive DNA and coding genes appear to contain high levels of methylcytosines. These results argue for similar functions of DNA methylation in stick insects as those already known for vertebrates

    Differential Expression of Xylanases and Endoglucanases in the Hybrid Derived from Intergeneric Protoplast Fusion between a Cellulomonas sp. and Bacillus subtilis

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    A stable hybrid obtained by protoplast fusion between a Cellulomonas sp. and Bacillus subtilis exhibits an altered pattern of enzyme induction with different cellulosic substrates. Unlike in the Cellulomonas sp., xylanase was induced in the hybrid organism specifically by xylan, and endoglucanase was induced by carboxymethyl cellulose. The amount and specific activity of xylanase produced by the hybrid were more than those produced by the Cellulomonas sp. β-Glucosidase which is cell bound or intracellular in the Cellulomonas sp. was secreted by the hybrid organism, and relative amounts of extracellular β-glucosidase were high. Furthermore, this extracellular β-glucosidase activity was dependent on the nature of the cellulosic substrate. Endoglucanases synthesized in the hybrid differed in their electrophoretic mobilities as compared with the parental enzymes

    Optical detection of antibody using silica-silver core-shell particles

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    Nearly monodispersed spherical particles of silica were synthesized and coated with thin layer of silver nanoparticles. Silver coated silica particles, forming core-shell particles exhibited a strong surface plasmon resonance peak at 453 nm. A very small amount (20 ÎĽg) of rabbit immunoglobulin in core-shell particle solution results in to a marked shift in surface plasmon resonance. Addition of 20 ÎĽg quantity of goat anti rabbit antibodies results in to a red shift of surface plasmon resonance to 494 nm. This demonstrates that silver coated silica particles are sensitive probes for rapid antibody-anti antibody kind of interaction investigations. Fourier transform infra red spectroscopy and scanning electron microscopy have been used to interpret the optical extinction spectroscopy results

    Hemimethylation of DNA prevents chromatin expression.

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