Life Sciences

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Shiv Nadar University

In this paper, we report the results derived from a statistical analysis of whistlers recorded at Varanasi during the period January 1990-December 1999. The monthly occurrence rate shows a maximum during January to March. In order to study the role of geomagnetic disturbance on the whistler occurrence rate, we have used the KP index and its variation. It is found that the occurrence probability monotonically increases with ∑KP (daily sum) values. It is found that, when ∑KP&gt;20, the occurrence rate is greater than the average value, in good agreement with results reported by other workers. In addition, we also present the probability of the observation of whistlers during weak/intense geomagnetic storms and also during the main phase and recovery phase of geomagnetic storms. © 2007 Elsevier Ltd. All rights reserved.

World University root node

(SoNS) School of Natural Sciences

Planetary and Space Science

Role of geomagnetic disturbance on whistler occurrence at a low latitude station

Genetic diversity among 47 ber accessions belonging to cultivated species (Ziziphus mauritiana Lam) and one wild accession of Ziziphus nummularia (Burm F) Willed was investigated using Inter-Simple Sequence Repeat (ISSR) markers. A total of 167 amplification products were detected with 18 ISSR primers of which 152 (89.96%) were polymorphic. Most of the primers that produced distinct bands (14 primers out of 18) contained dinucleotide repeats. Primers based on (AC)n and (AG)n repeats produced more polymorphic bands. Genetic similarity ranging from 43.07% to 90.30% suggested that the 48 Ziziphus genotypes used in the study were divergent. Cluster analysis based on UPGMA method and Bootstrap analysis separated all the 48 genotypes in four distinct clusters. The present study has successfully distinguished morphologically similar genotypes that emphasize the use of molecular markers to the taxonomists. Morphologically similar but genetically distinct genotypes, identified using ISSR markers could be potential sources for genotype identification and to resolve controversies over misnomination of her genotypes. Present study is the first report on the exploitation of ISSR markers in her for genetic diversity analysis.

Journal of Plant Biochemistry and Biotechnology

Assessment of genetic diversity in Ziziphus mauritiana using inter-simple sequence repeat markers

This paper emphasizes on mathematical and field work approach to diagnosing the environmental pollution for Indore, India. These applications are based on the time-series statistics and for three semi-industrial as well as residential areas. The generalized additive models finds as a best fit-model in terms of autocorrelation and reduction of over-dispersion. The interdisciplinary study works on the principal of pollutant source, meteorological parameters, pollutant types, emission rates and various chemical processes. Several chemical or industrial processes like iron and steel production, combustion of fossil fuels, biomass burning, thermal power plants are major polluter in most of the mega cities. © 2007 Springer Science+Business Media, LLC.

Bulletin of Environmental Contamination and Toxicology

A comparative emission profile of an urban area in Madhya Pradesh, India

Endothelial cell junctional adhesion molecule (JAM)-C has been proposed to regulate neutrophil migration. In the current study, we used function-blocking mAbs against human JAM-C to determine its role in human leukocyte adhesion and transendothelial cell migration under flow conditions. JAM-C surface expression in HUVEC was uniformly low, and treatment with inflammatory cytokines TNF-α, DL-1β, or LPS did not increase its surface expression as assessed by FACS analysis. By immunofluorescence microscopy, JAM-C staining showed sparse localization to cell-cell junctions on resting or cytokine-activated HUVEC. Surprisingly, staining of detergent-permeabilized HUVEC revealed a large intracellular pool of JAM-C that showed little colocalization with von Willebrand factor. Adhesion studies in an in vitro flow model showed that functional blocking JAM-C mAb alone had no inhibitory effect on polymorphonuclear leukocyte (PMN) adhesion or transmigration, whereas mAb to ICAM-1 significantly reduced transmigration. Interestingly, JAM-C-blocking mAbs synergized with a combination of PECAM-1, ICAM-1, and CD99-blocking mAbs to inhibit PMN transmigration. Overexpression of JAM-C by infection with a lentivirus JAM-C GFP fusion protein did not increase adhesion or extent of transmigration of PMN or evoke a role for JAM-C in transendothelial migration. These data suggest that JAM-C has a minimal role, if any, in PMN transmigration in this model and that ICAM-1 is the preferred endothelial-expressed ligand for PMN β2 integrins during transendothelial migration. Copyright © 2007 by The American Association of Immunologists, Inc.

Journal of Immunology

Neutrophil transmigration under shear flow conditions in vitro is junctional adhesion molecule-C independent

Escherichia coli contains multiple peptidoglycan-specific hydrolases, but their physiological purposes are poorly understood. Several mutants lacking combinations of hydrolases grow as chains of unseparated cells, indicating that these enzymes help cleave the septum to separate daughter cells after cell division. Here, we confirm previous observations that in the absence of two or more amidases, thickened and dark bands, which we term septal peptidoglycan (SP) rings, appear at division sites in isolated sacculi. The formation of SP rings depends on active cell division, and they apparently represent a cell division structure that accumulates because septal synthesis and hydrolysis are uncoupled. Even though septal constriction was incomplete, SP rings exhibited two properties of mature cell poles: they behaved as though composed of inert peptidoglycan, and they attracted the IcsA protein. Despite not being separated by a completed peptidoglycan wall, adjacent cells in these chains were often compartmentalized by the inner membrane, indicating that cytokinesis could occur in the absence of invagination of the entire cell envelope. Finally, deletion of penicillin-binding protein 5 from amidase mutants exacerbated the formation of twisted chains, producing numerous cells having septa with abnormal placements and geometries. The results suggest that the amidases are necessary for continued peptidoglycan synthesis during cell division, that their activities help create a septum having the appropriate geometry, and that they may contribute to the development of inert peptidoglycan. Copyright © 2007, American Society for Microbiology. All Rights Reserved.

Fulltext

Journal of Bacteriology

Role of peptidoglycan amidases in the development and morphology of the division septum in Escherichia coli

In the present study, 3217 UniGene sequences of Neurospora crassa downloaded from the National Center for Biotechnology Information (NCBI) were mined for the identification of microsatellites or simple sequence repeats (SSRs). A total of 287 SSRs detected gives density of 1SSR/14.6 kb of 4187.86 kb sequences mined suggests that only 250 (7.8%) of sequences contained SSRs. Depending on the repeat units, the length of SSRs ranged from 14 to 17 bp for mono-, 14 to 48 bp for di-, 18 to 90 bp for tri-, 24 to 48 bp for tetra-, 30 for penta- and 42 to 48 bp for hexa-nucleotide repeats. Tri-nucleotide repeats were the most frequent repeat type (88.8%) followed by di-nucleotide repeats (5.9%). An attempt was also made with the help of bioinformatics approach to find out primer pairs for identified SSRs and primers were found only for 239 sequences. But, this part needs experimental validation. Annotation of SSRs containing sequences was also carried out. © 2006 Elsevier GmbH. All rights reserved.

Microbiological Research

In silico mining in expressed sequences of Neurospora crassa for identification and abundance of microsatellites

Hematopoietic stem cells (HSCs) possess a distinct ability to perpetuate through self-renewal and to generate progeny that differentiate into mature cells of myeloid and lymphoid lineages. A better understanding of the molecular mechanisms by which HSCs replicate and differentiate from the perspective of developing new approaches for HSC transplantation is necessary for further advances. The interaction of the receptor tyrosine kinase-c-KIT-with its ligand stem cell factor plays a key role in HSC survival, mitogenesis, proliferation, differentiation, adhesion, homing, migration, and functional activation. Evidence that activating site-directed point mutations in the c-KIT gene contributes to its ligand-independent constitutive activation, which induces enhanced proliferation of HSCs, is accumulating. Similarly, and equally important, self-renewal is a process by which HSCs generate daughter cells via division. Self-renewal is necessary for retaining the HSC pool. Therefore, elucidating the molecular machinery that governs self-renewal is of key importance. The transcription factor, HOXB4 is a key molecule that has been reported to induce the in vitro expansion of HSCs via self-renewal. However, critical downstream effector molecules of HOXB4 remain to be determined. This concisely reviewed information on c-KIT and HOXB4 helps us to update our understanding of their function and mechanism of action in self-renewal, proliferation, and differentiation of HSCs, particularly modulation by c-KIT mutant interactions, and HOXB4 overexpression showing certain therapeutic implications. © Mary Ann Liebert, Inc.

Stem Cells and Development

Stem cell c-KIT and HOXB4 genes: Critical roles and mechanisms in self-renewal, proliferation, and differentiation

Random amplified polymorphic DNA (RAPD) technique was used as a tool for assessing genetic diversity and species relationships among 28 accessions of eggplant representing five species. Twenty-eight samples of eggplants were collected from different parts of the country. A total of 144 polymorphic amplified products were obtained from 14 decamer primers, which discriminated all the accessions. The value of Jaccard's coefficient ranged from 0.05 to 0.82. The similarity result indicates presence of high level of genetic diversity in eggplants and a dendrogram constructed by UPGMA method shows that S. incanum is closest to S. melongena followed by S. nigrum. Only one accession of S. nigrum and S. surattense was taken in the present study that showed grouping with each other. Genetically distinct genotypes identified using RAPD markers could be potential sources of germplasm for eggplant improvement.

Current Science

Genetic diversity within the genus Solatium (Solanaceae) as revealed by RAPD markers

DNA replication takes place at five different stages during the life cycle of Plasmodium falciparum including the human and mosquito hosts. DNA replication initiation, the rate-determining step is poorly understood in Plasmodium. Here we show that PfMCM4 and PfORC1, two members of prereplication initiation complex are expressed specifically in the nucleus during the trophozoite and schizont stages of the asexual parasitic life cycle where maximum amount of DNA replication takes place. Further, we show that these proteins are also expressed in gametocytes, where DNA replication also occurs. These results expand our knowledge on these proteins and resolves discrepancies arising from previous studies with respect to the expression pattern of replication initiation proteins during the parasite's life cycle. © 2006 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

FEMS Microbiology Letters

Analogous expression pattern of Plasmodium falciparum replication initiation proteins PfMCM4 and PfORC1 during the asexual and sexual stages of intraerythrocytic developmental cycle

Background: The ORF1 of hepatitis E virus (HEV) encodes a nonstructural polyprotein of ∼186 kDa that has putative domains for four enzymes: a methyltransferase, a papain-like cysteine protease, a RNA helicase and a RNA dependent RNA polymerase. In the absence of a culture system for HEV, the ORF1 expressed using bacterial and mammalian expression systems has shown an ∼186 kDa protein, but no processing of the polyprotein has been observed. Based on these observations, it was proposed that the ORF1 polyprotein does not undergo processing into functional units. We have studied ORF1 polyprotein expression and processing through a baculovirus expression vector system because of the high level expression and post-translational modification abilities of this system. Results: The baculovirus expressed ORF1 polyprotein was processed into smaller fragments that could be detected using antibodies directed against tags engineered at both ends. Processing of this ∼192 kDa tagged ORF1 polyprotein and accumulation of lower molecular weight species took place in a time-dependent manner. This processing was inhibited by E-64d, a cell-permeable cysteine protease inhibitor. MALDI-TOF analysis of a 35 kDa processed fragment revealed 9 peptide sequences that matched the HEV methyltransferase (MeT), the first putative domain of the ORF1 polyprotein. Antibodies to the MeT region also revealed an ORF1 processing pattern identical to that observed for the N-terminal tag. Conclusion: When expressed through baculovirus, the ORF1 polyprotein of HEV was processed into smaller proteins that correlated with their proposed functional domains. Though the involvement of non-cysteine protease(s) could not be be ruled out, this processing mainly depended upon a cysteine protease. © 2006 Sehgal et al; licensee BioMed Central Ltd.