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Differential Gene Expression Profiles (differential + gene_expression_profile)

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Life Sciences	50%

Selected Abstracts

Differential gene expression profiles in the venom gland/sac of Orancistrocerus drewseni (Hymenoptera: Eumenidae)

ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 4 2009
Ji Hyeong Baek
Abstract To determine differential gene expression profiles in the venom gland and sac (gland/sac) of a solitary hunting wasp species, Orancistrocerus drewseni Saussure (1857), a subtractive cDNA library was constructed by suppression subtractive hybridization. A total of 498 expressed sequence tags (EST) were clustered and assembled into 205 contigs (94 multiple sequences and 111 singletons). About 65% (134) of the contigs had matched BLASTx hits (E,10,4). Among these, 115 contigs had similarity to proteins with assigned molecular function in the Gene Ontology database, and most of them (112 contigs, 83%) were homologous to genes from Hymenoptera, particularly to Apis mellifera (98 contigs). The contigs encoding hyaluronidase and phospholipase A2, known to be main components of wasp venoms, were found in high frequencies (27 and 4%, respectively, as judged by the number of ESTs) in the gene ontology category of catalytic activity. Full-length open reading frames of hyaluronidase and phospholipase A2 were characterized and their abundance in the venom gland/sac was confirmed by quantitative real-time PCR. Several contigs encoding enzymes, including zinc-metallopeptidases that are likely involved in the processing and activation of venomous proteins or peptides, were also identified from the library. Discovery of venom gland/sac-specific genes should promote further studies on biologically active components in the venom of O. drewseni. © 2009 Wiley Periodicals, Inc. [source]

Intracellular biology and virulence determinants of Francisella tularensis revealed by transcriptional profiling inside macrophages

CELLULAR MICROBIOLOGY, Issue 7 2009
Tara D. Wehrly
Summary The highly infectious bacterium Francisella tularensis is a facultative intracellular pathogen, whose virulence requires proliferation inside host cells, including macrophages. Here we have performed a global transcriptional profiling of the highly virulent F. tularensis ssp. tularensis Schu S4 strain during its intracellular cycle within primary murine macrophages, to characterize its intracellular biology and identify pathogenic determinants based on their intracellular expression profiles. Phagocytosed bacteria rapidly responded to their intracellular environment and subsequently altered their transcriptional profile. Differential gene expression profiles were revealed that correlated with specific intracellular locale of the bacteria. Upregulation of general and oxidative stress response genes was a hallmark of the early phagosomal and late endosomal stages, while induction of transport and metabolic genes characterized the cytosolic replication stage. Expression of the Francisella Pathogenicity Island (FPI) genes, which are required for intracellular proliferation, increased during the intracellular cycle. Similarly, 27 chromosomal loci encoding putative hypothetical, secreted, outer membrane proteins or transcriptional regulators were identified as upregulated. Among these, deletion of FTT0383, FTT0369c or FTT1676 abolished the ability of Schu S4 to survive or proliferate intracellularly and cause lethality in mice, therefore identifying novel determinants of Francisella virulence from their intracellular expression profile. [source]

AN ALDOSTERONE-RELATED SYSTEM IN THE VENTROLATERAL MEDULLA OBLONGATA OF SPONTANEOUSLY HYPERTENSIVE AND WISTAR-KYOTO RATS

CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 1-2 2006
Natasha N Kumar
SUMMARY 1The actions of aldosterone include mediation of vasoconstriction, vascular fibrosis, endothelial dysfunction and sodium retention. These actions can contribute to hypertension. Recent studies implicate an abnormal aldosterone hormonal system in the brain in hypertension. However, the study of central aldosterone actions is still in its infancy, as the exact location and abundance of its components in the brain are uncertain. 2We aimed to detect components of the aldosterone cascade in the regions of the ventrolateral medulla oblongata (VLM)-containing neurons that regulate blood pressure and to see whether there are quantitative differences in these components between the spontaneously hypertensive rat (SHR) and normotensive Wistar-Kyoto (WKY) rat models. Tissues from four regions of the brainstem, namely, the rostral and caudal ventrolateral medulla (RVLM and CVLM, respectively), rostral pressor area and caudal pressor area, were examined. We measured mRNA expression of aldosterone synthase, mineralocorticoid receptor (MR1), 12-lipoxygenase (12-LO), serum- and glucocorticoid- inducible kinase and K-ras in male rats. Gene expression levels were measured using real-time reverse transcription,polymerase chain reaction. 3We detected all aldosterone components in all regions of the VLM. The K-ras levels were not significantly different in any of the regions. Expression of MR1 mRNA was lower in the RVLM of SHR (n = 5) compared with WKY rats (n = 5; t = 4.590; P = 0.002) and 12-LO mRNA levels were lower in the CVLM in SHR (n = 6) compared with WKY rats (n = 7; P = 0.04). Thus, we have shown for the first time that components of the aldosterone cascade are present in the VLM. Our results suggest that there may be a differential gene expression profile in the brainstem for genetic hypertension. [source]

Global gene expression profiling of wild type and lysC knockout Escherichia coli W3110

FEMS MICROBIOLOGY LETTERS, Issue 2 2007
Daniel Yuen-Teh Liu
Abstract Aspartokinase III, encoded by lysC, is responsible for the first step of lysine biosynthesis in Escherichia coli. In this study, a lysC knockout E. coli W3110 strain was generated to study the differential gene expression profiles of wild type and lysC knockout strains. Several significant changes were observed, including biosynthesis of lysine, oxaloacetate, ,-ketoglutarate and glutamate genes. Genes related to transporters and heat shock proteins were also affected by lysC knockout. The results indicated that the lysC knockout strain exhibited some phenomena similar to lysine starvation. The data generated by this study further clarify the systematic role of lysC in lysine biosynthesis. [source]

Identification of differentially expressed root genes upon rhizomania disease

MOLECULAR PLANT PATHOLOGY, Issue 6 2008
LAURE SCHMIDLIN
SUMMARY Rhizomania is one of the most devastating sugar beet diseases. It is caused by Beet necrotic yellow vein virus (BNYVV), which induces abnormal rootlet proliferation. To understand better the physiological and molecular basis of the disorder, transcriptome analysis was performed by restriction fragment differential display polymerase chain reaction (RFDD-PCR), which provided differential gene expression profiles between non-infected and infected sugar beet roots. Two distinct viral isolates were used to detect specific or general virus-induced genes. Differentially expressed genes were selected and identified by sequence analysis, followed by reverse Northern and reverse transcriptase PCR experiments. These latter analyses of different plants (Beta vulgaris and Beta macrocarpa) infected under distinct standardized conditions revealed specific and variable expressions. Candidate genes were linked to cell development, metabolism, defence signalling and oxidative stress. In addition, the expression of already characterized genes linked to defence response (pathogenesis-related protein genes), auxin signalling and cell elongation was also studied to further examine some aspects of the disease. Differential expression was retrieved in both B. vulgaris and B. macrocarpa. However, some candidate genes were found to be deregulated in only one plant species, suggesting differential response to BNYVV or specific responses to the BNYVV vector. [source]