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Expressed mRNAs (expressed + mrna)

Distribution by Scientific Domains

Life Sciences	75%

Selected Abstracts

Trichloroethylene effects on gene expression during cardiac development

BIRTH DEFECTS RESEARCH, Issue 7 2003
J. Michael Collier
Abstract BACKGROUND Halogenated hydrocarbon exposure is associated with changes in gene expression in adult and embryonic tissue. Our study was undertaken to identify differentially expressed mRNA transcripts in embryonic hearts from Sprague-Dawley rats exposed to trichloroethylene (TCE) or potential bio-transformation products dichloroethylene (DCE) and trichloroacetic acid (TCAA). METHODS cDNA subtractive hybridization was used to selectively amplify expressed mRNA obtained from control or halogenated hydrocarbon exposed rat embryos. The doses used were 1100 and 110 ppm (8300 and 830 ,M) TCE, 110 and 11 ppm (1100 and 110 ,M) DCE, and 27.3 and 2.75 mg/ml (100 and 10 mM) TCAA. Control animals were given distilled drinking water throughout the period of experiments. RESULTS Sequencing of over 100 clones derived from halogenated hydrocarbon exposed groups resulted in identification of numerous differentially regulated gene sequences. Up-regulated transcripts identified include genes associated with stress response (Hsp 70) and homeostasis (several ribosomal proteins). Down-regulated transcripts include extracellular matrix components (GPI-p137 and vimentin) and Ca2+ responsive proteins (Serca-2 Ca2+ -ATPase and ,-catenin). Two possible markers for fetal TCE exposure were identified: Serca-2 Ca2+ -ATPase and GPI-p137, a GPI-linked protein of unknown function. Differential regulation of expression of both markers by TCE was confirmed by dot blot analysis and semi-quantitative RT-PCR with levels of TCE exposure between 100 and 250 ppb (0.76 and 1.9 ,M) sufficient to decrease expression. CONCLUSIONS Sequences down-regulated with TCE exposure appear to be those associated with cellular housekeeping, cell adhesion, and developmental processes, while TCE exposure up-regulates expression of numerous stress response and homeostatic genes. Birth Defects Research (Part A) 67488,495, 2003. © 2003 Wiley-Liss, Inc. [source]

Glutamatergic neurons are present in the rat ventral tegmental area

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 1 2007
Tsuyoshi Yamaguchi
Abstract The ventral tegmental area (VTA) is thought to play an important role in reward function. Two populations of neurons, containing either dopamine (DA) or ,-amino butyric acid (GABA), have been extensively characterized in this area. However, recent electrophysiological studies are consistent with the notion that neurons that utilize neurotransmitters other than DA or GABA are likely to be present in the VTA. Given the pronounced phenotypic diversity of neurons in this region, we have proposed that additional cell types, such as those that express the neurotransmitter glutamate may also be present in this area. Thus, by using in situ hybridization histochemistry we investigated whether transcripts encoded by genes for the two vesicular glutamate transporters, VGluT1 or VGluT2, were expressed in the VTA. We found that VGluT2 mRNA but not VGluT1 mRNA is expressed in the VTA. Neurons expressing VGluT2 mRNA were differentially distributed throughout the rostro-caudal and medio-lateral aspects of the VTA, with the highest concentration detected in rostro-medial areas. Phenotypic characterization with double in situ hybridization of these neurons indicated that they rarely co,expressed mRNAs for tyrosine hydroxylase (TH, marker for DAergic neurons) or glutamic acid decarboxylase (GAD, marker for GABAergic neurons). Based on the results described here, we concluded that the VTA contains glutamatergic neurons that in their vast majority are clearly non-DAergic and non-GABAergic. [source]

An optimized method to separate reticulocytes from peripheral blood for molecular analysis

INTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 3 2009
R. PETRUZZELLI
Summary A method based on immunomagnetic sorting of reticulocytes from peripheral blood was set up and combined to a commercial extraction kit for the isolation of total RNA from whole blood. This procedure resulted in high-quality RNA samples suitable for molecular analysis. We used this procedure to analyse erythroid-specific transcripts, starting from peripheral blood samples, to search for differently expressed mRNAs in patients with hereditary persistence of foetal haemoglobin. After erythrocyte lysis, CD15+and CD45+ peripheral cells were negatively sorted to remove leucocyte populations that could have affected the subsequent screening procedure. The cell sorting and RNA extraction procedure was completed within 1,2 h of erythrocyte lysis, which represents a consistent saving of time compared with other procedures. Moreover, it produced 1 ,g of total RNA per ml of blood samples, which is sufficient for molecular analysis. Therefore, our method is a reliable and efficient tool to isolate RNA from specific cell subpopulations poorly represented in peripheral blood, particularly when accurate detection and characterization of highly unstable and poorly expressed molecules is required. [source]

Expression and molecular diversity of Tcf7l2 in the developing murine cerebellum and brain

JOURNAL OF NEUROSCIENCE RESEARCH, Issue 7 2009
Tommy A. Nazwar
Abstract The Wingless family of secreted proteins impinges on multiple aspects of vertebrate nervous system development, from early global patterning and cell fate decision to synaptogenesis. Here, we mapped the developmental expression of the Tcf7l2, which is key to the canonical Wingless signaling cascade, in the developing cerebellum. The exclusive and transient expression of Tcf7l2 in ventricular and Olig2-defined precursor cells within the cerebellar anlage, and its predominant expression in postmitotic neurons in the midbrain/inferior colliculus allowed us to ask whether cell type,specific differences are also reflected in splice isoform variability. We also included in this analysis intestinal epithelia, where Tcf7l2 function has been intensively studied. Our data reveal extensive variability of Tcf7l2 splicing in the central nervous system. Additional variability in brain-expressed Tcf7l2 is generated by a length polymorphism of expressed mRNAs in a stretch of normally nine adenines found at the beginning of exon 18, reminiscent of variability observed at the same site in cancers with microsatellite instability. A consensus emerging from our data is that the expression of isoforms comprising or lacking the C-clamp motif, which has been linked by in vitro studies to the regulation of cell growth, is indeed tightly correlated with the proliferative status in vivo. © 2009 Wiley-Liss, Inc. [source]