Search results for "MESH: Transcription"
showing 8 items of 18 documents
Effects of typical inducers on olfactory xenobiotic-metabolizing enzyme, transporter, and transcription factor expression in rats.
2010
International audience; Several xenobiotic-metabolizing enzymes (XMEs) have been identified in the olfactory mucosa (OM) of mammals. However, the molecular mechanisms underlying the regulation of these enzymes have been little explored. In particular, information on the expression of the transcriptional factors in this tissue is quite limited. The aim of the present study was to examine the impact of five typical inducers, Aroclor 1254, 3-methylcholanthrene, dexamethasone, phenobarbital, and ethoxyquin, on the activities and mRNA expression of several XMEs in the OM and in the liver of rats. We also evaluated the effects of these treatments on the mRNA expression of transcription factors an…
Genetic identification of neurons controlling a sexually dimorphic behaviour
2000
0960-9822 (Print) Journal Article Research Support, Non-U.S. Gov't; In the fruit fly Drosophila melanogaster, locomotor activity is sexually dimorphic: female flies constantly modulate their activity pattern whereas males show a steadier, stereotyped walking pace [1]. Here, we mapped the area of the brain controlling this behavioural dimorphism. Adult male Drosophila expressing a dominant feminising transgene in a small cluster of neurons in the pars intercerebralis exhibited a female-like pattern of locomotor activity. Genetic ablation of these neurons prevented the feminisation of the locomotor activity of transgenic males. The results suggest that this cluster of neurons modulates sex-sp…
The Genome of the Sea Urchin Strongylocentrotus purpuratus
2006
We report the sequence and analysis of the 814-megabase genome of the sea urchin Strongylocentrotus purpuratus , a model for developmental and systems biology. The sequencing strategy combined whole-genome shotgun and bacterial artificial chromosome (BAC) sequences. This use of BAC clones, aided by a pooling strategy, overcame difficulties associated with high heterozygosity of the genome. The genome encodes about 23,300 genes, including many previously thought to be vertebrate innovations or known only outside the deuterostomes. This echinoderm genome provides an evolutionary outgroup for the chordates and yields insights into the evolution of deuterostomes.
Effects of a high-fat diet on energy metabolism and ROS production in rat liver.
2011
International audience; BACKGROUND & AIMS: A high-fat diet affects liver metabolism, leading to steatosis, a complex disorder related to insulin resistance and mitochondrial alterations. Steatosis is still poorly understood since diverse effects have been reported, depending on the different experimental models used. METHODS: We hereby report the effects of an 8 week high-fat diet on liver energy metabolism in a rat model, investigated in both isolated mitochondria and hepatocytes. RESULTS: Liver mass was unchanged but lipid content and composition were markedly affected. State-3 mitochondrial oxidative phosphorylation was inhibited, contrasting with unaffected cytochrome content. Oxidative…
The columnar gene vnd is required for tritocerebral neuromere formation during embryonic brain development of Drosophila.
2006
International audience; In Drosophila, evolutionarily conserved transcription factors are required for the specification of neural lineages along the anteroposterior and dorsoventral axes, such as Hox genes for anteroposterior and columnar genes for dorsoventral patterning. In this report, we analyse the role of the columnar patterning gene ventral nervous system defective (vnd) in embryonic brain development. Expression of vnd is observed in specific subsets of cells in all brain neuromeres. Loss-of-function analysis focussed on the tritocerebrum shows that inactivation of vnd results in regionalized axonal patterning defects, which are comparable with the brain phenotype caused by mutatio…
The stable repression of mesenchymal program is required for hepatocyte identity: A novel role for hepatocyte nuclear factor 4α
2011
The concept that cellular terminal differentiation is stably maintained once development is complete has been questioned by numerous observations showing that differentiated epithelium may undergo an epithelial-to-mesenchymal transition (EMT) program. EMT and the reverse process, mesenchymal-to-epithelial transition (MET), are typical events of development, tissue repair, and tumor progression. In this study, we aimed to clarify the molecular mechanisms underlying these phenotypic conversions in hepatocytes. Hepatocyte nuclear factor 4α (HNF4α) was overexpressed in different hepatocyte cell lines and the resulting gene expression profile was determined by real-time quantitative polymerase…
An epistatic mini-circuitry between the transcription factors Snail and HNF4α controls liver stem cell and hepatocyte features exhorting opposite reg…
2011
Preservation of the epithelial state involves the stable repression of epithelial-to-mesenchymal transition program, whereas maintenance of the stem compartment requires the inhibition of differentiation processes. A simple and direct molecular mini-circuitry between master elements of these biological processes might provide the best device to keep balanced such complex phenomena. In this work, we show that in hepatic stem cell Snail, a transcriptional repressor of the hepatocyte differentiation master gene HNF4α, directly represses the expression of the epithelial microRNAs (miRs)-200c and-34a, which in turn target several stem cell genes. Notably, in differentiated hepatocytes HNF4α, p…
Annotation of microsporidian genomes using transcriptional signals
2012
EA GenoSol CT3; International audience; High-quality annotation of microsporidian genomes is essential for understanding the biological processes that govern the development of these parasites. Here we present an improved structural annotation method using transcriptional DNA signals. We apply this method to re-annotate four previously annotated genomes, which allow us to detect annotation errors and identify a significant number of unpredicted genes. We then annotate the newly sequenced genome of Anncaliia algerae. A comparative genomic analysis of A. algerae permits the identification of not only microsporidian core genes, but also potentially highly expressed genes encoding membrane-asso…