References of "Muller, Marc"
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See detailTHE FUNCTION OF HMG-BOX TRANSCRIPTION FACTORS Sox4a AND Sox4b IN ZEBRAFISH BONE DEVELOPMENT AND HOMEOSTASIS.
Aceto, Jessica ULg; Motte, Patrick ULg; Martial, Joseph ULg et al

in Journal of Gravitational Physiology : A Journal of the International Society for Gravitational Physiology (2008), 15

In mammals, the Sox4 gene is involved in development of endocardial crests, the brain, the lung, teeth, gonads and lymphocytes. Recently, Sox4 was shown to control bone mass and mineralization in mice. In ... [more ▼]

In mammals, the Sox4 gene is involved in development of endocardial crests, the brain, the lung, teeth, gonads and lymphocytes. Recently, Sox4 was shown to control bone mass and mineralization in mice. In zebrafish, two homologs for the mammalian Sox4 are present, sox4a and sox4b. Here we investigate the function of the sox4a and sox4b genes in cartilage and bone development in zebrafish. Therefore, we focus our attention on the first bone structures to be formed, the head skeleton and more precisely the pharyngeal cartilage. We show that both genes are expressed in the pharyngeal region, albeit at different time points during development. Double in situ hybridization experiments are used to exactly define the particular tissues where they are expressed. Furthermore, microinjection experiments of antisense oligonucleotides are used to block translation of these specific genes and to define their precise function during cartilage and bone development. [less ▲]

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See detailDetection of micro-RNA/gene interactions involved in angiogenesis using machine learning techniques
Huynh-Thu, Vân Anh ULg; Hiard, Samuel ULg; Geurts, Pierre ULg et al

Poster (2007, September)

Motivation: Angiogenesis is the process responsible for the growth of new blood vessels from existing ones. It is also associated with the development of cancer, as tumors need to be irrigated by blood ... [more ▼]

Motivation: Angiogenesis is the process responsible for the growth of new blood vessels from existing ones. It is also associated with the development of cancer, as tumors need to be irrigated by blood vessels for growing. New cancer therapies appear that exploit angiogenesis inhibitors, also called angiostatic agents, to asphyxiate and starve the tumors. Better understanding the regulatory mechanisms that control angiogenesis is thus fundamental. Recently, short non-coding RNA molecules, called micro-RNAs, have been discovered that are involved in post- transcriptional regulation of gene expressions. These molecules bind to RNA messengers following the base pairing rules, preventing them from being translated into proteins and/or tagging them for degradation. The main goal of this work is to use computational approaches to identify micro-RNAs involved in angiogenesis. Method: In order to identify genes involved in angiogenesis, bovine endothelial cells were treated by a known angiogenesis inhibitor [1], prolactin 16K, and their gene expression profile was compared to the profile of untreated cells. The genes were then divided into three classes: up-regulated, down-regulated, and unaffected genes. The 3'UTR regions of these genes were then analysed by machine learning techniques. Different approaches were considered. First, we described each gene by a vector of motif counts in their 3'UTR regions and used machine learning techniques to rank the motifs according to their relevance for separating the genes into the different classes. We considered successively motifs corresponding to the seeds of known micro- RNAs and also all possible motifs of a given length. To rank the motifs, we compared ensemble of decision trees and linear support vector machines. Second, we considered an approach called Segment and Combine that was proposed in [2]. Finally, we also carried out an exhaustive search of all motifs of a given length that satisfy some constraints on specificity and coverage with respect to a given gene category. Results: The ability of the different approaches at identifying relevant motifs was first assessed on genes predicted to be the target of some known miRNAs. In this simple setting, most methods were able to identify the micro-RNA seed. The results obtained on the genes regulated by prolactin 16K are also very encouraging. We were able to identify one micro-RNA already known to play a role in angiogenesis and several motifs are predicted by different approaches as very specific of up- or down-regulation by prolactin 16K. Their relationship with known micro-RNAs is certainly worth exploring. Conclusion: Machine learning approaches are promising techniques for the identification of micro-RNA/gene interactions. Future work will concern the application of the same kind of techniques on promoters for the identification of transcription factor binding sites. [less ▲]

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See detailThe function of the transcription factor Egr1 in zebrafish cartilage development
Dalcq, Julia ULg; Pasque, Vincent; Ramos, Sonia Davila et al

in Developmental Biology (2007, June 01), 306(1), 439-440

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See detailSox4b is required for pituitary expression of gata2 and specification of thyrotrope cells in zebrafish
Muller, Marc ULg; Mavropoulos, A.; Nica, G. et al

in Developmental Biology (2007, June 01), 306(1), 438-439

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See detailPROTEOMIC ANALYSIS OF WILD TYPE AND LUCIFERASE REPORTER HEPG2 CELLS EXPOSED TO TCDD
Lambert, Damien; Mazzucchelli, Gabriel ULg; De Pauw, Edwin ULg et al

in Organohalogen Compounds (2007), 69

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See detailAlteration of the estrogen hormone pathway in hepatic cells after exposure to polycyclic aromatic hydrocarbons
Brasseur, Catherine ULg; Widart, Stéphane; Muller, Marc ULg et al

in Toxicology Letters (2007), 172

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See detailNew experimental approach of identification and characterization of emerging risks in food safety (EMRISK).
Ribonnet, Laurence; Sergent, Thérèse; Nobels, Ingrid et al

Report (2007)

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See detailStudy of the flavonoids effect on the AhR-dependent transcription using reporter gene assays
Van Der Heiden, Edwige ULg; Bechoux, Nathalie ULg; Sergent, Thérèse et al

in Journal of Biotechnology (2007), 131(2, Suppl. S), 6

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See detailEffects of polycyclic aromatic hydrocarbons on hepatic steroid metabolism
Brasseur, Catherine ULg; Muller, Marc ULg; Widart, Stéphane et al

in Journal of Biotechnology (2007), 131(2, Suppl. S), 73

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See detailSet up of an experimental tool in order to investigate food chemical contaminant toxicity at realistic concentrations
Ribonnet, Laurence; Sergent, Thérèse; Nobels, Ingrid et al

in Toxicology Letters (2007), 172

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See detailTranscriptional regulation of the mouse doublecortin gene in differentiating neurons
Plumier, Jean-Christophe ULg; Muller, Marc ULg; Rogister, Bernard ULg et al

in International Journal of Developmental Neuroscience (2006, December), 24(8), 535

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See detailCloning of the prepro C-RFa gene and brain localization of the active peptide in Salmo salar
Montefusco-Siegmund, R. A.; Romero, A.; Kausel, G. et al

in Cell & Tissue Research (2006), 325(2), 277-285

In all vertebrates, the synthesis and release of prolactin (Prl) from pituitary lactotroph cells is tightly controlled by hypothalamic factors. We have cloned and characterized a hypothalamic cDNA from ... [more ▼]

In all vertebrates, the synthesis and release of prolactin (Prl) from pituitary lactotroph cells is tightly controlled by hypothalamic factors. We have cloned and characterized a hypothalamic cDNA from Atlantic salmon (Salmo salar) encoding C-RFa, a peptide structurally related to mammalian Prl-releasing peptide (PrRP). The deduced preprohormone precursor is composed of 155 amino acid residues presenting a 87.1% similarity to chum salmon C-RFa and a 100% similarity to all fish C-RFa in the bioactive precursor motifs. C-RFa-immunoreactive perikarya and fibres were located in the brain of S. salar, especially in the hypothalamus, olfactory tract, optic tectum and cerebellum. In contrast, immunolabelled fibres were not observed in the pituitary stalk or in the hypophysis. However, interestingly, we detected immunolabelled cells in the rostral pars distalis of the pituitary in the basolateral region in which Prl is synthesized. These results were confirmed by obtaining a strong signal by using reverse transcription/polymerase chain reaction (RTPCR) on mRNA from both hypothalamus and pituitary. These data show, for the first time, by immunohistochemistry and RT-PCR, that C-RFa is produced in pituitary cells. Finally, based on these results, a possible function for CRFa as a locally produced PrRP in this teleost is discussed. [less ▲]

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See detailIdentification of novel prolactin releasing peptide receptors of Cyprinus carpio and Salmo salar expressed in the pituitary gland
Romero, A. P.; Montefusco, R.; Lopez, Mauricio et al

in Journal of Experimental Zoology. Part A, Comparative Experimental Biology (2006, February 01), 305A(2), 171

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See detailExpression of the somatolactin beta gene during zebrafish embryonic development
Lopez, Mauricio; Nica, G.; Motte, Patrick ULg et al

in Gene Expression Patterns (2006), 6(2), 156-161

Somatolactin (Sl) is a pituitary hormone closely related to prolactin (Prl) and growth hormone that was until now only found in various fish species. We isolated the cDNA coding for zebrafish Sl beta and ... [more ▼]

Somatolactin (Sl) is a pituitary hormone closely related to prolactin (Prl) and growth hormone that was until now only found in various fish species. We isolated the cDNA coding for zebrafish Sl beta and we identified the gene encoding this hormone. We also obtained a 1 kb genomic fragment corresponding to the sl beta upstream promoter region. Furthermore, the sl beta expression pattern was examined during zebrafish embryogenesis using whole-mount in situ hybridization. Sl beta mRNA is first detected in a single cell at the anterior border of the neural plate starting at 23 h post fertilization (hpf). Sl beta-expressing cells also express the transcription factor pit1 and are located close to prl-expressing cells. Using combined fluorescent in situ hybridization, we show that sl beta- and prl-expressing cells are clearly distinct at 29 hpf. Starting at 30 hpf, the number of sl beta positive cells increases and their location becomes more clearly distinct from lactotrope cells, in a more posterior position. At later stages (48 hpf), sl beta expression was observed posterior to growth hormone expression, again in a distinct cell type. We show that zebrafish mutants aal, as well as mutants in the pit1 gene, are deficient in sl beta expression. In conclusion, sl beta expression defines a new, additional cell type in zebrafish pituitary that depends on pit1 and aal for its differentiation. (C) 2005 Elsevier B.V. All rights reserved. [less ▲]

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See detailModular changes of cis-regulatory elements from two functional Pit1 genes in the duplicated genome of Cyprinus carpio.
Kausel, G.; Salazar, M.; Castro, L. et al

in Journal of Cellular Biochemistry (2006), 99(3), 905-21

The pituitary-specific transcription factor Pit1 is involved in its own regulation and in a network of transcriptional regulation of hypothalamo-hypophyseal factors including prolactin (PRL) and growth ... [more ▼]

The pituitary-specific transcription factor Pit1 is involved in its own regulation and in a network of transcriptional regulation of hypothalamo-hypophyseal factors including prolactin (PRL) and growth hormone (GH). In the ectotherm teleost Cyprinus carpio, Pit1 plays an important role in regulation of the adaptive response to seasonal environmental changes. Two Pit1 genes exist in carp, a tetraploid vertebrate and transcripts of both genes were detected by RT-PCR analysis. Powerful comparative analyses of the 5'-flanking regions revealed copy specific changes comprising modular functional units in the naturally evolved promoters. These include the precise replacement of four nucleotides around the transcription start site embedded in completely conserved regions extending upstream of the TATA-box, an additional transcription factor binding site in the 5'-UTR of gene-I and, instead, duplication of a 9 bp element in gene-II. Binding of nuclear factors was assessed by electro mobility shift assays using extracts from rat pituitary cells and carp pituitary. Binding was confirmed at one conserved Pit1, one conserved CREB and one consensus MTF1. Interestingly, two functional Pit1 sites and one putative MTF1 binding site are unique to the Pit1 gene-I. In situ hybridization experiments revealed that the expression of gene-I in winter carp was significantly stronger than that of gene-II. Our data suggest that the specific control elements identified in the proximal regulatory region are physiologically relevant for the function of the duplicated Pit1 genes in carp and highlight modular changes in the architecture of two Pit1 genes that evolved for at least 12 MYA in the same organism. [less ▲]

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See detailTranscriptional regulation of the mouse doublecortin gene in differentiating neurons
Plumier, Jean-Christophe ULg; Muller, Marc ULg; Rogister, Bernard ULg et al

in International Journal of Developmental Neuroscience (2006), 24

Detailed reference viewed: 7 (2 ULg)