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Decoville Martine


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tél : 02.38.25.55.39 - fax : 02.38.25.55.83

Publications

2015   Références trouvées : 1

Sarou-Kanian V., Joudiou N., Louat F., Yon M., Szeremeta F., Meme S., Massiot D., Decoville M., Fayon F., Beloeil J.-C.  (2015)

Metabolite localization in living drosophila using High Resolution Magic Angle Spinning NMR

Scientific Reports (2015 5 9872 - doi : 10.1038/srep09872
We have developed new methods enabling in vivo localization and identification of metabolites through their (1)H NMR signatures, in a drosophila. Metabolic profiles in localized regions were obtained using HR-MAS Slice Localized Spectroscopy and Chemical Shift Imaging at high magnetic fields. These methods enabled measurement of metabolite contents in anatomic regions of the fly, demonstrated by a decrease in beta-alanine signals in the thorax of flies showing muscle degeneration.

We have developed new methods enabling in vivo localization and identification of metabolites through their (1)H NMR signatures, in a drosophila. Metabolic profiles in localized regions were obtained using HR-MAS Slice Localized Spectroscopy and Chemical Shift Imaging at high magnetic fields. These methods enabled measurement of metabolite contents in anatomic regions of the fly, demonstrated by a decrease in beta-alanine signals in the thorax of flies showing muscle degeneration.


2014   Références trouvées : 1

Charpentier, G. Louat, F. Bonmatin, J. M. Marchand, P. A. Vanier, F. Locker, D. Decoville, M.  (2014)

Lethal and sublethal effects of imidacloprid, after chronic exposure, on the insect model Drosophila melanogaster

Environmental science and technology (201) 48 (7) 4096-4102 - doi : 10.1021/es405331c
Neonicotinoids are subjected to vigilance because of environmental contaminations and deleterious effects on bees. Imidacloprid (IMI) is one of the most representative insecticides of this family. At chronic exposure, concentration-effect relationships are non linear. An insect model should allow a better description of this toxicity. We compared the lethal concentration 50% (LC50) of IMI for a Drosophila-field strain, after acute and chronic exposure. Relative to the acute LC50, the chronic LC50 was lowered by a factor of 29 for males (1.3 mM/45 muM), 52 for larvae (157 muM/3 muM) and more than 172 for females (>3.1 mM/18 muM). Chronic exposure also revealed significant lethal and sublethal effects, at concentrations 3-5 orders of magnitude lower than the chronic LC50. Mean mortalities reached 28% (at 3.91 nM) and 27% (at 39.1 nM) for females and males, respectively. Fecundity decreased of 16% at 1.96 nM. Mating increased of 30% at 0.391 nM. The LOEC (lowest observed effect concentration : 0.391 nM) was 46 000 times lower than the chronic LC50 for males ; it was 115 000 times lower than the chronic LC50 for females. This study illuminates effects that neonicotinoids can induce at very low concentrations. This is of particular interest for nontarget insects and for insect dependent species.

Neonicotinoids are subjected to vigilance because of environmental contaminations and deleterious effects on bees. Imidacloprid (IMI) is one of the most representative insecticides of this family. At chronic exposure, concentration-effect relationships are non linear. An insect model should allow a better description of this toxicity. We compared the lethal concentration 50% (LC50) of IMI for a Drosophila-field strain, after acute and chronic exposure. Relative to the acute LC50, the chronic LC50 was lowered by a factor of 29 for males (1.3 mM/45 muM), 52 for larvae (157 muM/3 muM) and more than 172 for females (>3.1 mM/18 muM). Chronic exposure also revealed significant lethal and sublethal effects, at concentrations 3-5 orders of magnitude lower than the chronic LC50. Mean mortalities reached 28% (at 3.91 nM) and 27% (at 39.1 nM) for females and males, respectively. Fecundity decreased of 16% at 1.96 nM. Mating increased of 30% at 0.391 nM. The LOEC (lowest observed effect concentration : 0.391 nM) was 46 000 times lower than the chronic LC50 for males ; it was 115 000 times lower than the chronic LC50 for females. This study illuminates effects that neonicotinoids can induce at very low concentrations. This is of particular interest for nontarget insects and for insect dependent species.


2013   Références trouvées : 1

Même, S., Joudiou, N., Szeremeta, F., Mispelter, J., Louat, F., Decoville, M., Locker, D., Beloeil, J-C.  (2013)

In vivo magnetic resonance microscopy of Drosophilae at 9.4 T

Magnetic Resonance Imaging 31 (1) 109-119 - doi : 10.1016/j.mri.2012.06.019
In preclinical research, genetic studies have made considerable progress as a result of the development of transgenic animal models of human diseases. Consequently, there is now a need for higher resolution MRI to provide finer details for studies of small animals (rats, mice) or very small animals (insects). One way to address this issue is to work with high-magnetic-field spectrometers (dedicated to small animal imaging) with strong magnetic field gradients. It is also necessary to develop a complete methodology (transmit/receive coil, pulse sequence, fixing system, air supply, anesthesia capabilities, etc.). In this study, we developed noninvasive protocols, both in vitro and in vivo (from coil construction to image generation), for drosophila MRI at 9.4 T. The 10*10*80-μm resolution makes it possible to visualize whole drosophila (head, thorax, abdomen) and internal organs (ovaries, longitudinal and transverse muscles, bowel, proboscis, antennae and optical lobes). We also provide some results obtained with a Drosophila model of muscle degeneration. This opens the way for new applications of structural genetic modification studies using MRI of drosophila.

In preclinical research, genetic studies have made considerable progress as a result of the development of transgenic animal models of human diseases. Consequently, there is now a need for higher resolution MRI to provide finer details for studies of small animals (rats, mice) or very small animals (insects). One way to address this issue is to work with high-magnetic-field spectrometers (dedicated to small animal imaging) with strong magnetic field gradients. It is also necessary to develop a complete methodology (transmit/receive coil, pulse sequence, fixing system, air supply, anesthesia capabilities, etc.). In this study, we developed noninvasive protocols, both in vitro and in vivo (from coil construction to image generation), for drosophila MRI at 9.4 T. The 10*10*80-μm resolution makes it possible to visualize whole drosophila (head, thorax, abdomen) and internal organs (ovaries, longitudinal and transverse muscles, bowel, proboscis, antennae and optical lobes). We also provide some results obtained with a Drosophila model of muscle degeneration. This opens the way for new applications of structural genetic modification studies using MRI of drosophila.


2011   Références trouvées : 1

Mouchel-Vielh, E., Rougeot, J., Decoville, M. & Peronnet, F.  (2011)

The MAP kinase ERK and its scaffold protein MP1 interact with the chromatin regulator Corto during Drosophila wing tissue development.

Bmc Developmental Biology 11 (1) 17
Background : Mitogen-activated protein kinase (MAPK) cascades (p38, JNK, ERK pathways) are involved in cell fate acquisition during development. These kinase modules are associated with scaffold proteins that control their activity. In Drosophila, dMP1, that encodes an ERK scaffold protein, regulates ERK signaling during wing development and contributes to intervein and vein cell differentiation. Functional relationships during wing development between a chromatin regulator, the Enhancer of Trithorax and Polycomb Corto, ERK and its scaffold protein dMP1, are examined here. 

Results : Genetic interactions show that corto and dMP1 act together to antagonize rolled (which encodes ERK) in the future intervein cells, thus promoting intervein fate. Although Corto, ERK and dMP1 are present in both cytoplasmic and nucleus compartments, they interact exclusively in nucleus extracts. Furthermore, Corto, ERK and dMP1 co localize on several sites on polytene chromosomes, suggesting that they regulate gene expression directly on chromatin. Finally, Corto is phosphorylated. Interestingly, its phosphorylation pattern differs between cytoplasm and nucleus and changes upon ERK activation.

Background : Mitogen-activated protein kinase (MAPK) cascades (p38, JNK, ERK pathways) are involved in cell fate acquisition during development. These kinase modules are associated with scaffold proteins that control their activity. In Drosophila, dMP1, that encodes an ERK scaffold protein, regulates ERK signaling during wing development and contributes to intervein and vein cell differentiation. Functional relationships during wing development between a chromatin regulator, the Enhancer of Trithorax and Polycomb Corto, ERK and its scaffold protein dMP1, are examined here.

Results : Genetic interactions show that corto and dMP1 act together to antagonize rolled (which encodes ERK) in the future intervein cells, thus promoting intervein fate. Although Corto, ERK and dMP1 are present in both cytoplasmic and nucleus compartments, they interact exclusively in nucleus extracts. Furthermore, Corto, ERK and dMP1 co localize on several sites on polytene chromosomes, suggesting that they regulate gene expression directly on chromatin. Finally, Corto is phosphorylated. Interestingly, its phosphorylation pattern differs between cytoplasm and nucleus and changes upon ERK activation.


2010   Références trouvées : 2

Rautureau, G. J. P. Vovelle, F. Schoentgen, F. Decoville, M. Locker, D. Damblon C. & Jouvensal, L.  (2010)

NMR structure of a phosphatidylethanolamine binding protein from Drosophila

Proteins-Structure Function and Bioinformatics - 78 (6) 1606-1610

Lamiable, O., Rabhi, M., Peronnet, F., Locker, D. & Decoville, M.  (2010)

Rm62, a DEAD box RNA helicase, complexes with DSP1 in Drosophila embryos.

Genesis 48, 244-253.


2009   Références trouvées : 2

Rautureau, G., Jouvensal, L., Vovelle, F., Schoentgen, F., Locker, D. & Decoville, M.  (2009)

Expression and characterization of the PEBP homolog genes from Drosophila.

Arch. Insect. Biochem. Physiol. 71, 55-69.

Goncalves, C., Ardourel, M.Y., Decoville, M., Breuzard, G., Midoux, P., Hartmann, B. & Pichon, C.  (2009)

An optimized extended DNA kappa B site that enhances plasmid DNA nuclear import and gene expression.

J. Gene Med. 11, 401-411.


2006   Références trouvées : 2

Salvaing, J ; Decoville, M ; Mouchel-Vielh, E ; Bussiere, M ; Daulny, A ; Boldyreva, L ; Zhimulev, I ; Locker, D ; Peronnet, F  (2006)

Corto and DSP1 interact and bind to a maintenance element of the Scr Hox gene : understanding the role of Enhancers of trithorax and Polycomb

Bmc Biology 4 Art No. 9
Background : Polycomb-group genes (PcG) encode proteins that maintain homeotic (Hox) gene repression throughout development. Conversely, trithorax-group (trxG) genes encode positive factors required for maintenance of long term Hox gene activation. Both kinds of factors bind chromatin regions called maintenance elements ( ME). Our previous work has shown that corto, which codes for a chromodomain protein, and dsp1, which codes for an HMGB protein, belong to a class of genes called the Enhancers of trithorax and Polycomb (ETP) that interact with both PcG and trxG. Moreover, dsp1 interacts with the Hox gene Scr, the DSP1 protein is present on a Scr ME in S2 cells but not in embryos.

Background : Polycomb-group genes (PcG) encode proteins that maintain homeotic (Hox) gene repression throughout development. Conversely, trithorax-group (trxG) genes encode positive factors required for maintenance of long term Hox gene activation. Both kinds of factors bind chromatin regions called maintenance elements ( ME). Our previous work has shown that corto, which codes for a chromodomain protein, and dsp1, which codes for an HMGB protein, belong to a class of genes called the Enhancers of trithorax and Polycomb (ETP) that interact with both PcG and trxG. Moreover, dsp1 interacts with the Hox gene Scr, the DSP1 protein is present on a Scr ME in S2 cells but not in embryos.

Rautureau, G ; Jouvensal, L ; Decoville, M ; Locker, D ; Vovelle, FO ; Schoentgen, FO  (2006)

Cloning, high yield over-expression, purification, and characterization of CG18594, a new PEBP/RKIP family member from Drosophila melanogaster

Protein Expression and Purification 48 (1) 90-97
The phosphatidylethanolamine-binding protein (PEBP) family is widely distributed in various species, from bacteria to mammals. These proteins seem to modulate important cell mechanisms : they control heterotrimeric G-proteins, inhibit the MAP-kinase and NF kappa B signaling pathways, and also serine proteases (thrombin, neuropsin, and chymotrypsin). In order to establish structure-function relationships for this family of proteins, our study focuses on PEBPs expressed within a single organism : Drosophila melanogaster, which constitutes a model system that lends itself well to establishing links between genes' expression and the corresponding proteins' functions, and to studying physiological mechanisms such as development.

The phosphatidylethanolamine-binding protein (PEBP) family is widely distributed in various species, from bacteria to mammals. These proteins seem to modulate important cell mechanisms : they control heterotrimeric G-proteins, inhibit the MAP-kinase and NF kappa B signaling pathways, and also serine proteases (thrombin, neuropsin, and chymotrypsin). In order to establish structure-function relationships for this family of proteins, our study focuses on PEBPs expressed within a single organism : Drosophila melanogaster, which constitutes a model system that lends itself well to establishing links between genes’ expression and the corresponding proteins’ functions, and to studying physiological mechanisms such as development.


2005   Références trouvées : 2

Dejardin, J ; Rappailles, A ; Cuvier, O ; Grimaud, C ; Decoville, M ; Locker, D ; Cavalli, G  (2005)

Recruitment of Drosophila Polycomb group proteins to chromatin by DSP1

Nature 434 (7032) 533-538
Polycomb and trithorax group (PcG and trxG) proteins maintain silent and active transcriptional states, respectively, throughout development(1). In Drosophila, PcG and trxG proteins associate with DNA regions named Polycomb and trithorax response elements (PRE and TRE), but the mechanisms of recruitment are unknown. We previously characterized a minimal element from the regulatory region of the Abdominal-B gene, termed Ab-Fab. Ab-Fab contains a PRE and a TRE and is able to maintain repressed or active chromatin states during development(2).

Polycomb and trithorax group (PcG and trxG) proteins maintain silent and active transcriptional states, respectively, throughout development(1). In Drosophila, PcG and trxG proteins associate with DNA regions named Polycomb and trithorax response elements (PRE and TRE), but the mechanisms of recruitment are unknown. We previously characterized a minimal element from the regulatory region of the Abdominal-B gene, termed Ab-Fab. Ab-Fab contains a PRE and a TRE and is able to maintain repressed or active chromatin states during development(2).

Rappailles, A ; Decoville, M ; Locker, D  (2005)

DSP1, a Drosophila HMG protein, is involved in spatiotemporal expression of the homoeotic gene Sex combs reduced

Biology of The Cell 97 (10) 779-785
Background information. The Pc-G (Polycomb group) and trx-G (trithorax group) genes play a key role in the regulation of the homoeotic genes. The homoeotic gene Scr (Sex combs reduced) contained in the Antennapedia complex specifies segmental identity of the labial and prothoracic segments in Drosophila. Regulation of Scr requires the action of different enhancer elements spread over several kilobases. We previously identified an HMGB (high mobility group)-like protein DSP1 (dorsal switch protein 1), which works like a trx-G protein for the normal Scr expression. Results. In the present study, we attempted to characterize the regulatory sequences involved in the maintenance of the Scr activation by DSP1.

Background information. The Pc-G (Polycomb group) and trx-G (trithorax group) genes play a key role in the regulation of the homoeotic genes. The homoeotic gene Scr (Sex combs reduced) contained in the Antennapedia complex specifies segmental identity of the labial and prothoracic segments in Drosophila. Regulation of Scr requires the action of different enhancer elements spread over several kilobases. We previously identified an HMGB (high mobility group)-like protein DSP1 (dorsal switch protein 1), which works like a trx-G protein for the normal Scr expression. Results. In the present study, we attempted to characterize the regulatory sequences involved in the maintenance of the Scr activation by DSP1.


2003   Références trouvées : 3

Martin, D ; Daulny, A ; Decoville, M ; Locker, D  (2003)

Mutagenesis analysis of the interaction between the dorsal Rel homology domain and HMG boxes of DSP1 protein

Journal of Biochemistry 134 (4) 583-589
DSP1 is an HMG-like protein of Drosophila melanogaster consisting of 386 amino acids with two HMG domains at the C-terminal end. It was shown to interact with Dorsal protein through the HMG domains and to enhance its DNA binding. Each HMG domain consists of approximately 80 amino acid residues, forming three alpha helices folded into an L-shaped structure. We have compared the interaction of various truncated and mutated forms of DSP1 with the dorsal Rel homology domain (RHD). In particular, we have mutated the conserved tryptophan residue 212 or 302 in A or B boxes or the lysine-rich region ((KKRK256)-K-253) of the A/B linker. Analysis by circular dichroism revealed that the protein tertiary structure is affected in these mutants. However, these mutations do not abolish the DSP1 binding to Dorsal, except if the two HMG boxes are altered, i.e., in a double mutant or in mutant isolated domain. Finally, studies on the enhancement of Dorsal DNA binding by DSP1 revealed that the DNA affinity is maximum in the presence of wild-type DSP1, is dramatically reduced when box A is altered, and is completely abolished when box B is altered.

DSP1 is an HMG-like protein of Drosophila melanogaster consisting of 386 amino acids with two HMG domains at the C-terminal end. It was shown to interact with Dorsal protein through the HMG domains and to enhance its DNA binding. Each HMG domain consists of approximately 80 amino acid residues, forming three alpha helices folded into an L-shaped structure. We have compared the interaction of various truncated and mutated forms of DSP1 with the dorsal Rel homology domain (RHD). In particular, we have mutated the conserved tryptophan residue 212 or 302 in A or B boxes or the lysine-rich region ((KKRK256)-K-253) of the A/B linker. Analysis by circular dichroism revealed that the protein tertiary structure is affected in these mutants. However, these mutations do not abolish the DSP1 binding to Dorsal, except if the two HMG boxes are altered, i.e., in a double mutant or in mutant isolated domain. Finally, studies on the enhancement of Dorsal DNA binding by DSP1 revealed that the DNA affinity is maximum in the presence of wild-type DSP1, is dramatically reduced when box A is altered, and is completely abolished when box B is altered.

Daulny, A ; Rappailles, A ; Landemarre, L ; Locker, D ; Decoville, M  (2003)

DSP1 interacts with bicoid for knirps enhancement

Genesis 36 (2) 104-113
DSP1 is an HIVIG-box protein which has been implicated in the regulation of homeotic genes in Drosophila melanogaster. Here we report that DSP1 is also involved in the regulation of the kni gap gene. Analysis of the phenotype of a null mutation of dsp1 (dspl(1)) reveals that the absence of maternal DSP1 results in A4 segmentation defects that are correlated with a diminution of the kni expression domain. Genetic interaction studies demonstrate that a bcd mutation enhances the A4 defect of dsp1(1). We present in vitro and in vivo evidences for a direct interaction between DSP1 and Bicoid, mediated by the BCD homeodomain and the HMG box of DSP1. Finally, we show by immunoprecipitation of cross-linked chromatin the association of DSP1 with the kni-regulating region and discuss the potential mechanism of DSP1-mediated activation of kni. (C) 2003 Wiley-Liss, Inc.

DSP1 is an HIVIG-box protein which has been implicated in the regulation of homeotic genes in Drosophila melanogaster. Here we report that DSP1 is also involved in the regulation of the kni gap gene. Analysis of the phenotype of a null mutation of dsp1 (dspl(1)) reveals that the absence of maternal DSP1 results in A4 segmentation defects that are correlated with a diminution of the kni expression domain. Genetic interaction studies demonstrate that a bcd mutation enhances the A4 defect of dsp1(1). We present in vitro and in vivo evidences for a direct interaction between DSP1 and Bicoid, mediated by the BCD homeodomain and the HMG box of DSP1. Finally, we show by immunoprecipitation of cross-linked chromatin the association of DSP1 with the kni-regulating region and discuss the potential mechanism of DSP1-mediated activation of kni. (C) 2003 Wiley-Liss, Inc.

Janke, C ; Martin, D ; Giraud-Panis, MJ ; Decoville, M ; Locker, D  (2003)

Drosophila DSP1 and rat HMGB1 have equivalent DNA binding properties and share a similar secondary fold

Journal of Biochemistry 133 (4) 533-539
The protein DSP1 belongs to the group of HMG-box proteins, which share the common structural feature of the HMG-box. This approximately 80 amino acid long motif binds DNA via the minor groove. DSP1 was discovered as a,transcriptional co-repressor of Dorsal in Drosophila melanogaster and then was shown to participate to the remodeling of chromatin. By means of sequence alignment and gene organization, DSP1 was classified as the fly homologue of the vertebrate proteins HMGB1/2. DSP1 contains two HMG boxes flanked by two glutamine-rich domains at the N-terminus. In addition, the HMG domain of DSP1 displays two differences in its primary sequence as compared to the vertebrate HMGB1 : a shorter acidic tail and a linker between the two boxes longer by 6 amino acids. By comparing several functional parameters of DSP1 with those of HMGB1, the present study establishes the functional equivalence of both proteins in terms of DNA recognition. The major structural difference between the two proteins, the glutamine-rich N-terminal tail of DSP1, which does not exist in HMGB1, did not interfere with any of the studied DNA-binding properties of the proteins.

The protein DSP1 belongs to the group of HMG-box proteins, which share the common structural feature of the HMG-box. This approximately 80 amino acid long motif binds DNA via the minor groove. DSP1 was discovered as a,transcriptional co-repressor of Dorsal in Drosophila melanogaster and then was shown to participate to the remodeling of chromatin. By means of sequence alignment and gene organization, DSP1 was classified as the fly homologue of the vertebrate proteins HMGB1/2. DSP1 contains two HMG boxes flanked by two glutamine-rich domains at the N-terminus. In addition, the HMG domain of DSP1 displays two differences in its primary sequence as compared to the vertebrate HMGB1 : a shorter acidic tail and a linker between the two boxes longer by 6 amino acids. By comparing several functional parameters of DSP1 with those of HMGB1, the present study establishes the functional equivalence of both proteins in terms of DNA recognition. The major structural difference between the two proteins, the glutamine-rich N-terminal tail of DSP1, which does not exist in HMGB1, did not interfere with any of the studied DNA-binding properties of the proteins.


2001   Références trouvées : 1

Decoville, M ; Giacomello, E ; Leng, M ; Locker, D  (2001)

DSP1, an HMG-like protein, is involved in the regulation of homeotic genes

Genetics 157 (1) 237-244
The Drosophila dsp1 gene, which encodes an HMG-like protein, was originally identified in a screen for corepressors of Dorsal. Here we report that loss of dsp1 function causes homeotic transformations resembling those associated with loss of function in the homeotic genes Sex combs,reduced (Scr), Ultrabithorax (Ubx), and Abdominal-B. The expression pattern of Scr is altered in dsp1 mutant imaginal discs, indicating that dsp1 is required for normal expression of this gene. Genetic interaction studies reveal that a null allele of dsp1 enhances trithorax-group gene (trx-G) mutations and partially suppresses Polycomb-group gene (Pc-G) mutations. On the contrary, overexpression of dsp1 induces an enhancement of the transformation of wings into halteres and of the extra sex comb phenotype of Pc. In addition, dsp1 male mutants exhibit a mild transformation of A4 into A5. Comparison of the chromatin structure at the Mcp locus in wild-type and dsp1 mutant embryos reveals that the 300-bp DNase I hypersensitive region is absent in a dsp1 mutant context. We propose that DSP1 protein is a chromatin remodeling factor, acting as a trx-G or a Pc-G protein depending on the considered function.

The Drosophila dsp1 gene, which encodes an HMG-like protein, was originally identified in a screen for corepressors of Dorsal. Here we report that loss of dsp1 function causes homeotic transformations resembling those associated with loss of function in the homeotic genes Sex combs,reduced (Scr), Ultrabithorax (Ubx), and Abdominal-B. The expression pattern of Scr is altered in dsp1 mutant imaginal discs, indicating that dsp1 is required for normal expression of this gene. Genetic interaction studies reveal that a null allele of dsp1 enhances trithorax-group gene (trx-G) mutations and partially suppresses Polycomb-group gene (Pc-G) mutations. On the contrary, overexpression of dsp1 induces an enhancement of the transformation of wings into halteres and of the extra sex comb phenotype of Pc. In addition, dsp1 male mutants exhibit a mild transformation of A4 into A5. Comparison of the chromatin structure at the Mcp locus in wild-type and dsp1 mutant embryos reveals that the 300-bp DNase I hypersensitive region is absent in a dsp1 mutant context. We propose that DSP1 protein is a chromatin remodeling factor, acting as a trx-G or a Pc-G protein depending on the considered function.


2000   Références trouvées : 1

Decoville, M ; Giraud-Panis, MJ ; Mosrin-Huaman, C ; Leng, M ; Locker, D  (2000)

HMG boxes of DSP1 protein interact with the Rel homology domain of transcription factors

Nucleic Acids Research 28 (2) 454-462
Formation of the dorsoventral axis in Drosophila melanogaster is mediated through control of the expression of several genes by the morphogen Dorsal. In the ventral part of the embryo Dorsal activates twist and represses ren amongst others, Recently, several proteins have been shown to assist Dorsal in the repression of ten, one of which is DSP1, a HMG box protein that was isolated as a putative co-repressor of Dorsal. In this report we used a DSP1 null mutant to ascertain in vivo the involvement of DSP1 in Dorsal-mediated repression of ten but not in the activation of twist.

Formation of the dorsoventral axis in Drosophila melanogaster is mediated through control of the expression of several genes by the morphogen Dorsal. In the ventral part of the embryo Dorsal activates twist and represses ren amongst others, Recently, several proteins have been shown to assist Dorsal in the repression of ten, one of which is DSP1, a HMG box protein that was isolated as a putative co-repressor of Dorsal. In this report we used a DSP1 null mutant to ascertain in vivo the involvement of DSP1 in Dorsal-mediated repression of ten but not in the activation of twist.


1998   Références trouvées : 1

Mosrin-Huaman, C ; Canaple, L ; Locker, D ; Decoville, M  (1998)

DSP1 gene of Drosophila melanogaster encodes an HMG-domain protein that plays multiple roles in development

Developmental Genetics 23 (4) 324-334
DSP1 is an HMG-box containing protein of Drosophila melanogaster which was first identified as a co-repressor of the Dorsal protein. Recently, the analysis of the structure of the gene has led vs to propose that DSP1 is the Drosophila equivalent of the ubiquitous vertebrate HMG 1/2 proteins. In the present paper, the patterns of expression of DSP1 protein and RNA in adult flies and during development are reported. in the adults DSP1 protein is located in nurse cells of ovaries and in brain. During eggs development uniform expression of DSP1 protein persists until the end of germband retraction.

DSP1 is an HMG-box containing protein of Drosophila melanogaster which was first identified as a co-repressor of the Dorsal protein. Recently, the analysis of the structure of the gene has led vs to propose that DSP1 is the Drosophila equivalent of the ubiquitous vertebrate HMG 1/2 proteins. In the present paper, the patterns of expression of DSP1 protein and RNA in adult flies and during development are reported. in the adults DSP1 protein is located in nurse cells of ovaries and in brain. During eggs development uniform expression of DSP1 protein persists until the end of germband retraction.


1997   Références trouvées : 1

Canaple, L ; Decoville, M ; Leng, M ; Locker, D  (1997)

The Drosophila DSP1 gene encoding an HMG 1-like protein : Genomic organization, evolutionary conservation and expression

Gene 184 (2) 285-290
The gene that encodes the dorsal switch protein (DSP1) has been isolated from a Drosophila melanogaster cosmid library. It is organized into seven exons and six introns. The relative position of the introns within the region coding for the high mobility group (HMG) domains are identical to those of vertebrate HMG 1/2 genes. The close similarity between DSP1 and HMG 1/2 genes strongly suggests that these genes derived from a common ancestral gene. DSP1 encodes, at least, two distinct mRNAs that differ in the length of their 5'-untranslated region and coding sequence. Detailed sequence analysis shows that alternative splicing of precursor mRNA gives rise to the two isoform mRNAs found in Drosophila cells.

The gene that encodes the dorsal switch protein (DSP1) has been isolated from a Drosophila melanogaster cosmid library. It is organized into seven exons and six introns. The relative position of the introns within the region coding for the high mobility group (HMG) domains are identical to those of vertebrate HMG 1/2 genes. The close similarity between DSP1 and HMG 1/2 genes strongly suggests that these genes derived from a common ancestral gene. DSP1 encodes, at least, two distinct mRNAs that differ in the length of their 5’-untranslated region and coding sequence. Detailed sequence analysis shows that alternative splicing of precursor mRNA gives rise to the two isoform mRNAs found in Drosophila cells.


1996   Références trouvées : 1

Cizeau, J ; Decoville, M ; Leng, M ; Locker, D  (1996)

Large deletions induced in the white gene of Drosophila melanogaster by the antitumoral drug cis-dichlorodiammineplatinum(II) : Influence of non-homologous recombination

Mutation Research-Fundamental and Molecular Mechanisms of Mutagenesis 356 (2) 197-202
We have studied two mutants carrying large deletions induced in the white gene of Drosophila by the antitumoral drug cisplatin. The breakpoints of the deletions were located by southern analysis and the sequences of the deletion junctions were determined. Two base-pair repeats are associated with the ends of these deletions ; one of the repeats is preserved in the new junction after the deletion. DNA sequences such as A-T rich, alternating purine/pyrimidine tracts, polypurine-polypyrimidine tracts and topoisomerase I and II cleavage sites are found near the junctions. These results suggest that illegitimate recombinational processes are involved in the generation of cisplatin-induced large deletions.

We have studied two mutants carrying large deletions induced in the white gene of Drosophila by the antitumoral drug cisplatin. The breakpoints of the deletions were located by southern analysis and the sequences of the deletion junctions were determined. Two base-pair repeats are associated with the ends of these deletions ; one of the repeats is preserved in the new junction after the deletion. DNA sequences such as A-T rich, alternating purine/pyrimidine tracts, polypurine-polypyrimidine tracts and topoisomerase I and II cleavage sites are found near the junctions. These results suggest that illegitimate recombinational processes are involved in the generation of cisplatin-induced large deletions.


1995   Références trouvées : 1

Locker, D ; Decoville, M ; Maurizot, JC ; Bianchi, ME ; Leng, M  (1995)

Interaction between cisplatin-modified DNA and the HMG boxes of HMG-1 - DNAse-I footprinting and circular-dichroism

Journal of Molecular Biology 246 (2) 243-247
The interactions between the two boxes A and B of HMG 1 and cis-diamminedichloroplatinum(II)-modified DNA containing a single intrastrand cross-link at the d(GpG) site were studied by DNase I footprinting and circular dichroism. The DNAase I cleavage patterns of the HMG box-platinated DNA complexes are identical, the two boxes inhibiting the DNase I cutting over at least 15 and 12 nucleotide residues in the platinated strand and the complementary strand, respectively As judged by circular dichroism, the two boxes have the same a-helical content (56%) and they induce the same conformational changes in the platinated DNA.

The interactions between the two boxes A and B of HMG 1 and cis-diamminedichloroplatinum(II)-modified DNA containing a single intrastrand cross-link at the d(GpG) site were studied by DNase I footprinting and circular dichroism. The DNAase I cleavage patterns of the HMG box-platinated DNA complexes are identical, the two boxes inhibiting the DNase I cutting over at least 15 and 12 nucleotide residues in the platinated strand and the complementary strand, respectively As judged by circular dichroism, the two boxes have the same a-helical content (56%) and they induce the same conformational changes in the platinated DNA.


1994   Références trouvées : 1

Cizeau, J ; Decoville, M ; Leng, M ; Locker, D  (1994)

Deletions induced in the white and vermilion genes of drosophila-melanogaster by the antitumor drug cis-dichlorodiammineplatinum(ii)

Mutation Research-Fundamental and Molecular Mechanisms of Mutagenesis 311 (1) 31-38
This paper describes the analysis of cisplatin induced mutations at the white (w) and vermilion (upsilon) loci located on the X chromosome of Drosophila melanogaster. Twenty-eight w and eight upsilon mutants have been found in a male genetic context and 42 w mutants in a female genetic context. In these latter experiments, genetic analysis showed the presence of multi-locus deficiencies in 18 out of 42 w mutants. Eighteen w and three upsilon intragenic mutations were analyzed at the molecular level. Seventeen w and three upsilon mutants carry deletions within the gene, ranging in size from 4 to 109 base pairs. Sequence analysis of the mutants indicates that most of them were produced by non-homologous recombinational events occurring between short (2-5 bp) sequence repeats on both sides of the deletion, one repeat being retained at the new junction. These results differ largely from those obtained in prokaryotic and other eukaryotic cells.

This paper describes the analysis of cisplatin induced mutations at the white (w) and vermilion (upsilon) loci located on the X chromosome of Drosophila melanogaster. Twenty-eight w and eight upsilon mutants have been found in a male genetic context and 42 w mutants in a female genetic context. In these latter experiments, genetic analysis showed the presence of multi-locus deficiencies in 18 out of 42 w mutants. Eighteen w and three upsilon intragenic mutations were analyzed at the molecular level. Seventeen w and three upsilon mutants carry deletions within the gene, ranging in size from 4 to 109 base pairs. Sequence analysis of the mutants indicates that most of them were produced by non-homologous recombinational events occurring between short (2-5 bp) sequence repeats on both sides of the deletion, one repeat being retained at the new junction. These results differ largely from those obtained in prokaryotic and other eukaryotic cells.


1993   Références trouvées : 1

Decoville, M ; Schwartz, A ; Locker, D ; Leng, M  (1993)

Detection of minor adducts in cisplatin-modified DNA by transcription footprinting

Febs Letters 323 (1-2) 55-58
Two DNA restriction fragments containing either a d(GC)5 or a d(TTGCTTGATTAGTTGTGTT) insert were subjected to reaction with cis-diamminedichloroplatinum(II) and were then used as templates for RNA synthesis by T7 RNA polymerase. Within the d(GC)5 insert, interstrand cross-links are preferentially formed. Within the second insert, the reactivity order of the potential binding sites is d(ApG) > d(GpC/GpC) = d(GpA) > d(GpTpG). In the presence of cyanide ions, the adducts are much less stable at the d(GpA) sites than at the d(GpCpG) sites, in double-stranded DNA.

Two DNA restriction fragments containing either a d(GC)5 or a d(TTGCTTGATTAGTTGTGTT) insert were subjected to reaction with cis-diamminedichloroplatinum(II) and were then used as templates for RNA synthesis by T7 RNA polymerase. Within the d(GC)5 insert, interstrand cross-links are preferentially formed. Within the second insert, the reactivity order of the potential binding sites is d(ApG) > d(GpC/GpC) = d(GpA) > d(GpTpG). In the presence of cyanide ions, the adducts are much less stable at the d(GpA) sites than at the d(GpCpG) sites, in double-stranded DNA.


1992   Références trouvées : 1

Decoville, M ; Moreau, P ; Viegaspequignot, E ; Locker, D  (1992)

Genomic organization and nucleotide-sequence of a long mosaic repetitive DNA in the mouse genome

Mammalian Genome 2 (3) 172-185
A long mosaic repetitive sequence (LMRS) was isolated from a mouse liver genome library using a mouse repetitive DNA as a probe. LMRS exhibits the following features : (1) it is almost 15 kb in length ; (2) it is partly organized in tandem array and frequently interrupted by other repeated sequences ; and (3) it is located predominantly on the A3 band of the mouse X Chromosome (Chr). One fragment of LMRS (B6) shows restriction fragment length polymorphism (RFLP) between different mouse strains, and is thus potentially useful for mapping studies. The nucleotide sequence confirms a mosaic organization of LMRS which includes three repeats in the 5' part, showing similarity with the 5' end of L1Md-A2, and seven long A + T rich segments in the central part of the element. Our findings suggest that this sequence may have arisen from the duplication of an ancestral motif and has expanded by successive waves of amplification and invasion by foreign sequences.

A long mosaic repetitive sequence (LMRS) was isolated from a mouse liver genome library using a mouse repetitive DNA as a probe. LMRS exhibits the following features : (1) it is almost 15 kb in length ; (2) it is partly organized in tandem array and frequently interrupted by other repeated sequences ; and (3) it is located predominantly on the A3 band of the mouse X Chromosome (Chr). One fragment of LMRS (B6) shows restriction fragment length polymorphism (RFLP) between different mouse strains, and is thus potentially useful for mapping studies. The nucleotide sequence confirms a mosaic organization of LMRS which includes three repeats in the 5’ part, showing similarity with the 5’ end of L1Md-A2, and seven long A + T rich segments in the central part of the element. Our findings suggest that this sequence may have arisen from the duplication of an ancestral motif and has expanded by successive waves of amplification and invasion by foreign sequences.


1988   Références trouvées : 1

Decoville, M ; Malfoy, B ; Locker, D  (1988)

Studies of a novel repetitive sequence family in the genome of mice

European Journal of Biochemistry 174 (4) 679-684


1982   Références trouvées : 1

Decoville, M ; Motta, R  (1982)

Interacting genetic-factors controlling the antibody-response against the h-2.2 specificity

Immunogenetics 15 (3) 279-285


Mots-clés

Maître de conférences , IRM, signaux, images et expression des gènes