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Molecular Plant 2010年第4期3卷 670-677页

作者： Caroline Servet Natalia Conde e Silva Dao-Xiu Zhou Institut de biologie des Plantes Universite Paris-sud 11 91405 Orsay France

Histone acetylation/deacetylation is a dynamic process and plays an important role in gene regulation. Histone acetylation homeostasis is regulated by antagonist actions of histone acetyltransferases （HAT） and deacetylases （HDAC）. Plant genome encodes multiple HATs and HDACs. The Arabidopsis HAT gene AtGCNS/HAGlplays an essential role in many plant development processes, such as meristem function, cell differentiation, leaf and floral organogenesis, and responses to environmental conditions such as light and cold, indicating an important role of this HAT in the regulation of both long-term developmental switches and short-term inducible gene expression. AtGCN5 targets to a large number of promoters and is required for acetylation of several histone H3 lysine residues. Recruitment of AtGCN5 to target promoters is likely to be mediated by direct or indirect interaction with DNA-binding transcription factors and/or by interaction with acetylated histone lysine residues on the targets. Interplay between AtGCN5 and other HATand HDAC is demonstrated to control specific regulatory pathways. Analysis of the role of AtGCN5 in light-inducible gene expression suggests a function of AtGCN5 in preparing chromatin commitment for priming inducible gene activation in plants.

关键词： Light regulation chromatin structure and remodeling gene regulation leaf/vegetative development meristem development.

Growth Inhibition Occurs Independently of Cell Mortality in Tomato (Solanum lycopersicum) Exposed to High Cadmium Concentrations

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Journal of Integrative Plant Biology 2008年第3期50卷 300-310页

作者： Christine delpre Stanley Lutts Unitde biologie vgtale Universitcatholique de Louvain5(Bte 13) Place Croix du Sud1348 Louvain-la-NeuveBelgium Unitde biologie vgtale Universit catholique de Louvain5(Bte 13) Place Croix du Sud1348 Louvain-la-NeuveBelgium

In order to analyze the adaptation potential of tomato shoots to a sudden increase in Cd concentration, tomato plants （Solanum lycopersicum L. var. Ailsa Craig） were exposed under controlled environmental conditions to a high dose of this heavy metal （250 μm CdCl2） in nutrient solution for 7 and 14d. Both root and shoot growth was completely inhibited but all plants remained alive until the end of the treatment. Cell viability remained unaffected but the activity of the mitochondrial alternative pathway was stimulated by Cd stress at the expense of the cytochrome pathway. Cadmium concentration was higher in roots than in shoots and a decrease in the rate of net Cd translocation was noticed during the second week of stress. Cadmium decreased both leaf conductance （gl） and chlorophyll concentration. However, the effect on net CO2 assimilation remained limited and soluble sugars accumulated in leaves. Photochemical efficiency of PSII （FvlFm） was not affected despite a decrease in the number of reaction centers and an inhibition of electron transfer to acceptors of PSII. It is concluded that tomato shoot may sustain short term exposure to high doses of cadmium despite growth inhibition. This property implies several physiological strategies linked to both avoidance and tolerance mechanisms.

关键词： cadmium chlorophyll fluorescence growth heavy metal toxicity Lycopersicon esculentum tomato

Identification of Ca2+ signaling components in neural stem/progenitor cells during differentiation into neurons and glia in intact and dissociated zebrafish neurospheres

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Science China(Life Sciences) 2018年第11期61卷 1352-1368页

作者： Man Kit Tse Ting Shing Hung Ching Man Chan Tiffany Wong Mike Dorothea Catherine Leclerc Marc Moreau Andrew L.Miller Sarah E.Webb Division of Life Science & State Key Laboratory of Molecular Neuroscience HKUSTClear Water BayHongKongChina centre de biologie du developpement(CBD) Centre de Biologie Integrative(CBI)Universite de ToulouseCNRSUPSToulouse F-31062France

The development of the CNS in vertebrate embryos involves the generation of different sub-types of neurons and glia in a complex but highly-ordered spatio-temporal manner. Zebrafish are commonly used for exploring the development, plasticity and regeneration of the CNS, and the recent development of reliable protocols for isolating and culturing neural stem/progenitor cells(NSCs/NPCs) from the brain of adult fish now enables the exploration of mechanisms underlying the induction/specification/differentiation of these cells. Here, we refined a protocol to generate proliferating and differentiating neurospheres from the entire brain of adult zebrafish. We demonstrated via RT-qPCR that some isoforms of ip3 r, ryr and stim are upregulated/downregulated significantly in differentiating neurospheres, and via immunolabelling that 1,4,5-inositol trisphosphate receptor(IP3 R) type-1 and ryanodine receptor(RyR) type-2 are differentially expressed in cells with neuron-or radial glial-like properties. Furthermore, ATP but not caffeine(IP3 R and RyR agonists, respectively), induced the generation of Ca^(2+) transients in cells exhibiting neuron-or glial-like morphology. These results indicate the differential expression of components of the Ca^(2+) -signaling toolkit in proliferating and differentiating cells. Thus, given the complexity of the intact vertebrate brain, neurospheres might be a useful system for exploring neurodegenerative disease diagnosis protocols and drug development using Ca^(2+) signaling as a read-out.

关键词： Ca^2+ signaling neurospheres zebrafish neural stem/progenitor cells differentiation IP3receptors ryanodine receptors STIM and Orai

Role of the ejaculatory bulb in biosynthesis of the male pheromone cis-vaccenyl acetate in Drosophila melanogaster

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Integrative Zoology 2007年第2期2卷 89-99页

作者： Gaëlle GUIRAUDIE-CAPRAZ Dang Ba PHO Jean-Marc JALLON UnitéMixte de Recherche Universitéde Paris-sud et centre National de la Recherche Scientifique n°8620 University of Paris SudOrsayFrance

In Drosophila melanogaster,the male ejaculatory bulb is the site of synthesis of a male-specific pheromone,cis-vaccenyl acetate,which functions as both an attractant and an *** long monounsaturated acetate is structurally similar to a number of shorter gland-synthesized moth *** cell monolayer that forms the Drosophila male ejaculatory bulb wall is responsible for the production and secretion of cis-vaccenyl acetate into the seminal *** dissected bulbs were incubated with sodium[14-C]-acetate(or deuterated acetate),a labeled acetate ester was *** labeled acetate ester co-migrated with cis-vaccenyl acetate in thin layer *** of the abdomens of males from which the ejaculatory bulbs had been removed,or the abdomens of females,with radiolabeled acetate did not yield any acetate ester,but did yield other lipid products,including *** the isolated labeled acetate ester was hydrolyzed,no radioactive vaccenol was *** strongly suggests that the acetyl group is incorporated via a transacetylation reaction,but that the vaccenyl moiety is not synthetized in the *** transacetylation enzyme activity was localized in the microsomal subfraction of the bulb homogenate,and its affinity for vaccenol was not very different from that reported for monounsaturated alcohol substrates in moths.

关键词： cis-vaccenyl acetate Drosophila melanogaster ejaculatory bulb male pheromone microsomes transacetylation

The scaffold protein menin is essential for activating the MYC locus and MYC-mediated androgen receptor transcription in androgen receptor-dependent prostate cancer cells

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Cancer Communications 2021年第12期41卷 1427-1430页

作者： Yakun Luo Virginie Vlaeminck-Guillem Romain Teinturier Razan Abou Ziki Philippe Bertolino Muriel Le Romancer Chang Xian Zhang department of Tumor Escape Resistance and ImmunityUniversitéLyonUniversitéClaude Bernard Lyon 1INSERM 1052CNRS 5286Centre Léon BérardCentre de Recherche en Cancérologie de LyonLyon 69008France centre de biologie sud Hôpital Lyon SudHospices Civils de LyonPierre-Bénite 69310France

dear Editor,The proto-oncogene MYC has a well-documented role in driving androgen receptor(AR)oncogenic functions in prostate cancer(PCa cells)[1]and was recently reported as a key activator in the regulation of AR transcription[2].Dissecting the mechanisms underlying MYC-mediated AR regulation may be crucial for better understanding PCa development and improving its *** recently demonstrated that menin,encoded by the MEN1 gene,plays an oncosuppressive role in the generation of ARlow/CD44+microinvasive prostate adenocarcinoma in mice but exerts oncogenic effects specifically in ARdependent human PCa cells,both likely by modulating AR transcription and AR targets[3].We herein wondered whether this oncogenic function of menin would occur through its interaction with other factors known to play a crucial role forAR transcription in PCa,in particular,MYC.

关键词： cancer likely MYC

Influence of nitrogen sources on growth and mycotoxin production by isolates of Pyrenophora tritici-repentis from wheat

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The Crop Journal 2016年第2期4卷 119-128页

作者： Noureddine Bouras Michael D.Holtz Reem Aboukhaddour Stephen E.Strelkov department of Agricultural Food and Nutritional Science410 Agriculture/Forestry CentreUniversity of Alberta Laboratoire de biologie des Systemes Microbiens(LBSM) Ecole Normale Superieure de KoubaAlgiersAlgeria departement de biologie Faculte des Sciences de la Nature et de la Vie et Sciences de la TerreUniversite de Ghardaia Field Crop development centre Alberta Agriculture and Food

The fungus Pyrenophora tritici-repentis(Died.) Drechs. infects the leaves and kernels of wheat,causing tan spot and red smudge, respectively. Isolates of P. tritici-repentis have been reported to be both phytopathogenic and mycotoxigenic. This research investigates the influence of nitrogen sources on growth and production of mycotoxins by eight different isolates of P. tritici-repentis. A synthetic agar medium(SAM) was used with different nitrogen sources, both inorganic [(NH4Cl, NH4NO3and(NH4)2SO4)] and organic(L-alanine, L-histidine, and L-lysine), at a concentration of 37.5 mmol L-1. Individual isolates exhibited different growth rates that varied according to the nitrogen source added to the medium. The choice of nitrogen source also had a major effect on production of the mycotoxins emodin, catenarin and islandicin. The highest concentrations of emodin, 54.40 ± 4.46 μg g-1, 43.07 ± 23.39 μg g-1and28.91 ± 4.64 μg g-1of growth medium, were produced on the complex medium(V8-potato dextrose agar) by the isolates Alg-H2, 331-2 and TS93-71 B, respectively. A relatively high concentration of emodin also was produced by isolates Az35-5(28.29 ± 4.71 μg g-1of medium)and TS93-71B(27.03 ± 4.09 μg g-1of medium) on synthetic medium supplemented with L-alanine. The highest concentrations of catenarin(174.54 ± 14.46 μg g-1and 104.87 ±6.13 μg g-1of medium) were recorded for isolates TS93-71 B and Alg-H2 on synthetic medium supplemented with L-alanine and NH4 Cl, respectively. The highest concentration of islandicin(4.64 ± 0.36 μg g-1medium) was observed for isolate 331-2 in the presence of L-lysine. There was not a close relationship between mycelial growth and mycotoxin production by the fungal isolates. This is the first report on the influence of nitrogen sources on the production of mycotoxins by P. tritici-repentis.

关键词： Catenarin Emodin Islandicin Nitrogen source Tan spot Triticum aestivum

The High Light Response and Redox Control of Thylakoid FtsH Protease in Chlamydomonas reinhardtii

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Molecular Plant 2017年第1期10卷 99-114页

作者： Fei Wang Yafei Qi Alizee Malnoe Yves Choquet Francis-Andre Wollman Institut de biologie Physico-Chimique Unite Mixte de Recherche 7141 Centre National de la Recherche Scientifique/Universite Pierre et Marie Curie Paris 75005 France

In Chlamydomonas reinhardtii, the major protease involved in the maintenance of photosynthetic machinery in thylakoid membranes, the FtsH protease, mostly forms large hetero-oligomers （-1 MDa） comprising FtsH1 and FtsH2 subunits, whatever the light intensity for growth. Upon high light exposure, the FtsH subunits display a shorter half-life, which is counterbalanced by an increase in FTSH1/2 mRNA levels, resulting in the modest upregulation of FtsH1/2 proteins. Furthermore, we found that high light increases the protease activity through a hitherto unnoticed redox-controlled reduction of intermolecular disulfide bridges. We iso- lated a Chlamydomonas FTSH1 promoter-deficient mutant, ftsh1-3, resulting from the insertion of a TOC1 transposon, in which the high light-induced upregulation of FTSH1 gene expression is largely lost. In ftsh1- 3, the abundance of FtsH1 and FtsH2 proteins are loosely coupled （decreased by 70% and 30%, respectively） with no formation of large and stable homo-oligomers. Using strains exhibiting different accumulation levels of the FtsH1 subunit after complementation of ftsh1-3, we demonstrate that high light tolerance is tightly correlated with the abundance of the FtsH protease. Thus, the response of Chlamydomonas to light stress involves higher levels of FtsH 1/2 subunits associated into large complexes with increased proteolytic activity.

关键词： chloroplast protease regulation of gene expression photoinhibition Chlamydomonas reinhardtii

Efficient visual learning by bumble bees in virtual-reality conditions:Size does not matter

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Insect Science 2023年第6期30卷 1734-1748页

作者： Gregory Lafon Marco Paoli Benjamin HPaffhausen Gabriela de Brito Sanchez Mathieu Lihoreau Aurore Avarguès-Weber Martin Giurfa centre de Recherches sur la Cognition Animale Centre de Biologie Intégrative(CBI)University of ToulouseCNRSUPSToulouseFrance French Academy of Sciences for University Professors Institut Universitaire de France(IUF)ParisFrance

Recent developments allowed establishing virtual-reality (VR) setups to study multiple aspects of visual learning in honey bees under controlled experimental conditions. Here, we adopted a VR environment to investigate the visual learning in the buff-tailed bumble bee Bombus terrestris. Based on responses to appetitive and aversive reinforcements used for conditioning, we show that bumble bees had the proper appetitive motivation to engage in the VR experiments and that they learned efficiently elemental color discriminations. In doing so, they reduced the latency to make a choice, increased the proportion of direct paths toward the virtual stimuli and walked faster toward them. Performance in a short-term retention test showed that bumble bees chose and fixated longer on the correct stimulus in the absence of reinforcement. Body size and weight, although variable across individuals, did not affect cognitive performances and had a mild impact on motor performances. Overall, we show that bumble bees are suitable experimental subjects for experiments on visual learning under VR conditions, which opens important perspectives for invasive studies on the neural and molecular bases of such learning given the robustness of these insects and the accessibility of their brain.

关键词： Bombus terrestris bumble bees interindividual size/weight differences reinforcement responses visual learning virtual reality

Epigenomic Modification and Epigenetic Regulation in Rice

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Journal of Genetics and Genomics 2012年第7期39卷 307-315页

作者： Yu Zhao Dao-Xiu Zhou National Key Laboratory for Crop Genetic Improvement Huazhong Agricultural University Wuhan 430070 China Institut de biologie des Plantes Universite' Paris sud Orsay 91405 France

Epigenomes including genome-wide histone modification and DNA methylation profiles are important for genome activity and fof defining gene expression patterns of plant development and responses to various environmental conditions. Rice is the most important crop plant and serves as a model for cereal genomics. Rice epigenomic landscape is emerging and the function of chromatin modification regulators in gene expression, transposon repression and plant development is being characterized. Epigenomic variation that gives rise to stable or transgenerational heritable epialleles related to variation of important agronomical traits or stress responses is being characterized in rice. Implication of epigenomic variation in rice heterosis is being exploited.

关键词： Epigenetics Epigenomics Ot3,za sativa

Population genetic structure of the biological control agent Macrolophus pygmaeus in Mediterranean agroecosystems

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Insect Science 2017年第5期24卷 859-876页

作者： Jean-Claude Streito Cecile Clouett Faten Hamdi Nathalie Gauthier IRD UMR (INRA/IRDICiradlMontpellier SupAgro) Centre de Biologie pour la Gestion des Populations INRA UMR (INRA/IRDI CiradlMontpellier SupAgro) Centre de Biologie pour la Gestion des Populations 755 avenue du Campus Agropolis CS 30016 34988Montferrier-sur-Lez France

Biological control of agricultural pests relies on knowledge of agroecosystem functionality, particularly when affected by the use of mass-produced biological agents. Incorporating pre- and/or post-release information such as genetic diversity and struc- ture on these agents using molecular-based approaches could advance our knowledge of how they perform in agroecosystems. We evaluated the population genetics of Macrolo- phus pygmaeus, the most widely used predatory mirid against many arthropod pests of greenhouse crops in the Mediterranean region, using the mitochondrial Cytb sequence and microsatellite data, and population genetics and phylogeny approaches. We investigated commercially mass-produced insects （i.e., commercial insects either mass-reared in the laboratory for many generations, or purchased by farmers and released in the greenhouses） and ＂wild＂ insects （i.e., that occur naturally outside or are collected in nature for release in the greenhouses）. The mirids were mainly collected in agroecosystems in which solana- ceous plants are grown in northern Spain, southern France and Greece. Both molecular markers and approaches distinguished 2 genetically differentiated populations. The less genetically diverse population, hereafter named the ＂commercial＂ strain included all indi- viduals from laboratory mass-rearings and most releases of commercially bred individuals. The most genetically diverse population mainly comprised individuals originating from noncultivated environments, or from releases of＂wild＂ individuals. Rare examples of hy- bridization between M. pygmaeus from the 2 populations were observed and asymmetric gene flow was revealed. These findings provide new insights into what happens to M. pyg- maeus released in the agroecosystems we studied, and show that it is possible to monitor some commercial strains.

关键词： biological control commercial vs. wild strains Macrolophus pygmaeus microsatellites mtCytb population genetics