66 research outputs found

    Termite digestomes as a potential source of symbiotic microbiota for lignocelluloses degradation: a review

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    Termites thrive in great abundance in terrestrial ecosystems and the symbiotic gut microbiota play important roles in digestion of lignocelluloses and nitrogen metabolism. Termites are excellent models of biocatalysts as they inhabit dense microbes in their guts that produce digestive enzymes to decompose lignocelluloses and convert it to end products such as sugars, hydrogen, and acetate. Different of digestive system between lower and higher termites which lower termites dependent on their dual decomposing system, consisting of termite's own cellulases and gut's protists. Higher termites decompose cellulose using their own enzymes, because of the absence of symbiotic protists. Termite gut prokaryotes efficiently support lignocelluloses degradation. In this review, a brief overview of recent experimental works, development and commercialization is discussed. Significant progress has been made to isolate cellulolytic strains from termites and optimise the digestion efficiency of cellulose. Future perspective should emphasize the isolation of cellulolytic strains from termites, genetically modifying or immobilization of the microbes which produce the desired enzyme and thus benefits on the microbiology and biotechnology

    Proteomics of Buccal Cavity Mucus in Female Tilapia Fish (Oreochromis spp.): A Comparison between Parental and Non-Parental Fish

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    Mouthbrooding is an elaborate form of parental care displayed by many teleost species. While the direct benefits of mouthbrooding such as protection and transportation of offsprings are known, it is unclear if mouthbrooding offers additional benefits to embryos during incubation. In addition, mouthbrooding could incur negative costs on parental fish, due to limited feeding opportunities. Parental tilapia fish (Oreochromis spp.) display an elaborated form of parental care by incubating newly hatched embryos in oral buccal cavity until the complete adsorption of yolk sac. In order to understand the functional aspects of mouthbrooding, we undertake a proteomics approach to compare oral mucus sampled from mouthbrooders and non-mouthbrooders, respectively. Majority of the identified proteins have also been previously identified in other biological fluids or mucus-rich organs in different organisms. We also showed the upregulation of 22 proteins and down regulation of 3 proteins in mucus collected from mouthbrooders. Anterior gradient protein, hemoglobin beta-A chain and alpha-2 globin levels were lower in mouthbrooder samples. Mouthbrooder oral mucus collectively showed increase levels of proteins related to cytoskeletal properties, glycolytic pathway and mediation of oxidative stress. Overall the findings suggest cellular stress response, probably to support production of mucus during mouthbrooding phase

    CD8+ T Cells and IFN-γ Mediate the Time-Dependent Accumulation of Infected Red Blood Cells in Deep Organs during Experimental Cerebral Malaria

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    Background: Infection with Plasmodium berghei ANKA (PbA) in susceptible mice induces a syndrome called experimental cerebral malaria (ECM) with severe pathologies occurring in various mouse organs. Immune mediators such as T cells or cytokines have been implicated in the pathogenesis of ECM. Red blood cells infected with PbA parasites have been shown to accumulate in the brain and other tissues during infection. This accumulation is thought to be involved in PbA–induced pathologies, which mechanisms are poorly understood. Methods and Findings: Using transgenic PbA parasites expressing the luciferase protein, we have assessed by real-time in vivo imaging the dynamic and temporal contribution of different immune factors in infected red blood cell (IRBC) accumulation and distribution in different organs during PbA infection. Using deficient mice or depleting antibodies, we observed that CD8 + T cells and IFN-c drive the rapid increase in total parasite biomass and accumulation of IRBC in the brain and in different organs 6–12 days post-infection, at a time when mice develop ECM. Other cells types like CD4 + T cells, monocytes or neutrophils or cytokines such as IL-12 and TNF-a did not influence the early increase of total parasite biomass and IRBC accumulation in different organs. Conclusions: CD8 + T cells and IFN-c are the major immune mediators controlling the time-dependent accumulation of P. berghei-infected red blood cells in tissues

    Ribonuclease Activity of Dis3 Is Required for Mitotic Progression and Provides a Possible Link between Heterochromatin and Kinetochore Function

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    BACKGROUND: Cellular RNA metabolism has a broad range of functional aspects in cell growth and division, but its role in chromosome segregation during mitosis is only poorly understood. The Dis3 ribonuclease is a key component of the RNA-processing exosome complex. Previous isolation of the dis3-54 cold-sensitive mutant of fission yeast Schizosaccharomyces pombe suggested that Dis3 is also required for correct chromosome segregation. METHODOLOGY/PRINCIPAL FINDINGS: We show here that the progression of mitosis is arrested in dis3-54, and that segregation of the chromosomes is blocked by activation of the mitotic checkpoint control. This block is dependent on the Mad2 checkpoint protein. Double mutant and inhibitor analyses revealed that Dis3 is required for correct kinetochore formation and function, and that this activity is monitored by the Mad2 checkpoint. Dis3 is a member of the highly conserved RNase II family and is known to be an essential subunit of the exosome complex. The dis3-54 mutation was found to alter the RNaseII domain of Dis3, which caused a reduction in ribonuclease activity in vitro. This was associated with loss of silencing of an ura4(+) reporter gene inserted into the outer repeats (otr) and central core (cnt and imr) regions of the centromere. On the other hand, centromeric siRNA maturation and formation of the RITS RNAi effector complex was normal in the dis3-54 mutant. Micrococcal nuclease assay also suggested the overall chromatin structure of the centromere was not affected in dis3-54 mutant. CONCLUSIONS/SIGNIFICANCE: RNase activity of Dis3, a core subunit of exosome, was found to be required for proper kinetochore formation and establishment of kinetochore-microtubule interactions. Moreover, Dis3 was suggested to contribute to kinetochore formation through an involvement in heterochromatic silencing at both outer centromeric repeats and within the central core region. This activity is likely monitored by the mitotic checkpoint, and distinct from that of RNAi-mediated heterochromatin formation directly targeting outer centromeric repeats

    Early phase of plasticity-related gene regulation and SRF dependent transcription in the hippocampus

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    Hippocampal organotypic cultures are a highly reliable in vitro model for studying neuroplasticity: in this paper, we analyze the early phase of the transcriptional response induced by a 20 \ub5M gabazine treatment (GabT), a GABA-Ar antagonist, by using Affymetrix oligonucleotide microarray, RT-PCR based time-course and chromatin-immuno-precipitation. The transcriptome profiling revealed that the pool of genes up-regulated by GabT, besides being strongly related to the regulation of growth and synaptic transmission, is also endowed with neuro-protective and pro-survival properties. By using RT-PCR, we quantified a time-course of the transient expression for 33 of the highest up-regulated genes, with an average sampling rate of 10 minutes and covering the time interval [10 3690] minutes. The cluster analysis of the time-course disclosed the existence of three different dynamical patterns, one of which proved, in a statistical analysis based on results from previous works, to be significantly related with SRF-dependent regulation (p-value<0.05). The chromatin immunoprecipitation (chip) assay confirmed the rich presence of working CArG boxes in the genes belonging to the latter dynamical pattern and therefore validated the statistical analysis. Furthermore, an in silico analysis of the promoters revealed the presence of additional conserved CArG boxes upstream of the genes Nr4a1 and Rgs2. The chip assay confirmed a significant SRF signal in the Nr4a1 CArG box but not in the Rgs2 CArG box

    Application of the fission yeast Schizosaccharomyces pombe in human nutrition

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    10.1093/femsyr/foac064FEMS YEAST RESEARCH2

    セントロメア ヒストン H3 バリアント CENP-A ノ キョクザイ ニ エイキョウ オ アタエル GATA インシ Ams2 ノ キノウ タンキュウ

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    京都大学0048新制・課程博士博士(理学)甲第10024号理博第2685号新制||理||1364(附属図書館)UT51-2003-H445京都大学大学院理学研究科生物科学専攻(主査)教授 柳田 充弘, 教授 西田 栄介, 教授 宮田 隆学位規則第4条第1項該当Doctor of ScienceKyoto UniversityDA
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