87 research outputs found

    TALE-mediated plant genome visualization

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    Live imaging of the dynamics of nuclear organization provides the opportunity to uncover the mechanisms responsible for four-dimensional genome architecture. Here, we describe the use of fluorescent protein (FP) fusions of transcription activator-like effectors (TALEs) to visualize endogenous genomic sequences in Arabidopsis thaliana. The ability to engineer sequence-specific TALEs permits the investigation of precise genomic sequences. We could detect TALE-FP signals associated with centromeric, telomeric, and rDNA repeats and the signal distribution was consistent with that observed by fluorescent in situ hybridization. TALE-FPs are advantageous because they permit the observation of intact tissues. We used our TALE-FP method to investigate the nuclei of several multicellular plant tissues including roots, hypocotyls, leaves, and flowers. Because TALE-FPs permit live-cell imaging, we successfully observed the temporal dynamics of centromeres and telomeres in plant organs. Fusing TALEs to multimeric FPs enhanced the signal intensity when observing telomeres. We found that the mobility of telomeres was different in subnuclear regions. Transgenic plants stably expressing TALE-FPs will provide new insights into chromatin organization and dynamics in multicellular organisms

    The Phosphate Fast-Responsive Genes <i>PECP1</i> and <i>PPsPase1</i> Affect Phosphocholine and Phosphoethanolamine Content

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    International audiencePhosphate starvation-mediated induction of the HAD-type phosphatases PPsPase1 (AT1G73010) and PECP1 (AT1G17710) has been reported in Arabidopsis (Arabidopsis thaliana). However, little is known about their in vivo function or impact on plant responses to nutrient deficiency. The preferences of PPsPase1 and PECP1 for different substrates have been studied in vitro but require confirmation in planta. Here, we examined the in vivo function of both enzymes using a reverse genetics approach. We demonstrated that PPsPase1 and PECP1 affect plant phosphocholine and phosphoethanolamine content, but not the pyrophosphate-related phenotypes. These observations suggest that the enzymes play a similar role in planta related to the recycling of polar heads from membrane lipids that is triggered during phosphate starvation. Altering the expression of the genes encoding these enzymes had no effect on lipid composition, possibly due to compensation by other lipid recycling pathways triggered during phosphate starvation. Furthermore, our results indicated that PPsPase1 and PECP1 do not influence phosphate homeostasis, since the inactivation of these genes had no effect on phosphate content or on the induction of molecular markers related to phosphate starvation. A combination of transcriptomics and imaging analyses revealed that PPsPase1 and PECP1 display a highly dynamic expression pattern that closely mirrors the phosphate status. This temporal dynamism, combined with the wide range of induction levels, broad expression, and lack of a direct effect on Pi content and regulation, makes PPsPase1 and PECP1 useful molecular markers of the phosphate starvation response

    Development of unit for elective subject from fifth to ninth grade to improve cooperative creation (3)

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    本研究は, 「21世紀型の教科学力」の新たな観点としての「協同的創造力」の育成をめざして, 自分たちで新たな文化を創造する子どもを育てる協同的創造学習のあり方について実証的に研究を進め, 単元モデルと評価方法を開発することを目的としている。そこで, 教科学習を「協同的創造学習」としてとらえ直すとともに, 中学校での従来の選択教科の時間に加えて, 小学校第5・6学年合同の選択教科の時間を新設して「協同的創造力」を特化して育むことにし, 本年度は, 選択教科の単元モデルの充実・改善と評価方法の確立に取り組んだ。その結果, 選択教科において, これまで開発した単元モデルをより充実させたり, 新たな単元モデルを開発したりすることができた。また, 評価の観点を整理し, 子どもの意識調査やカリキュラム評価に継続して取り組むことによって, 子どもの思いを汲み取り単元を見直していくことができた。今後も必修教科と選択教科のつながりや関連性, 各学年の系統性を整理するとともに, 協同的創造力育成の手だてを整理し, 来年度に向けて, これまで培ったものを生かす新たな学習開発を模索していきたいと考えている
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