{"_buckets": {"deposit": "473aa852-3d2a-4785-bfdd-b33598c3666a"}, "_deposit": {"created_by": 21, "id": "1442", "owners": [21], "pid": {"revision_id": 0, "type": "depid", "value": "1442"}, "status": "published"}, "_oai": {"id": "oai:ir.soken.ac.jp:00001442", "sets": ["20"]}, "author_link": ["0", "0", "0"], "item_1_biblio_info_21": {"attribute_name": "書誌情報（ソート用）", "attribute_value_mlt": [{"bibliographicIssueDates": {"bibliographicIssueDate": "2009-03-24", "bibliographicIssueDateType": "Issued"}, "bibliographic_titles": [{}]}]}, "item_1_creator_2": {"attribute_name": "著者名", "attribute_type": "creator", "attribute_value_mlt": [{"creatorNames": [{"creatorName": "上田, 弥生"}], "nameIdentifiers": [{"nameIdentifier": "0", "nameIdentifierScheme": "WEKO"}]}]}, "item_1_creator_3": {"attribute_name": "フリガナ", "attribute_type": "creator", "attribute_value_mlt": [{"creatorNames": [{"creatorName": "ウエダ, ヤヨイ"}], "nameIdentifiers": [{"nameIdentifier": "0", "nameIdentifierScheme": "WEKO"}]}]}, "item_1_date_granted_11": {"attribute_name": "学位授与年月日", "attribute_value_mlt": [{"subitem_dategranted": "2009-03-24"}]}, "item_1_degree_grantor_5": {"attribute_name": "学位授与機関", "attribute_value_mlt": [{"subitem_degreegrantor": [{"subitem_degreegrantor_name": "総合研究大学院大学"}]}]}, "item_1_degree_name_6": {"attribute_name": "学位名", "attribute_value_mlt": [{"subitem_degreename": "博士（理学）"}]}, "item_1_description_1": {"attribute_name": "ID", "attribute_value_mlt": [{"subitem_description": "2009041", "subitem_description_type": "Other"}]}, "item_1_description_12": {"attribute_name": "要旨", "attribute_value_mlt": [{"subitem_description": "　In flowering plants, after the transition from vegetative growth to reproductive development, primordial germ cell initials differentiate from somatic cells in flowers. Several genes that control the early stages of germ-cell development have been identified, however, little is known about the molecular mechanism determining the germ cell fate during sexual reproduction in plants. The \u003ci\u003eMEL1  (MEIOSIS ARRESIED ATLEPTOTENE1)\u003c/i\u003e is the only plant ARGONAUTE (AGO) gene specifically expressing at the primordial germ cells. AGO proteins are known to be a key player in gene-silencing pathways guided by small RNAs. PlWl-domain containing subfamily has important roles in maintaining germ stem cells in animal. In plant, however, there is no \u003ci\u003eAGO\u003c/i\u003e gene which belonging to PIWI subfamily. Therefore, a specific AGO gene system in plant germ cell development would be suggested.\u003cbr /\u003e　In this study, I focused on the characterization gene expressed at early stages of germ cells development specifically in relation to the MEL1 function. MEL1 is well-characterized ARGONAUTE family that has essential functions in germ cell development. To date the rice \u003ci\u003eMEL1\u003c/i\u003e is the only gene available for investigating a genetic system conducting plant germ cell initiation and maintenance. A large portion of the genes identified specific in very early stages in germ cell development had unknown function However, comparison of gene expression profiles between wild-type and \u003ci\u003emell-1\u003c/i\u003e mutant down- or  up-regulated in\u003ci\u003emell-1\u003c/i\u003e mutant revealed many possible causal genes for \u003ci\u003emell-1\u003c/i\u003e dysfunction, i.e. most of which are not characterized previously. Of these genes, the \u003ci\u003eOsSPLl4\u003c/i\u003e, one of\u003ci\u003e SQUAMOSA(SQUA)\u003c/i\u003e promoter-binding-like(\u003ci\u003eSPL\u003c/i\u003e) family genes, encoding a putative transcription factor, revealed to up-regulated in the \u003ci\u003emell-l\u003c/i\u003e mutant in both Affymetrix (Fold change=4.37) and Agilent (=3.01) microarray. Sequence and experimental analyses indicated that eleven \u003ci\u003eOsSPL\u003c/i\u003e genes including \u003ci\u003eOsSPL14\u003c/i\u003e were putative targets of \u003ci\u003eOsmiR156\u003c/i\u003e, suggesting a possibility that the \u003ci\u003eOsSPL14\u003c/i\u003e should be directly targeted by the rice MEL1 AGO with \u003ci\u003emiR156\u003c/i\u003e microRNA as a guide molecule. Moreover, the volume of \u003ci\u003emiR156\u003c/i\u003e RNA detected in the co-IP fraction with the anti-MEL1antibody 3.2-fold more than in that with the pre-immune serum. The detection level of \u003ci\u003emiRl56\u003c/i\u003e depended on that of the MEL1 protein, as the \u003ci\u003emiR156\u003c/i\u003e co-IP with the MEL1 immune complex protein, but few or not with precipitates recovered using \u003ci\u003emell-1\u003c/i\u003e mutant or preimmune serum. These data strongly suggest that the MEL1forms a complex with the \u003ci\u003emiR156\u003c/i\u003e microRNA \u003ci\u003ein vivo\u003c/i\u003e. These results strongly suggested that the \u003ci\u003emiR156\u003c/i\u003emicroRNA was one of good candidates of guide RNA molecules of the MEL1 AGO.\u003cbr /\u003e　Analysis performed in each section and results obtained from the  analysis are summarized as follows.\u003cbr /\u003e　In the Section 1, the whole transcriptome profiles of plant reproductive process, including early stages that are difficult to be dissected in \u003ci\u003eArabidopsis\u003c/i\u003e, was obtained by using the Affymetrix rice genome array analysis and provided as a dataset of rice reproductive expression atlas. In addition, using the atlas data, the gene expression patterns of several genes that the are highly expressed in early development stage were investigated. A large part of genes that are expressed in early reproductive development remains uncharacterized because most of pre-meiotic stage specific genes were not categorized to any functions by GO analysis. However, the expression patterns of other meiosis-related genes were well corresponded previous reports. The specific genes that were found in this study may have the crucial function at early germ cells development stages.\u003cbr /\u003e　In the section 2, to confirm the spatial and temporal expression of the \u003ci\u003eMEL1\u003c/i\u003e gene, mRNA \u003ci\u003ein situ\u003c/i\u003e hybridization was performed on the anther sections with the \u003ci\u003eMSP1\u003c/i\u003e gene as cellular marker of young anther tissues. Expression of the \u003ci\u003eMEL1\u003c/i\u003e was earlier than that of the \u003ci\u003eMSP1\u003c/i\u003e, which clearly indicates that the \u003ci\u003eMEL1\u003c/i\u003emRNA expression start at the archesporial initials. The \u003ci\u003eMEL1\u003c/i\u003e expression is not required for the germ-cell initiation, but for the maintenance of germ cells. In the Section 2, \u003ci\u003ein situ\u003c/i\u003e hybridization of the \u003ci\u003eOsNOZZLE(OsNZZ)\u003c/i\u003e, a putative rice ortholog of \u003ci\u003eArabidopsis\u003c/i\u003e \u003ci\u003eSPOLOCYTELESS|NOZZLE\u003c/i\u003e was also performed.  Different from the \u003ci\u003eMEL1\u003c/i\u003e and the, \u003ci\u003eMSP1\u003c/i\u003e,the \u003ci\u003eOsNZZ\u003c/i\u003e mRNA was expressed both in developing anther wall layers and sporogenous cells similar that of \u003ci\u003eArabidopsis\u003c/i\u003e \u003ci\u003eSPL/NZZ\u003c/i\u003e, but it was not detected in archesporial cells. Although their function is not the same as \u003ci\u003eArabidopsis\u003c/i\u003e SPL/NZZ, OsNZZ\u003c/i\u003e may have function in early germ cell development.\u003cbr /\u003e　In the Section 3, the microarray at 1-cm young panicle, several genes responsive for environmental stresses and/or hormone-responsive genes up-regulated. It suggests that absence of the MEL1 may cause stressful condition, thus many stress-response genes and ethylene signaling-related gene are induced. TheMEL1 may inhibits stress responses in germ cells to accomplish precise germ cell division and meiosis. In addition, some transposable element-like transcripts were also up-regulated in \u003ci\u003emel-1\u003c/i\u003e mutant. It was demonstrated that \u003ci\u003eDrosophila piwi \u003c/i\u003e mutations impact retrotransposon mobility. MEL1 may also suppress the activity of transposable elements during rice germ-cell development. On the other hand, many genes related to cell structure and cycle were down-regulated in the \u003ci\u003emell-1\u003c/i\u003e mutant. These results may indicated that in\u003ci\u003emell-1\u003c/i\u003e mutant, the failure of pre-meiotic mitosis of sporogenous cells in the \u003ci\u003emell-1\u003c/i\u003e mutant anther (Nonomura et al. 2007) was caused by down-regulation of these genes. At pre-meiotic S/G2 stage of young anthers, few genes were affected by the \u003ci\u003emell-1\u003c/i\u003e mutation. Most of up- and down-regulation of genes in the later stages of pre-meiotic germ-cell development might be secondary effects of \u003ci\u003emell-1\u003c/i\u003e mutation.\u003cbr /\u003e　Finally, the Section 4 suggested a possibility that the rice MEL1 AGO directly regulated the \u003ci\u003eOsSPL14\u003c/i\u003egene with the plant specific microRNA, \u003ci\u003emiR156\u003c/i\u003e as described above.\u003cbr /\u003e\u003cbr /\u003e　Results obtained in this thesis will provide new and useful information to understand the gene functions in initiation of germ cells development and maintenance of germ cell identity in rice.", "subitem_description_type": "Other"}]}, "item_1_description_18": {"attribute_name": "フォーマット", "attribute_value_mlt": [{"subitem_description": "application/pdf", "subitem_description_type": "Other"}]}, "item_1_description_7": {"attribute_name": "学位記番号", "attribute_value_mlt": [{"subitem_description": "総研大甲第1249号", "subitem_description_type": "Other"}]}, "item_1_select_14": {"attribute_name": "所蔵", "attribute_value_mlt": [{"subitem_select_item": "有"}]}, "item_1_select_16": {"attribute_name": "複写", "attribute_value_mlt": [{"subitem_select_item": "複写不可"}]}, "item_1_select_17": {"attribute_name": "公開状況", "attribute_value_mlt": [{"subitem_select_item": "全文公開可"}]}, "item_1_select_8": {"attribute_name": "研究科", "attribute_value_mlt": [{"subitem_select_item": "生命科学研究科"}]}, "item_1_select_9": {"attribute_name": "専攻", "attribute_value_mlt": [{"subitem_select_item": "18 遺伝学専攻"}]}, "item_1_text_10": {"attribute_name": "学位授与年度", "attribute_value_mlt": [{"subitem_text_value": "2008"}]}, "item_creator": {"attribute_name": "著者", "attribute_type": "creator", "attribute_value_mlt": [{"creatorNames": [{"creatorName": "UEDA, Yayoi", "creatorNameLang": "en"}], "nameIdentifiers": [{"nameIdentifier": "0", "nameIdentifierScheme": "WEKO"}]}]}, "item_files": {"attribute_name": "ファイル情報", "attribute_type": "file", "attribute_value_mlt": [{"accessrole": "open_date", "date": [{"dateType": "Available", "dateValue": "2016-02-17"}], "displaytype": "simple", "download_preview_message": "", "file_order": 0, "filename": "甲1249_要旨.pdf", "filesize": [{"value": "305.9 kB"}], "format": "application/pdf", "future_date_message": "", "is_thumbnail": false, "licensetype": "license_11", "mimetype": "application/pdf", "size": 305900.0, "url": {"label": "要旨・審査要旨", "url": "https://ir.soken.ac.jp/record/1442/files/甲1249_要旨.pdf"}, "version_id": "c646c88b-853e-41c7-903b-e204830f0f74"}, {"accessrole": "open_date", "date": [{"dateType": "Available", "dateValue": "2016-02-17"}], "displaytype": "simple", "download_preview_message": "", "file_order": 1, "filename": "甲1249_本文.pdf", "filesize": [{"value": "13.9 MB"}], "format": "application/pdf", "future_date_message": "", "is_thumbnail": false, "licensetype": "license_11", "mimetype": "application/pdf", "size": 13900000.0, "url": {"label": "本文", "url": "https://ir.soken.ac.jp/record/1442/files/甲1249_本文.pdf"}, "version_id": "e5e9abac-941c-4842-9390-3b7a7cbc607a"}]}, "item_language": {"attribute_name": "言語", "attribute_value_mlt": [{"subitem_language": "eng"}]}, "item_resource_type": {"attribute_name": "資源タイプ", "attribute_value_mlt": [{"resourcetype": "thesis", "resourceuri": "http://purl.org/coar/resource_type/c_46ec"}]}, "item_title": "Molecular characterization of genes essential for early development of germ cells in rice", "item_titles": {"attribute_name": "タイトル", "attribute_value_mlt": [{"subitem_title": "Molecular characterization of genes essential for early development of germ cells in rice"}, {"subitem_title": "Molecular characterization of genes essential for early development of germ cells in rice", "subitem_title_language": "en"}]}, "item_type_id": "1", "owner": "21", "path": ["20"], "permalink_uri": "https://ir.soken.ac.jp/records/1442", "pubdate": {"attribute_name": "公開日", "attribute_value": "2010-03-24"}, "publish_date": "2010-03-24", "publish_status": "0", "recid": "1442", "relation": {}, "relation_version_is_last": true, "title": ["Molecular characterization of genes essential for early development of germ cells in rice"], "weko_shared_id": -1}