{"_buckets": {"deposit": "955d5132-95ff-4ed3-8542-c5bfce50188e"}, "_deposit": {"created_by": 21, "id": "1693", "owners": [21], "pid": {"revision_id": 0, "type": "depid", "value": "1693"}, "status": "published"}, "_oai": {"id": "oai:ir.soken.ac.jp:00001693", "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": "2010-03-24", "bibliographicIssueDateType": "Issued"}, "bibliographic_titles": [{}]}]}, "item_1_creator_2": {"attribute_name": "著者名", "attribute_type": "creator", "attribute_value_mlt": [{"creatorNames": [{"creatorName": "大久保, 佑亮"}], "nameIdentifiers": [{"nameIdentifier": "0", "nameIdentifierScheme": "WEKO"}]}]}, "item_1_creator_3": {"attribute_name": "フリガナ", "attribute_type": "creator", "attribute_value_mlt": [{"creatorNames": [{"creatorName": "オオクボ, ユウスケ"}], "nameIdentifiers": [{"nameIdentifier": "0", "nameIdentifierScheme": "WEKO"}]}]}, "item_1_date_granted_11": {"attribute_name": "学位授与年月日", "attribute_value_mlt": [{"subitem_dategranted": "2010-03-24"}]}, "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": "2010043", "subitem_description_type": "Other"}]}, "item_1_description_12": {"attribute_name": "要旨", "attribute_value_mlt": [{"subitem_description": "　The body of vertebrates is composed of many repeated structures such as vertebrae,\u003cbr /\u003eribs, skeletal muscles and subcutaneous tissues. These are based on transient\u003cbr /\u003emetameric structures, called somites, which are produced sequentially at certain\u003cbr /\u003espatiotemporal intervals in an anterior to posterior sequence concomitant with the\u003cbr /\u003eposterior elongation of presomitic mesoderm (PSM). The periodicity is regulated by the\u003cbr /\u003esegmentation CLOCK which undergoes the oscillation of \u003ci\u003eHes\u003c/i\u003e gene expression under\u003cbr /\u003ethe control of Notch signaling within a cell. The traveling wave of the CLOCK is\u003cbr /\u003eobserved from the tail bud region and stops in the anterior PSM where a new somite is\u003cbr /\u003egenerated. This waved pattern is generated by the change of gene expression in each\u003cbr /\u003ecell and not by cell movement. If the CLOCK oscillates among individual cells without\u003cbr /\u003esynchrony, the waved pattern will not be generated. Thus, it is required for the additional\u003cbr /\u003emechanism which works in a non-cell-autonomous manner to synchronize the CLOCK\u003cbr /\u003ephase among neighboring cells.\u003cbr /\u003e\u003cbr /\u003e　In zebrafish, the CLOCK and its synchronization mechanism has been well\u003cbr /\u003eunderstood. A coupled oscillator model was proposed to link these two phenomena; it\u003cbr /\u003ehas been explained that 1) INPUT receives OUTPUT from neighboring cells, 2)\u003cbr /\u003eEffectors of the CLOCK are activated by the INPUT and operate as CLOCK\u003cbr /\u003ecomponents, 3) OUTPUT transmits information reflecting its own CLOCK phase to\u003cbr /\u003eneighboring cells. Therefore, they correct their CLOCKs each other by coupling their\u003cbr /\u003eCLOCKs. In the zebrafish somitogenesis, it was demonstrated that INPUT is Notch\u003cbr /\u003esignaling from Notch1a, the CLOCK is Her1/7 that shows oscillation via the\u003cbr /\u003enegative-feedback mechanism and OUTPUT is DeltaC oscillation controlled by Her1/7.\u003cbr /\u003e\u003cbr /\u003e　However, it has been difficult to reveal the synchronization mechanism in mouse\u003cbr /\u003esomitogenesis because the CLOCK itself disappears in a simple gene knockout mouse\u003cbr /\u003ethat lacks function of Notch signaling, since Notch signal is a core component of the\u003cbr /\u003eCLOCK. Furthermore, the segmentation CLOCK components involved in the regulation\u003cbr /\u003eare more complicated in mice as compared with zebrafish. In the mouse PSM, Lfng, a\u003cbr /\u003eglycosyltransferase that is not implicated in zebrafish, oscillates upon activation by\u003cbr /\u003eNotch activity and repression by Hes7, and acts as a negative regulator for Notch\u003cbr /\u003esignaling via modifying Notch1 receptor. Hence, the cyclic expression of Lfng makes a\u003cbr /\u003eNotch signal oscillation as a segmentation CLOCK.\u003cbr /\u003e\u003cbr /\u003e　To reveal the mechanism to generate synchronized CLOCK oscillation in mice, I first\u003cbr /\u003eexamined Dll1 expression pattern that works as an OUTPUT in zebrafish. The results\u003cbr /\u003ethat Dll1 transcripts slightly oscillated in the PSM but its protein did not show clear\u003cbr /\u003eoscillation indicate that the OUTPUT mechanism of the coupling in mice is different from\u003cbr /\u003ethat of zebrafish. Next, I performed mosaic embryo analyses to clarify the\u003cbr /\u003esynchronization mechanism. The mosaic analysis using wild-type and gene-knockout\u003cbr /\u003e(KO) cell is a powerful method to ask the mechanism involved in the cell-cell\u003cbr /\u003ecommunication. I conducted two types of mosaic embryo analyses using Dll1-null and\u003cbr /\u003eLfng-null cells. If the coupled oscillator model via Notch signaling is utilized to generate\u003cbr /\u003ethe synchronized CLOCK oscillation in mouse somitogenesis, it is thought that INPUT is\u003cbr /\u003eNotch signaling through Notch1 receptor, the CLOCK is the oscillation of Hes7 and\u003cbr /\u003eOUTPUT is an unknown factor through a transmitter Dll1. In Dll1-null mosaic embryos,\u003cbr /\u003eDll1-KO cells do not have Dll1 which acts as a transmitter of the CLOCK to transmit its\u003cbr /\u003eown CLOCK state to neighboring cells but they have Notch1 (receiver). Therefore, I\u003cbr /\u003eexpected that Dll1-KO cells must show incomplete coupling with neighboring wild-type\u003cbr /\u003ecell, but should not interfere synchronized oscillation of the CLOCK among wild-type\u003cbr /\u003ecells because Dll1-KO cells cannot transmit signals. I found that the CLOCK showed\u003cbr /\u003eabnormal pattern in Dll1-null mosaic embryos, however, it exhibited synchronized\u003cbr /\u003eoscillation to some degree. Therefore, the reduction of coupling cells may have caused\u003cbr /\u003eabnormal CLOCK pattern. On the other hand, CLOCK synchronization will be disrupted\u003cbr /\u003ein the Lfng-null mosaic embryo if Notch signal regulates synchronized CLOCK\u003cbr /\u003eoscillation through a coupling mechanism as zebrafish and if Lfng is involved in the\u003cbr /\u003ecoupling mechanism. Lfng-null mosaic embryos showed severer defect in the\u003cbr /\u003esynchronized CLOCK oscillation compared with the Dll1-null mosaic embryos. These\u003cbr /\u003eresults suggest that Notch signal also exhibits dual roles in the CLOCK and its\u003cbr /\u003esynchronization through the coupling mechanism as in the case of zebrafish.\u003cbr /\u003eSurprisingly, Lfng KO cells in Lfng-null mosaic embryos showed either positive or\u003cbr /\u003enegative Notch activity. This result was unexpected since Notch activity should be\u003cbr /\u003eup-regulated in the absence of Lfng as expected from the analysis of Lfng KO embryo.\u003cbr /\u003eTherefore, the oscillation of Notch activity in Lfng KO cells in Lfng-null mosaic embryos\u003cbr /\u003emust be caused by the presence of wild-type cells that have functional Lfng. These\u003cbr /\u003eresults suggest that Lfng works on Notch signaling via not only \u003ci\u003ecis-\u003c/i\u003e but also \u003ci\u003etrans-\u003c/i\u003e\u003cbr /\u003eregulation mechanisms and Dll1 activity might be regulated by Lfng. Accordingly, I\u003cbr /\u003eexplored in detail the role of Lfng in the Notch signaling by co-culture experiments using\u003cbr /\u003eNotch signal reporter luciferase assay. The results indicate that Lfng alter the Notch\u003cbr /\u003esignaling activity by modifying Dll1 and Notch1.\u003cbr /\u003e\u003cbr /\u003e　In this study, I propose a new coupling mechanism to generate synchronized\u003cbr /\u003eoscillation of segmentation CLOCK in the mouse. It is possible to consider that Lfng can\u003cbr /\u003ework as the OUTPUT which retains/reflects CLOCK phase information and alters Notch\u003cbr /\u003esignaling to synchronize CLOCK phase among neighboring cells through the coupling\u003cbr /\u003emechanism. Therefore, in mouse somitogenesis, the following five elements are\u003cbr /\u003erequired for the coupling mechanism, 1) INPUT; Notch signaling, 2) CLOCK; the\u003cbr /\u003eoscillation of Hes7 expression, 3) OUTPUT; Lfng expression reflecting CLOCK phase\u003cbr /\u003einformation, 4) transmitter; Dll1 and 5) receiver; Notchl. In mice, expressions of both\u003cbr /\u003eDll1 and Notch1 are not regulated by the CLOCK.", "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1347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": "印刷物から複写可"}]}, "item_1_select_17": {"attribute_name": "公開状況", "attribute_value_mlt": [{"subitem_select_item": "要旨のみ公開"}]}, "item_1_select_8": {"attribute_name": "研究科", "attribute_value_mlt": [{"subitem_select_item": "複合科学研究科"}]}, "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": "2009"}]}, "item_creator": {"attribute_name": "著者", "attribute_type": "creator", "attribute_value_mlt": [{"creatorNames": [{"creatorName": "OKUBO, Yusuke", "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1347_要旨.pdf", "filesize": [{"value": "337.3 kB"}], "format": "application/pdf", "future_date_message": "", "is_thumbnail": false, "licensetype": "license_11", "mimetype": "application/pdf", "size": 337300.0, "url": {"label": "要旨・審査要旨", "url": "https://ir.soken.ac.jp/record/1693/files/甲1347_要旨.pdf"}, "version_id": "22870eaa-f99b-498a-8581-acbe93f501d3"}]}, "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": "The coupling mechanism to generate synchronized oscillation of segmentation clock in mouse", "item_titles": {"attribute_name": "タイトル", "attribute_value_mlt": [{"subitem_title": "The coupling mechanism to generate synchronized oscillation of segmentation clock in mouse"}, {"subitem_title": "The coupling mechanism to generate synchronized oscillation of segmentation clock in mouse", "subitem_title_language": "en"}]}, "item_type_id": "1", "owner": "21", "path": ["20"], "permalink_uri": "https://ir.soken.ac.jp/records/1693", "pubdate": {"attribute_name": "公開日", "attribute_value": "2011-01-19"}, "publish_date": "2011-01-19", "publish_status": "0", "recid": "1693", "relation": {}, "relation_version_is_last": true, "title": ["The coupling mechanism to generate synchronized oscillation of segmentation clock in mouse"], "weko_shared_id": -1}