{"created":"2023-06-20T13:20:58.287670+00:00","id":1043,"links":{},"metadata":{"_buckets":{"deposit":"404b6f98-6aa4-4232-b8bc-d637f9129342"},"_deposit":{"created_by":1,"id":"1043","owners":[1],"pid":{"revision_id":0,"type":"depid","value":"1043"},"status":"published"},"_oai":{"id":"oai:ir.soken.ac.jp:00001043","sets":["2:430:20"]},"author_link":["0","0","0"],"item_1_creator_2":{"attribute_name":"著者名","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"齋藤, 憲二"}],"nameIdentifiers":[{"nameIdentifier":"0","nameIdentifierScheme":"WEKO"}]}]},"item_1_creator_3":{"attribute_name":"フリガナ","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"サイトウ, ケンジ"}],"nameIdentifiers":[{"nameIdentifier":"0","nameIdentifierScheme":"WEKO"}]}]},"item_1_date_granted_11":{"attribute_name":"学位授与年月日","attribute_value_mlt":[{"subitem_dategranted":"2008-03-19"}]},"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_12":{"attribute_name":"要旨","attribute_value_mlt":[{"subitem_description":"　　Continuation of spermatogenic process throughout life relies on a proper<br />regulation of self-renewal and differentiation of spermatogonial stem cells which is<br />present in a special cellular organization called a niche. In spite of biological<br />significance of the spermatogonial stem cells, little is known about their behavior and<br />properties because of a lack of model system to approach the stem cell maintenance<br /> and differentiation in several organisms. <br />　　In this study, I show the presence of subpopulations in zebrafish type A<br />spermatogonia which is classically considered homogeneous pepulation varying in<br />size, location pattern and cell cycle phase. Morphological analysis showed two types<br />of type A sperrnatogonia that are focalized distant from basement membranes (termed<br />type A<small>dt</small>) and close to basement membranes (A<small>cl</small>). The thymidine analogue <br />5-bromo-2'-deoxyuridine (BrdU) incorporation experiments showed that duration of <br />cell cycle of the type A<small>cl</small> spermatogonia was longer than that of the.type A<small>dt</small> <br />spermatogonia. Tracing label-retaining cells (LRCs), after 4 weeks of chase, I <br />observed occasionally BrdU-positive type A<small>cl</small> spermatogonia. Immunohistochemical<br /> analysis using antibody against zebrafish homologue of Synthetic lethal mutant of <br />dpb11-1 (zSld5) which is able to distinguish between the guiescent cells and the <br />proliferation cells showed that type A<small>cl</small> spermatogonia could be divided into two<br />subpopulations. One population is zSld5-positive type A<small>cl</small> spermatogonia and the other <br />is zSld5-negative type A<small>cl</small> spermatogonia In addition, many LRCs are contained in a<br />latter population. All the results suggest that type zSld5-negative type A<small>cl</small> spermatogonia <br />are most undifferentiated type A spermatogonia. <br />　　It is generally known that spermatogonial stem cells have ability to restore <br />spermatogenesis when a testis was damaged by a drug or irradiation. To elucidate the<br />characterization of type A spermatogonia, I examined the effect of cytotoxic reagent <br />busulfan on male germ cells. As a result, only type A<small>cl</small> spermatogonia survived after <br />treatment of busulfan, and then recovered spermatogenesis. The morphological <br />observation suggests that type A<small>cl</small> spermatogonia are the most resistant cell population <br />against busulfan in the zebrafish testis. Detailed analysis revealed that the number of <br />zSld5-positive type type A<small>cl</small> spermatogonia increased transiently after busulfan treatment, while the number of type zSld5-negative type A<small>cl</small> spermatogonia relatively stabilized. These results suggest that both zSld5-negative and zSld5-positive type A<small>cl</small> spermatogonia would posses a feature of spermatogonial stem cells, like a actual stem cell and a potential stem cell, respectively. <br />　　Furthermore, I developed the <i>in vitro</i> culture condition for supporting the maintenance and proliferation of type A spermatogonia by the use of Sertoli feeder ZtA6-6 cells for 1 month or so. <br />　　This study represents the first step towards further understanding the character of spermatogonial stem cells and molecular mechanisms to maintain the undifferentaition status in teleosts.","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1161号","subitem_description_type":"Other"}]},"item_1_select_14":{"attribute_name":"所蔵","attribute_value_mlt":[{"subitem_select_item":"有"}]},"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":"2007"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"SAITO, Kenji","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","filename":"甲1161_要旨.pdf","filesize":[{"value":"234.1 kB"}],"format":"application/pdf","licensetype":"license_11","mimetype":"application/pdf","url":{"label":"要旨・審査要旨","url":"https://ir.soken.ac.jp/record/1043/files/甲1161_要旨.pdf"},"version_id":"37fb3810-fe45-4aa8-8f70-e89ccdc11674"},{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2016-02-17"}],"displaytype":"simple","filename":"甲1161_本文.pdf","filesize":[{"value":"5.2 MB"}],"format":"application/pdf","licensetype":"license_11","mimetype":"application/pdf","url":{"label":"本文","url":"https://ir.soken.ac.jp/record/1043/files/甲1161_本文.pdf"},"version_id":"857c3abf-e201-4010-8ecf-1df9cae7ee5a"}]},"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":"Characterization of type A spermatogonia and development of the culture system in zebrafish","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"Characterization of type A spermatogonia and development of the culture system in zebrafish"},{"subitem_title":"Characterization of type A spermatogonia and development of the culture system in zebrafish","subitem_title_language":"en"}]},"item_type_id":"1","owner":"1","path":["20"],"pubdate":{"attribute_name":"公開日","attribute_value":"2010-02-22"},"publish_date":"2010-02-22","publish_status":"0","recid":"1043","relation_version_is_last":true,"title":["Characterization of type A spermatogonia and development of the culture system in zebrafish"],"weko_creator_id":"1","weko_shared_id":1},"updated":"2023-06-20T15:54:19.734701+00:00"}