{"created":"2023-06-20T13:20:52.292329+00:00","id":932,"links":{},"metadata":{"_buckets":{"deposit":"237266ba-beea-498f-b06a-894f76b9b757"},"_deposit":{"created_by":1,"id":"932","owners":[1],"pid":{"revision_id":0,"type":"depid","value":"932"},"status":"published"},"_oai":{"id":"oai:ir.soken.ac.jp:00000932","sets":["2:430:20"]},"author_link":["9951","9953","9952"],"item_1_creator_2":{"attribute_name":"著者名","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"濱田, 玲"}],"nameIdentifiers":[{}]}]},"item_1_creator_3":{"attribute_name":"フリガナ","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"ハマダ, アキラ"}],"nameIdentifiers":[{}]}]},"item_1_date_granted_11":{"attribute_name":"学位授与年月日","attribute_value_mlt":[{"subitem_dategranted":"1998-03-24"}]},"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_12":{"attribute_name":"要旨","attribute_value_mlt":[{"subitem_description":"  Chloroplasts are intracellular organelles in plants which contain the entire machinery necessary for the process of photosynthesis.  They contain their own genetic systems and a number of chloroplast components are encoded in their genomes.  The genetic system of the chloroplast has many features in common with prokaryotic organisms and is distinct from the (eukaryotic) nuclear-cytoplasmic system.  These features have been invoked in support of the hypothesis that green-plant cells evolved from a symbiosis between an eukaryotic host cell and a photosynthetic prokaryote.  Especially, the chloroplasts of green plants are thought to have evolved from cyanobacterial endosymbionts.  The size of chloroplast genomes is very small compared with general prokaryotes.  The reduction reflects that genes required for free-living existence were lost, most genes useful to the symbiosis were transferred to the nucleus of the host, and some genes were retained within the chloroplast.  These remaining genes encoding chloroplast products now comprise plastid genomes.  The conservation of gene content among chloroplasts of distantly related taxa suggests that most gene transfer occurred early in organelle evolution.  However, evidence of modern gene transfer has been accumulating, suggesting that the process continues, albeit at a greatly reduced rate.<br />  The chlI  gene encodes a subunit of magnesium chelatase, which catalyzes the insertion of magnesium into protoporphyrin IX.  It locates on the nuclear genome of several land plants, although it locates on the chloroplast genome of several algae.  During the study of the chloroplast genome structure of the green alga Chlorella vulgaris, I found chlI  on the chloroplast.  The amino acid sequence deduced from C. vulgaris chlI  consists of 354 residues.  It showed greater similarity to those of land plants than to those of non-green algae, suggesting that the green alga C. vulgaris is more closely related to land<br />plants than non-green algae. Northern hybridization revealed a single band at 1.85 kb which was much longer than that expected from the nucleotide sequence, suggesting that chlI  would be co-transcribed with the neighboring trnR gene.  Primer extension revealed a single extension product at position -294 upstream of the translation start site.  This matches perfectly with the -35 and -10 regions of the E. coli consensus promoter sequence.  RNase protection assay revealed the 3 ' end of the transcripts which showed the existence of the co-transcripts of chlI  and trnR.  Although another riboprobe revealed the existence of the tRNA-Arg, the processed chlI  mRNA could not be detected, suggesting that trnR contributed to the stabilization of the transcript, and that the chlI  transcripts were immediately degraded after the processing of tRNA.<br />  The chloroplast genome of C. vulgaris has ten genes not found in land plants.  Many of these genes could have been transferred to the nucleus within the green algal lineage giving rise to land plants.  Considering the possibility of the transfer of chlI  in C. vulgaris, the chloroplast and nuclear DNA were analyzed by Southern hybridization.  However no chl I -like sequence was detected in the nuclear DNA.<br />  It is generally believed that extensive rearrangements occurred within the chloroplast genomes during the evolution of land plants from green algae.  At the same time, gene transfer to the nucleus would occur.  It has been reported that the tufA coding elongation factor Tu (EF-Tu) was transferred within the Charophyceae which was believed to be green algal lineage giving rise to land plants.  chlI  will be one of such genes, because it was detected only in the chloroplast genome of C. vulgaris but not in those of any land plants.  Therefore, I tried to detect chlI  from Charophyceae Nitella and Chara, which were believed to be direct ancestors of land plants. Amplification of Nitella chloroplast DNA revealed a chlI  which showed the highest similarity with that of Chlorella.  Southern hybridization using the chloroplast gene as a probe revealed the existence of a chl I -like structure in the nuclear DNA from Nitella.  The hybridization pattern was completely different from that observed in the chloroplast DNA.  Northern hybridization revealed a single band at 1.4 kb at the poly(A)-RNA, though the signal at the poly(A)- RNA is under detestable in this experimental condition.  It is suggesting that Nitella chlI  is still transcribed from the chloroplast DNA.  To confirm the existence of a chl I -Like sequence, amplification of the sequence of nuclear DNA was attempted using a primer pair specific to the chloroplast chl I .  However, the chl I -like sequences could not be amplified, suggesting that the sequence of nuclear chl I -like was quite different from that of chloroplast chl I .  Acquisition of function by a relocated gene requires the gain of compartment-specific regulatory sequences, upstream and downstream, and an amino-terminal transit peptide sequence.  The chl I -like sequence of Nitella will be in this stage which is changing the structure to adapt in the nucleus.  The chloroplast encoded chlI  is well conserved and will retain its function until the nuclear chlI  will acquire the function.  Moreover, the peculiar nucleotide sequences of chlI  were found from Chara.  The amino acid sequences deduced from them were the same, though the nucleotide sequences were different at 11 sites, which were found at the third letter of the codons.  In connection with these chlI  structures, gene transfer from the AT-biased chloroplast genome to the GC-biased nuclear genome is discussed.","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332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":"1997"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"HAMADA, Akira","creatorNameLang":"en"}],"nameIdentifiers":[{}]}]},"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332_要旨.pdf","filesize":[{"value":"322.3 kB"}],"format":"application/pdf","licensetype":"license_11","mimetype":"application/pdf","url":{"label":"要旨・審査要旨 / Abstract, Screening Result","url":"https://ir.soken.ac.jp/record/932/files/甲332_要旨.pdf"},"version_id":"429933f0-fa7d-459c-8f5c-b3f8ed1f744a"},{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2016-02-17"}],"displaytype":"simple","filename":"甲332_本文.pdf","filesize":[{"value":"4.9 MB"}],"format":"application/pdf","licensetype":"license_11","mimetype":"application/pdf","url":{"label":"本文","url":"https://ir.soken.ac.jp/record/932/files/甲332_本文.pdf"},"version_id":"28e09e91-c9e7-4b70-9913-025fc4596516"}]},"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 structure and the location of chlI genesin algae","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"The structure and the location of chlI genesin algae"},{"subitem_title":"The structure and the location of chlI genesin algae","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":"932","relation_version_is_last":true,"title":["The structure and the location of chlI genesin algae"],"weko_creator_id":"1","weko_shared_id":1},"updated":"2023-06-20T14:42:11.654538+00:00"}