For the Establishment of Estuarine Environmant Moniroring Network

島根大学Environmental System Inc.Scedule:17-18 March 2003, Vemue: Kanazawa, Japan, Kanazawa Citymonde Hotel, Project Leader : Hayakawa, Kazuichi, Symposium Secretariat: XO kamata, Naoto, Edited by:Kamata, Naoto

Ⅲ.Chemistry

島根大学金沢大学大学院自然科学研究科 環境科学Editor : Tazaki, Kazue |田崎, 和

Perturbed gap-filling synthesis in nucleotide excision repair causes histone H2AX phosphorylation in human quiescent cells

Human histone H2AX is rapidly phosphorylated on serine 139 in response to DNA double-strand breaks and plays a crucial role in tethering the factors involved in DNA repair and damage signaling. Replication stress caused by hydroxyurea or UV also initiates H2AX phosphorylation in S-phase cells, although UV induced H2AX phosphorylation in non-cycling cells has recently been observed. Here we study the UV induced H2AX phosphorylation in human primary fibroblasts under growth-arrested conditions. This reaction absolutely depends on nucleotide excision repair (NER) and is mechanistically distinct from the replication stress-induced phosphorylation. The treatment of cytosine-β-D-arabinofuranoside strikingly enhances the NER-dependent H2AX phosphorylation and induces the accumulation of replication protein A (RPA) and ATR-interacting protein (ATRIP) at locally UV-damaged subnuclear regions. Consistently, the phosphorylation appears to be mainly mediated by ataxia-telangiectasia mutated and Rad3-related (ATR), although Chk1 (Ser345) is not phosphorylated by the activated ATR. The cellular levels of DNA polymerases δ and ε and proliferating cell nuclear antigen are markedly reduced in quiescent cells. We propose a model that perturbed gap-filling synthesis following dual incision in NER generates single-strand DNA gaps and hence initiates H2AX phosphorylation by ATR with the aid of RPA and ATRIP

Ryukyu Limestone" of Okinawa-Jima, South Japan : A Stratigraphical and Sedimentological Study

The "Ryukyu Limestone", the host of the Quaternary geology of the Ryukyu Islands, is divided fundamentally into the main limestones and the accessory limestones. This division is based on the differences in lithological characters, fossil assemblages, distribution and thickness of beds, age of sedimentation, etc. The main limestones composing the major part of the "Ryukyu Limestone" constitute the Ryukyu Group together with the contemporaneous noncalcareous deposits, and they are the basement of the accessory limestones. The Ryukyu Group is divided stratigraphically into two formations; the Lower and the Upper. The Lower Formation is the sediments which accumulated in the basins of the tectonic origin or in the valleys of the eroded basement and is represented by various lithofacies. On the other hand, the Upper Formation is more widely distributed than the Lower Formation, and its stratigraphical sequence of the lithofacies is rather constant everywhere. The Upper Formation is subdivided into the A, B and C Members based on characteristic fossil assemblages. Within these Members, the A Member is represented by some foraminiferal and molluscan fossils showing deeper water than a coral reef environment. Furthermore, the Cycloclypeus-Operculina bed of this Member, being fairly continuous, is a good horizon marker for the correlation of the Ryukyu Group not only in Okinawa-jima but also other islands. The biolithite facies, though poor in the Ryukyu Group as a whole, is recognized in the C Member of the Upper Formation and a part of the Lower Formation. In order to analyse the sedimentary environments of the Ryukyu Group, the petrography and the fossil analysis under the optical microscope were made in connection to the field observation. As a result, the sedimentary environments of the Ryukyu Group can be generally inferred to have been shifted from the land prevailing condition disqualified for coral reef formation to the favourable condition for reef building, though the process of reef forming of the latter was interrupted for a short time by the intervention of deep sea environment as represented by the A Member in the Upper Formation. As for the age of the Ryukyu Group, it is regarded to be Early and early Middle Pleistocene from the paleontological and stratigraphical aspects. The geologic structure of the Ryukyu Group is composed of many tilting blocks brought in by faulting after the completion of sedimentation. These tectonic movements of the maximum stage brought about the original configuration of the present islands. Since then, to the fringing areas of these emerged blocks the accessory limestones represented by the Minatogawa Limestone Formation were attached. However, it is also evident that mainly the tectonic movements affected the mode of the Ryukyu Group sedimentation such as local unconformities between the Lower and the Upper Formation and accelerated the change to shallow water of the sedimentary environment. Therefore, the Ryukyu Group is the product of transgression due to tectonism, especially shown in the later stage. Contrasting with the main limestone deposition, the accessory limestones were the deposits formed under the influence of the eustatic sea level changes. Lastly, the Quaternary geohistory of the Ryukyu Islands is reviewed from the viewpoint of the "Ryukyu limestone" stratigraphy

オキナワトウノリュウキュウセッカイガン : ソノソウジョガクテキタイセキガクテキケンキュウ

京都大学0048新制・課程博士理学博士甲第1939号理博第481号新制||理||261(附属図書館)5500UT51-52-N4京都大学大学院理学研究科地質学鉱物学専攻(主査)教授 亀井 節夫, 教授 中沢 圭二, 教授 笹嶋 貞雄学位規則第5条第1項該当Kyoto UniversityDA

Middle miocene-pliocene freshwater gastropods of the Churia group, west-central Nepal

Volume: 1Start Page: 166End Page: 17