The Jurassic System in SW Japan: review of recent research

The present state of the art in Jurassic oceanicplate stratigraphy in Japan is the result of research over the last two decades. Radiolarian biochronology puts age constraints on the development of fore-arc basin deposits, which cover Permian and Jurassic accretionary complexes of the Outer Zone, facing the Pacific. Special attention is given to the “Torinosu-type” reef-limestone blocks in the Upper Jurassic-Lower Cretaceous fore-arc basin deposits that derived from a shallow-marine continental margin such as the Inner Zone shelf, facing Eurasia. Further progress was achieved in dating and defining sedimentary environments in the Inner Zone Tetori Group. Erosive events during the process of Jurassic accretion are also discussed in relation to the Late Mesozoic geologic and tectonic setting.     

Lamin B1 duplications cause autosomal dominant leukodystrophy

Adult-onset autosomal dominant leukodystrophy (ADLD) is a slowly progressive neurological disorder characterized by symmetrical widespread myelin loss in the central nervous system, with a phenotype similar to chronic progressive multiple sclerosis. In this study, we identify a genomic duplication that causes ADLD. Affected individuals carry an extra copy of the gene for the nuclear laminar protein lamin B1, resulting in increased gene dosage in brain tissue from individuals with ADLD. Increased expression of lamin B1 in Drosophila melanogaster resulted in a degenerative phenotype. In addition, an abnormal nuclear morphology was apparent when cultured cells overexpressed this protein. This is the first human disease attributable to mutations in the gene encoding lamin B1. Antibodies to lamin B are found in individuals with autoimmune diseases, and it is also an antigen recognized by a monoclonal antibody raised against plaques from brains of individuals with multiple sclerosis. This raises the possibility that lamin B may be a link to the autoimmune attack that occurs in multiple sclerosis.     

Continuous cell supply from a Sox9-expressing progenitor zone in adult liver, exocrine pancreas and intestine

The liver and exocrine pancreas share a common structure, with functioning units (hepatic plates and pancreatic acini) connected to the ductal tree. Here we show that Sox9 is expressed throughout the biliary and pancreatic ductal epithelia, which are connected to the intestinal stem-cell zone. Cre-based lineage tracing showed that adult intestinal cells, hepatocytes and pancreatic acinar cells are supplied physiologically from Sox9-expressing progenitors. Combination of lineage analysis and hepatic injury experiments showed involvement of Sox9-positive precursors in liver regeneration. Embryonic pancreatic Sox9-expressing cells differentiate into all types of mature cells, but their capacity for endocrine differentiation diminishes shortly after birth, when endocrine cells detach from the epithelial lining of the ducts and form the islets of Langerhans. We observed a developmental switch in the hepatic progenitor cell type from Sox9-negative to Sox9-positive progenitors as the biliary tree develops. These results suggest interdependence between the structure and homeostasis of endodermal organs, with Sox9 expression being linked to progenitor status.     

Structure and dynamics of rotary V<Subscript>1</Subscript> motor

Rotary ATPases are unique rotary molecular motors that function as energy conversion machines. Among all known rotary ATPases, F₁-ATPase is the best characterized rotary molecular motor. There are many high-resolution crystal structures and the rotation dynamics have been investigated in detail by extensive single-molecule studies. In contrast, knowledge on the structure and rotation dynamics of V₁-ATPase, another rotary ATPase, has been limited. However, recent high-resolution structural studies and single-molecule studies on V₁-ATPase have provided new insights on how the catalytic sites in this molecular motor change its conformation during rotation driven by ATP hydrolysis. In this review, we summarize recent information on the structural features and rotary dynamics of V₁-ATPase revealed from structural and single-molecule approaches and discuss the possible chemomechanical coupling scheme of V₁-ATPase with a focus on differences between rotary molecular motors.     

New, Unexpected Pyranose-Furanose Rearrangement Towards the Synthetic Studies on Rare Sugars and Nucleosides

Preparation of rare aminosugars such as N-acetylgalactosamine （GalNAc） in large quantities is of importance for the chemo-enzymatic synthesis of oligosaccharides. Starting from naturally abundant N-acetylglucosarnine （GIcNAc）, the regio-and stereoselective and new functional group transformation play important roles as the key reactions.     

上海中心城区道路灰尘中氯代多环芳烃的时空分布特征

选取了上海中心城区的道路灰尘作为研究对象, 运用气相色谱-质谱(gas chromatography-mass spectrometry, GC/MS)联用技术对道路灰尘中20种氯代多环芳烃(chlorinated polycyclic aromatic hydrocarbons, ClPAHs)进行了检测, 分析了道路灰尘中ClPAHs的时空分布特征和毒性当量(toxic equivalent quantity, TEQ)等. 结果表明, 11种ClPAHs的检出率均大于50%, 说明ClPAHs在上海中心城区道路灰尘中普遍存在. 研究区域内的ClPAHs浓度呈现出明显的季节特征, 即冬季>夏季, 冬季∑ClPAHs浓度最高为24.9 ng/g干重. 在空间分布上, 交通枢纽区浓度最高(冬季为21.2 ng/g干重, 夏季为10.7 ng/g干重), 建筑施工区、商业区次之, 近绿地区最低. 在道路灰尘中最主要的两个组分是6-ClBaP和7-ClBaA. ClPAHs在冬季和夏季的TEQ范围分别为0.01~4.81和0.01~1.78 ng-TEQ/g干重, 其中 7-ClBaA在ClPAHs总毒性当量中的贡献最大.     

The Jurassic System in SW Japan: review of recent research

The present state of the art in Jurassic oceanicplate stratigraphy in Japan is the result of research over the last two decades. Radiolarian biochronology puts age constraints on the development of fore-arc basin deposits, which cover Permian and Jurassic accretionary complexes of the Outer Zone, facing the Pacific. Special attention is given to the “Torinosu-type” reef-limestone blocks in the Upper Jurassic-Lower Cretaceous fore-arc basin deposits that derived from a shallow-marine continental margin such as the Inner Zone shelf, facing Eurasia. Further progress was achieved in dating and defining sedimentary environments in the Inner Zone Tetori Group. Erosive events during the process of Jurassic accretion are also discussed in relation to the Late Mesozoic geologic and tectonic setting.