Irregular sleep–wake cycle associated with malignant brain tumor in an adolescent

Sleep and Biological Rhythms - We report an adolescent case of malignant brain tumor who presented with an irregular sleep–wake cycle as the first significant clinical symptom. The patient...     

Extracellular and Intracellular Mechanisms of Mechanotransduction in Three-Dimensionally Embedded Rat Chondrocytes

Purpose

Articular cartilage homeostasis involves modulation of chondrocyte matrix synthesis in response to mechanical stress (MS). We studied extracellular and intracellular mechanotransduction pathways mediating this response.

Methods

We first confirmed rapid up-regulation of the putative chondro-protective cytokine, interleukin (IL)-4, as an immediate response to MS. We then studied the role of IL-4 by investigating responses to exogenous IL-4 or a specific IL-4 inhibitor, combined with MS. Next we investigated the intracellular second messengers. Since chondrocyte phenotype alters according to the extracellular environment, we characterized the response to mechanotransduction in 3-dimensionally embedded chondrocytes.

Results

Expression of aggrecan and type II collagen was significantly up-regulated by exogenous IL-4 whereas MS-induced matrix synthesis was inhibited by an IL-4 blocker. Further, MS-induced matrix synthesis was completely blocked by a p38 MAPK inhibitor, while it was only partially blocked by inhibitors of other putative second messengers.

Conclusion

IL-4 mediates an extracellular pathway of mechanotransduction, perhaps via an autocrine/paracrine loop, while p38 mediates an intracellular pathway prevalent only in a 3-dimensional environment.     

Discovery of new hydrothermal activity and chemosynthetic fauna on the Central Indian Ridge at 18°-20° S

Indian Ocean hydrothermal vents are believed to represent a novel biogeographic province, and are host to many novel genera and families of animals, potentially indigenous to Indian Ocean hydrothermal systems. In particular, since its discovery in 2001, much attention has been paid to a so-called 'scaly-foot' gastropod because of its unique iron-sulfide-coated dermal sclerites and the chemosynthetic symbioses in its various tissues. Despite increasing interest in the faunal assemblages at Indian Ocean hydrothermal vents, only two hydrothermal vent fields have been investigated in the Indian Ocean. Here we report two newly discovered hydrothermal vent fields, the Dodo and Solitaire fields, which are located in the Central Indian Ridge (CIR) segments 16 and 15, respectively. Chemosynthetic faunal communities at the Dodo field are emaciated in size and composition. In contrast, at the Solitaire field, we observed faunal communities that potentially contained almost all genera found at CIR hydrothermal environments to date, and even identified previously unreported taxa. Moreover, a new morphotype of 'scaly-foot' gastropod has been found at the Solitaire field. The newly discovered 'scaly-foot' gastropod has similar morphological and anatomical features to the previously reported type that inhabits the Kairei field, and both types of 'scaly-foot' gastropods genetically belong to the same species according to analyses of their COI gene and nuclear SSU rRNA gene sequences. However, the new morphotype completely lacks an iron-sulfide coating on the sclerites, which had been believed to be a novel feature restricted to 'scaly-foot' gastropods. Our new findings at the two newly discovered hydrothermal vent sites provide important insights into the biodiversity and biogeography of vent-endemic ecosystems in the Indian Ocean.     

Cloning of an endoglycanase gene from Paenibacillus cookii and characterization of the recombinant enzyme

An endoglycanase gene of Paenibacillus cookii SS-24 was cloned and sequenced. This Pgl8A gene had an open reading frame of 1,230 bp that encoded a putative signal sequence (31 amino acids) and mature enzyme (378 amino acids: 41,835 Da). The enzyme was most homologous to a β-1,3-1,4-glucanase of Bacillus circulans WL-12 with 84% identity. The recombinant enzyme hydrolyzed carboxymethyl cellulose, swollen celluloses, chitosan and lichenan but not Avicel, chitin powder or xylan. With chitosan as the substrate, the optimum temperature and hydrolysis products of the recombinant enzyme varied at pH 4.0 and 8.0. This is the first report that characterizes chitosanase activity under different pH conditions.     

日本农业生物技术年报(2011年)

本报告介绍了日本转基因作物的消费、监管、公众认知、研究和生产方面的最新状况。     

The role of OsBRI1 and its homologous genes, OsBRL1 and OsBRL3, in rice

Since first identifying two alleles of a rice (Oryza sativa) brassinosteroid (BR)-insensitive mutant, d61, that were also defective in an orthologous gene in Arabidopsis (Arabidopsis thaliana) BRASSINOSTEROID INSENSITIVE1 (BRI1), we have isolated eight additional alleles, including null mutations, of the rice BRI1 gene OsBRI1. The most severe mutant, d61-4, exhibited severe dwarfism and twisted leaves, although pattern formation and differentiation were normal. This severe shoot phenotype was caused mainly by a defect in cell elongation and the disturbance of cell division after the determination of cell fate. In contrast to its severe shoot phenotype, the d61-4 mutant had a mild root phenotype. Concomitantly, the accumulation of castasterone, the active BR in rice, was up to 30-fold greater in the shoots, while only 1.5-fold greater in the roots. The homologous genes for OsBRI1, OsBRL1 and OsBRL3, were highly expressed in roots but weakly expressed in shoots, and their expression was higher in d61-4 than in the wild type. Based on these observations, we conclude that OsBRI1 is not essential for pattern formation or organ initiation, but is involved in organ development through controlling cell division and elongation. In addition, OsBRL1 and OsBRL3 are at least partly involved in BR perception in the roots.     

Yeast ARV1 is required for efficient delivery of an early GPI intermediate to the first mannosyltransferase during GPI assembly and controls lipid flow from the endoplasmic reticulum

Glycosylphosphatidylinositol (GPI), covalently attached to many eukaryotic proteins, not only acts as a membrane anchor but is also thought to be a sorting signal for GPI-anchored proteins that are associated with sphingolipid and sterol-enriched domains. GPI anchors contain a core structure conserved among all species. The core structure is synthesized in two topologically distinct stages on the leaflets of the endoplasmic reticulum (ER). Early GPI intermediates are assembled on the cytoplasmic side of the ER and then are flipped into the ER lumen where a complete GPI precursor is synthesized and transferred to protein. The flipping process is predicted to be mediated by a protein referred as flippase; however, its existence has not been proven. Here we show that yeast Arv1p is an important protein required for the delivery of an early GPI intermediate, GlcN-acylPI, to the first mannosyltransferase of GPI synthesis in the ER lumen. We also provide evidence that ARV1 deletion and mutations in other proteins involved in GPI anchor synthesis affect inositol phosphorylceramide synthesis as well as the intracellular distribution and amounts of sterols, suggesting a role of GPI anchor synthesis in lipid flow from the ER.