Recovery of physiological traits in saplings of invasive Bischofia tree compared with three species native to the Bonin Islands under successive drought and irrigation cycles

Partial leaf shedding induced by hydraulic failure under prolonged drought can prevent excess water consumption, resulting in delayed recovery of carbon productivity following rainfall. To understand the manner of water use of invasive species in oceanic island forests under a fluctuating water regime, leaf shedding, multiple physiological traits, and the progress of embolism in the stem xylem under repeated drought-irrigation cycles were examined in the potted saplings of an invasive species, Bischofia javanica Blume, and three endemic native species, Schima mertensiana (Sieb. Et Zucc, ) Koitz., Hibiscus glaber Matsum, and Distylium lepidotum Nakai, from the Bonin Islands, Japan. The progress of xylem embolism was observed by cryo-scanning electron microscopy. The samples exhibited different processes of water saving and drought tolerance based on the different combinations of partial leaf shedding involved in embolized conduits following repeated de-rehydration. Predawn leaf water potential largely decreased with each successive drought-irrigation cycle for all tree species, except for B. javanica. B. javanica shed leaves conspicuously under drought and showed responsive stomatal conductance to VPD, which contributed to recover leaf gas exchange in the remaining leaves, following a restored water supply. In contrast, native tree species did not completely recover photosynthetic rates during the repeated droughtirrigation cycles. H. glaber and D. lepidotum preserved water in vessels and adjusted leaf osmotic rates but did not actively shed leaves. S. mertensiana exhibited partial leaf shedding during the first cycle with an osmotic adjustment, but they showed less responsive stomatal conductance to VPD. Our data indicate that invasive B. javanica saplings can effectively use water supplied suddenly under drought conditions. We predict that fluctuating precipitation in the future may change tree distributions even in mesic or moist sites in the Bonin Islands

Transmission of cell stress from endoplasmic reticulum to mitochondria: enhanced expression of Lon protease

The rat homologue of a mitochondrial ATP-dependent protease Lon was cloned from cultured astrocytes exposed to hypoxia. Expression of Lon was enhanced in vitro by hypoxia or ER stress, and in vivo by brain ischemia. These observations suggested that changes in nuclear gene expression (Lon) triggered by ER stress had the potential to impact important mitochondrial processes such as assembly and/or degradation of cytochrome c oxidase (COX). In fact, steady-state levels of nuclear-encoded COX IV and V were reduced, and mitochondrial-encoded subunit II was rapidly degraded under ER stress. Treatment of cells with cycloheximide caused a similar imbalance in the accumulation of COX subunits, and enhanced mRNA for Lon and Yme1, the latter another mitochondrial ATP-dependent protease. Furthermore, induction of Lon or GRP75/mtHSP70 by ER stress was inhibited in PERK (−/−) cells. Transfection studies revealed that overexpression of wild-type or proteolytically inactive Lon promoted assembly of COX II into a COX I–containing complex, and partially prevented mitochondrial dysfunction caused by brefeldin A or hypoxia. These observations demonstrated that suppression of protein synthesis due to ER stress has a complex effect on the synthesis of mitochondrial-associated proteins, both COX subunits and ATP-dependent proteases and/or chaperones contributing to assembly of the COX complex

A fluorescent microporous crystalline dendrimer discriminates vapour molecules

A self-assembled crystalline microporous dendrimer framework (MDF) exhibits novel turn-on and ratiometric fluorescence upon exposure to solvent vapours. The donor–acceptor character, combined with the large surface area (>650 m2 g−1), allows the MDF to discriminate vapours of volatile solvents with turn-on and colour change of photoluminescence

A rat model of human FENIB (familial encephalopathy with neuroserpin inclusion bodies)

金沢大学大学院医学系研究科脳細胞分子学FENIB (familial encephalopathy with neuroserpin inclusion bodies) is caused by intracellular accumulation/polymerization of mutant neuroserpins in the endoplasmic reticulum (ER). Transgenic rats overexpressing megsin (Tg meg), a newly identified serine protease inhibitor (serpin), demonstrated intraneuronal periodic-acid Schiff (PAS)-positive inclusions distributed throughout deeper layers of cerebral cortex, CA1 of the hippocampus, and substantia nigra. Hippocampal extracts from Tg meg rats showed increased expression of ER stress proteins, and activation of caspases-12 and -3, associated with decreased neuronal density. Enhanced ER stress was also observed in dopaminergic neurons in the substantia nigra, in parallel with decreased neuronal viability and motor coordination. In each case, PAS-positive inclusions were also positive for megsin. These data suggest that overexpression of megsin results in ER stress, eventuating in the formation of PAS-positive inclusions. Tg meg rats provide a novel model of FENIB, where accumulation of serpins in the ER induces selective dysfunction/loss of specific neuronal populations. © 2006 Elsevier Inc. All rights reserved

Anxiety- and depression-like behavior in mice lacking the CD157/BST1 gene, a risk factor for Parkinson\u27s disease

金沢大学疾患モデル総合研究センターCD157, known as bone marrow stromal cell antigen-1, is a glycosylphosphatidylinositolanchored ADP-ribosyl cyclase that supports the survival and function of B-lymphocytes and hematopoietic or intestinal stem cells. Although CD157/Bst1 is a risk locus in Parkinson\u27s disease (PD), little is known about the function of CD157 in the nervous system and contribution to PD progression. Here, we show that no apparent motor dysfunction was observed in young knockout (CD157-/-) male mice under less aging-related effects on behaviors. CD157-/- mice exhibited anxiety-related and depression-like behaviors compared with wild-type mice. These behaviors were rescued through treatment with anti-psychiatric drugs and oxytocin. CD157 was weakly expressed in the amygdala and c-Fos immunoreactivity in the amygdala was less evident in CD157-/- mice than in wild-type mice. These results demonstrate for the first time that CD157 plays a role as a neuro-regulator and suggest a potential role in pre-motor symptoms in PD. © 2014 Lopatina, Yoshihara, Nishimura, Zhong, Akther, Fakhrul, Liang, Higashida, Sumi, Furuhara, Inahata, Huang, Koizumi, Yokoyama, Tsuji, Petugina, Sumarokov, Salmina, Hashida, Kitao, Hori, Asano, Kitamura, Kozaka, Shiba, Zhong, Xie, Sato, Ishihara and Higashida.CC-BY 4.

配位ナノ空間を用いた共役高分子の集積構造制御

京都大学0048新制・課程博士博士(工学)甲第20410号工博第4347号新制||工||1674(附属図書館)京都大学大学院工学研究科合成・生物化学専攻(主査)教授 北川 進, 教授 松田 建児, 教授 杉野目 道紀学位規則第4条第1項該当Doctor of Philosophy (Engineering)Kyoto UniversityDGA

Preferential orientation of anisotropic polythiophene rods toward macroscopic chain ordering

International audienceThe orientation of polymer chains plays an important role in governing the mechanical, optical, and electronic properties of polymeric materials. Here, we report on the fabrication of anisotropic polythiophene particles with controlled lengths using a metal–organic framework template, in which the alignment of the polymer chains was retained without a host support. The formation of the rod-shaped particles with long length allowed for the facile preferential orientation of the polymer particles, and consequently resulted in the macroscopic chain alignment of unprocessable polythiophene