OsRAN2, essential for mitosis,enhances cold tolerance in rice by promoting export of intranuclear tubulin and maintaining cell division under cold stress

With global climate change, abnormally low temperatures have affected the world's rice production. Many genes have been shown to be essential for molecular improvement of rice cold‐tolerance traits. However, less is known about the molecular cellular mechanism of their response to cold stress. Here, we investigated OsRAN2 involved in regulation of cell division during cold stress in rice. Expression of OsRAN2 was increased under cold treatment, but not during salt and drought stress. The mean root mitotic index was closely related to the expression level of OsRAN2. Knockdown transgenic rice lines showed an aberrant organization of spindles during mitosis and stunted growth during development. Overexpression of OsRAN2 enhanced cold tolerance in rice. The transgenic rice overexpressing OsRAN2 showed maintained cell division, decreased proportion of cells with intranuclear tubulin and formation of a normal nuclear envelope under the cold condition. Our study suggests a mechanism for OsRAN2 in regulating cold resistance in rice by maintaining cell division through promoting the normal export of intranuclear tubulin at the end of mitosis. This insight could help improve the cold‐tolerance trait in rice.     

Evolutionary process of a tetranucleotide microsatellite locus in Acipenseriformes

The evolutionary dynamics of the tetra-nucleotide microsatellite locus Spl-106 were investigated at the repeat and flanking sequences in 137 individuals of 15 Acipenseriform species, giving 93 homologous sequences, which were detected in 11 out of 15 species. Twenty-three haplotypes of flanking sequences and three distinct types of repeats, type I, type II and type III, were found within these 93 sequences. The MS-Align phylogenetic method, newly applied to microsatellite sequences, permitted us to understand the repeat and flanking sequence evolution of Spl-106 locus. The flanking region of locus Spl-106 was highly conserved among the species of genera Acipenser, Huso and Scaphirhynchus, which diverged about 150 million years ago (Mya). The rate of flanking sequence divergence at the microsatellite locus Spl-106 in sturgeons is between 0.011% and 0.079% with an average at 0.028% per million years. Sequence alignment and phylogenetic trees produced by MS-Align showed that both the flanking and repeat regions can cluster the alleles of different species into Pacific and Atlantic lineages. Our results show a synchronous evolutionary pattern between the flanking and repeat regions. Moreover, the coexistence of different repeat types in the same species, even in the same individual, is probably due to two duplication events encompassing the locus Spl-106 that occurred during the divergence of Pacific lineage. The first occured before the diversification of Pacific species (121–96 Mya) and led to repeat types I and II. The second occurred more recently, just before the speciation of A. sinensis and A. dabryanus (69–10 Mya), and led to repeat type III. Sequences in the same species with different repeat types probably corresponds to paralogous loci. This study sheds a new light on the evolutionary mechanisms that shape the complex microsatellite loci involving different repeat types.     

双斑蟋若虫后足的再生观察

研究蟋蟀若虫是否具有再生的能力,在实验室内对直翅目蟋蟀科的双斑蟋Gryllus bimaculata de Geer若虫后足的再生情况进行初步观察。结果表明:双斑蟋若虫的后足确实具有再生的能力,且再生足的伸长生长与正常足一样,均出现于虫体蜕皮时。再生的过程主要分为3个阶段:突起期、“肢芽”期、短小足期。实验结果还表明:再生能力与断肢发生的时间及断肢部位有关;断肢部位离肢体越远,再生能力越强;断肢发生的时间越早,再生能力越强。     

绵羊fertilin β基因编码区的钓取与结构分析

Fertilin β与精卵的结合和融合有密切关系。为探讨fertilin β蛋白在绵羊受精过程中的作用机理, 采用RACE技术, 首次钓取了该基因的编码区。结果绵羊fertilin β基因的编码区cDNA全长为2,217 bp。同源性分析显示, 绵羊的fertilin β氨基酸序列与牛、猪和人的fertilin β具有79.4%、66.7%和58.1%的同源性。系统发育分析表明, 绵羊fertilin β与牛属于同一分支, 并且也显示了绵羊和牛分类地位最近, 这和传统的分类一致。Fertilin β蛋白结构域分析显示, 绵羊fertilin β去整合素识别序列为TDE, 与牛的序列相同。除了上述三肽序列外, 紧随X-D/E-E的ECD保守序列, 从而形成了X-D/E-ECD五肽保守序列, 在绵羊fertilin β中该五肽序列为TDECE。     

西双版纳苦丁茶挥发油的化学成分

苦丁茶为中国南部及西南部的民间传统药用植物,经两千多年的应用和医学临床试验证明,苦丁茶具有清热解毒、抑菌消炎、抗衰老、降血脂、改善血液粘稠度和微循环、清除人体自由基及增强人体免疫能力等功效,被誉为保健茶、美容茶、降压茶和益寿茶[1,2]。苦丁茶来源较复杂,共有5科1     

The JAK–STAT Pathway Is Critical in Ventilator-Induced Diaphragm Dysfunction

Mechanical ventilation (MV) is one of the lynchpins of modern intensive-care medicine and is life saving in many critically ill patients. Continuous ventilator support, however, results in ventilation-induced diaphragm dysfunction (VIDD) that likely prolongs patients’ need for MV and thereby leads to major associated complications and avoidable intensive care unit (ICU) deaths. Oxidative stress is a key pathogenic event in the development of VIDD, but its regulation remains largely undefined. We report here that the JAK–STAT pathway is activated in MV in the human diaphragm, as evidenced by significantly increased phosphorylation of JAK and STAT. Blockage of the JAK–STAT pathway by a JAK inhibitor in a rat MV model prevents diaphragm muscle contractile dysfunction (by ~85%, p < 0.01). We further demonstrate that activated STAT3 compromises mitochondrial function and induces oxidative stress in vivo, and, interestingly, that oxidative stress also activates JAK–STAT. Inhibition of JAK–STAT prevents oxidative stress-induced protein oxidation and polyubiquitination and recovers mitochondrial function in cultured muscle cells. Therefore, in ventilated diaphragm muscle, activation of JAK–STAT is critical in regulating oxidative stress and is thereby central to the downstream pathogenesis of clinical VIDD. These findings establish the molecular basis for the therapeutic promise of JAK–STAT inhibitors in ventilated ICU patients.     

高血压患者用药的依从性

高血压是人类健康面临的一个重要挑战,对患者及其家庭和社会造成了巨大的疾病负担。药物治疗是控制高血压的重要手段,合理应用抗高血压药能使90%的患者血压处于正常范围,但实际高血压的控制率仍很低,且发病率逐年上升,究其根本原因,是由于患者用药依从性不良。本文综述了高血压患者用药依从性的概念、现状及评估方法,并对其影响因素进行了详细的阐述,指出应积极干预及加强健康教育,以最大限度提高患者的用药依从性,降低高血压带来的靶器官损害,并进一步对寻求更准确、客观的用药依从性评估方法做出展望。     

白簕叶挥发油的化学成分

用GCMS联用技术首次研究了云南西双版纳白簕叶挥发油的化学成分,并应用色谱峰面积归一化法计算各成分的相对含量。一共分离出108个峰,确认了其中的81种成分,所鉴定的组分占挥发油总量的96.50%,主要是萜烯类及其含氧衍生物等。     

垂体瘤转化基因1(PTTG1)的表达变化对人前列腺癌细胞LNCaP生长增殖的影响

垂体肿瘤转化基因1(PTTG1)具有促进肿瘤生长和转移的作用.通过上调或下调基因表达的策略,观察PTTG1基因对人前列腺癌细胞株LNCaP细胞生长增殖的影响.利用PCR技术分离出PTTG1全长cDNA,分别正向和反向插入真核表达载体pIRES2-EGFP,重组载体分别命名为正义PTTG1-S/pIRES2-EGFP(即pI-P-S)和反义PTTG1-AS/pIRES2-EGFP(即pI-P-AS),将这两种重组载体稳定转染LNCaP细胞,通过流式细胞仪和MTT法分别检测了细胞周期和细胞增殖的情况.转染正义PTTG1后处于S期和G2期的细胞明显增加,细胞生长增殖能力增强;相反,转染反义PTTG1后处于S期和G2期细胞明显减少,细胞生长增殖能力减弱(P<0.05).结果表明,PTTG1能明显改变人前列腺癌细胞株LNCaP的细胞周期和细胞生长增殖能力,它的异常表达可能参与前列腺癌细胞生长增殖过程.