纳木措湖沿岸表层水细菌群落特征及影响因素

为了探究夏季纳木措湖沿岸表层水体细菌群落特征,为以后纳木措湖细菌的研究打下基础,围绕纳木措湖一周选取采样点19个。现场采集水样,进行理化因子测定,运用高通量测序技术获取上述样点的16S rDNA数据,根据多样性指数和丰富度指数计算比较各样点的细菌群落多样性和丰富度,根据各样点细菌群落在门和属水平的分布来研究纳木措各样点细菌分布差异,基于Spearman相关性系数来衡量理化因子与α-多样性指数的相关性,采用冗余分析（redundancy analysis, RDA）探究理化因子与细菌群落分布之间的关系。在纳木措水体中共获得细菌4 137个OTU（operational taxonomic units）,属于87门204纲498目645科1 185属。门水平优势菌群为变形菌门（Proteobacteria,39.61%）、拟杆菌门（Bacteroidetes,13.41%）和厚壁菌门（Firmicutes,12.61%）,其中,变形菌门以γ-变形菌为优势菌群,其次为β-变形菌和α-变形菌。属水平有71.67%的未知细菌菌属。纳木措Shannon多样性指数显示,纳木措细菌种类比较丰富。Spearman相关性系数显示,水体细菌α-多样性指数与环境因子之间没有相关性。RDA分析表明,影响纳木措水体细菌群落结构的主要理化因子为温度（P=0.002,F=5.7）。纳木措沿岸表层水体细菌群落分布差异较为明显,细菌群落比较丰富,有许多未知菌种需进一步鉴定,有广阔的研究前景。     

Visualization of Golgia apparatus as an intracellular calcium store by laser scanning confocal microscope

Using laser scanning confocal microscopy,we have found that the in cells loaded with fluo-3/AM,highest intracellular Ca^2 in the perinuclear region is associated with the Golgi apparatus.The spatiotemporal subcellular distribution of Ca^2 in living human fibroblasts exposing to calcium-free medium in response to agonists has been investigated.PDGF,which releases Ca^2 from intracellular stores by inositol(1,4,5)-trisphosphate pathway ,produced a biphasic transient rise in intracellular calcium.The initial rise was resulted from a direct release of calcium from the golgi apparatus.Calcium could be also released from and reaccumulated into the Golgi apparatus by the stimulation of thapsigargin,an inhibitor of the Ca^2 transport ATPase of intracellular calcium store,Permeablizing the plasma membrane by 10μM digitonin resulted in the calcium release from the Golgi apparatus and depletion of the internal calcium store.These results suggest that the Golgi apparatus plays a role in Ca^2 regulation in signal transduction.     

Arabidopsis SOI33／AtENT8 Gene Encodes a Putative Equilibrative Nucleoside Transporter That Is Involved in Cytokinin Transport In Planta

The plant phytohormone cytokinin plays an important role in many facets of plant growth and development by regulating cell division and differentiation. Recent studies have shed significant light into the mechanisms of cytokinin metabolism and signaling. However, little is known about how the hormone is transported in planta, although it has been proposed that the hormone is presumably transported in nucleoside-conjugated forms. Here, we report the identification and characterization of cytokinin transporters in Arabidopsis. We previously reported that a gain-of-function mutation in the PGA22/AtlPT8 gene caused overproduction of cytokinins in planta. In an effort to screen for suppressor of pga22/atipt8 (soi) mutants, we identified a mutant soi33-1. Molecular and genetic analyses indicated that S0133 encodes a putative equilibrative nucleoside transporter (ENT), previously designated as AtENT8. Members of this small gene family are presumed to be involved in the transport of nucleosides in eukaryodc cells. Under conditions of nitrogen starvation, loss-of-function mutations in SOI33/AtENT8 or in a related gene AtENT3 cause a reduced sensitivity to the nucleoside-type cytokinins isopentenyladenine riboside (iPR) and transzeatin riboside (tZR), but display a normal response to the free base-type cytokinins isopentenyladenine (iP) and trans-zeatin (tZ). Conversely, overexpression of SOI33/AtENT8 renders transgenic plants hypersensitive to iPR but not to iP. An in planta measurement experiment indicated that uptake efficiency of^3Hlabeled iPR was reduced more than 40% in soi33 and atent3 mutants. However, a mutation in AtENT1 had no substantial effect on the cytokinin response and iPR uptake efficiency. Our results suggest that SOI33/AtENT8 and AtENT3 are involved in the transport of nucleoside-type cytokinins in Arabidopsis.     

小鼠P311蛋白与类赖氨酰氧化酶-1相互作用的鉴定

P311是利用抑制差减杂交技术从小鼠肺组织中筛选到的一个肺泡发育上游调节基因.它高水平表达于肺泡发育的相关阶段,而在慢性阻塞性肺病(chronic obstructive pulmonary disease,COPD)患者肺组织中表达水平大大下降.为深入探讨P311蛋白的作用机制,构建pGBKT7-P311诱饵表达载体,利用酵母双杂交技术,从小鼠肺组织cDNA文库中筛选出P311相互作用蛋白类赖氨酰氧化酶-1(lysyl oxidase-like 1,Loxl-1).并通过体内外免疫共沉淀及双分子荧光互补实验进行验证.为进一步研究P311蛋白的生物学功能提供新的思路。     

百合科寄主植物对韭菜迟眼蕈蚊的生物效应

室内分别用百合科韭菜、大葱、大蒜和圆葱饲喂韭菜迟眼蕈蚊Bradysia odoriphaga Yang et Zhang幼虫,研究了4种寄主植物对其生长发育和繁殖的影响;用气-质谱联用分析技术,检测了人工合成大蒜素及大蒜、圆葱和韭菜的乙醇提取物的主要化学成分。结果表明,4种供试寄主植物对韭菜迟眼蕈蚊生长发育和繁殖的影响存在差异,幼虫取食韭菜最有利于其生长发育和繁殖;取食大蒜和圆葱对其生长发育和繁殖表现出明显的不利性,主要表现为幼虫死亡率增加,幼虫期延长,蛹重减轻,单雌产卵量降低;而取食大葱的影响介于取食韭菜与取食大蒜和圆葱之间。大蒜、圆葱的乙醇提取物和人工合成的大蒜素均对韭菜迟眼蕈蚊1龄幼虫有不同程度的杀虫活性,大蒜和圆葱的乙醇提取物（干粉,2 g/mL）稀释100和200倍,处理后48 h对1龄幼虫的校正死亡率分别达54.7%、28.0%和49.4%、22.7%;10%大蒜素稀释500和1 000倍,处理后48 h校正死亡率达100%和80.0%。成分分析表明硫醚类化合物可能是大蒜和圆葱中含有的杀虫活性物质之一。     

中华鲎虫外部形态结构的初步观察

中华鲎虫体由头、躯干和尾3部分组成.头部具1对复眼和1个无节幼体眼,复眼后有1个颈感器.第1触角细小、棒状,第2触角退化.口器由上唇、大颚和2对小颚组成,上唇为头部的突起物,大颚和2对小颚为附肢,第2小颚的皮肤皱褶延长扩大形成头胸甲.雌体躯干部由36个体节组成,雄体39个体节,前30节具附肢,共57对.雌体躯干部后6个体节无附肢,雄体躯干部后9个体节无附肢.尾节分叉,细长多节,具刚毛,左右两根尾鞭的分节不对称.     

气质联用结合多变量分析研究蜂蜜的挥发性成分

为探究不同蜜源蜂蜜中的挥发性标记物并籍以对这些蜂蜜进行有效区分,本研究优化了静态顶空气相色谱-质谱联用技术(SHS-GC-MS)检测蜂蜜中挥发性化合物的方法,采用此方法分析了油菜蜜、椴树蜜、荆条蜜和洋槐蜜等4种蜂蜜总计38份样品的挥发性成分,并结合主成分分析(PCA)和聚类分析(CA)等对蜂蜜进行区分。研究结果表明,采用SHS-GC-MS共检测到23种化合物。4种蜂蜜的挥发性成分在物质种类或含量上存在明显差异,其中3-苯丙酸乙酯可作为油菜蜜的典型挥发性代谢物质;1-异丙烯基-3-甲基苯和反式玫瑰醚可作为椴树蜜的典型挥发性代谢物质;在荆条蜜和洋槐蜜中均未发现典型挥发性代谢物质。PCA可以将4种蜂蜜进行很好地区分,PC1、PC2和PC3累计贡献率达到77.3%,表明模型有效;当临界值取10时,CA可以将同种蜂蜜聚为一类。SHS-GC-MS检测的蜂蜜挥发性成分结果结合多变量分析,可用于区分不同蜜源蜂蜜。研究结果为蜂蜜溯源和鉴别提供了理论依据。     

青藏高原高寒草甸植被特征与温度、水分因子关系

以广布于青藏高原的高寒草甸为研究对象,进行模拟增温实验,探讨高寒草甸植被特征与温度、水分因子关系,并试图论证高寒草甸植被是否符合生物多样性代谢理论.结果表明:①高寒草甸植被物种多样性的对数与绝对温度的倒数呈显著线性递减关系,空气-地表-浅层土壤(0-20 cm)温度(R2 ＞0.6,P＜0.01)较深层土壤(40-100 cm)温度(R2＜0.5,P＜0.05)对物种多样性影响大;其植被新陈代谢平均活化能为0.998-1.85 eV,高于生物多样性代谢理论预测值0.6-0.7 eV,这是高寒草甸植被对长期低温环境适应进化的结果.②除趋势对应分析和冗余分析显示,温度对植被地上部分影响较大,而土壤水分对全株影响均较大,适当的增温与降水均可极显著促进高寒草甸植被生长.③逐步回归和通径分析显示,40 cm、60 cm深度土壤水分对植被地上部分产生直接影响,20 cm高度空气相对湿度和40 cm深度土壤温度对其产生间接影响;40 cm深度土壤温度和60 cm深度土壤水分对植被地下部分产生直接影响,红外地表温度对其产生间接影响.深层土壤温度和水分对高寒草甸植被具有影响作用,这可能与增温后冻土的融化有关,但其机理尚待进一步研究.     

替米沙坦在糖尿病防治中的应用

替米沙坦是经典的抗血压病药物。近年来人们发现替米沙坦除可以抑制血管紧张素Ⅱ-1型受体外,还可以部分激活过氧化物酶体增殖物激活受体γ。得益于其双靶点的作用机制,替米沙坦可以通过改善糖脂代谢紊乱和缓解糖尿病带来的并发症而使糖尿病或糖尿病高危病人获益。本文就替米沙坦在糖尿病预防和治疗中的作用及相关的机制研究作一阐述。     

生物信息大分子功能的研究——酵母甘露聚糖对鼠Sarcoma-180瘤生长的抑制效应

酵母甘露聚糖（Mannan,简称Man）是能参与生物信息流影响生物体、特别是在糖基化方面起着重要调控作用的生物信息大分子.它是否能在抑制生物机体中肿瘤生长方面具有重要作用？研究结果表明：酵母甘露聚糖既能使患S-180瘤鼠的体质增强的同时又有抑制其体内所患S-180瘤生长的功效.Man抑制患鼠机体内的S-180瘤生长的功效（抑瘤率）随用量的增加而提高,当Man用量达360 mg（40 mg/Kg/d·9d）时,其抑瘤率达98.4％的最高水平,此时鼠体重增加1.66倍.Man的抑瘤功效有最佳适用量并存在性别敏感性,通常是雄性鼠的抑瘤率高于雌性鼠.Man抑制鼠S-180肿瘤生长的作用优于市售5-氟尿嘧啶的作用.