小麦eIF3c基因片段的克隆及序列分析

根据真核翻译起始因子eIF3c的保守序列,搜索小麦EST,由拼接的序列设计引物,从普通小麦‘川麦107'幼苗总RNA中克隆出1102bp的小麦eIF3c1基因片段命名为WeIF3c1.序列分析表明,该片段推断的氨基酸序列与两个拟南芥、水稻、甜樱桃、人类、线虫、老鼠等物种的真核翻译起始因子eIF3c相比较同源性分别为69、61%、85%、72%、38%、36%和38%.     

拟南芥冷诱导CBF/DREB类结合因子的克隆及其生物信息学分析

CBF/DREB结合因子广泛存在于植物中,主要参与诸如干旱、高盐以及冷胁迫等相关基因的表达调控.以拟南芥DNA为模板,PCR扩增出3个冷诱导的CBF/DREB结合因子,即CBF1、CBF2及CBF3,利用生物信息学手段对三者的cDNA序列、氨基酸序列的相似性、组成成分、理化性质、疏水性/亲水性、功能域、进化树、二级结构及DNA保守域的三级结构等进行了较为全面的分析.结果显示,CBF1、CBF2和CBF3的氨基酸序列同源性很高,达到91.4%,且都属于亲水性蛋白,三者在理化性质以及蛋白质二级结构乃至三级结构上也极为相似.另外, CBF1和CBF2都不具跨膜结构,CBF3含有1个跨膜螺旋.     

A 14 000-year record of paleoenvironmental change in the western basin of China's third largest lake,Lake Taihu

Effect of leaf extract of Ocimum sanctum on (i) the specific and non-specific immune responses and (ii) disease resistance against Aeromonas hydrophila was investigated in Oreochromis mossambicus. Sheep red blood cells (SRBC) and Heat aggregated bovine serum albumin (HA-BSA) were used as antigens for specific and non-specific immune response studies, respectively. Antigens were administered through intraperitoneal route. Anti-SRBC antibody titres were determined by direct haemagglutination and anti-bacterial antibodies were determined by bacterial agglutination. Nitroblue tetrazolium (NBT) assay was used to determine neutrophil activity. Disease resistance was measured in terms of relative percent survival (RPS). The immunostimulatory effect of the leaf extract of O. sanctum, when administered through intraperitoneal and oral routes was obvious. Leaf extract of O. sanctum, when administered intraperitoneally, stimulated both antibody response and neutrophil activity. Dietary intake of O. sanctum also enhanced the antibody response and disease resistance against A. hydrophila. Possibility of using O. sanctum as immunostimulant in the maintenance of finfish health in intensive freshwater aquaculture is suggested.     

Involvement of the Akt/NF-κB Pathways in the HTNV-Mediated Increase of IL-6, CCL5, ICAM-1, and VCAM-1 in HUVECs

Background

Hantaan virus (HTNV) infection causes a severe form of HFRS(hemorrhagic fever with renal syndrome)in Asia. Although HTNV has been isolated for nearly forty years, the pathogenesis of HFRS is still unknown, and little is known regarding the signaling pathway that is activated by the virus.

Methodology/Principal Findings

Cardamonin was selected as a NF-κB inhibitor, and indirect immunofluorescence assays were used to detect the effect of cardamonin on HTNV-infected HUVECs. The effect of cardamonin on the HTNV-induced phosphorylation of Akt and DNA-binding activity of NF-κB were determined using Western blot analysis and electrophoretic mobility shift assays (EMSAs), respectively. Then, flow cytometric and quantitative real-time PCR analyses were performed to quantify the expression levels of the adhesion molecules ICAM-1 and VCAM-1, and the concentrations of IL-6, IL-8, and CCL5 in HUVEC supernatants were examined using ELISA. The results showed that cardamonin did not effect the proliferation of HUVECs or the replication of HTNV in HUVECs. Instead, cardamonin inhibited the phosphorylation of Akt and nuclear transduction of NF-κB and further reduced the expression of the adhesion molecules ICAM-1 and VCAM-1 in HTNV-infected HUVECs. Cardamonin also inhibited the secretion of IL-6 and CCL5, but not IL-8.

Conclusion/Significance

HTNV replication may not be dependent upon the ability of the virus to activate NF-κB in HUVECs. The Akt/NF-κB pathways may be involved in the pathogenesis of HFRS; therefore, cardamonin may serve as a potential beneficial agent for HFRS therapy.     

ABP1:生长素结合蛋白中的超级明星

涵盖拟南芥、玉米等模式植物中生长素信号传递过程中涉及到生长素结合蛋白(Auxin Binding Protein,简称ABP1)的研究进展和最新实验技术。ABP1是一种在植物中广泛存在的低丰度糖蛋白,多以一种β桶为主的同源二聚体的形式出现,C端则能自由地与其它蛋白相互作用。ABP1这种蛋白大多位于内质网腔,也有少量存在于质膜上或附近和细胞壁中。但是,只有位于质膜的ABP1才有生长素结合能力,参与激活多种针对生长素的早期电化学反应。然而,ABP1不像其它受体能控制基因的开关,这就无法解释生长素那形形色色的强大功能。因此,ABP1还不能叫做生长素受体。但是,也不能否认这样一种可能,那就是ABP1位于另一条与基因调控相平行的细胞学信号传递途径中,或至少有关联。到目前为止,在植物生长发育过程中ABP1相当重要,这是勿庸质疑的了,然而,ABP1到底扮演着一个什么样的角色,却还不甚明了。     

距离分析方法与杂种优势

对于75个小麦品种两年的试验结果,采用不同方法进行距离比较分析。结果表明:用表型平均值相关阵经主成分转换,计算品种间欧氏距离,再用类平均法聚类,似乎是适宜的距离分析方法。D~2值在年份间较稳定,不同年份的D~2估值,可用于预测杂种优势。根据13个性状估算的品种间距离(D~2)与株粒重杂种优势(H)之间呈曲线关系,其理论方程是:Y=-3.65 6.665X--0.1288X~2。根据该方程推算:D~2=25.87时,H出现最大值。     

Lipid accumulation and growth of Chlorella zofingiensis in flat plate photobioreactors outdoors

Culturing microalgae using natural sunlight is an effective way to reduce the cost of microalgae-based biodiesel production. In order to evaluate the feasibility of culturing Chlorella zofingiensis outdoors for biodiesel production, effects of nitrogen limitation and initial cell concentration on growth and lipid accumulation of this alga were investigated in 60 L flat plate photobioreactors outdoors. The highest μmax and biomass productivity obtained was 0.994 day(-1) and 58.4 mg L(-1)day(-1), respectively. The lipid content was much higher (54.5% of dry weight) under nitrogen limiting condition than under nitrogen sufficient condition (27.3%). With the increasing initial cell concentrations, the lipid contents declined, while lipid concentrations and productivities increased. The highest lipid content, lipid concentration, and lipid productivity obtained was 54.5%, 536 mg L(-1) and 22.3 mg L(-1)day(-1), respectively. This study demonstrated that it was possible to culture C. zofingiensis under outdoor conditions for producing biodiesel feedstock.     

Elevated Soluble CD163 Plasma Levels Are Associated with Disease Severity in Patients with Hemorrhagic Fever with Renal Syndrome

Background

Hantaan virus is a major zoonotic pathogen that causesing hemorrhagic fever with renal syndrome (HFRS). Although HFRS pathogenesis has not been entirely elucidated, the importance of host-related immune responses in HFRS pathogenesis has been widely recognized. CD163, a monocyte and macrophage-specific scavenger receptor that plays a vital function in the hosts can reduce inflammation, is shed during activation as soluble CD163 (sCD163). The aim of this study was to investigate the pathological significance of sCD163 in patients with HFRS.

Methods

Blood samples were collected from 81 hospitalized patients in Tangdu Hospital from October 2011 to January 2014 and from 15 healthy controls. The sCD163 plasma levels were measured using a sandwich ELISA, and the relationship between sCD163 and disease severity was analyzed. Furthermore, CD163 expression in 3 monocytes subset was analyzed by flow cytometry.

Results

The results demonstrated that sCD163 plasma levels during the HFRS acute phase were significantly higher in patients than during the convalescent stage and the levels in the healthy controls (P<0.0001). The sCD163 plasma levels in the severe/critical group were higher than those in the mild/moderate group during the acute (P<0.0001). A Spearman correlation analysis indicated that the sCD163 levels were positively correlated with white blood cell, serum creatine, blood urea nitrogen levels, while they were negatively correlated with blood platelet levels in the HFRS patients. The monocyte subsets were significantly altered during the acute stage. Though the CD163 expression levels within the monocyte subsets were increased during the acute stage, the highest CD163 expression level was observed in the CD14++CD16+ monocytes when compared with the other monocyte subsets.

Conclusion

sCD163 may be correlated with disease severity and the disease progression in HFRS patients; however, the underlying mechanisms should be explored further.     

Hantavirus infection: a global zoonotic challenge

Hantaviruses are comprised of tri-segmented negative sense single-stranded RNA, and are members of the Bunyaviridae family. Hantaviruses are distributed worldwide and are important zoonotic pathogens that can have severe adverse effects in humans. They are naturally maintained in specific reservoir hosts without inducing symptomatic infection. In humans, however, hantaviruses often cause two acute febrile diseases, hemorrhagic fever with renal syndrome (HFRS) and hantavirus cardiopulmonary syndrome (HCPS). In this paper, we review the epidemiology and epizootiology of hantavirus infections worldwide.

Open image in new window