羊蹄甲属植物种子的裂解色谱鉴定法研究

本文探索了裂解气相色谱法作为植物种子分类表征方法的可能性。对豆科植物中不同属、不同亚属及相同亚属的共10种种子的裂解色谱图,用分区编码法进行区别,分析结果表明,不同种子最少有一个编码不同,方法简易快速,可为高等植物种子的区分提供一种佐证手段。     

Molecular characterization of avian-like H1N1 swine influenza a viruses isolated in Eastern China, 2011

Currently, three predominant subtypes of influenza virus are prevalent in pig populations worldwide: H1N1, H3N2, and H1N2. European avian-like H1N1 viruses, which were initially detected in European pig populations in 1979, have been circulating in pigs in eastern China since 2007. In this study, six influenza A viruses were isolated from 60 swine lung samples collected from January to April 2011 in eastern China. Based on whole genome sequencing, molecular characteristics of two isolates were determined. Phylogenetic analysis showed the eight genes of the two isolates were closely related to those of the avian-like H1N1 viruses circulating in pig populations, especially similar to those found in China. Four potential glycosylation sites were observed at positions 13, 26, 198, 277 in the HA1 proteins of the two isolates. Due to the presence of a stop codon at codon 12, the isolates contained truncated PB1-F2 proteins. In this study, the isolates contained 591Q, 627E and 701N in the polymerase subunit PB2, which had been shown to be determinants of virulence and host adaptation. The isolates also had a D rather than E at position 92 of the NS1, a marker of mammalian adaptation. Both isolates contained the GPKV motif at the PDZ ligand domain of the 3′ end of the NS1, a characteristic marker of the European avian-like swine viruses since about 1999, which is distinct from those of avian, human and classical swine viruses. The M2 proteins of the isolates have the mutation (S31N), a characteristic marker of the European avian-like swine viruses since about 1987, which may confer resistance to amantadine and rimantadine antivirals. Our findings further emphasize the importance of surveillance on the genetic diversity of influenza A viruses in pigs, and raise more concerns about the occurrence of cross-species transmission events.     

ErbB-4受体介导卵巢癌细胞增殖、侵袭等生物学行为的实验研究

探讨ErbB- 4受体在卵巢癌细胞增殖、侵袭等生物学行为中的作用.免疫组化检测ErbB- 4受体在卵巢癌细胞株OVCAR-3表达;噻唑蓝比色法(MTT)测定不同浓度的ErbB- 4单克隆抗体(Ab-3)对体外培养的卵巢癌OVCAR-3细胞增殖的影响;流式细胞仪检测细胞周期和凋亡;侵袭实验观察Ab-3对OVCAR-3侵袭能力的影响.结果表明,ErbB- 4在OVCAR-3细胞株中呈阳性表达;不同浓度(0.625～10 μg/ml)的Ab-3均能抑制OVCAR-3细胞生长,且具有浓度和时间依赖性,其作用72 h的中效浓度为4.48 μg/ml.流式细胞仪检测发现Ab-3(2.0 μg/ml)作用24、48及72 h后,OVCAR-3细胞出现S期阻滞,肿瘤细胞的凋亡率逐渐增加;抗体处理组穿透侵袭小室滤膜的细胞数(78.0±6.1)明显少于对照组(132.0±17.2)(P<0.01).因此,Ab-3可抑制内源性ErbB- 4表达的OVCAR-3细胞株的增殖、侵袭能力,诱导细胞凋亡.     

OC-IΔD86 (Oryzacystatin-IΔD86)基因的原核表达及活性分析

根据OC-IΔD86基因序列, 设计合成了7条寡核苷酸片段, 通过重叠延伸PCR技术合成了OC-IΔD86基因, 利用设计好的BamH I/ Xho I酶切位点将OC-IΔD86基因克隆到原核表达载体pet21b中, 在1 mmol/L的IPTG 诱导后5 h, OC-IDD86融合基因在大肠杆菌中得到表达, 表达产物处于可溶状态, 其表达量占总蛋白的11.4%, 可溶性蛋白的16.4%; 利用Ni-NTA系统纯化该蛋白并经PEG20000浓缩后, 活性分析表明该蛋白酶抑制剂在体外表现出对木瓜蛋白酶明显的抑制作用。这为转OC-IΔD86基因的抗根结线虫植物基因工程抗体制备, 以及进一步体内的抗根结线虫研究奠定了基础。     

Necroptosis的调控机制及其在组织及细胞缺血损伤中的作用和意义

Necroptosis不同于坏死和凋亡,具有坏死的细胞形态特点和自噬的活化,并且是主动耗能的,是被一系列信号传导通路所调控的细胞死亡机制。Necroptosis的发现和确认为细胞死亡的逆转和治疗开创了一个新的研究和应用途经。RIPl激酶是调控Necroptosis形成的关键酶,Necrostatins则是一类小分子化合物,它通过特异性地抑制细胞RIPl激酶而抑制Necroptosis的形成。     

不同浓度和形态磷处理下内生真菌感染对高羊茅的影响

以感染内生真菌(endophyte-infected,EI)和不感染内生真菌(endophyte-free,EF)的高羊茅(Festuca arundinacea Schreb.)为材料,在温室沙培条件下研究内生真菌对高羊茅适应缺磷及利用不同形态磷肥的影响。结果表明,1)缺磷条件下,高羊茅EI和EF植株生长差异不显著;正常供磷条件下,高羊茅EI植株拥有更多分蘖数和绿叶数。说明正常供磷条件下内生真菌改善了宿主高羊茅的生长。2)与水溶性磷相比,高羊茅根有机酸和酸性磷酸酶(acid phosphatase,APase)活性在难溶性磷条件下显著增加,而根总酚含量无显著变化。在水溶性磷条件下,高羊茅EI植株根总酚含量显著高于EF植株,此时EI植株比EF植株拥有更多分蘖数和绿叶数,说明在水溶性磷条件下内生真菌对宿主地上部生长具有一定贡献。在难溶性磷条件下,虽然高羊茅EI植株根总酚含量仍然高于EF植株,但同时EI植株根有机酸含量显著低于EF植株,因此内生真菌感染只是增大了宿主植物的根冠比,而对分蘖数和绿叶数等无显著影响,说明内生真菌对宿主利用难溶性磷贡献不大。可见,内生真菌对宿主植物的生长在水溶性磷条件下更有利。     

A simple and sensitive spectrofluorimetric method for the determination of furosemide using zinc(II)–1,4‐bis(imidazol‐1‐ylmethyl)benzene complexes

A novel spectrofluorometric method for the determination of furosemide (FUR) is described. The method is based on enhancement of fluorescence emission of FUR in the presence of zinc (II) complexes of 1,4‐bis(imidazol‐1‐ylmethyl)benzene. Under optimum conditions, the enhanced fluorescence intensity is linearly related to the concentration of FUR. The proposed method has been successfully applied to the determination of FUR in pharmaceutical preparations. The possible mechanism of this reaction is discussed briefly based on data from fluorescence spectroscopy, UV–vis absorption and infrared spectroscopy. Copyright © 2012 John Wiley & Sons, Ltd.     

Improved production of citric acid by Yarrowia lipolytica using oleic acid as the oxygen‐vector and co‐substrate

Yarrowia lipolytica is able to secrete large amounts of citric acid (CA), which is greatly affected by the dissolved oxygen concentration (DOC) in the fermentation medium. In this study, oleic acid was selected as oxygen‐vector to improve DOC during CA fermentation. When 2% (v/v) of oleic acid was added to the culture broth, higher DOC (>42.1%) was determined throughout the CA synthesis phase. The yield of CA reached a maximum of 32.1 g/L (25.4% higher than the control) and the biomass was 8.8 g/L. The substrate uptake rate, products formation rate and key enzyme activities were also determined, and the results indicated that CA synthesis was strengthened with oleic acid addition. Furthermore, it was detected that oleic acid could be assimilated by the cells, which means that oleic acid could be served both as oxygen‐vector and co‐substrate for CA synthesis by Y. lipolytica. In a bioreactor with working volume of 3 L, the highest concentration of CA reached to 36. 4 g/L in the presence of 2% (v/v) oleic acid after 192 h of fermentation. These results confirmed that oleic acid could be applied in the large‐scale production of CA by Y. lipolytica.     

北极狐β-防御素103基因 (CBD103) 启动子活性及转录调控元件分析

本研究旨在筛选调控北极狐毛色基因CBD103的启动子活性区域及转录因子结合位点,为揭示CBD103基因调控北极狐毛色形成的分子遗传机制提供依据。克隆获得了北极狐CBD103基因5′侧翼区2 123 bp的片段,并构建了4个不同长度的启动子缺失片段表达载体,通过双荧光素酶检测系统对启动子活性进行检测。对启动子活性最高区域预测出的3个特异性蛋白1 (Sp1)转录因子结合位点分别进行点突变并构建3个突变载体,利用双荧光素酶检测系统测定其活性。结果显示,在构建的4个不同长度启动子缺失片段中1 656 (-1 604/+51)区域活性最高,在此区域构建的3个突变载体的启动子活性较野生型(片段1 656)均显著降低,说明-1 604/+51区域为北极狐CBD103基因的核心启动子区,-1 552/-1 564、-1 439/-1 454和-329/-339区域为正调控区域。文中成功获得了北极狐CBD103基因的核心启动子区域和正调控区域,这为进一步研究该基因调控北极狐被毛颜色分子遗传机制奠定了基础。     

Functional analysis of gene duplications in Saccharomyces cerevisiae

Gene duplication can occur on two scales: whole-genome duplications (WGD) and smaller-scale duplications (SSD) involving individual genes or genomic segments. Duplication may result in functionally redundant genes or diverge in function through neofunctionalization or subfunctionalization. The effect of duplication scale on functional evolution has not yet been explored, probably due to the lack of global knowledge of protein function and different times of duplication events. To address this question, we used integrated Bayesian analysis of diverse functional genomic data to accurately evaluate the extent of functional similarity and divergence between paralogs on a global scale. We found that paralogs resulting from the whole-genome duplication are more likely to share interaction partners and biological functions than smaller-scale duplicates, independent of sequence similarity. In addition, WGD paralogs show lower frequency of essential genes and higher synthetic lethality rate, but instead diverge more in expression pattern and upstream regulatory region. Thus, our analysis demonstrates that WGD paralogs generally have similar compensatory functions but diverging expression patterns, suggesting a potential of distinct evolutionary scenarios for paralogs that arose through different duplication mechanisms. Furthermore, by identifying these functional disparities between the two types of duplicates, we reconcile previous disputes on the relationship between sequence divergence and expression divergence or essentiality.