有效抽提乙醇中螨标本的核DNA

对如何有效地从乙醇保存的叶螨中抽提核基因组DNA作了探讨。70％乙醇保存的叶螨标本,经过干燥,TEN洗涤,蛋白酶K消化,酚—氯仿抽提,2倍体积无水乙醇沉淀等步骤,得到叶螨核基因组DNA沉淀,再用TE或无菌水溶解后,以其为模板,进行随机引物PCR扩增。结果显示.该方法抽提的DNA无Taq酶抑制物,且其纯度达到进行PCR反应对模板要求的程度。这为采用AP-PCR技术研究螨的系统分类提供了便利。     

Fructose uptake in Bifidobacterium longum NCC2705 is mediated by an ATP-binding cassette transporter

Recently, a putative ATP-binding cassette (ABC) transport system was identified in Bifidobacterium longum NCC2705 that is highly up-regulated during growth on fructose as the sole carbon source. Cloning and expression of the corresponding ORFs (bl0033-0036) result in efficient fructose uptake by bacteria. Sequence analysis reveals high similarity to typical ABC transport systems and suggests that these genes are organized as an operon. Expression of FruE is induced by fructose, ribose, or xylose and is able to bind these sugars with fructose as the preferred substrate. Our data suggest that BL0033-0036 constitute a high affinity fructose-specific ABC transporter of B. longum NCC2705. We thus suggest to rename the coding genes to fruEKFG and the corresponding proteins to FruE (sugar-binding protein), FruK (ATPase subunit), FruF, and FruG (membrane permeases). Furthermore, protein-protein interactions between the components of the transporter complex were determined by GST pulldown and Western blot analysis. This revealed interactions between the membrane subunits FruF and FruG with FruE, which in vivo is located on the external side of the membrane, and with the cytoplasmatic ATPase FruK. This is in line with the proposed model for bacterial ABC sugar transporters.     

动物的模仿和玩耍学习行为

简要介绍了模仿和玩耍两种学习类型的基本概念、特点、类型和适应意义,提供了两张图片和大量实例。     

Wogonin inhibits IGF-1-stimulated cell growth and estrogen receptor α expression in breast adenocarcinoma cell and angiogenesis of chick chorioallantoic membrane

The aim of the present study was to investigate the involvements of insulin-like growth factor-1 (IGF-1) and estrogen receptor α (ERα) in the inhibitory effect of wogonin on the breast adenocarcinoma growth. Moreover, the effect of wogonin on the angiogenesis of chick chorioallantoic membrane (CAM) was also investigated. MCF-7 cells (human breast adenocarcinoma cell line) were subjected to several drugs, including IGF-1, wogonin and ER inhibitor ICI182780, alone or in combination. MTT assay was used to detect breast cancer proliferation. Western blot was used to analyze ERα and p-Akt expression levels. CAM models prepared from 6-day chicken eggs were employed to evaluate angiogenesis inhibition. The results showed wogonin and ICI182780 both exhibited a potent ability to blunt IGF-1-stimulated MCF-7 cell growth. Either of wogonin and ICI182780 significantly inhibited ERα and p-Akt expressions in IGF-1-treated cells. The inhibitory effect of wogonin showed no difference from that of ICI182780 on IGF-1-stimulated expressions of ERα and p-Akt. Meanwhile, wogonin at different concentrations showed significant inhibitory effect on CAM angiogenesis. These results suggest the inhibitory effect of wogonin on breast adenocarcinoma growth via inhibiting IGF-1-mediated PI3K-Akt pathway and regulating ERα expression. Furthermore, wogonin has a strong anti-angiogenic effect on CAM model.     

Overexpression of genes of the cell wall stimulon in clinical isolates of Staphylococcus aureus exhibiting vancomycin-intermediate- S. aureus-type resistance to vancomycin

Custom-designed gene chips (Affymetrix) were used to determine genetic relatedness and gene expression profiles in Staphylococcus aureus isolates with increasing MICs of vancomycin that were recovered over a period of several weeks from the blood and heart valve of a patient undergoing extensive vancomycin therapy. The isolates were found to be isogenic as determined by the GeneChip based genotyping approach and thus represented a unique opportunity to study changes in gene expression that may contribute to the vancomycin resistance phenotype. No differences in gene expression were detected between the parent strain, JH1, and JH15, isolated from the nares of a patient contact. Few expression changes were observed between blood and heart valve isolates with identical vancomycin MICs. A large number of genes had altered expression in the late stage JH9 isolate (MIC = 8 microg/ml) compared to JH1 (MIC = 1 microg/ml). Most genes with altered expression were involved in housekeeping functions or cell wall biosynthesis and regulation. The sortase-encoding genes, srtA and srtB, as well as several surface protein-encoding genes were downregulated in JH9. Two hypothetical protein-encoding genes, SAS016 and SA2343, were dramatically overexpressed in JH9. Interestingly, 27 of the genes with altered expression in JH9 grown in drug-free medium were found to be also overexpressed when the parental strain JH1 was briefly exposed to inhibitory concentrations of vancomycin, and more than half (17 of 27) of the genes with altered expression belonged to determinants that were proposed to form part of a general cell wall stress stimulon (S. Utaida et al., Microbiology 149:2719-2732, 2003).     

板栗疫病菌绿色荧光与红色荧光蛋白共定位载体的构建

低毒病毒-板栗疫病菌组合是研究病毒与宿主相互作用的一个优秀的模式系统.我们构建了含绿色荧光蛋白基因gfp的载体pCPXHY2GFP与含红色荧光蛋白基因rfp的载体pCPXG418RFP,并用于转化野生型菌株EP155,获得了以潮霉素为筛选标记、表达绿色荧光蛋白的转化株pCPXHY2GFP/EP155和以G418为筛选标记、表达红色荧光蛋白的转化株pCPXG418RFP/EP155.将载体pCPXG418RFP转化pCPXHY2GFP/EP155,获得的转化株能观察到绿色荧光蛋白与红色荧光蛋白共定位的现象.板栗疫病菌绿色荧光与红色荧光共定位载体pCPXHY2GFP与pCPXG418RFP的构建,为深入研究病毒与宿主相互作用的分子机制提供了强有力的研究材料.     

海洋生态资本理论框架下的生态系统服务评估

海洋生态资本指能够直接或间接作用于人类社会经济生产、提供有用的产品流或服务流的海洋生态资源。海洋生态资本价值由海洋生态资源存量价值和海洋生态系统服务价值组成。海洋生态资本评估包括海洋生态资源存量评估和海洋生态系统服务评估。在海洋生态资本理论框架体系下,针对我国近海生态系统服务的开发与利用情况,建立了评估海洋生态系统服务的物质量和价值量的技术框架。基于物质量可量化、价值量可货币化、数据可获得性三条评估原则,筛选出9个指标定量评估海洋生态系统服务的物质量和价值量,并给出了对应的评估方法、计算公式、参数和数据来源。海洋供给服务采用养殖生产、捕捞生产和氧气生产3个指标评估;海洋供给服务采用气候调节、废弃物处理2个指标评估;海洋文化服务采用休闲娱乐、科研服务2个指标评估;海洋支持服务采用物种多样性维持、生态系统多样性维持2个指标评估。养殖生产、捕捞生产等指标采用市场价格法进行评估;氧气生产、废弃物处理、科研服务等指标采用替代成本法进行评估;气候调节指标采用替代市场价格法进行评估;休闲娱乐指标采用旅行费用法或收入替代法进行评估;物种多样性维持、生态系统多样性维持等指标采用条件价值法进行评估。该套方法体系已经应用于山东省7个沿海地级市和福建省东山湾、罗源湾的近海生态系统服务价值评估,已经得到学术界和海洋管理部门的认可,被国家标准《海洋生态资本评估技术导则》吸收采用。该套方法紧密切合国家生态文明建设需求,可为海洋主管部门的生态资本核算、生态补偿业务、环评审批提供关键技术手段,也为海洋生态系统服务的精确评估提供了科学基础。     

退耕还林地结构与生态功能的耦合关系

退耕还林的林地结构与生态功能效益是退耕还林工程的关键性问题。基于典型黄土高原丘陵沟壑地7种代表性的退耕还林模式的野外调查和取样分析结果,选取14个林地结构因子和2个代表性生态功能因子,对林地结构进行因子分析,并构建了林地结构与生态功能的灰色关联度模型和耦合协调度模型。用建立的模型分析吴起县退耕还林地7种模式的林地结构、土壤侵蚀及地表径流数据,结果表明,不同林地结构因子间相关度不同,经过主成分分析降维为4个主成分因子,分别反映了林分的乔木层结构指标、上层结构生物量指标、土壤层指标及其它指标;不同林地结构因子与生态功能的关联度系数不同,林地结构因子对地表径流的影响明显高于对土壤侵蚀率的影响,其中林分组成对径流的影响最明显,土壤因子影响最不明显;草本层生物量、枯落物生物量等近地表的相关结构对土壤侵蚀的作用明显。不同退耕还林模式的林地结构与生态功能的耦合协调度状况都不良好,仍需要进行调整和改善。     

意大利蜜蜂对两种油菜花朵气味的偏爱性

【目的】明确意大利蜜蜂Apis mellifera ligustica（简称“意蜂”）对两种油菜（甘蓝型胜利油菜 Brassica napus cv. Shengli和芥菜型马尾油菜 B. juncea cv. Mawei）的气味偏爱性及选择行为特征。【方法】本研究开展大田访花偏爱性试验、室外群体气味偏爱性试验以及室内“Y”型嗅觉仪行为反应和学习记忆试验,测定意蜂蜂群及青年采集蜂对甘蓝型胜利油菜和芥菜型马尾油菜两种油菜花朵的选择次数,并通过采集蜂训练时及训练后的喙伸反应率分析两种油菜花朵气味对采集蜂学习记忆能力的影响,最终评估意蜂蜂群及个体对这两种油茶花朵气味的选择性。【结果】大田试验12:00-13:00时间段,访问胜利油菜的意蜂数量显著高于访问马尾油菜的数量(P<0.05）。群体气味偏爱性试验14:00-15:00时间段意蜂访问胜利油菜的数量显著高于访问马尾油菜的数量（P<0.05）。行为反应试验结果显示意蜂选择胜利油菜的次数（3.86±2.83）显著高于访问马尾油菜的次数（2.28±1.87）（P<0.05）。在学习记忆试验中,随着训练次数的增加,意蜂对两种油菜花朵气味的喙伸反应率逐渐升高,相同的训练次数,意蜂对两种油菜气味的学习能力差异不显著（P>0.05）;训练结束后,随着时间的增加,意蜂对胜利油菜及马尾油菜的气味记忆逐渐下降,在24 h对胜利油菜的气味记忆明显高于对马尾油菜的气味记忆（P<0.05）。【结论】本研究证明意蜂较偏爱胜利油菜的花朵气味,花朵气味是影响其采集偏爱的重要因素,气味响应性试验可定量分析蜜蜂对花朵气味的嗅觉敏感性。