黑翅土白蚁踪迹信息素组分数量的柱层析分离和活性测定分析

本文分析了在活性限浓度进行生物活性测定时,黑翅土白蚁Odontotermes formosanu Shiraki对踪迹信息素的行为反应特点以及使用不同踪迹线载体对踪迹信息素活性的影响。并设计标准生物活性测试方法,测定了采用柱层析方法分离的黑翅土白蚁踪迹信息素各分离馏分的活性,发现黑翅土白蚁踪迹信息素用22%乙酸乙酯/正己烷洗脱液等度洗脱分离后的各馏分中包含两个强活性区段,推测黑翅土白蚁踪迹信息素至少包含2个有轻微极性差异的组分。     

黑翅土白蚁和黄翅大白蚁翅面微刻点的扫描电镜观察

Roonwal及其合作者(1967—1987)对白蚁翅面微刻点(Wing microsculpturing)进行了广泛的研究,发现至少存在8种类型的微刻点,并对其进化、分类学和生态学意义进行了讨论。但他们的观察主要是在光镜下进行的,电镜下的观察极少。国内尚未见有关的报道。我们对黑翅土白蚁和黄翅大白蚁的翅面微刻点进行了扫描电镜观察,现将结果报道如下。     

合成黑翅土白蚁踪迹信息素类似物的生物活性

合成了黑翅土白蚁踪迹信息素类似物(Z,Z)-3,6-十二碳二烯醇-1（DDE-OH）,该类似物对黑翅土白蚁工蚁具有和信息素提取物类似的行为反应。活性反应阈值为10^-3～10 ng/cm,大于10 ng/cm时产生较强的驱避作用。最佳活性浓度DDE-OH与信息素提取物的活性反应之间没有显著差别。     

黑翅土白蚁菌圃共生菌对小麦秸秆的生物降解

【目的】探究黑翅土白蚁(Odontotermes formosanus)菌圃共生菌在木质纤维素降解上的应用潜力,增加秸秆降解菌种资源并为秸秆资源产业化利用提供理论依据。【方法】以刚果红染色法、羧甲基纤维素钠平板分离筛选具有木质纤维素降解活性的黑翅土白蚁菌圃共生菌并测定共生菌产酶情况。在常温液态发酵条件下,评估不同菌种以及复合菌群对小麦(Triticum aestivum L.)秸秆的降解效果,利用傅里叶红外光谱、X射线晶体衍射和冷场扫描电镜分析降解前后小麦秸秆的理化性质。【结果】从黑翅土白蚁菌圃中分离得到具有木质纤维素降解活性的5种真菌和3种细菌,经鉴定为青霉属(Penicillium) 2种,紫霉属(Purpureocillium) 1种,曲霉属(Aspergillus) 1种,弯孢聚壳霉属(Eutypella) 1种,芽孢杆菌属(Bacillus) 1种,埃希氏菌属(Escherichia) 1种,寡养单胞菌属(Stenotrophomonas) 1种。经酶活测定和单菌降解试验筛选出4种高效降解菌株[桔青霉(Penicillium citrinum)、红绶曲霉(Aspergillus nomiae)、枯草芽孢杆菌(Bacillus subtilis)、大肠杆菌(Escherichia coli)]组成复合菌群。经常温液态发酵,4种菌组成的复合菌群的综合降解能力最强,在12 d内干物质降解率达到24.35%,纤维素降解率达到47.24%,半纤维素降解率达到35.75%,木质素降解率达到32.72%。降解后小麦秸秆内部化学键和分子间作用力受到破坏,木质纤维素复合结构受到破坏,纤维素结晶度从37.40%降低至32.97%,秸秆表面严重崩解,结构蓬松。【结论】从黑翅土白蚁菌圃中分离得到的桔青霉、红绶曲霉、枯草芽孢杆菌、大肠杆菌所组成的复合菌群对小麦秸秆有着优良的降解效果,具备秸秆生物降解产业化的潜在开发价值。     

黑翅土白蚁与其它二种白蚁种群间的相容性

将黑翅土白蚁Odontotermes formosanus(Shiraki)与另外2个种群的白蚁按一定比例放置于同一培养皿中观察其斗争情况,研究黑翅土白蚁与台湾乳白蚁Coptotermes formosanus(Shiraki)和黑胸散白蚁Reticulitermes chinensisSnyder的相容性。结果表明,实验一开始,双方的工蚁和兵蚁都立即进入激烈的嘶咬斗争,在不同配比下,开始5min内的斗争次数均在40次左右,5h后开始5min内的斗争次数陡然下降,几乎不发生争斗。各种群白蚁在其数量占优势的情况下均表现出显著的斗争优势;而在双方数量相当时,黑翅土白蚁工蚁的斗争能力明显强于另外2个种群的工蚁。结果表明,自然界中不可能出现黑翅土白蚁与家白蚁和黑胸散白蚁群体的偶然性融合,黑翅土白蚁很可能在其群体建立的地区中占据优势。     

黑翅土白蚁触角感器的扫描电镜观察

【目的】通过黑翅土白蚁Odontotermes fomosanus(Shiraki)幼蚁、工蚁、兵蚁触角感器种类、数量及分布的研究,分析不同龄幼蚁、工蚁和兵蚁的触角感器特征,为进一步研究触角感器发育特点及不同个体的行为分化机制提供参考。【方法】通过扫描电镜观察触角形态,分析触角节数、感器种类、数量及分布特征。【结果】工蚁、兵蚁、幼蚁个体触角长度差异显著,触角长度顺序:工蚁>兵蚁>3龄幼蚁>2龄幼蚁>1龄幼蚁;触角感器共有9种类型,分别为短毛形感器、长毛形感器、短刺形感器、长刺形感器、锥状B?hm氏鬃毛、球状钟形感器、刺突状钟形感器、球状钟形感器与刺突状钟形感器中间型、长刺具泡状感器。工蚁、兵蚁缺少长刺具泡状感器。幼蚁触角感器种类和数量随龄数而增加,1龄幼蚁具7种感器,缺少球状钟形感器和球状钟形感器与刺突状钟形感器中间型2种类型;2龄幼蚁具有8种感器,缺球状钟形感器;3龄幼蚁具有全部9种类型感器。【结论】黑翅土白蚁幼蚁、工蚁、兵蚁触角节数和感器显著差异,可作为幼蚁龄数以及非生殖品级判别的形态指标,应用于白蚁非生殖品级行为多型等相关研究。     

氯化钠含量对黑翅土白蚁生存的影响

【目的】为摸清堤坝土埝中氯化钠对黑翅土白蚁Odontotermes formosanus Shiraki生存的影响,合理确定防治黑翅土白蚁危害堤坝的氯化钠含量值,确保堤坝工程安全运行。【方法】选取有黑翅土白蚁生存和无黑翅土白蚁生存两类堤坝的土埝,进行土埝中氯化钠含量的测试。【结果】有黑翅土白蚁生存的堤坝土埝氯化钠含量在0.02%以下,无黑翅土白蚁生存的堤坝土埝氯化钠含量在0.19%以上。【结论】研究成果对黑翅土白蚁危害堤坝的防治具有很好的实用价值。     

黑翅土白蚁有翅成虫复眼的形态结构

采用组织切片法光镜下观察黑翅土白蚁Odontotermes formosanus(Shiraki)有翅成虫的复眼形态结构及光、暗适应条件下色素颗粒移动的规律。结果如下:(1)头正前方观,复眼外部形态略呈圆形。(2)有翅成虫复眼类型属于并列像眼,每只复眼约由360个小眼组成。(3)每个小眼是由1套屈光器(1个角膜和1个晶锥)、小网膜色素细胞、视杆和基细胞等几部分组成。小网膜色素细胞内均含有丰富的色素颗粒。(4)在光适应条件状态下,屈光器及视杆周围的色素颗粒主要分布在视杆部位的上侧,暗度适应条件状态时则较均匀地分布于视杆两侧上下;性别对色素颗粒分布无明显影响。     

绿僵菌与白僵菌对黑翅土白蚁的室内毒力测定

白蚁是世界性的主要害虫之一,世界各大洲都有分布,其为害面积约占全球总面积的50％,尤其在热带、亚热带地区,白蚁为害更为突出(李桂祥等,1989)。福建省的白蚁种类之多位居全国第三。     

黑翅土白蚁基因组DNA提取方法的优化

目的 为快速地提取到质量较好的黑翅土白蚁基因组DNA进行白蚁种群多样性的研究,对基因组DNA提取方法进行了比较与改进.方法 先初步采取CTAB法与蛋白酶K法对黑翅土白蚁基因组DNA的提取方法进行比较,再利用正交设计法对蛋白酶K法中裂解液、蛋白酶、RNA酶及作用时间4个因素进行优化.结果 蛋白酶K法获得的基因组DNA的质量与产量稍优于CTAB法;较佳的提取步骤组合为:裂解液150 μL,蛋白酶K 6μL,作用时间1h,RNA酶可不添加.结论 采用优化后的方法获得的基因组DNA为模板进行PCR扩增,得到了清晰、稳定的扩增谱带,完全可用于相关后续实验.     

生物有机肥对板栗土壤微生物群落代谢活性的影响

2011年在陕西省柞水县下梁镇沙坪村板栗园,设置对照、施用复合肥和施用生物有机肥3个处理,于板栗收获期采集土壤样品,并运用Biolog方法研究了生物有机肥对土壤微生物群落代谢能力的影响.结果表明:生物有机肥处理的微生物群落碳源利用率(AWCD)、Shannon均匀度、丰富度指数和McIntosh指数均显著高于对照和复合肥处理;与对照相比,施用生物有机肥处理的土壤微生物对糖类和多聚物类碳源的利用能力增强,而施用复合肥处理对各类碳源的利用能力均较弱.主成分分析表明,不同施肥处理的土壤微生物群落明显不同,起分异作用的碳源主要为糖类和氨基酸类.     

The titerless infected-cells preservation and scale-up (TIPS) method for large-scale production of NO-sensitive human soluble guanylate cyclase (sGC) from insect cells infected with recombinant baculovirus

Compounds capable of stimulating soluble guanylate cyclase (sGC) activity might become important new tools to treat hypertension. While rational design of these drugs would be aided by elucidation of the sGC three-dimensional structure and molecular mechanism of activation, such efforts also require quantities of high quality enzyme that are challenging to produce. We implemented the titerless infected-cells preservation and scale-up (TIPS) methodology to express the heterodimeric sGC. In the TIPS method, small-scale insect cell cultures were first incubated with a recombinant baculovirus which replicated in the cells. The baculovirus-infected insect cells (BIIC) were harvested and frozen prior to cell lysis and the subsequent escape of the newly replicated virus into the culture supernatant. Thawed BIIC stocks were ultimately used for subsequent scale up. As little as 1 mL of BIIC was needed to infect a 100-L insect cell culture, in contrast to the usual 1 L of high-titer, virus stock supernatants. The TIPS method eliminates the need and protracted time for titering virus supernatants, and provides stable, concentrated storage of recombinant baculovirus in the form of infected cells. The latter is particularly advantageous for virus stocks which are unstable, such as those for sGC, and provides a highly efficient alternative for baculovirus storage and expression. The TIPS process enabled efficient scale up to 100-L batches, each producing about 200 mg of active sGC. Careful adjustment of expression culture conditions over the course of several 100-L runs provided uniform starting titers, specific activity, and composition of contaminating proteins that facilitated development of a process that reproducibly yielded highly active, purified sGC.     

Design and synthesis of small semi-mimetic peptides with immunomodulatory activity based on Myelin Basic Protein (MBP)

Summary Experimental allergic encephalomyelitis (EAE) is induced in susceptible animals by immunodominant determinants of myelin basic protein (MBP). Analogs of these disease-associated peptides have been identified with disease progression upon coimmunization. Usage of peptides, with disease-specific immunomodulatory capacity in vivo is limited, however, due to their sensitivity to proteolytic enzymes. Alternative approaches include the development of mimetic molecules which maintain the biological function of an original peptide, yet are stable and able to elicit their response in pharmacological quantities. A novel technique was employed to design a series of semi-mimetic peptides, based on the guinea pig MBP_72–85 peptide used to induce EAE in Lewis rats. We used isonipecotic (iNip) and aminocaproic (Acp) acids as templates. Acp-MBP_72–85 peptide derived analogues were effective in inducing EAE compared to iNip-peptide analogues which were ineffective at 350g. These findings suggest that the design and synthesis of semi-mimetic peptide molecules with immunomodulatory potential is possible and that eventually these molecules may form the basis for the development of novel and more effective disease-specific therapeutic agents.     

连翘种子挥发油抑真菌及在猪油脂酸败过程中的作用

利用滤纸片法观察不同浓度连翘种子挥发油对啤酒酵母、产黄青霉以及黑曲霉的抑制作用,并测定了其最小杀菌浓度;利用猪油体系对连翘种子挥发油在油脂酸败过程中的作用进行了初步探索。结果表明连翘种子挥发油对这三种真菌均有很好的抑制作用,最小杀菌浓度分别为:啤酒酵母为3.91×10-4mL/100 mL,产黄青霉为7.81×10-4mL/100 mL,黑曲霉为3.13×10-3mL/100 mL;而连翘种子挥发油对猪油具有促进其氧化的作用。     

Screening of human vascular endothelial growth factor (VEGF) receptor Flt-1 domain and study on its biological activity

Four human vascular endothelial growth factor receptor Flt-1 cDNA fragments containing extracellular domain loops 2, 1–2, 2–3 and 1–3 respectively were amplified from human placental cDNA library by PCR and used for screening ligand binding domains by yeast two-hybrid system. The result showed that, not only loop 1–3, but also the smaller fragment loop 2–3 could bind to hVEGF₁₆₅. Recombinant expression plasmids pPIC9K/Flt-1(1–3) and pPIC9K/Flt-1(2–3) were constructed and transformed toPichia. pastoris host strain GS115, cultured in flasks, and expressed under the induction of 1% methanol. The expressed product existed in supernatant in the form of soluble molecules and contained more than 60% of total protein after being induced for 4d. After being purified by CM-Sepharose FF and Sephacryl S-100 chromatography, its purity reached above 90%. Biological assayin vitro showed that the binding capacity of expressed soluble Flt-1 (2–3) to hVEGF₁₆₅ and its inhibiting effect on the proliferation of human umbilical veins endothelial cells (HUVEC) stimulated with hVEGF₁₆₅ were close to those of sFlt-1(1–3). Animal test showed that sFlt-1(2–3) could inhibit the formation of regenerate blood vessels stimulated with hVEGF₁₆₅ significantly.     

The anti-inflammatory effect of neuropeptide Y (NPY) in rats is dependent on dipeptidyl peptidase 4 (DP4) activity and age

Neuropeptide Y (NPY)-induced modulation of the immune and inflammatory responses is regulated by tissue-specific expression of different receptor subtypes (Y1–Y6) and the activity of the enzyme dipeptidyl peptidase 4 (DP4, CD26) which terminates the action of NPY on Y1 receptor subtype. The present study investigated the age-dependent effect of NPY on inflammatory paw edema and macrophage nitric oxide production in Dark Agouti rats exhibiting a high-plasma DP4 activity, as acknowledged earlier. The results showed that NPY suppressed paw edema in adult and aged, but not in young rats. Furthermore, plasma DP4 activity decreased, while macrophage DP4 activity, as well as macrophage CD26 expression increased with aging. The use of NPY-related peptides and Y receptor-specific antagonists revealed that anti-inflammatory effect of NPY is mediated via Y1 and Y5 receptors. NPY-induced suppression of paw edema in young rats following inhibition of DP4 additionally emphasized the role for Y1 receptor in the anti-inflammatory action of NPY. In contrast to the in vivo situation, NPY stimulated macrophage nitric oxide production in vitro only in young rats, and this effect was mediated via Y1 and Y2 receptors. It can be concluded that age-dependant modulation of inflammatory reactions by NPY is determined by plasma, but not macrophage DP4 activity at different ages.     

烟粉虱在温室内甘薯寄主上生物学特性的研究

对烟粉虱Bemisia tabaci(Gennadius)在温室内甘薯寄主上主要生物学特性的研究表明：烟粉氮成虫喜光、喜湿,晴朗高温时活动性强,但扩散飞行能力弱;多在白天交尾,多在中午产卵,具有强的惫鬃性．若虫一生脱皮3次,若虫(除一龄初期)固定生活。卵的孵化及成虫的羽化也多发生在中午。雌雄性比为1．628：1,成虫平均寿命14．25天,雌成虫平均寿命比雄成虫长6．9天,每雌平均产卵158．5粒。以两性生殖为主,也可孤雌生殖,两性生殖的产卵量及卵孵化率均高于孤雌生殖。     

Asymmetric synthesis of the four diastereoisomers of a novel non-steroidal farnesoid X receptor (FXR) agonist: Role of the chirality on the biological activity

An asymmetric synthetic strategy was designed for the preparation of the four possible diastereoisomers of 3,6-dimethyl-1-(2-methylphenyl)-4-(4-phenoxyphenyl)-4,8-dihydro-1H-pyrazolo[3,4-e][1,4]thiazepin-7-one, a non-steroidal FXR agonist, we recently discovered following a virtual screening approach. The results obtained from an AlphaScreen assay clearly demonstrated that only the isomer endowed with 4R,6S absolute configuration is responsible for the biological activity. A deep investigation of the different putative binding modes adopted by these enantiomerically pure ligands using computational modeling studies confirmed the enantioselectivity of FXR towards this class of molecules.     

利用PMCA技术实验不同剂量MCT联合DTT对PrP~(sc)转化的抑制效应

蛋白质错误折叠循环扩增(protein misfolding cyclic amplification,PMCA)技术,是一种具有感染性的朊蛋白(PrPsc)体外扩增的技术,可用于抑制细胞型朊蛋白(PrPc)向PrPsc转化药物的筛选.本研究在Saborio等提供的方法基础上,成功优化了最佳扩增时间,利用优化的PMCA技术实验了不同剂量氮芥(mechlorethamine,MCT)联合二硫苏糖醇(dithiothreitol,DTT)对PrPsc转化的抑制效应.结果发现,MCT联合DTT能体外抑制PrPc向PrPsc的转化,抑制作用具有明显的量效关系.利用针对人PrPc不同结构域的抗体发现,MCT联用DTT可使抗体6H4的抗原表位隐蔽,该表位位于PrPc第1个α螺旋区内,是构象转化的主要部位.对其机制的深入探讨,将有助于新一类可传播性海绵状脑病(transmissible spongiform encephalopathy,TSE)治疗药物的研发.