Aquatic birnavirus induces apoptosis through activated caspase-8 and -3 in a zebrafish cell line

In this study, the possible influence of temperature on infectious pancreatic necrosis virus (IPNV)-induced apoptosis in a zebrafish liver epithelium (ZLE) cell line was investigated. At a lower temperature (18 degrees C), there was expression of viral proteins VP2 and VP3 at 4 h post-infection (p.i.). At this time no expression was found in the high temperature group at 28 degrees C. The cell survival ratio was 52 and 18% at 24 and 48 h p.i., respectively, during IPNV infection at 18 degrees C. In addition, we assayed for apoptosis in IPNV-infected cells with terminal deoxynucleotidyl transferase (TdT)-mediated end labelling (TUNEL) of DNA at different dosages of virus. We found a ratio of apoptotic cells of 8 and 25% at 12 and 18 h p.i., respectively, in the multiplicity of infection (MOI) 1 group. The MOI 10 group had 20 and 45% apoptotic cells at 12 and 18 h, respectively. Furthermore, at 18 degrees C IPNV activated the caspase-8 and 3 from 1.5 to 2 times at 12 and 18 h p.i., respectively. Taken together, these findings suggest that successful virus replication occurs at the low temperature (18 degrees C) compared with the non-permissive temperature of 28 degrees C. Thus, IPNV replication is capable of activating caspase-8 and -3 and inducing host apoptosis.     

Cloning and expression of a surface immunogenic protein in Streptococcus dysgalactiae isolated from fish and its application in enzyme‐linked immunosorbent assays to diagnose S. dysgalactiae infections in fish

Lancefield group C Streptococcus dysgalactiae (GCSD) causes severe necrotic lesions in the caudal peduncle in the genus Seriola farmed in Japan. To develop a sero‐diagnostic method for GCSD infection in farmed fish, we attempted to identify a surface immunogenic protein that induces an antibody after infection with GCSD by immunoblot analysis using sera collected from infected fish. A protein obtained from sodium dodecyl sulfate (SDS) extracts of GCSD was identified as S. dysgalactiae surface immunogenic protein (Sd‐Sip). Sd‐Sip exhibited more than 94% homology with a surface antigen or a hypothetical protein from S. dysgalactiae mammalian isolates at the nucleotide sequence level. Expression of the recombinant Sd‐Sip (rSd‐Sip) was confirmed by immunoblot analysis, that is, its reactivity to GCSD‐infected sera. Antibody detection ELISA using rSd‐Sip and their usefulness for diagnosis of GCSD infection were examined. GCSD‐infected sera collected from farmed amberjack, Seriola dumerili (Risso), showed strong reaction with immobilized rSd‐Sip. Meanwhile, sera immunized by other pathogenic bacteria of fish were showed ELISA values similar to those of non‐infected sera. These results of this study suggest that the antibody detection ELISA using rSd‐Sip is an effective diagnostic method for GCSD infection in fish.     

农杆菌浸润瞬时表达分析番木瓜miR162a的研究

农杆菌浸润瞬时表达方法不仅在蛋白互作、鉴定基因沉默抑制子及基因功能研究方面得到广泛应用,目前还应用在小RNA的研究中.在对植物microRNA的研究中,农杆菌浸润方法通过将将转基因导入农杆菌浸润本生烟瞬时表达,可以快速、稳定地对植物microRNA进行检测和鉴定,样品在几天内就可分析完成,比获得稳定遗传的转基因有优势.笔者借鉴国外拟南芥microRNA瞬时表达分析的方法,克隆了番木瓜的miR62a前体序列连接到双元表达载体pSuper1300上构建成35S::cpa-miR162a质粒,导人农杆菌GV3101后浸润本生烟,浸润后48 h提取本生烟叶片总RNA后通过miRNA northern blot检测到miR162a,而本生烟和番木瓜自身则无法检测到低丰度的miR162a.本文介绍的农杆菌浸润瞬时表达方法能够在体外加工产生成熟的miRNA,该技术有助于对microRNA的结构-功能的相关性及靶标验证进一步研究.     

应用伪钝绥螨防治苹果全爪螨的试验

1987～1988年田间应用试验表明,青岛地区生态条件可以满足伪钝绥螨生存和发展的要求.5月下或6月初,以1:50的益害比,释放伪钝绥螨,可控制苹果全爪螨为害,减少果园施用杀螨剂3次。伪钝绥螨在当地可以自然越冬,完成周年循环,建立种群,成为控制叶螨发生的有效天敌。     

Potato plant response to seed tuber bacterization in the field in various rotations

The effects of a seed tuber treatment with antagonistic isolates of fluorescentPseudomonas spp. were investigated on potato plants from 1981 to 1984. The experimental plots were located in fields in short and long rotations of potato. The short rotations are characterized by serious yield reductions which are caused by unknown microbial factors. The reductions varied from 30% in 1982 to only 3% in 1983 in the 3-year rotations. A statistically significant increase in yield (four to five months after planting) of ware potatoes varying from 9 to 20% was obtained in these plots through tuber bacterization, but only in 1981. In 1982 and 1983 initially significant improvements in shoot or tuber weight of seed potatoes were no longer detectable at ware potato harvest at the end of the growing period. Seed tuber bacterization had no effect on tuber yield in long rotations. Initial colonization of basal root parts by 53×10⁴ colony forming units (cfu) of antibiotic-resistant mutants per gram of root (fresh) dropped significantly to 20×10⁴ cfu per gram after three months. The bacterization effect on tuber yield depended on the development of harmful microbial activity and of introduced antagonists during the growing period. Seed tuber bacterization is more promising for seed potatoes than for ware potatoes in short rotations, the latter being harvested two months later.Samenvatting De invloed van pootgoedbehandeling met antagonistische isolaten van fluorescerendePseudomonas-soorten op de aardappelteelt, werd onderzocht in de periode van 1981 tot en met 1984. De proefvelden maakten deel uit van zowel ruime als nauwe rotaties met aardappelen. Kenmerkend voor de nauwe rotatie is, dat de opbrengst aanzienllijk gereduceerd wordt als gevolg van de aanwezigheid van nog onbekende microbiële factoren. Deze opbrengstverlaging varieerde van 30% in 1982 tot slechts 3% in 1983 in de 3-jarige rotaties. Pootgoedbacterisatie had in deze proefvelden een significante toename van de eindopbrengst (vier tot vijf maanden na pootdatum) van consumptieaardappelen tot gevolg, die varieerde van 9 tot 20%, echter allen in 1981. In 1982 en 1983 werd het effect van bacterisatie ook in de loop van de groeiperiode onderzocht. Aanvankelijk significante toenames van zowel spruit-als knolgewicht waren aan het einde van het groeiseizoen niet meer aantoonbaar. Pootgoedbacteristie bleek geen effect te hebben op aardappel in ruimte rotaties. Aanvankelijk werden de basale wortelgedeelten gekoloniseerd door antibioticum-resistente mutanten met 53×10⁴ kolonievormende eenheden (kve) per gram wortel(vers); dit aantal liep (drie maanden na pootdatum) echter significant terug tot 20×10⁴ kve per gram. Het effect van bacterisatie op de eindopbrengst werd bepaald door de ontwikkeling van de schadelijke microbiële activiteit en de ontwikkeling van de geïntroduceerde antagonisten tijdens het groeiseizoen. Pootgoedbacterisatie in nauwe rotaties biedt meer mogelijkheden voor de teelt van pootaardappelen dan die van consumptieaardappelen, die geruime tijd later geoogst worden.     

肌肉注射硫酸安普霉素在猪体内的药代动力学和生物利用度研究

对6头健康猪单剂量静脉注射、肌肉注射国产硫酸安普霉素,研究其在猪体内的药代动力学和生物利用度.用微生物法测定血清药物浓度,结果平均回收率为99.03%,血清最低检测浓度为0.05μg/ml,日内日间变异系数为2.2%～5.1%,且血清浓度在0.05～3μg/ml范围呈良好线性关系(r＝0.9965).对猪静注、肌注硫酸安普霉素20mg/kg后,经MCPKP药代动力学计算机程序处理,体内药物运转符合开放型二室模型,肌肉注射0.856h后达峰药浓度Cmax为36.09±1.22μg/ml;t1/2分别为1.58±0.67h、1.06±0.11h,CLB分别为0.15L/kg/h、0.17 L/kg/h,V1分别为0.71L/kg、0.1L/kg,绝对生物利用度为AUC i.m/AUC i.v＝88.47%±3.32%,上述药代动力学数据为动物临床用药提供有价值的理论依据.     

应用TaqMan-MGB探针进行松材线虫的实时荧光定量检测技术研究

 松材线虫是国际公认的最重要的检疫性有害生物之一,也是我国2类检疫危险性有害生物,我国口岸多次从货物的木质包装中截获该线虫。由于松材线虫与拟松材线虫在形态上极其相似,难以区分,幼虫更无法用于鉴定。传统的形态学鉴定、生化以及其他分子技术等方法存在费时、准确度不高、灵敏度低等缺点,不易形成标准。我们设计筛选一对引物以及一条MGB探针,对松材线虫进行实时荧光PCR检测。建立了一条从1 pg到10⁴pg标准曲线,相关系数r=0.965。该检测方法省时、准确、快速、无污染。     

重庆地区柑桔衰退病毒多态性研究

柑桔衰退病毒(CTV)存在着复杂的株系分化现象.在使用弱毒株交叉保护防治柑桔衰退病时需要对田间病毒株系组成进行分析,并对选用的株系进行单蚜分离纯化.作者运用限制性片段长度多态性和单链构象多态性对田间获得的168个CTV样品和2个蚜传毒株的外壳蛋白基因进行分析,了解重庆市田间CTV组群构成情况,发现田间CTV以多株系混合发生为主,其中主要是CP/HinfⅠRFLP第1、3和6组群,约占总数的90%,并以强毒株混合感染为主.甜橙中CP/HinfⅠRFLP的组群构成最为复杂.单头褐色桔蚜从柚类至甜橙传播CTV的效率低(不足1%),该蚜的取食可改变CTV的株系组成.     

利用菜青虫细胞检测几种有机溶剂和有机磷农药的毒力

用MTT法研究了5种有机溶剂对菜青虫细胞生长的影响及3种有机磷农药对细胞的毒力。并用微量点滴法测定了3种农药对菜青虫3龄幼虫的毒力。结果表明,5种有机溶剂除二甲苯外,其余4种二甲亚砜、乙醇、丙酮、乙酸乙酯对菜青虫细胞低浓度处理时均无很大毒性。1％浓度处理16小时后细胞存活率仍分别可达99.8％、98％、97.2％、91％。分别用菜青虫细胞测得3种有机磷农药的LC_(50)为:甲基对硫磷,106μs/ml;克线磷,147μg/ml;水胺硫磷,183μg/ml。用微量点滴法测得3种有机磷农药对菜青虫3龄幼虫的LD_(50)分别为:甲基对硫磷,0.458μg/头,克线磷,45.012μg/头;水胺硫磷,0.505μg/头。     

Production and evaluation of monoclonal antibodies for the detection of beet mild yellowing luteovirus and related strains

A sugar-beet-infecting isolate of beet mild yellowing luteovirus (BMYV), and aBrassica-infecting isolate of beet western yellows luteovirus (BWYV) were used to produce monoclonal antibodies for epidemiological studies with BMYV and related field strains. Thirty-four monoclonal antibodies were tested for their reaction with 9 luteoviruses in triple-antibody-sandwich enzyme-linked immunosorbent assay. One (MAFF 24) is now routinely used in the UK for detecting BMYV and BWYV in plants and aphids, although it does not discriminate between them. Heterologous reactions were detected between some of the monoclonal antibodies and potato leafroll virus (PLRV), bean leafroll virus (BLRV) and barley yellow dwarf virus (BYDV-RPV). 38% of antibodies raised to BWYV reacted with PLRV compared with 4% of those raised to BMYV. Monoclonal antibodies were produced which distinguished a sugar-beet-infecting isolate of BMYV with differing host range and serological properties from the commonly-occurring field strain.