枯草芽孢杆菌224 yplQ基因敲除及其对溶血性的影响

为了确定枯草芽孢杆菌224(Bacillus subtilis 224,BS224)的溶血基因或引起溶血的主效基因,以枯草芽孢杆菌224基因组DNA为模板,用PCR方法分别扩增yplQ基因上游约1.0 kb和yplQ基因下游0.5 kb两段DNA序列,并以携带新霉素抗性基因的重组质粒pMD18-T-neo为骨架,构建基于yplQ基因位点的基因阻断质粒pMD18-T-neo-yplQ,线性化后电转化至枯草芽孢杆菌224,通过新霉素抗性平板得到36个neor抗性转化子,基因组PCR鉴定和核苷酸测序证明,确定yplQ18为yplQ基因缺失菌株,将其接种到5%的绵羊血琼脂平板上进行溶血性检测,仍能引起溶血。结果表明,单独敲除枯草芽孢杆菌224染色体上yplQ基因对菌株的溶血性无影响或影响不大。     

In vitro blastogenic responses of peripheral lymphocytes from marmosets to phytohemagglutinin and to autologous lymphocytes transformed by Epstein-Barr virus

White-lipped marmosets were evaluated for their cell mediated immune (CMI) response to EBV to determine the feasibility of CMI studies in marmoset models for EBV oncogenesis. The mitogen, cell concentrations, the length of incubation period and serum requirements were defined for in vitro lymphocyte stimulation tests. The level of response of each animal was dependent on the concentration of phytohemagglutinin-P (PHA-P) and was independent of cell densities employed. The rate of tritiated-thymidine incorporation by mononuclear cells due to PHA-P increased exponentially between 2–4 days. This test was reproducible for a given batch of PHA-P when the cells were cultured in the presence of 10% heat inactivated fetal bovine serum. The five white-lipped marmosets were seronegative for EBV antigens and did not show lymphocyte stimulation with EBV particles and EBV soluble antigen, but two of these animals exhibited significant stimulation with autologous lymphocytes transformed in vitro by B95-8 virus. Despite the limited amount of blood (3–4 ml) that could be obtained from each animal in a single bleeding, it was possible to perform multiple lymphocyte stimulation assays with the protocol used.     

大白菜胞质雄性不育系育性相关线粒体DNA片断的克隆及*序列分析

利用PCR技术从大白菜(Brassica campestrisL.ssp.Penkinsis)新型胞质雄性不育材料CMS7311的线粒体基因组中扩增出与细胞质雄性不育相关的片断,并克隆测序。序列分析表明,该片断和报道的Poli-ma-orf224序列完全相同,没有发生变异,说明CMS7311的不育机理与PolimaCMS相似,也反映了细胞质雄性不育变异的保守性。     

Potential use of lymphocyte blastogenic responses in diagnosis of bovine tuberculosis

A comparison of in vitro lymphocyte responses and delayed type tuberculin skin test responses was made in an animal experimentally exposed to a Mycobacterium bovis-infected animal and in cattle naturally infected with M. bovis. Tuberculin skin tests did not suppress in vitro lymphocyte responses to M. bovis PPD and to M. avium PPD tuberculin. The whole blood test used in these studies provided for considerable savings in time as compared to use of purified lymphocytes for evaluating in vitro cellular responses. Variations in the responsiveness of lymphocytes to specific mycobacterial antigens was observed, therefore, it is recommended that profiles be established using three or more tests conducted at 14-day intervals.     

Molecular Gastronomy: Overview of a Controversial Food Science Discipline

ABSTRACT

This paper discusses the origins of the food science discipline, molecular gastronomy. Molecular gastronomists explore the physical changes that occur as food is prepared for human consumption and attempt to identify optimum methods of creating a dish for pleasurable flavor and texture. Molecular gastronomy was founded by Hervé This and Nicholas Kurti as an academic discipline; however, the phrase “molecular gastronomy” is often misused in the media to refer to chefs who apply techniques developed by scientists to their own style of cooking. Although a confusion of terminology, the association of molecular gastronomy with the practice of cooking follows the natural progression of bench research to practical application that Kurti and This foresaw when they proposed this new field of research.     

奶牛乳腺上皮细胞中miR-224靶基因的初步验证

利用生物信息学方法预测出miR-224可能的靶基因为ACADM、ACAT1、ALDH2和LPL,然后用实时荧光定量法检测了miR-224与其靶基因在奶牛乳腺上皮细胞中的表达量。结果显示:(1)miR-224的相对表达量。转染shNc组表达量低于转染mimics组而高于inhibitor组。(2)靶基因荧光定量结果表明,ACADM、ALDH2和LPL基因转染shNc组表达量低于转染inhibitor组而高于mimics组。(3)经SPSS22.0相关性分析表明:在乳腺上皮细胞中,ACADM、ALDH2和LPL基因的表达量与miR-224的表达量呈显著负相关,ACAT1基因与miR-224没有显著联系。初步验证说明,ACADM、ALDH2和LPL基因可能是miR-224的靶基因,为进一步探索miR-224在奶牛乳牛乳腺上皮细胞发挥的作用提供了一定的理论依据和研究基础。     

大白菜CMS96细胞质雄性不育分子特性研究

大白菜CMS96细胞质不育系是由大白菜株系与甘蓝型油菜细胞质不育源杂交、多代回交后获得的。该不育系生长势旺、不育性稳定,不育度和不育株率均为100%,蜜腺正常,在大白菜杂种一代生产中具有广阔的应用前景。为了定位大白菜CMS96细胞质不育所属的类型和获得其不育有关的特异序列,依据atp9、coxI、orf138和orf224保守序列设计4对引物,对3组11份大白菜材料线粒体DNA进行PCR扩增,每组材料内包含同核异质PolCMS、OguCMS、CMS96三种大白菜不育系和一种共用保持系。结果表明,atp9和coxI引物在所有材料中均有扩增产物,供试材料间没有差异;而orf138和orf224引物扩增产物存在差异。orf138引物仅在全部OguCMS和CMS96不育系中扩增出309bp特异带,而保持系和PolCMS不育系没有扩增产物;orf224引物仅在所有PolCMS中扩增出689bp特异带,而保持系、OguCMS和CMS96不育系没有扩增产物。同时,对保持系和不育系花组织mRNA进行RT-PCR分析,进一步验证了orf138和orf224引物扩增产物的特异性和一致性。同源性分析结果表明,利用orf138引物所获得的309bp大白菜mtDNA特异片段均与萝卜OguCMS、甘蓝型油菜OguCMS萝卜体细胞杂种所具有的Oguorf138高度同源,二者有172个核苷酸完全相同,有58个氨基酸完全相同;orf224引物所获得的689bp大白菜mtDNA特异片段与甘蓝型油菜的Polorf224高度同源,二者有677个核苷酸完全相同,有225个氨基酸完全相同,同源性均达到100%。初步认为大白菜OguCMS和CMS96不育系具有相似性,OguCMS萝卜所具有的orf138是导致二者不育的原因;Pol甘蓝型油菜所具有的Polorf224是导致大白菜PolCMS不育的原因。     

细胞质雄性不育相关基因orf224的克隆及其植物表达载体的构建

利用 PCR技术从油菜 Polim a不育系中扩增出细胞质雄性不育相关基因 orf 2 2 4 ,并将其克隆到p GEM- T Easy载体上得到重组质粒 p GEMORF。在此基础上 ,用限制性内切酶将 orf 2 2 4基因从质粒 p GEMORF上切下 ,连接在 p BI12 1质粒的 Ca MV 35 S启动子和 NOS终止子之间。经 PCR和酶切鉴定 ,得到了 orf 2 2 4基因的植物表达载体 p BIORF     

Comparative study of various Chlamydia strains--preliminary study (author's transl)]

The chlamydia order comprises two species (Chlamydia trachomatis and Chlamydia psittaci) which are the only ones which can be rigorously differentiated with experimental criteria. However, the clinical study of chlamydia demonstrates the existence of various syndromes due to pathogenic agents. Some observations also seem to indicate the possibility of antigenic differences between isolated strains, during abortions, among small ruminants.We have entered upon a comparative study of various Chlamydia psittaci strains in order to look for objective criteria of differentiation of the strains extracted from small ruminants from those which were isolated from other animal species. Chlamydia taken from samples of ovine and caprine origin by direct isolation on embryonated egg or on cellular cultures were also compared by the following methods: seroneutralization on embryonated eggs and on cell cultures, characteristics of the plaques on cell cultures, crossed-immunofluorescence, toxic effects, lethal action on the foetus of the pregnant mouse, crossed-immunoelectrophoresis by agar gel (simple or double quantitative diffusion), electrophoresis by polyacrylamide gel.The use of those numerous techniques has enabled us to observe significant differences between those strains. However, it is not yet possible to propose a classification defining several groups. The specificity of these differences, especially between ovine and caprine strains, should become clear through the studies now in progress: in particular through the method using the interference of specific antigens compared on the one hand by serioimmunologic methods and, on the other hand, by tests setting an immunity to cellular mediation into action.