Epitopic characterisation of Turkish bovine viral diarrhoea virus (BVDV) isolates using monoclonal antibodies

In this study, 15 bovine viral diarrhoea viruses (BVDV) isolated from the field in Turkey were characterised for their biotype, cloned and eventually analysed for their epitopic composition in terms of glycoprotein E2. Immunoplaque assay, plaque assay, limiting dilution and streptavidin-biotin-peroxidase techniques were used for biotype characterisation, cloning of cytopathic (cp) and noncytopathic (ncp) biotypes and epitope analysis, respectively. While 14 out of 15 BVDV isolates were distinguished as ncp biotype, 1 isolate was found to be containing both biotypes (cp + ncp). According to the reactivity patterns of isolates with 15 monoclonal antibodies, 4 different antigenic groups could be formed. There were no antigenic differences between the isolates derived from the same animal with various time intervals. On the other hand, biotype clones isolated from the same animal exhibited difference in one epitope. This is the first study describing antigenic characterisation of BVDV field isolates in Turkey.     

肌肉生长抑制素基因在不同动物中的研究进展

肌肉生长抑制素(myostatin,MSTN)基因也叫生长分化因子(growth differentiation factor-8,GDF8),其作为肌肉生长发育及分化的负向调控因子,可通过抑制正向调控因子--生肌决定因子(myogenic determination gene,MyoD)的转录活性来抑制成肌细胞的增殖和分化。MSTN基因在进化过程中具有较高的突变性,在不同动物中的表达量和表达范围均不相同。作者就该基因的表达、生物学功能、作用机制及在不同动物中的研究进展进行了详细阐述。     

柑橘衰退病毒基因RNAi载体的构建

基于转化病毒基因介导抗性,通过在植物表达载体p CAMBIA 2301上插入启动子–内含子–终止子的方式,构建一种含有发夹结构的、通用型强的RNAi载体骨架结构;以柑橘衰退病毒(citrus tristeza virus,CTV)的p25、p20和p23基因保守序列为模板设计正向片段和反向片段,先后与骨架载体连接,成功构建了3个RNAi载体(分别命名为ds2301–p25、ds2301–p20和ds2301–p23),并将载体ds2301–p23注射入墨西哥莱蒙叶片。制作p23基因的地高辛标记探针,用Northern杂交检测是否有si RNA产生。结果表明:用Northern杂交可以检测到p23特异的si RNA,在墨西哥莱蒙叶片中瞬时表达的农杆菌ds2301–p23可以发生RNAi,表达有效的si RNA。本研究中构建的骨架载体可以广泛用于RNAi载体的构建,含有柑橘衰退病毒基因片段的3个载体可以用于基因功能分析及具有CTV抗性的柑橘种质资源获得。     

Comparison of ultrasonographic findings with clinical activity index (CIBDAI) and diagnosis in dogs with chronic enteropathies.

Intestinal wall thickness is neither a specific nor sensitive ultrasound parameter for detecting intestinal inflammation. We hypothesize that mucosal echogenicity, lymphadenomegaly, and secondary findings of the gastrointestinal tract would be more sensitive and specific markers for detecting and differentiating causes of chronic inflammatory bowel disease in dogs. Fifty-six client-owned dogs with chronic diarrhea and 10 control dogs were examined with two-dimensional, gray-scale ultrasound (time 0, 4, and 10 weeks post therapy) and small intestinal mucosal biopsies were performed at the 0- and 4-week time points. The clinical activity was assessed at each time point using the canine inflammatory bowel disease activity index (CIBDAI). Fifty-one dogs had inflammatory infiltration of the duodenal mucosa and were divided into three groups, food-responsive disease, idiopathic inflammatory bowel disease, and protein-losing enteropathy, based on their response to the different treatments and histology. Two different patterns of increased echogenicity of the mucosa were detected: hyperechoic speckles and hyperechoic striations. A normal, hypoechoic bowel mucosa in dogs with chronic diarrhea had a sensitivity of 80% and a specificity of 81% for the diagnosis of food-responsive disease. Hyperechoic striations had a sensitivity of 75% and a specificity of 96% for dogs with protein-losing enteropathy. Hyperechoic speckles were non-specific for diagnosing inflammatory bowel disease. There was a significant relationship between ultrasound score and CIBDAI at t0, but not following therapy. Mucosal echogenicity may be a better parameter for detecting inflammatory bowel disease than bowel wall thickness in dogs with chronic diarrhea.     

农杆菌转化花粉愈伤组织获取纯合的转基因水稻植株

应用农杆菌介导法成功地将玉米转座子Ds导入粳稻(OryzasattvaI.subsp.japontca)中花11的花粉愈伤组织中,基因转化以对除草剂PPT有抗性的Bar基因和潮霉素抗性基因Hpt为选择标记.共获得了18个独立的转基因绿苗,其中单倍体11株,二倍体7株.转基因植株均抗除草剂BASTA.考查了二倍体植株种子后代(T1)对BASTA的抗性,7个株系的所有植株均抗BASTA,而未发生感抗分离,表明外源基因在转基因植株中是纯合的.PCR和Southernblotting的研究支持上述结果.对获得纯合转基因株系的各种方法做作了比较和讨论.     

特色植物辣木的应用价值及发展前景分析

目的研究水分胁迫对多油辣木(Moringa oleifera Lam.)苗期主要性状和光合参数的影响,揭示水分胁迫与辣木光合作用及生理指标之间的关系,为辣木栽培管理、抗性筛选提供理论参考。方法以多油辣木PKM1为供试材料,采用盆栽控水试验,设置充分供水(TA)、轻度水分胁迫(TB)、中度水分胁迫(TC)、重度水分胁迫(TD)和严重水分胁迫(TE) 5个水分处理,分析水分胁迫下辣木苗期生理指标和光合参数的变化。结果(1) 水分胁迫下,辣木苗期的株高、茎粗、叶片数、叶干重、茎干重、根干重、叶面积、根含水量、根长、根幅和根粗呈递减趋势,根冠比呈递增趋势。(2) 水分胁迫下辣木苗期叶片的叶绿素含量呈递减趋势,F_o值呈递增趋势,F_m、F_v、(F_v/F_m)、(F_v/F_o)、qP和rETRmax值均呈递减趋势。结论适度干旱有利于辣木苗期生长发育。干旱胁迫条件下,辣木仍保持较高光合能力和根冠比,是其抗旱耐旱的重要生理基础。     

玻璃扯旗鱼性别特征及其幼鱼性别分化的组织学初探

应用形态学、解剖学及组织学方法对玻璃扯旗鱼的性别特征及其幼鱼性别分化基本过程进行研究。结果显示:在6月龄玻璃扯旗雌鱼卵巢中能观察到各时相的卵母细胞,在雄鱼精小管管腔内有大量精子;4月龄以上玻璃扯旗雌鱼的腹部隆起,并有淡黄色颗粒状组织,而雄鱼无类似结构;100日龄以上雌鱼的臀鳍有钩状小齿,但2月龄前的幼鱼无该组织。5~50日龄幼鱼性腺发育状态显示:10日龄以下幼鱼的体内无分化明显的生殖腺;15日龄幼鱼体内有生殖包囊,且15日龄之前仅在腹腔一侧可观察到性腺组织,而25日龄幼鱼的腹腔两侧均有对称分布的类卵巢结构;至30日龄时,部分幼鱼可观察到有棒状精巢,性腺开始分化。本研究中探明了玻璃扯旗鱼性别分化及性腺发育的关键时间节点,该结果可为进一步研究其分子调控机制提供参考。     

林业院校新生信息意识现状调查与分析

信息素养是信息时代背景下社会成员所必备的素质,其内容包括信息意识、信息知识、信息能力、信息道德以及信息安全等方面的内容。通过对西南林业大学2012级部分新生进行信息素养教育中的信息意识开展问卷调查,了解林业院校新生信息意识现状,为高校进一步提升大学生信息素养教育提供重要的理论支撑。     

Genetic diversity and molecular epidemiology of the T strain of Plum pox virus

Very limited information is available on the origin, diversity and evolution of Plum pox virus (PPV) ‘Turkey’ (T) strain. Phylogenetic analyses based on partial sequences of 421 isolates and complete genome sequences of 57 isolates, representing the geographical distribution of PPV-T in Turkey, revealed the existence of several monophyletic and, in some cases, geographically limited groups within the PPV-T strain (Ankara-Konya1-Kayseri, Ankara-Balkan, Istanbul, Konya2 and Balkan). PPV-T diversity (0.018%) was found to be greater than that of PPV strains D and Rec but lower than that of the M strain when including the newly described and divergent M-Istanbul isolates, suggesting a long evolutionary history for PPV-T. The European part of Turkey in the Balkans, close to Bulgaria where PPV was identified for the first time, appears as a likely centre of origin for PPV-T isolates. The colonization of various parts of Turkey by diverse isolates from that region, followed by secondary local spread, is the most likely scenario for the diffusion of PPV-T in Turkey.