Isolation,Identification and Phylogenetic Analysis of Important Functional Genes of Porcine Pseudorabies Virus LC Strain

To find out the reason of the reproductive failure in pregnant sows in a hoggery in Guangdong, the mixture with brain, lymph nodes and lungs of farm abortion stillbirth were identified by PCR, virus isolation and culture, tissue culture infective dose (TCID₅₀) assay, homology and phylogenetic analysis of the important functional genes (gB, gC, gD and gE) and animal test. The results showed that the mixture was proved to be porcine pseudorabies virus (PRV) positive samples. The typical cytopathogenic effect was induced in the third passage of Vero cell and the titer of the fifth passage was 10^-6.8/0.1 mL. The sequence analysis and phylogenetic relationship of gB, gC, gD and gE genes showed that it was a Chinese PRV variant, which was named as LC strain. The typical pseudorabies clinical and pathological symptoms were presented in 12-week-old piglets inoculated with LC strain. The results demonstrated that a local pseudorabies virus had been isolated, suggesting that the Bartha-K61 vaccine was not fully effective for controlling the current epidemic of pseudorabies in China.     

玉树地区牦牛皮蝇蛆病防治效果观察

采用阿维菌素泼背剂对306头幼年牦牛进行牛皮蝇病的防治,并于2007年4月进行了防治效果的考察,结果防治群感染率为阴性,而对照群的感染率为99.33%,感染强度4.77个瘤包/牛。     

四个绵羊品种MHC-DQA1基因exonⅡ多态性分析

为了比较和揭示洼地绵羊、杜泊羊、小尾寒羊及特克赛尔绵羊4个绵羊品种MHC-DQA1基因的遗传多态性,采用PCR-RFLP技术对4个绵羊品种224个样本的MHC-DQA1基因exonⅡ的315 bp片段进行多态性分析;并对基因型频率和等位基因频率进行统计,运用Popgen32软件计算相应的遗传参数.结果表明,AluI-R...     

羊弓形虫病间接ELISA诊断方法的建立

为比较5种弓形虫抗原的诊断效果,建立实用的羊弓形虫病诊断方法,本研究制备了弓形虫速殖子全虫抗原和4个重组蛋白(GRA1、MIC3、MAG、BAG1),正交试验比较其免疫反应性,从中筛选出相对优势抗原并建立羊弓形虫病间接ELISA(iELISA)诊断方法,用于检测弓形虫特异的IgG抗体。研究结果表明：除BAG1外上述4种抗原均具有较好的免疫反应性,综合考虑选择致密颗粒蛋白1(GRA1)作为诊断抗原建立了GRA1-iELISA,其检测弓形虫抗体灵敏度大于1∶100(血清稀释度),且不与羊莫氏巴贝斯虫、吕氏泰勒虫、捻转血毛线虫阳性血清发生交叉反应,特异性良好;运用建立的方法和改良凝集试验分别对采自山羊屠宰场的80份血清样品进行检测,测得的弓形虫感染阳性率分别为28.75%(23/80)和31.25%(25/80),二者总符合率为82.5%。本研究建立的ELISA检测方法对羊弓形虫病的诊断以及商业化试剂盒的开发具有重要参考价值。     

77份裸燕麦品种籽粒相关性状分析北大核心CSCD

对77份裸燕麦品种籽粒品质等相关性状进行测定,运用聚类分析方法对测定指标进行分类比较,并采用灰色关联度进行综合评价,以期筛选出籽粒性状在青海表现良好的裸燕麦品种。主要研究结果如下:1)供试燕麦品种千粒重变异系数最高为49.29%,籽粒粗脂肪和粗蛋白含量变异系数相对较低,分别为12.23%和9.83%;千粒重与籽粒长度、宽度和直径呈极显著正相关;籽粒含水率与粗蛋白、淀粉含量呈极显著负相关,籽粒粗蛋白含量与粗脂肪含量呈极显著负相关;2)灰色关联分析表明77份裸燕麦品种籽粒性状综合评价较高的3个品种分别为5号(0.679)、73号(0.676)和26号(0.649);3)供试燕麦性状聚类分析表明,77份裸燕麦品种可被分成6个类群,其中类群Ⅵ中综合评价前10的品种占70%,包括综合评价较高的3个品种(5号、73号和26号),可考虑作为优异燕麦品种的选择区域。     

高精料饲喂产生脂多糖对奶山羊血浆游离氨基酸分配的影响及其机制

为了探讨高精料饲喂产生LPS对奶山羊血浆游离氨基酸重分配的影响及其机制,本研究选用奶山羊6只,随机分为2组,分别饲喂精粗比为4∶6(低精料组)和6∶4(高精料组)的日粮,交叉试验设计,分2期进行,每期14d。在试验第3周测定瘤胃液pH、血液中LPS含量和游离氨基酸含量。结果表明,自第3周,高精料组山羊开始出现亚急性瘤胃酸中毒,外周血液中LPS含量显著升高(P<0.05);血浆中各氨基酸含量均发生变化,表现为Glu、Ala含量极显著降低(P<0.01),Gln、Arg、Thr、Lys、总非必需氨基酸、总游离氨基酸、总生糖氨基酸均显著低于低精料组(P<0.05)。结果提示,饲粮中精饲料比例增加,血浆氨基酸发生重分配,其机理可能与瘤胃pH下降和血液中LPS含量升高有关。     

不同发育期牦牛红细胞数、血红蛋白及肌红蛋白的测定及意义

用常规方法对同一海拔高度不同发育期牦牛几项指标进行测定。结果:随着牦牛年龄的增长血液中Hb含量、HCT值逐渐增加,而RBC明显降低,差异显著(P<0.05),即随年龄的增长Hb、HCT与RBC的变化呈负相关;心肌和骨骼肌Mb含量随着年龄的增长均呈逐渐递增的趋势,心肌中Mb含量均显著高于骨骼肌,差异显著(P<0.05)。结论:牦牛在生长发育过程中逐渐增加血液中Hb、HCT和骨骼肌、心肌中Mb含量增强机体有氧代谢机制。     

Mycobacterium bovis cultured from commercially pasteurized cows' milk: laboratory cross-contamination

The ability of Mycobacterium paratuberculosis to survive the commercial pasteurization process of raw milk remains controversial. In a study undertaken in Venezuela to culture M. paratuberculosis from commercially pasteurized cows' milk, 83-200 ml containers of milk were processed and cultured on Herrold's egg yolk slants. No M. paratuberculosis was cultured but a total of six colonies of Mycobacterium bovis were isolated from one container each from two different milk providers. Because laboratory cross-contamination was suspected, the laboratory records were reviewed and spoligotyping was carried out on the isolated individual colonies. On the day before these milk specimens were processed, the biological safety cabinet had been used for the isolation of M. bovis from lymph nodes from infected cattle. Spoligotyping showed that that the colonies isolated from the milk all had the same pattern as the strains isolated from the lymph nodes that were processed the previous day. As far as we know, this is the first report of cross-contamination in a veterinary mycobacterial laboratory. False-positive cultures in the mycobacterial laboratory are not rare. In this setting M. bovis was isolated because it is the most common manipulated organism in this laboratory. We believe that reports on the isolation of M. paratuberculosis from commercially pasteurized milk should exclude cross-contamination before reporting, especially when this organism is routinely isolated from animal material in the same lab.     

藏北典型高寒草甸地上生物量的遥感估算模型

本研究利用2010和2011年6-9月高寒嵩草草甸群落地上生物量数据和同期的中分辨率成像光谱仪(moderate resolution imaging spectroradiometer,MODIS)影像数据,建立了西藏自治区拉萨当雄高寒草甸的地上生物量遥感估算模型。在探讨群落地上生物量与归一化植被指数(normalized difference vegetation indices,NDVI)、增强型植被指数(enhanced vegetation indices,EVI)以及地表水分指数(land surface water indices, LSWI)相关关系的基础上,构建了群落地上生物量与各指数的线性或非线性(包括对数函数、二次多项式、三次多项式、幂函数、增长曲线、指数函数)估算模型,并进行了模型验证。结果表明, 1)3个指数中EVI的模拟效果最好,NDVI次之,LSWI最差;2)所有模型中线性模型的模拟效果最好,EVI的线性模型为:y=174.225x,R²=0.975, P<0.001,NDVI的线性模型为:y=115.478x,R²=0.956, P<0.001;3)在预测效果方面,幂函数模型最好,线性模型次之,其平均误差分别仅为9.76%和10.8%,因此,两者都可以用于高寒草甸群落地上生物量的模拟。     

猕猴外周血液中多潜能调控因子Oct4、Nanog和Sox2基因的表达

采用半定量RT-PCR对采自幼体(2岁以内)、亚成体(2～5岁)和成体(5岁以上)猕猴共28份外周血样品进行分析.结果显示,幼体和亚成体猕猴所有外周血样品均转录表达Oct4、Nanog和Sox2基因,大部分成体猕猴外周血样品(8/12)表达Oct4、Nanog和Sox2基因,少数样品仅表达Oct4和Sox2(2/12)或Oct4和Nanog(1/12),1份样品不表达3个基因;同一年龄组内,Sox2表达水平均显著高于Oct4和Nanog(P≤0.05),幼体组Oct4和Nanog的表达水平没有显著性差异(P＞0.05),亚成体组和成体组Oct4的表达水平均显著高于Nanog(P≤0.05);在不同年龄组间,Oct4和Nanog表达水平没有显著性差异(P＞0.05),幼体组Sox2表达水平显著高于成体组(P≤0.05).结果表明,在生理条件下Oct4、Nanog和Sox2基因在不同年龄段猕猴外周血中均转录表达,不同基因表达水平存在一定差异,随年龄增加这些基因表达量有降低的趋势.