猪流行性腹泻病毒实时荧光定量RT-PCR检测方法的建立

根据Gen Bank报道的N基因高度保守核苷酸序列,设计并合成一对引物。上下游引物与Gen Bank中登录的153株猪流行性腹泻病毒(PEDV)N基因全长序列匹配度分别是100%和97%。以本实验室分离流行毒株为模板,利用SYBR Green I荧光染料法进行RT-PCR扩增,获得扩增产物构建重组质粒作为阳性对照,建立检测猪流行性腹泻病毒核酸的方法。同一样品进行3次重复试验,变异系数0.9%。通过对临床样品进行检测和测序验证,核酸检测结果中的阳性样品准确率为100%。本研究所建立的荧光定量PCR检测方法具有快速、灵敏、准确等优点,可用于临床PEDV的检测及分子流行病学调查。     

Immune responses of orange-spotted grouper,Epinephelus coioides,against virus-like particles of betanodavirus produced in Escherichia coli

Betanodaviruses are the causative agents of viral nervous necrosis (VNN), a serious disease of cultured marine fish worldwide. Virus-like particles (VLPs) are one of the good novel vaccine candidates to control this disease. Until now, betanodavirus vaccine studies mainly focused on the humoral immune response and mortality after virus challenge. However, little is known about the activation of genes responsible for cellular and innate immunity by vaccines. In the present study, VLPs of orange-spotted grouper nervous necrosis virus (OGNNV) were produced in prokaryotes and their ability to enter Asian sea bass cells was the same as native virus, suggesting that they possess a similar structure to OGNNV. VLPs immunogenicity was then determined by intramuscularly vaccinating Epinephelus coioides at different concentrations (1.5 or 15 μg g^?1 fish body weight, FBW) and immunizing frequencies (administration once, twice and thrice). A single vaccination with the dosage of 1.5 μg g^?1 FBW is enough to provoke high titer antibodies (average 3 fold higher than that of negative control) with strong neutralizing antibody titer as early as 1 week post immunization. Furthermore, quantitative PCR analysis revealed that eleven genes associated with humoral, cellular and innate immunities were up-regulated in the liver, spleen and head kidney at 12 h post immunization, correlating with the early antibody response. In conclusion, we demonstrated that VLP vaccination induced humoral immune responses and activated genes associated with cellular and innate immunity against betanodavirus infection in orange-spotted grouper.     

遮荫胁迫下外源一氧化氮对高羊茅的生理调控作用

用外源一氧化氮(NO)供体硝普钠(SNP)处理遮荫胁迫下的2个高羊茅(Festuca arundinacea)品种,探讨外源NO对遮荫胁迫下其叶绿素含量、膜透性、丙二醛(MDA)含量、抗氧化酶活性及脯氨酸(Pro)含量的影响.结果表明:外源NO可以显著提高遮荫胁迫下高羊茅叶片的叶绿素含量(P＜0.05),减弱质膜相对透性的增加,减缓膜质过氧化产物MDA含量的升高,促进Pro的积累,提高超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)的活性(P＜0.05).遮荫胁迫下高羊茅品种踏火二号的电解质渗透率、MDA含量、CAT活性和Pro含量的变化显著(P＜0.05),NO的作用效果     

动物产品中硒富集的研究

<正>硒具有抗癌、抗氧化、抗心血管疾病等功效,因此富集硒的动物产品受到了越来越多的关注。饲料中添加的硒源主要有无机硒(亚硒酸钠、纳米硒)和有机硒(酵母硒、蛋氨酸硒),不同硒源在动物组织中的沉积量差异很大。Behne等(1983)用含0.3mg/kg硒的日粮饲喂兔子,各组织硒含量从高到低依次为肾脏、肝脏、     

欧盟皮内变态反应比较试验法结合ELISA检测牛结核病的研究

现在应用较多的牛结核病检疫方法有变态反应、ELISA等方法。检疫牛结核病目前OIE唯一指定方法是皮内变态反应,该方法也是最古老的方法之一,经过多次改进,仍然为各国所用。该方法的不足是非特异性反应过高,且只能检测细胞免疫状态。牛结核     

草原蝗虫密度的抽样技术研究

在蝗虫密度为０．０５～８．５０头／ｍ２的不同类型草地，以投环方式统计不同大小（０．０２、０．０５、０．１０、０．２０、０．３５ｍ２）的铁环击中或套入蝗虫数，计算调查地蝗虫平均数，以笼罩法作为“真值”对照，对不同大小铁环调查数进行统计检验。结果表明，在调查密度范围内，以０．０５、０．１０、０．２０ｍ２铁环的调查数较接近“真值”，其精确性随蝗虫密度的高低略有变动。根据草地蝗虫为Ｐｏｉｓｓｏｎ分布的特点，采用Ｐｏｉｓｓｏｎ置信域和二项式抽样法，建立以０．１０ｍ２环中蝗虫的出现率估测平均密度和反估计的二项式抽样模型，并进行统计检验。最后，以Ｐｏｉｓｓｏｎ置信值为概率保证，提出了理论抽样数计算模型。     

民猪生殖器官PRLR基因表达发育变化

试验以民猪为试验材料,长白猪为对照组,分别在1、2.5、4、6、8月龄时进行卵巢、输卵管和子宫取样,对促乳素受体（PRLR）基因表达的发育性变化规律进行研究。结果表明,生殖器官中PRLR的表达量与生殖器官的解剖指标存在正相关。PRLR在1、2.5、4、6和8月龄的民猪和长白猪的卵巢、输卵管和子宫中均有表达。民猪和长白猪卵巢PRLR mRNA表达水平从1月龄至8月龄呈现逐渐上升趋势,在8月龄达到最高水平,民猪卵巢PRLRmRNA表达水平显著高于长白猪（P〈0.05）。民猪和长白猪输卵管PRLR mRNA表达量随月龄增加呈上升趋势,在8月龄达到最高水平,品种间差异不显著。民猪子宫PRLR mRNA表达量随月龄增加而升高,在6月龄达到最高水平,8月龄显著下降（P〈0.05）,长白猪子宫PRLR mRNA表达量随月龄增加而升高,在8月龄达到最高水平,品种间在6月龄差异显著（P〈0.05）。     

鸽新城疫病

鸽新城疫(ND)是由新城疫病毒(NDV)引起鸽等家禽发生的一种急性、败血性、高度接触性传染性疾病,主要表现为呼吸系统、消化系统和神经系统的综合症状,如呼吸困难、下痢、神经机能紊乱等。由于该病与鸡新城疫病属同由一种RNA病毒引起,相互之间可以发生交叉感染,加上鸽的流动性大,所以鸽新城疫的发病率和死亡率都极高,以幼鸽为主的鸽群发病率可达100%,死亡率可达90～95%,常给养鸽者和其它家禽养殖者造成重大经济损失。是近几年来多发的一种家禽传染病。鸽新城疫(ND)以幼鸽最易感,但成年鸽的感受性同样比较高,死亡率也较大。病鸽、带毒的健…     

壳聚糖对仔猪生长性能及血清中类胰岛素生长因子-Ⅰ和生长激素水平的影响

本文旨在研究日粮中添加不同剂量壳聚糖对仔猪生产性能及血清中类胰岛素生长因子-I(IGF-I)和生长激素(GH)水平的影响。试验选择60日龄大白×长白×VI系杂交仔猪96头,随机分为4个日粮处理组,每个处理3个重复,每个重复8头,进行为期21 d的饲养试验。4种日粮分别是在基础日粮中添加0、0 .01 %、0 .05 %、0.1 %的壳聚糖配制而成。结果表明,壳聚糖对仔猪生长性能的影响呈二次剂量依赖关系,添加0 .01 %~0 .05 %壳聚糖能够提高仔猪平均日增重、平均日采食量及增重耗料比,并可提高仔猪血清中IGF-Ι和GH含量。而添加更高水平时生长性能却有下降趋势。因此,在本试验条件下初步得出,0 .01 %~0 .05 %为壳聚糖在仔猪日粮中的适宜添加量。     

Evaluation of immunogenicity and protective efficacy of Actinobacillus pleuropneumoniae HB04C(-) mutant lacking a drug resistance marker in the pigs

Previously, we reported the construction and characterization of a genetically defined Actinobacillus pleuropneumoniae (A. pleuropneumoniae) apxIIC gene mutant, HB04C(-), which conferred protection to mice against infection with A. pleuropneumoniae. In this study, we further evaluated HB04C(-) for safety and its ability to elicit protective immunity in pigs. It was demonstrated that a dose of 2 x 10(8) CFU HB04C(-) was safe to the pigs via intranasal or intramuscular injection. Immunization with a dose of 2 x 10(8) HB04C(-) by both intranasal and intramuscular routine could yield equal protective efficacy and elicited significant protection against experiment challenge with homologous or heterologous serotypes of a virulent A. pleuropneumonia. Taken together, HB04C(-) might serve as a promising vaccine candidate against infection with A. pleuropneumoniae.