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RT—PCR和RFLP对我国部分传染性支气管炎病毒分离株分型 总被引:2,自引:0,他引:2
用2 对引物分别对4 株传染性支气管炎病毒(IBV)标准毒株(Gray、M41、H120、MA5)和5 株国内地方分离株(KF8、18KF7、QF3、XF7、XF18)进行RT-PCR,结果均获得了与预期大小一致的片段。对此2 种PCR 产物进行了限制性片段长度多态性(RFLP)分析,分别用3 种限制性内切酶(HaeⅢ、HinfⅠ、PvuⅡ)进行酶切,根据不同的酶切图谱将测试的IBV 毒株分为不同的基因型。2 对引物的PCR 产物酶切分型结果基本一致。9 株IBV 毒株分为3 种基因型,即H120、M41、XF7、XF18、MA5 和KF8 属于Ⅰ型,Gray 属于Ⅱ型,QF3、18KF7 属于Ⅲ型 相似文献
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不同引物RT-PCR方法检测猪繁殖与呼吸综合征病毒的比较研究 总被引:9,自引:5,他引:9
用3对分别针对猪繁殖与呼吸综合征病毒(PRRSV)的ORF7、ORF5和ORF5的PCR引物N1/N2、AdGP5.1/AdGP5.2和RFLP5.1/RFLP5.2进行RT-PCR,检测PRRSV,从其敏感性、特异性和临床样品检出率等方面进行比较,在此基础上进一步建立一步法RT-PCR检测方法。结果显示:3对引物对PRRSV均有很高的特异性;应用N1/N2引物病毒最低检测量为7.9 TC ID50,而AdGP5.1/AdGP5.2引物和RFLP5.1/RFLP5.2引物PCR最低检测量为79 TC ID50;运用N1/N2、AdGP5.1/AdGP5.2和RFLP5.1/RFLP5.2引物分别进行RT-PCR扩增检测临床样品,PRRSV检出率分别为28/48、27/48和25/48,且用AdGP5.1/AdGP5.2和RFLP5.1/RFLP5.2引物检测的阳性样品,用N1/N2引物检测也都呈阳性。运用N1/N2引物,通过一步法RT-PCR成功地从PRRSV S1株中扩增出374 bp的目的基因片段。结果表明,用N1/N2引物扩增PRRSV目的基因,其敏感性和临床样品检出率更高,更适合临床样品PRRSV的检测。 相似文献
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为了分析2009年安徽省和江苏省周边地区流行的猪繁殖与呼吸综合征病毒(PRRSV)的遗传变异特征,采用RT—PCR方法对该地区分离的22株PRRSV的Nsp2和ORF5基因进行了扩增、克隆和测序,并进行序列分析。结果表明:22株PRRSV均属于美洲型毒株,其中21个毒株的Nsp2存在30个氨基酸的不连续缺失,与高致病性PRRSV有相同的缺失特征;而且此21个毒株的ORF5基因推导的氨基酸序列也发生多处突变,集中出现在毒力相关位点、抗原表位和糖基化位点序列中。只有HZNJ株与疫苗株的同源性较高。进化树分析显示,21个分离株与高致病性PRRSV处在同一进化分支,而HZNJ株与疫苗毒株有较近的亲缘关系,进一步说明高致病性PRRSV已成为该地区的优势流行毒株。 相似文献
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对3个中国广东的鸽Ⅰ型副粘病毒分离株(P4,P5和P7)基因组RNA以反转录-聚合酶链反应法(RT-PCR)扩增了F基因75%的基因区域(343-1673nt),其中毒株P4和P7准确扩增出预期大小明亮的DNA片段,而P5扩增出片段很淡,用该RT-PCR产物作模板以相同引物再作PCR,结果可以扩增出大小与预期一致的明亮条带,此方法可以快速检测鸽Ⅰ型副粘病毒(PPMV-1)。 相似文献
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采用限制性酶切片段长度多态性和PCR指印技术对牛结核分枝杆菌分型研究 总被引:3,自引:1,他引:2
5株牛结核分枝杆菌DNA经PvuⅡ消化后,用来自IS1081中的248bp荧光探针杂后后进行限制性酶切片长度多态性(RFLP)分型,5株牛分离株中4株具有相同杂交带型,剩余的1株在3.6kb处多了1条带。将248bp探针对北京牛结核分枝杆菌分离株的RFLP分型法结果与直接反向PCR分型法对上述分离株分型结果比较发现:5株牛结核分枝杆菌分离株中有2株具有相同的PCR指印带型,剩余3株牛结核分枝相杆菌分离株则PCR指印带各不相同,上述结果显示出,直接反向PCR分型法较标准的RFLP分型法分型能力强。直接PCR法对新疆牛结核分枝杆菌分离株的分型结果显示出,PCR指印带型中带数较少,且与北京牛结核分枝杆菌分离株的PCR指印带型截然不同。 相似文献
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鸡贫血病毒国内分离株的酶切图谱多态性分析 总被引:2,自引:1,他引:1
用套式PCR 扩增了鸡贫血病毒(CAV)长度为687 bp 的特异片段,以Hae Ⅲ、Hinf Ⅰ、Hpa Ⅱ分别酶切,通过聚丙烯酰胺凝胶电泳分析了其限制性酶切片段的多态性。对几株国内外分离株的分析表明,TK5803和山东分离株SJ1、SJ2 应属于Todd 的限制性内切酶酶切图谱多态性分析法(RFLP)分类中的第2 组;吉林JL1 株和哈尔滨CL1 株相同,但与其他任何毒株均不相同,大连DL1 株也不同于任何现有毒株,因而都不能归属于Todd 划分的7 个小组;荷兰弱毒株与目前发现的所有毒株均不同,具有其特征性的酶切图谱。 相似文献
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番鸭细小病毒弱毒株VP2基因的分子克隆与序列测定 总被引:2,自引:0,他引:2
将番鸭细小病毒(MDPV)强毒Q株经番鸭胚连续传代,获得致弱株MDPV-26,根据已发表的MDPV的全基因序列,设计了1对引物LHMP7/LHMP8,同时在这2条引物中分别加入2种限制性核酸内切酶Sac Ⅱ和KpnⅠ的酶切位点,应用PCR技术扩增了MDPV0-26株的VP2基因片段,将扩增后的基因片段重组到pMD18-T质粒载体上,并对插入片段进行序列测定,测序结果表明,弱毒株MDPV-26与强毒株MDPV-Q的VP2基因序列相同率达99.7%,与国外分离株的同源性为98.3%,说明强,弱毒株的VP2基因序列变化不大。 相似文献
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为了建立区分疫苗株与广西分离株的检测方法,根据GenBank上的山羊痘病毒序列设计1对引物,用来扩增山羊痘病毒P32基因,通过对国内疫苗株及6株广西分离株的P32基因进行克隆、测序比较发现,所有广西分离株核苷酸651位的碱基全部由T变为C,647位~652位核苷酸构成由TGTATA变异为TGTACA,多了1个限制性内切酶Bsp 1407Ⅰ位点,因此用特异性引物扩增出739bp的目的片段后,再用限制性内切酶BsP1407 Ⅰ进行酶切分析。疫苗株可以切成135hp和604bp3个片段,广西分离株可以切成135、226、378bp3个片段。结果表明,所建立的PCR—RFLP方法可以区分疫苗株和广西分离株。 相似文献
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魏静 《四川畜牧兽医学院学报》2009,(4):28-32
在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。 相似文献
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本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。 相似文献
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REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air. 相似文献
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Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF
Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo. 相似文献
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乳酸杆菌作为益生菌广泛用于人和动物.本文综述了乳酸杆菌改善宿主健康的机制.乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道.文章重点讨论了乳酸杆菌表面成分(表面蛋白、脂磷壁酸和肽聚糖)与肠道受体(C型凝集素受体、Toll样受体和Nod样受体),阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制. 相似文献