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从滨州地区某养鸡场疑似鸡传染性法氏囊病病鸡初步分离到一株记为HSJ12分离株的IBDV毒株,从该分离株中提取总RNA,采用RT-PCR技术扩增VP4基因。结果表明,测序结果与GenBank中报道的IBDV VP4序列同源性在95%～99%之间。将VP4基因测序序列与GenBank上报道的23个序列进行系统遗传进化树分析,证实其与ks株同源性最近,而与23-82、OH株同源性最远。 相似文献
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蜜蜂残翼病病毒(DWV)是引起蜜蜂残翼病的病原体,可侵染各发育阶段的蜜蜂,在蛹期危害不明显,但羽化后出现翅膀残缺并迅速死亡;成年蜜蜂发病后翅膀畸形、腹部萎缩和褪色。呈隐性感染的蜜蜂虽然无明显临床症状,但其寿命也会缩短。由于DWV与传播媒介瓦螨密切相关而被大量研究。近年来的研究表明,DWV是引发"蜂群崩溃失调症"(CCD)的主要病毒之一,DWV在全球范围的流行已成为蜜蜂蜂群非正常消失的一个重要原因。论文结合近年来对残翼病的最新研究成果,综述了蜜蜂残翼病的病原学、流行病学、临床症状及检测与防控方面的最新研究进展。 相似文献
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《中国兽医学报》2015,(10):1584-1588
牛病毒性腹泻病毒(bovine viral diarrhea virus,BVDV)属于瘟病毒属,是养牛业中常见的病原体。通过MDBK细胞首次从广西分离获得1株牛源牛病毒性腹泻病毒,命名为GX4。设计引物对其全基因组进行扩增,获得其全基因序列,测序结果表明,GX4全基因组为12 218bp,编码3 898个氨基酸,GenBank登录号JN704144.1。对全基因序列进行分析,根据其5′-UTR,确定GX4属于BVDV-1b基因亚型;与BVDV其他参考毒株的比对发现,GX4与巴西分离株IBSP4ncp同源性最高,核苷酸同源性为94.4%,推导氨基酸同源性为96.2%,并且P125基因无外源序列插入,属于非细胞病变型。分子流行病学的结果,揭示了目前流行株的差异性,为该病的防控措施的制定提供参考。 相似文献
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蜜蜂残翼病毒是引起蜜蜂残翼病的病原体。吉林出入境检验检疫局检验检疫技术中心将成功分离鉴定得到的中国首株蜜蜂残翼病毒毒株命名为"中国DWV-JL1株",全长9 826 nt。本文主要研究中国DWVJL1株核苷酸序列位置为2 880~3 792 nt之间的片段,该段序列为编码衣壳蛋白的一部分,为相对保守序列。通过RT-PCR、克隆及质粒双酶切鉴定分析,得到一段大小约900 bp的片段。通过BLAST、进化树及残基化分析,有96%~97%的同源性。氨基酸序列差异性仅为7%。该段序列与韩国株的亲缘关系最近,而与欧洲和美洲各国家获得的毒株序列亲缘关系较远,推测中国DWV-JL1株起源于亚洲。 相似文献
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本研究在MDBK细胞培养物中发现并分离出1株HoBi样瘟病毒,将该毒株命名为JS12/01。应用RT-PCR方法分段扩增该毒株的全基因组序列,并对其基因组序列进行分析。结果显示,该毒株基因序列2端分别为5′端非编码区(5′untranslated region,5′-UTR)和3′端非编码区(3′untranslated region,3′-UTR),编码区为11 700nt。与GenBank中登录的部分瘟病毒属代表毒株5′-UTR区序列进行进化分析,结果表明,该毒株属于HoBi样瘟病毒巴西源亚型。本研究中的HoBi样瘟病毒JS12/01株为国内首次分离鉴定,证实了该病毒在中国的存在,需要对该病毒的扩散与流行采取预防措施。 相似文献
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从云南某牛场疑似BVDV感染的病料通过接种MDBK细胞分离到1株BVDV,将其命名为BVDV/W。该分离毒株连传15代均不产生CPE,为NCP型BVDV。通过电镜检测可观察到直径为 40～60nm病毒粒子。该分离病毒能被牛病毒性腹泻标准阳性血清中和,且能被BVDV IFA荧光抗体识别;针对常用作BVDV基因分型的5′-UTR设计特异性引物,经RT-PCR可扩增出288bp特异性片段。将所测的目的片段序列与中参考序列进行同源性比较,结果显示与293株和Y2株同源关系较近,分别为90.0%和89.9%,与2014年以来我国报道的分离株同源性在88%左右,具有一定的代表性。5′-UTR遗传进化分析证实该分离毒株为BVDV-1型。动物回归试验显示,该分离毒株可引起出现体温升高、腹泻、粘膜病等典型的BVD/MD症状,表明该毒株为1株BVD强毒株。 相似文献
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猪繁殖与呼吸综合征病毒国内分离经典株与变异株的全基因组序列分析 总被引：1，自引：1，他引：0
通过分段设计引物,对猪繁殖与呼吸综合征病毒(PRRSV)LX、JX株基因组进行RT-PCR扩增,对各片段cDNA进行克隆和序列测定,拼接后获得全基因组序列。结果,PRRSV LX株全基因组序列长度为15 412 bp(不包括PolyA尾),PRRSV JX株全基因组序列长度为15 320 bp(不包括PolyA尾)。序列分析表明,JX株全基因组核苷酸序列与LX株、JXA1、VR2332、CH-1a、BJ-4、LV同源性分别为91.1%、98.6%、91.0%、94.6%、90.9%、61.7%;LX株全基因组核苷酸序列与JX株、JXA1、VR2332、CH-1a、BJ-4、LV同源性分别为91.1%、89.7%、99.7%、91.5%、99.7%、62.2%。对不同分离株的5′-UTR、Nsp2进行了序列比较,并根据5′-UTR、Nsp2、ORF5的基因序列和氨基酸序列,对国内外分离株进行了系统进化分析。根据5′-UTR核苷酸序列,可将PRRSV美洲型毒株分为4个亚群,LX株和JX株分别属于经典美洲型和"高热病"变异型。根据Nsp2氨基酸序列分析了不同分离株的分子进化关系,表明依据Nsp2序列美洲型分离株可初步划分为5个亚群,JX株独立于其他毒株,独自处于一个分支。依据ORF5序列也可将美洲型分离株划分为5个亚群。本研究为探讨PRRSV的分子进化奠定了基础。 相似文献
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《黑龙江畜牧兽医》2010,(5)
为了检测感染辽西地区中华蜜蜂的囊状幼虫病病毒(Sacbrood bee virus,SBV),克隆辽西地区中华蜜蜂囊状幼虫病病毒部分结构基因并分析,试验设计中华蜜蜂囊状幼虫病病毒5′端2对特异性引物,用Trizol法提取囊状幼虫病病毒总RNA,通过RT-PCR方法扩增病毒基因组的部分序列,转入pMD18-T载体进行克隆扩增后测序。结果表明:测序的SBV部分基因总长831bp,编码序列长496bp,与我国广东省的病毒序列同源性为94%;根据不同地区此病毒5′端序列进行遗传进化分析,发现至少有3个不同的蜜蜂囊状幼虫病病毒基因型。结果说明不同地区SBV5′端结构基因存在的差异可能与致病性有关。 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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以国际标准强毒Ｒ株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离ＭＧ,并收集感染鸡所产蛋分离ＭＧ。结果表明,人工感染４８小时后上、下呼吸道及肺已被全面感染,９６小时气囊已被感染,１２０小时输卵管已能分离到ＭＧ,卵巢始终分离不到ＭＧ。人工感染鸡自１４４小时便能在其所产蛋中分离出ＭＧ。药物治疗能在７２小时内消除感染,油乳剂苗则需２４天后逐渐降低蛋内ＭＧ分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内ＭＧ,但以研制的种蛋浸泡剂药浴效果为最好。 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