山羊Sox2基因克隆、原核表达和GST融合蛋白纯化

本研究旨在克隆山羊Sox2基因,构建pGEX-Sox2原核表达重组质粒,从大肠杆菌中获得纯化的GST-Sox2融合蛋白.应用RT-PCR方法从6周龄胎山羊生殖嵴扩增Sox2基因编码全序列,将其克隆到pMD18-T载体,然后再亚克隆到pGEX-KG表达载体.重组质粒pGEX-Sox2转化大肠杆菌BL21(DE3),经IPTG诱导,用SDS-PAGE电泳及Western blotting检测GST-Sox2融合蛋白表达,用谷胱甘肽Sepharose 4B介质分离纯化该融合蛋白.结果表明,山羊Sox2基因编码序列全长为960 bp;在优化的表达条件(1 mmo|·L-1 IPTG,22℃诱导16h)下,重组质粒(pGEX-Sox2)在大肠杆菌得到了高效表达;谷胱甘肽Sepharose 4B颗粒纯化蛋白得到预期大小的融合蛋白(约60 ku).结论,本研究克隆了山羊Sox2基因,获得了纯化的GST-Sox2融合蛋白,为制备其多克隆抗体奠定了基础,为进一步研究山羊iPS细胞(Induced pluripotent stem cells)创造了条件.     

犬瘟热病毒N基因原核表达及多克隆抗体的制备

采用PCR方法扩增犬瘟热病毒N基因,将其克隆至原核表达载体p ET-32a(+)中,构建犬瘟热N基因原核表达重组质粒,然后转化大肠杆菌BL21(DE3)菌株,经IPTG诱导表达重组N蛋白。从包涵体中纯化重组蛋白,制备多克隆抗体,采用Western blot检测其特异性。结果显示PCR扩增得到犬瘟热N基因,重组N蛋白在大肠杆菌BL21(DE3)菌株中得到表达,制备的多克隆抗体能与N蛋白特异性反应。     

新城疫病毒F基因在大肠埃希菌中的表达及其抗原性分析

构建新城疫病毒融合蛋白F基因的原核表达载体,并将其在宿主菌BL21(DE3)感受细胞中表达.以含有融合蛋白F基因的重组质粒pMD19T-F为模板,设计特异性引物,应用PCR技术扩增获得F基因的F1片段,定向插入原核表达载体pET-28a,构建重组质粒pET-F1,将构建成功的重组质粒pET-F1转化宿主菌BL21(DE3)感受态细胞经IPTG诱导,将其在宿主菌细胞中表达,表达产物用SDS-PAGE和Western blot方法检测.结果显示,成功克隆出了新城疫病毒F1基因片段序列852 bp.构建的pET-F1载体经PCR、双酶切、测序鉴定均无误,转化表达宿主菌后经SDS-PAGE和Western blot检测结果显示,目的基因被成功表达,并具有良好的反应原性.成功构建了新城疫病毒的融合蛋白F基因原核表达载体,转化宿主细胞后成功表达了融合蛋白F1重组蛋白片段.     

鼠伤寒沙门菌鞭毛蛋白与新城疫病毒F蛋白的融合表达及免疫原性分析

应用PCR技术分别扩增鼠伤寒沙门菌鞭毛蛋白fliC基因以及含有新城疫病毒F蛋白部分表位的基因片段,通过柔性肽(Gly4Ser)2编码序列将二者串联并克隆到质粒pET30a+上,获得重组原核表达质粒pET-fliC-F,将其转化入大肠埃希菌BL21(DE3)中表达。Western blot证实重组菌表达的fliC-F融合蛋白能与小鼠抗fliC和抗F蛋白两种多抗血清发生特异性反应。动物试验显示,fliC-F融合蛋白能够刺激C3H/HeJ小鼠产生针对F蛋白的特异性血清抗体,说明原核表达系统表达的fliC-F融合蛋白具有较好的免疫原性。     

水牛iPS细胞转录因子Sox2及协助蛋白HA2-TAT的原核表达

为探讨干细胞转录因子与穿膜肽融合表达蛋白对水牛体细胞诱导重编程的可行性,本试验对水牛iPS细胞转录因子Sox2与细胞穿膜肽HIV TAT进行融合表达,以获得具有自主穿膜功能的Sox2蛋白,建立非转基因水牛iPS生产技术体系。首先人工合成了HA2-TAT序列,并将pET-32a（＋）质粒改造为pET-HA2-TAT基础表达载体,再通过双酶切定向克隆将水牛Sox2基因插入pET-HA2-TAT得到原核表达载体pET-NLS-Sox2-TAT;重组质粒转化大肠杆菌BL21（DE3）,经IPTG诱导,用SDS-PAGE电泳和Western blot检测融合蛋白表达,再用Ni 2＋柱进行纯化融合蛋白。结果表明,成功表达了融合蛋白HA2-TAT（24 400）和NLS-Sox2-TAT（57 700）;纯化蛋白NLS-Sox2-TAT在咪唑浓度为365.30mmol/L时,出现蛋白洗脱峰,经Western blot验证表达的融合蛋白具有免疫原性。     

鸡源性HMGB1蛋白的原核表达及多克隆抗体制备

从鸡胚原代细胞CEF中扩增出鸡HMGB1基因,构建重组原核表达质粒p ET-28a-ch HMGB1,并将p ET-28a-ch HMGB1转入大肠杆菌BL21(DE3)中,于37℃进行诱导表达,经SDS-PAGE分析表明该重组蛋白可以在大肠杆菌中高效表达且以可溶性蛋白的形式存在。蛋白通过Ni-NAT纯化树脂亲和纯化,并作为免疫原制备鼠抗ch HMGB1多克隆抗体血清。该多克隆抗体同时具有ELISA、Western blot和IFA效价,且特异性识别禽源细胞内HMGB1蛋白。     

牛结节性皮肤病病毒p32蛋白膜外区可溶性表达及多克隆抗体制备

为获得牛结节性皮肤病病毒(LSDV)p32可溶性蛋白并制备其多克隆抗体,截取了LSDV的P32基因膜外区序列,并构建了重组表达质粒pColdⅠ-P32,在大肠埃希氏菌BL21(DE3) pLysS细胞中经低温诱导表达,然后用钴离子亲和层析纯化以可溶性形式表达的重组蛋白,使用纯化的p32截短蛋白免疫昆明小鼠制备多克隆抗体,并通过Western blot鉴定。结果表明,成功使用钴离子亲和层析纯化获得LSDV p32可溶性膜外区蛋白,制备的多克隆抗体可以特异性识别LSDV感染的牛组织蛋白。获得的纯度较高的LSDV p32截短蛋白和特异性良好的多克隆抗体,为建立LSDV抗原检测方法及亚单位疫苗的研制奠定了基础。     

A型塞内卡病毒VP1蛋白的原核表达及其多克隆抗体的制备

A型塞内卡病毒(SVA)是一种新发传染病病原。研究旨在对SVA的衣壳蛋白VP1进行原核表达,并制备其多克隆抗体。以SVA广西分离株SVA-GX01(GenBank登录号：MK039162)RNA为模版,通过RT-PCR扩增结构蛋白VP1基因,构建重组质粒pET-32a-VP1并转化表达菌株大肠杆菌BL21(DE3)进行诱导表达。在非变性条件下,将纯化的重组蛋白免疫新西兰大白兔制备多克隆抗体。纯化的多克隆抗体进行间接ELISA测定效价,同时进行Western blot与间接免疫荧光分析。结果表明,重组蛋白pET-32a-VP1在大肠杆菌BL21(DE3)以可溶性与包涵体两种形式表达,分子量约为49 kDa。纯化后多克隆抗体效价高达1∶64 000。Western blot与间接免疫荧光(IFA)分析显示,多克隆抗体能跟SVA抗原特异性结合。重组SVA-VP1蛋白及其多克隆抗体的成功制备为猪塞内卡病毒血清学检测方法的建立提供了良好的生物材料。     

蛋鸡TRPV6基因的原核表达、纯化及抗体制备

为制备蛋鸡TRPV6蛋白多克隆抗体,根据其基因序列,设计1对特异性引物,以卵巢组织中提取的总RNA为模板,扩增蛋鸡TRPV6基因1 801～2 176nt的375bp序列,构建原核表达质粒pET-32a（＋）-TRPV6;将重组质粒转化BL21（DE3）,经IPTG诱导表达TRPV6融合蛋白,通过镍离子螯合柱纯化后免疫新西兰大白兔,获得兔抗鸡TRPV6多克隆抗体,分别通过酶联免疫吸附试验（ELISA）法和Western blot检测抗体的效价和抗体特异性。结果表明,试验成功构建原核表达载体pET-32a（＋）-TRPV6,SDS-PAGE蛋白电泳检测发现目的蛋白大小约35 000;Western blot分析显示,表达的TRPV6融合蛋白具有良好的免疫原性,其抗体可与大肠杆菌表达的产物特异性结合;ELISA显示其抗体效价达1∶100 000。获得纯化的融合蛋白和多克隆抗体对研究TRPV6钙离子通道在蛋鸡髓质骨形成的作用机理具有重要作用。     

猪源化抗PEDV单链抗体基因的构建及其在大肠杆菌中的表达

通过BL21(DE3)原核表达系统制备抗猪流行性腹泻病毒(PEDV)猪源化单链抗体scFv-Fc。提取抗PEDV杂交瘤细胞2D1的总RNA,通过反转录与SOE-PCR方法获得单链抗体scFv基因,同时提取猪脾脏组织的总RNA,RT-PCR获得猪免疫球蛋白恒定区Fc基因。通过SOE-PCR方法将scFv与Fc连接获得猪源性单链抗体scFv-Fc融合基因,构建重组质粒pET-28a-scFv-Fc,将该重组质粒转入BL21(DE3)原核表达菌进行诱导表达,SDS-PAGE分析及Western blot检测融合蛋白的特异性,再对表达蛋白进行纯化和复性,通过间接ELISA鉴定融合蛋白与PEDV的结合活性。结果显示,插入pET-28a载体的scFv-Fc序列长度1 128bp,抗PEDV猪源化单链抗体的相对分子质量为45 800,重组蛋白具有较高的特异性。本研究成功构建了pET-28a-scFv-Fc原核表达系统,重组蛋白具有较高的免疫反应性,为PEDV重组抗体的研究奠定理论基础。     

商会自治的基石——商会自治规范研究

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。     

癸氧喹酯干混悬剂含量测定的改进

采用高效液相色谱法测定癸氧喹酯干混悬剂的含量,在2-250μg/mL范围内,峰面积的常用对数与进样量浓度的常用对数呈良好的线性关系,R^2=1(n=5),平均回收率为99.24%~99.51%,RSD在0.05%~0.28%。此方法分析时间短,样品前处理简便、定量结果准确,重现性好,结果满意,为其质量控制提供了依据。     

猪毛色遗传的研究进展

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。     

Comparison of 2 methods of centesis of the bursa of the biceps brachii tendon of horses

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.     

不同样本商品蜂蜜中硒含量的测定

用硝酸和高氯酸消化蜂蜜,使硒游离出来,在微酸性环境下,硒和2,3-二氨基萘(DAN)生成有较强荧光的物质,用环己烷萃取,在激发波长378nm,荧光波长518nm处测定其荧光强度。蜂蜜中硒含量范围:0.10～0.82μg/g。表明:蜂蜜应视为天然富硒营养品。     

乳酸杆菌益生作用机制的研究进展

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。     

中华人民共和国农业部公告 第267号

为贯彻落实《兽药生产质量管理规范》(简称《兽药GMP》),进一步推动兽药GMP实施进程,我部制定了《兽药生产质量管理规范检查验收办法》,现予公告。本公告自2003年6月1日起施行。附件:兽药生产质量管理规范检查验收办法二○○三年四月十日第一章 总则 第一条 为推动《兽药生产质量管理规范》(以下简称兽药GMP)的实施,规范兽药GMP检查验收工作,制定本办法。 第二条 农业部负责全国兽药GMP管理和检查验收工作;负责制修订兽药GMP检查验收管理规定;负责兽药GMP检查员队伍建设和监督管理工作,负责国际兽药贸易中GMP互认工作。 …     

鸡败血支原体垂直传播模式及其阻断方法

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。     

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.