哈萨克羊抑制素α基因原核表达载体的构建及其诱导表达

本实验以新疆哈萨克羊睾丸组织为实验材料,提取组织总RNA,经反转录得到c DNA并以此为模板,用以Gen Bank(NM_001308579.1)序列为参考设计的特异性引物进行PCR扩增,之后将扩增产物与p ET32a(+)载体相连,构建重组质粒p ET32a(+)-INHα。将构建好的重组质粒转化到受体菌E.coli BL21中,经IPTG诱导,表达p ET32a(+)-INHα重组蛋白。对扩增产物的测序鉴定结果显示INHα基因克隆成功;经过酶切和测序鉴定确定准确构建了p ET32a(+)-INHα重组载体;经Tricine-SDS-PAGE电泳鉴定,检测到INHα基因编码区全序列表达的重组蛋白单一条带,这说明原核表达载体构建成功并在原核细胞中正常表达,这为今后绵羊INHα基因的免疫功能研究提供了参考依据。     

奶牛溶菌酶基因原核表达载体的构建

为了构建奶牛溶菌酶(lysozyme,LYZ)原核表达载体,试验人工设计并合成LYZ基因CDS序列,将其克隆至表达载体p ET32T,转化大肠杆菌TOP10,筛选阳性菌株提取质粒,对重组质粒进行PCR扩增、双酶切及测序鉴定。结果表明:PCR扩增和双酶切产物的分子质量分别为1 000 bp和400 bp,与预期大小一致;扩增产物经测序鉴定,也与目的片段完全一致。说明原核表达载体LYZp ET32T构建成功。     

猪肺炎支原体黏附因子基因R1R2区的克隆及表达

根据GenBank登录的猪肺炎支原体232株P97基因和J株黏附因子基因设计了1对引物，以我国猪肺炎支原体Z株(强毒株)基因组DNA为模板，通过PCR方法扩增了该株黏附因子基因的部分序列。经序列分析后，重新设计了1对带有EcoRI和HindⅢ酶切位点的引物，并经引物的定点突变，PCR扩增了Z株黏附因子的R1R2区。扩增产物经双酶切后克隆到表达载体pET-32(a) 中。该重组质粒经酶切鉴定后，将其具有正确阅读框架的重组质粒转化到大肠杆菌BL21(DE3)感受态细胞，37℃下经IPTG诱导表达，得到相对分子质量约29000的融合蛋白，表达量约为11％。     

弓形虫微线体蛋白MIC3基因的克隆及原核表达

根据编码MIC3的已知基因序列设计并合成一对引物,应用PCR技术从弓形虫RH株的基因组DNA中扩增编码MIC3的全长基因,克隆入pGEX-KG表达载体,转化入E.coli DH5α感受态细胞,经含氨苄青霉素琼脂平板筛选,小量抽提质粒进行酶切、PCR及DNA测序鉴定.然后阳性重组质粒转化入E.coli BL21-CodonPlus,IPTG诱导,表达产物经SDS-PAGE和Western-blot分析鉴定.结果显示,扩增的MIC3基因与GenBank中相应基因序列（AJ132530）的同源性达99.6 %,表达的MIC3融合蛋白表观分子量约为66 ku,且可被兔抗弓形虫免疫血清识别.说明所获得的表达蛋白质具有一定的反应原性,为下一步利用重组蛋白建立弓形虫的诊断方法和研制弓形虫的亚单位疫苗奠定了基础.     

鸡白介素18基因原核表达质粒构建

根据已发表的江西土鸡白介素 -1 8(Ch IL-1 8) c DNA编码基因序列设计引物 ,用PCR技术从 p MDCh IL-1 8质粒扩增出编码鸡IL-1 8成熟蛋白基因 ,重组于 p BV2 2 0表达载体上 ,将重组质粒转化大肠杆菌 JM1 0 9(DE3 ) ,转化子经温度诱导的表达产物 ,SDS-PAGE电泳鉴定约 2万 ,N端开头 1 5个氨基酸序列测定分析 ,证明获得了鸡 IL-1 8成熟蛋白 ,为今后深入研究鸡 IL -1 8的生物学特性及其临床应用打下了基础     

鸡柔嫩艾美耳球虫HN株3-1E基因的原核表达与鉴定

根据已报道的柔嫩艾美耳球虫3-1E基因序列设计引物,以孢子化卵囊总RNA为模板,用RT-PCR方法扩增得到1条特异片段,将扩增产物克隆至p MD-18T载体,转化感受态菌JM109,经酶切鉴定获得阳性重组质粒并对其进行测序。测序结果与已发表的国内外相关虫株的3-1E基因序列比较,核苷酸的同源性均在99.2%~99.8%,氨基酸的同源性均在98.2%~100%。然后将重组质粒和表达载体p GEX-4T-1分别用Xho I和EcoR I酶切后构建重组表达载体p GEX-3-1E,并将其转化入大肠杆菌BL21中,提取质粒经酶切和PCR鉴定正确后,用IPTG诱导表达。表达产物经SDS-PAGE和Western blot检测显示,3-1E基因在大肠杆菌中成功表达,融合蛋白的分子量为44.7 ku,诱导表达5 h的蛋白表达量可达到30%以上。     

表达PRRSV E基因重组质粒在小鼠诱导的体液免疫应答

利用 PCR技术对猪繁殖与呼吸综合征病毒 (PRRSV) BJ- 4株的 E基因进行修饰和改造 ,在 E基因上游加入 Kozak序列 ,扩增并克隆 E基因。将 E基因 c DNA亚克隆至真核表达载体 pc DNA3.1( )中 ,构建了真核重组表达质粒 pc DNA- E。用pc DNA- E免疫小鼠 ,经免疫荧光抗体试验检测结果表明 ,重组质粒 pc DNA- E经 3次免疫后 ,所有小鼠血清抗体均为阳性 ,说明pc DNA- E在小鼠体内可诱导特异性的体液免疫应答反应。     

鸡柔嫩艾美尔球虫ZJ株3-1E基因的原核表达及鉴定

本实验对E．tenellaZJ株的3-1E基因进行了克隆和表达。根据已报道的柔嫩艾美尔球虫3-1E基因序列设计引物,以孢子化卵囊总RNA为模板,用RT—PCR方法扩增得到一条特异片段,将扩增产物克隆至pUCM—T,转化感受态菌DH5仅,经酶切鉴定获得阳性重组质粒并对其进行测序。测序结果与参考序列比较,核苷酸同源性为99．5％。然后将重组质粒和表达载体pET-30a分别以EcoRⅠ、SalⅠ酶切后构建重组表达载体pET-30a-3—1E,并将其转化入大肠杆菌BL21中,提取质粒经酶切和PCR鉴定正确后,用IPTG诱导表达。表达产物经SDS—PAGE和Westernblot检测显示,3-1E基因在大肠杆菌中成功表达;融合蛋白的分子量约为27ku,诱导6h的蛋白表达量可达到47、024％。     

大肠杆菌铜锌超氧化物歧化酶基因的克隆与序列测定

试验以E.coliMG1655的基因组DNA为模板,通过PCR技术扩增sodC基因,PCR产物经纯化回收后克隆至pMD18-T载体中,转化E.coliDH5α感受态细胞,筛选阳性克隆,提取质粒进行SacI和KpnI酶切及PCR扩增鉴定,并对sodC基因片段进行序列测定。试验成功克隆了sodC基因,获得的基因与报道的sodC基因序列同源性达到99.6%,为进一步构建重组表达载体奠定了基础。     

单增李斯特菌lmo2193基因克隆与原核表达

为了对单增李斯特菌新疆绵羊脑炎临床分离株LM90SB2的lmo2193基因进行克隆及其原核表达,采用PCR方法扩增lmo2193基因,连接pMD19-T载体进行克隆,筛选阳性菌进行测序比对。将目的基因克隆至原核表达质粒p ET32a中,构建重组质粒pET32a-2193,并转化大肠杆菌感受态细胞,经诱导表达后,利用SDS-PAGE和Western blot鉴定重组蛋白。结果显示:扩增得到的lmo2193基因序列长度为1 077 bp,与预期一致;该基因在大肠杆菌中大量表达,经SDS-PAGE检测和Western blot鉴定分析表明该产物为1个60 ku左右的融合重组蛋白。本研究成功克隆lmo2193基因,并获得大量表达,为进一步研究lmo2193基因功能奠定基础。     

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。     

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.     

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。