牛γ-干扰素基因的克隆及序列分析

根据GenBank中已公布的牛γ-干扰素(BovIFN-γ)基因序列设计引物,应用一步法逆转录-聚合酶链式反应(RT-PCR)技术,以从牛外周血淋巴细胞提取的总RNA为模板,扩增出γ-干扰素成熟肽基因片断,并对其进行了克隆、测序及序列分析.结果表明,试验所设计引物可以成功用于扩增牛γ-干扰素成熟肽基因片段,所扩增序列与GenBank中已有序列同源性达99.77%.     

鸭的NPY基因克隆和适应性检验分析

根据已知的鸭近缘物种及哺乳动物的神经肽Y(Neuropeptide Y,NPY)基因序列设计引物,利用RT-PCR技术从高邮鸭生殖轴组织总RNA中克隆出NPY基因cDNA序列,采用生物信息学方法分析不同物种间序列同源性和进化关系,并利用PAML4b检测位点选择压力.序列分析结果表明,克隆获得的鸭NPY基因cDNA片段序...     

1株塞内卡病毒A型的基因组序列与演化分析

旨在分析塞内卡病毒A型(Senecavirus A,SVA)CH-HNCY-2019株的基因组特性和演化,参考SVA毒株SVV-001(GenBank No.NC011349)全基因组序列设计8对引物,通过RT-PCR扩增和测序获得SVA CH-HNCY-2019株全基因序列并进行序列分析.结果显示,SVA分离株CH-...     

奶牛白细胞介素2基因的克隆及序列分析

根据GenBank发表的奶牛白细胞介素2(IL-2)基因序列,设计一对特异性引物,应用RT-PCR技术扩增奶牛IL-2基因,琼脂糖电泳显示扩增出的片段约为477bp。回收片段,克隆入pMD18-T载体,经菌落PCR、酶切及重组质粒PCR鉴定,测序结果显示,克隆的奶牛IL-2基因与GenBank发表的奶牛IL-2基因序列同源性为98.7%。该序列与水牛和山羊的IL-2基因序列同源性最大,在95%以上;氨基酸和抗原性比较分析显示,奶牛的IL-2与山羊及水牛的IL-2在这两方面有较高的同源性。     

鸭疫里氏杆菌吉林分离株16S rRNA系统分析及其OmpA基因克隆

为研究鸭疫里氏杆菌(RA) 16S rRNA变异与OmpA基因之间的关系,提取了RA吉林分离株JL-RA1和JL-RA3总DNA,并设计特异性引物扩增两株RA保护性抗原OmpA全基因序列.结果显示,扩增出的16S rRNA序列大小均为1478 bp,OmpA片段序列大小均为1164 bp,与预期结果一致.扩增的16S rRNA与GenBank中已知的RA 16S rRNA序列同源性高达99.0％ ～99.9％,扩增的OmpA序列与GenBank中已知的RA OmpA序列同源性达93.3％ ～ 100％,编码蛋白质的氨基酸序列同源性为96％～100％.     

奶牛乳腺炎源性大肠杆菌csgC基因的克隆及载体构建

根据GenBank上发表的curli菌毛csgC基因序列设计了1对特异性引物.从患乳腺炎的奶牛乳汁中分离出致病性大肠杆菌,经生物学鉴定后,提取全基因组DNA为模板,PCR扩增出csgC基因,连入pMD18-T克隆载体,测序,结果表明,扩增片段含有333个核苷酸,编码111个氨基酸的成熟蛋白,与已报道的大肠杆菌W3110的全基因组DNA中的csgC基因序列最相近,氨基酸序列同源性为99.7%.该基因与原核表达载体pET32a+相连,转入BL21(DE3)感受态细胞.挑选阳性菌落经PCR鉴定和酶切鉴定后表明成功构建原核表达载体pET32a+/csgC.     

非洲猪瘟病毒MGF505-3R蛋白的原核表达研究

为获得非洲猪瘟病毒(African swine fever virus,ASFV)体外诱导表达的MGF505-3R蛋白.实验依据GenBank中报道的MGF505-3R基因序列设计引物,引入His标签,以ASFV基因全序列为模板扩增目的基因.将目的基因克隆至原核表达载体pGEX-6p-1,并转入大肠杆菌Transett...     

萨能奶山羊早期胚胎性别鉴定体系的建立

根据GenBank中山羊的SRY(sex determining region of the Y)基因序列设计跨度为437 bp和346bp的两对嵌套式雄性特异性引物,同时根据GenBank中山羊的β-珠蛋白基因序列设计跨度为304 bp和174 bp的两对嵌套式常染色体引物作为内标引物,对提纯的萨能奶山羊血液DNA样品和胚胎细胞DNA样品进行PCR(polymerase chain reaction)以准确鉴定早期胚胎性别.扩增产物用琼脂糖凝胶电泳分析表明:通过10μL、20μL体系,56℃退火条件下,雄性胚胎具有346 bp SRY基因序列扩增带及304bp和174 bp常染色基因扩增带;而雌性胚胎只有304 bp和174 bp常染色基因扩增带.     

用PCR进行绵羊早期胚胎性别鉴定技术

根据绵羊SRY(sex determining region of the Y)基因中的同源序列,设计跨度为170 bp两对半嵌套式性别特异性引物,同时根据β-珠蛋白基因序列设计240 bp常染色体引物作为内标引物,对绵羊胚胎细胞DNA样品进行PCR (polymerase chain reaction)扩增,确定了绵羊胚胎性别鉴定的反应体系.结果表明在该反应条件下,雄性胚胎具有170 bpSRY基因序列扩增带及240 bp β-珠蛋白基因序列扩增带;而雌性胚胎只有240 bp常染色体基因序列扩增带.因此这个鉴定体系是可行的.     

奶牛粒细胞-巨噬细胞集落刺激因子的原核表达及其活性检测

为了表达奶牛粒细胞-巨噬细胞集落刺激因子(GM-CSF)并对其活性进行检测.根据GenBank中登录的牛GM-CSF基因序列(U22385),设计一对特异性引物;采用RT-PCR方法,以LPS体外诱导的奶牛肺泡巨噬细胞为材料,从总RNA中扩增出奶牛GM-CSF cDNA基因,克隆到pGEM-T载体中,经酶切鉴定与序列测定,结果显示克隆的奶牛GM-CSF基因与GenBank中登录的牛GM-CSF基因序列的核苷酸和氨基酸的同源性分别为99.7%和99.3%.构建pET32a-GM-CSF原核表达重组质粒,经IPTG诱导表达,SDS-PAGE结果显示重组蛋白大小约为35 ku.分别运用集落形成试验与MTT比色法测定重组蛋白活性,结果显示重组奶牛GM-CSF蛋白能够诱导粒细胞前体呈集落性生长并具有较强的体外增殖淋巴细胞的活性,为下一步临床试验奠定了基础.     

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.     

Mechanism of Action of Probiotic Function of Lactobacilli

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。 …