Inhibition of porcine circovirus type 1 and type 2 production in PK-15 cells by small interfering RNAs targeting the Rep gene

Porcine circovirus type 1 (PCV1) and type 2 (PCV2) are two genotypes of porcine circovirus. Both of them are presumed to be widespread in the swine population. Currently, there is no specific treatment for their infections. RNA interference (RNAi) is a sequence-specific RNA degradation mechanism mediated by small interfering RNA (siRNA), which represents a possible therapeutic application for the treatment of viral infections. In this study, three siRNA expression plasmids (pS-RepA, pS-RepB and pS-RepC) were generated to target three different coding regions of the Rep protein (Rep) of PCV. These siRNAs were used to inhibit PCV production in a porcine kidney cell line, PK-15 cells. Our results revealed that Rep gene expression was inhibited by pS-RepA, pS-RepB and pS-RepC to different degrees. Moreover, our study also showed that the production of PCV1 and PCV2 was reduced by these siRNAs. pS-RepC, which targets the middle region of Rep gene, proved to be the most efficient siRNA for inhibition of Rep expression and viral production. Taken together, our data suggest that RNAi could be investigated as a potential treatment for PCV infection.     

不同投喂方式对革胡子鲶消化酶的影响

在（25±1）℃水温、自然光照条件下,设3种投喂方式饲养革胡子鲶（clarias leath-er）：第1种连续投喂整个试验期间不间断,第2和3种分别连续投喂3、7 d 后饥饿1 d,3种方式分别以R0（对照组）、R1/3、R1/7表示,试验周期共45 d。结果显示：R0、R1/3和R1/7组胃、后肠和肝脏中蛋白酶活性影响差异不显著,但前肠和中肠内蛋白酶活性影响存在差异(P<0.05)。R0、R1/3、R1/7组的胃、前肠、中肠、后肠和肝脏中淀粉酶影响不显著,R0、R1/3、R1/7的胃、前肠和肝脏内脂肪酶活性影响差异显著(P<0.05),而R0、R1/3、R1/7组中肠和后肠中脂肪酶活性影响差异不显著(P>0.05)。     

关于生物安全隔离区建设试点的几点思考

动物疫病区划管理是当前国际通行的动物疫病管理措施,目的是实现动物疫病控制或净化,提高动物卫生水平,促进动物、动物产品的国际贸易。2003年,世界动物卫生组织(OIE)提出了动物疫病区域化管理新模式--生物安全隔离区划,即在同一生物安全管理系统下,通过采取监测、控制和生物安全管理措施,建立并维持无一种或多种特定动物疫病状态的无疫生物安全隔离区。虽然该概念提出时间较短,但已引起了全世界范围的广泛关注,欧盟和澳大利亚、泰国等一些畜牧业发达国家都在进行积极地研究和探索。我国也在无疫示范区建设基础上,根据OIE有关标准和建议,研究制定生物安全隔离区建设和评价标准,并着手开展试点工作。     

胸膜莫肺炎放线杆菌APXIV部分基因片段的表达及纯化

参照GenBank中已发表的ApxIV基因序列,以自行分离的App DNA为模板,利用PCR方法扩增出ApxIV3'端,大小为552bp的保守基因序列.将PCR产物克隆到pMD18-T Simple Vector中,获得重组质粒pMD-ApxIV,对其重组质粒pMD-ApxIV进行BamHI、HindIII双酶切,并将酶切产物克隆到原核表达载体pET-32a(+)中,构建了重组表达质粒pET-ApxIV.将表达质粒转化至大肠杆菌BL21中,用IPTG诱导表达,通过SDS-PAGE和Western blot分析,结果表明pET-ApxIV在BL21中成功表达,并能被App阳性血清所识别,具有良好的免疫原性.表达蛋白的分子质量约为39.5KDa.利用HiTrap FF crude columns将表达的蛋白进行了纯化.     

辉煌后涅槃 涅槃中轮回——2009豆市年度投资报告

经过2008年全球金融危机引爆的资本市场“去杠杆化”后．全球大豆市场走势将逐步回归供需面的引导。由于全球走出经济危机尚需时日,2009年国内外大豆期价很难走出单边行情．预期将更倾向于宽幅区间振荡行情。如果2009年美豆种植面积减少．2009年下半年经济好转,流动性再度充裕．那么2009／10年度美豆的农场价格有可能高于本年度。但年度均价在未来的1到2个年度仍倾向于下滑。     

Effect of Fermentation Bed with Spent Mushroom Substrate of Pleurotus eryngii on Weaning Piglets

[Objective] The paper was to investigate effects on fermentation bed temperature,growth performance,diarrhea rate and digestive en-zyme activity of weaning piglets by using spent mushroom substrate of Pleurotus eryngii as padding.[Method] A total of 120 weaning piglets(Duroc × Landrace ×Yorkshire) with average initial body weight of(8.0 ±0.5)kg were allocated to five dietary treatments in a randomized complete block design for 42 d,each of which was replicated three times with eight piglets per replicate(half male,half female).The padding for control group was(50% sawdust +50% rice husk);experimental group Ⅰ 100% spent mushroom substrate;experimental group Ⅱ(15% sawdust +15% rice husk +70% spent mushroom substrate);experimental group Ⅲ(25% sawdust +25% rice husk +50% spent mushroom substrate);experimental group Ⅳ(35% sawdust +35% rice husk +30% spent substrate).[Result] There was no significant difference in surface temperature of fermentation bed between experimental groups and control group(P0.05).Compared with the control group,the temperature under 20 cm of fermentation bed in ex-perimental groups I,Ⅱ and Ⅲ increased significantly(P0.05).Except for experimental group Ⅳ,other three experimental groups had higher aver-age daily gain(P0.05) and experimental group Ⅰ had higher average daily feed intake(P0.05) compared to the control group.The diarrhea rate and mortality of weaning piglets in experimental groups Ⅱ,Ⅲ and Ⅳ were significantly decreased compared with the control group(P0.05).Compared with the control group,other three experimental groups had higher digestive enzyme activity in duodenal contents except for experimental group Ⅳ(P0.05).[Conclusion] Spent mushroom substrate of P.eryngii can be used as fermentation bed padding,and the optimal proportion was experimental group Ⅲ.     

DNA Barcoding:An Effective Tool for Species Identification of Lepidopteran Oak Pests

[Objective] The paper was to improve the efficiency and accuracy of early forecast of Lepidopteran oak-infesting pests.[Method] DNA barcoding technique was established for quick species identification using mitochondrial cytochrome C oxidase subunit Ⅰ(COⅠ) as the standard gene.This barcoding technique was used to amplify and sequence genomic DNA samples from eggs and pupae of 11 species of Lepidopteran pests collected from oak.[Result] The DNA barcoding standard genes of 594-708 bp were determined from eggs and pupae of Lepidopteran insects.There were differences of 0-2 bases in DNA barcode sequences between conspecific eggs and pupae,with the sequence identity of 99.7%-100%.The average content of A,T,G and C of DNA barcode sequences from Lepidopteran insects were 30.7%,38.5%,14.9% and 15.9%,respectively.The obtained DNA barcode sequences had 91.4%-100% identity and 0-8.6% difference degree with GenBank-deposited DNA barcode sequences from organisms of the genetically-closest relationship.Among them,DNA barcode sequences from egg and pupa samples of 10 Lepidopteran insects(No.1-20) had 99%-100% identity and 0-1.0% difference degree with homologous sequences in GenBank database,while the remaining samples(No.21-22) had high difference degree(8.6%) with homologous sequences.[Conclusion] The established DNA barcoding technique is an effeetive tool for species identification of Lepidopteran pests using genomic DNA from eggs and pupae of Lepidopteran insects.     

喷雾干燥鱼浆蛋白粉营养成分分析

本试验对鱼粉加工废水鱼浆蛋白粉(经浓缩、水解、喷雾干燥得到的副产品)进行营养成分分析,其中粗蛋白质含量达64.08%,钙2.67%、磷1.12%,钙磷比例合理;各氨基酸含量分别为:赖氨酸3.29%,蛋氨酸0.94%,谷氨酸5.17%,牛磺酸2.50%。     

农村养蚕小窍门

笔者已多年从事蚕桑生产,深入蚕户,积累了许多有用的经验,供广大蚕农借鉴。1“防尘口罩”的制作很多蚕农都知道,杀灭病原,严防蚕病发生,关键是消毒严格、彻底。但在蚕体蚕座使用防僵粉或鲜石灰粉时,灰尘很大,气味刺鼻,所以常常草草了事。要使药物撒周到,很简单,就是把平常用的口罩用水打湿后再用,粉粒就会粘附在口罩上,并且气味也减小了。2经济、实用的熟蚕自动上蔟登蔟剂现有很多蚕农推广熟蚕自动上蔟,这样可以节省劳力和时间。目前农村养蚕用于熟蚕自动上蔟的登蔟剂最常用的有两种,即樟脑丸和鲜腥草(俗名侧耳根),它们都有一种特殊的气味,…     

一例肉鸽念珠菌病的诊疗

柳州市郊某养鸽户2007年3月12日购入60日龄肉鸽150对,4月15日后陆续出现发病死亡,曾用环丙沙星混水饮用和庆大霉素注射治疗,无明显效果,前来求诊。笔者根据流行病学、临床症状、病理剖检变化及实验室检查结果综合分析,确诊为白色念珠菌感染,经采用消毒鸽舍、口服制霉菌素、饮用1∶2000硫酸铜等综合措施1周后,控制了病情,现将诊治情况报告如下。1发病情况与临床症状养鸽户3月12日购入60日龄肉鸽150对,用稍加改造的旧屋地面平养,采用玉米粒、绿豆饲喂。4月15日鸽子开始发病:精神委顿,双目无神,羽毛松乱、干燥、无光泽,肛门周围羽毛粘有稀粪,采…