潘集区发展现代农业促进农民增收的现状、问题和对策

本文介绍了潘集区发展现代农业促进农民增收的现状,并针对其出现的问题及机遇,提出了相应的对策建议.     

Protection of pigs against post-weaning multisystemic wasting syndrome by a recombinant adenovirus expressing the capsid protein of porcine circovirus type 2

Post-weaning multisystemic wating syndrome (PMWS) associated with PCV2 was one of the most costly diseases currently faced by the swine industry. In order to develop a vaccine to control this disease, we previously constructed a recombinant adenovirus expressing the capsid of PCV2. Here, we examined the protection of swine against PMWS by the recombinant adenovirus. Eighteen 32-day-old pigs were assigned to three groups each with six. Group 1 was vaccinated subcutaneously with rAd-Cap and boosted 2 weeks later. Thirty-seven days after first vaccination, Groups 1 and 2 were oronasally challenged with virulent PCV2 isolate, 4 and 7 days later, intramuscularly exposed to keyhole limpet hemocyanin (KLH). Group 3 remained unchallenged but with KLH. The results showed that high level of PCV2-specific ELISA antibody and neutralizing antibody could be induced at 37 days after first vaccination. After challenge, pigs in vaccinated group had no clearly clinical signs, although some of them had increased rectal temperatures (>/=40 degrees C) for short time. The pyrexic phase in vaccinated group was significantly lighter than that in challenge-control group (P<0.05). The relative daily weight gain in vaccinated-challenged group was similar to that in empty control group. But it was significantly high compared to the challenge-control group (P<0.05). Mean while the pathological lesions and virema presented in vaccinated group were milder than those in control group. It indicated that the recombinant adenovirus was able to confer significant protection against clinical disease and reduce pathogenic lesions induced by PCV2 challenge, even though it could not provide complete virological protection. The recombinant adenovirus might be an attractive candidate vaccine for preventing the disease associated with PCV2 infection.     

A peptide of foot-and-mouth disease virus serotype Asia1 generating a neutralizing antibody response, and an immunostimulatory peptide

The epitopes of the capsid of foot-and-mouth disease virus (FMDV) play important roles in the construction of highly immunogenic subunit vaccines. However few epitopes have been found for FMDV serotype Asia1. In this study we screened for epitopes of the VP1 and VP2 proteins of FMDV serotype Asia1 isolate, YNBS/58. Fragments consisting of amino acids 133-163 of VP1 and amino acids 1-33 of VP2 contained epitopes, and both induced lymphoproliferation in guinea pigs. Only the VP1 fragment induced neutralizing antibodies but the VP2 peptide dramatically increased the neutralizing antibody response induced by the VP1 peptide.     

Streptococcus suis infections in humans: the Chinese experience and the situation in North America

Infections caused by Streptococcus suis are considered a global problem in the swine industry. In this animal species, S. suis is associated with septicemia, meningitis, endocarditis, arthritis and, occasionally, other infections. Moreover, it is an agent of zoonosis that afflicts people in close contact with infected pigs or pork-derived products. Although sporadic cases of S. suis infection in humans have been reported, a large outbreak due to S. suis serotype 2 emerged in the summer of 2005 in Sichuan, China. A similar outbreak was observed in another Chinese province in 1998. Symptoms reported in these two outbreaks include high fever, malaise, nausea and vomiting, followed by nervous symptoms, subcutaneous hemorrhage, septic shock and coma in severe cases. The increased severity of S. suis infections in humans, such as a shorter incubation time, more rapid disease progression and higher rate of mortality, underscores the critical need to better understand the factors associated with pathogenesis of S. suis infection. From the 35 capsular serotypes currently known, serotype 2 is considered the most virulent and frequently isolated in both swine and humans. Here, we review the epidemiological, clinical and immunopathological features of S. suis infection in humans.     

Clinical comparison of recovery from total intravenous anesthesia with propofol and inhalation anesthesia with isoflurane in dogs

The characteristics of recovery from total intravenous anesthesia (TIVA) with propofol and inhalation anesthesia with isoflurane was clinically compared in 149 client-owned dogs that anesthetized for surgical or diagnostic procedures. In all dogs, anesthesia was induced with an intravenous injection of propofol following premedication with acepromazine or diazepam. As a result, 58 dogs anesthetized with propofol-TIVA showed slower but smoother recovery than 91 dogs anesthetized with isoflurane anesthesia. The dogs stood at 34.5 +/- 19.3 and 27.7 +/- 17.2 min after propofol-TIVA and isoflurane anesthesia, respectively. Adverse effects, including hypersalivation, neurologic excitement (paddling, muscle tremor/twitching, opisthotonos) and vomiting/retching, were observed in similar infrequent incidences during the recovery from both anesthetic protocols. Propofol-TIVA is suggested to be an alternative anesthetic protocol for canine practice.     

二化螟dsRNA降解酶基因的克隆与表达分析

为解析二化螟Chilo suppressalis体内参与降解双链RNA(double-stranded RNA,dsRNA)的关键核酸酶的功能,克隆二化螟不同的非专一性核酸酶（non-specific nuclease,NUC）基因,并对这些基因进行生物信息学分析和组织定量表达分析,同时对dsRNA降解酶（dsRNA degrading nuclease,dsRNase）活力的组织分布进行研究。结果显示,共克隆获得5个NUC基因,其中有4个编码dsRNase亚家族基因（CsdsRNase1～CsdsRNase4）和1个编码Endonuclease G亚家族基因（CsEndoG）。5个NUC基因的开放阅读框核苷酸序列长度范围为828～1 338 bp,编码275～445个氨基酸残基,其分子量大小为31.68～49.57 kD,预测等电点为5.48～9.42。CsdsRNase1和CsdsRNase2含有信号肽序列,两者相似度极高,且与家蚕Bombyx mori和斜纹夜蛾Spodoptera litura中具有dsRNA降解酶活力的dsRNase同源聚类;CsdsRNase1和CsdsRN...     

中华卵索线虫人工室内培养技术

为室内大量繁殖中华卵索线虫Ovomermis sinensis,采用个体由大到小的斜纹夜蛾Spodoptera litura、棉铃虫Helicoverpa armigera和黏虫Mythimna separata作为宿主,测定被中华卵索线虫寄生后3种宿主的体长和体重,研究宿主种类对中华卵索线虫有效率、雌雄比和体长的影响以及寄生强度对线虫雌雄比的影响。结果显示,被中华卵索线虫寄生后,斜纹夜蛾、棉铃虫和黏虫生长减缓。在相同感染比例下（除宿主与线虫比为1∶15外）,3种宿主的线虫有效率之间差异不显著。当寄生强度为5时,3种宿主体内脱出的中华卵索线虫均为雌线虫;当寄生强度从10增到40时,斜纹夜蛾、棉铃虫和黏虫所脱出的雌性比分别由100.0%、90.0%、83.9%降为0;相同寄生强度下,从斜纹夜蛾体内脱出的雌性比显著高于从棉铃虫与黏虫体内脱出的雌性比。斜纹夜蛾、棉铃虫和黏虫体内脱出雌线虫和雄线虫平均体长分别为14.8、13.8、12.8 cm和8.0、7.5和7.5 cm。当中华卵索线虫与宿主按照比例20∶1～25∶1侵染斜纹夜蛾、按照15∶1侵染棉铃虫和黏虫时,能获得线虫最适雌雄比（1∶1...     

小麦矮腥黑粉菌g9890基因编码效应蛋白的生物信息学分析及亚细胞定位

为明确小麦矮腥黑粉菌Tilletia controversa g9890基因编码效应蛋白的生物学功能,根据小麦矮腥黑粉病菌转录组测序结果,筛选出效应蛋白g9890,通过PCR技术获得g9890基因cDNA的全长序列,并对其进行生物信息学以及亚细胞定位分析。多种生物信息学数据库分析表明,g9890基因全长为1 038 bp（包括终止密码子）,共编码345个氨基酸,相对分子质量为37 353.32,理论等电点为5.02。g9890效应蛋白不稳定系数为15.94,疏水性指数为-0.312,是一种亲水性且稳定的蛋白。将g9890基因与pbin-GFP载体重组,利用冻融法转化至根癌农杆菌Agrobacterium tumefaciens GV3101中,将其注入烟草进行瞬时表达分析,并通过共聚焦激光显微镜观测该基因的定位状况,结果显示,g9890定位在细胞膜和细胞核上。     

非亲和性稻瘟病菌对水稻的诱导抗性

为研究稻瘟病菌Magnaporthe oryzae不同菌株间的相互作用,选择与单抗性基因系水稻IRBL5-M （携带抗性基因Pi5）表现为亲和性的菌株HN52与非亲和性的菌株HN119为研究对象,将其单独或混合接种到单抗性基因系水稻IRBL5-M中,并通过荧光显微镜观察接种后水稻叶鞘的发病情况及病斑面积,测定接种后水稻内相关抗性基因OsWRKY45、OsNPR1、OsPR10、OsMAPK2的表达量以及活性氧的变化。结果显示,相较于单独接种亲和性菌株,混合接种后单抗性基因系水稻IRBL5-M病斑发病面积减少;混合接种中亲和性菌株HN52菌丝侵染能力降低,侵染菌丝细胞间扩展率显著降低73.13%;同时单抗性基因系水稻IRBL5-M中OsWRKY45、OsNPR1、OsPR10和OsMAPK2抗性基因表达量显著增加,水稻叶片中活性氧含量增加,表明在菌株混合侵染过程中,非亲和性菌株可通过激发水稻的抗性反应来降低亲和性菌株对水稻的侵染程度。