PEDV分离株S1基因的重组杆状病毒真核表达

为了研究猪流行性腹泻病毒(porcine epidemic diarrhea virus,PEDV)分离株(PEDV/LA/2014/02)纤突蛋白(S1)的真核表达及其反应原性,本研究利用杆状病毒真核表达系统表达出重组His-PEDV-S1蛋白。利用在线软件分析PEDV S1基因在sf9细胞内的稀有密码子,经优化密码子后的基因进行人工合成,合成后的PEDV S1基因被克隆至杆状病毒的穿梭载体(pFastBac HT A)中,转化大肠杆菌DH10Bac感受态细胞进行重组,PCR方法验证后将重组成功的杆状病毒基因组转染sf9细胞,获得包装成功的杆状病毒,该病毒进一步接种sf9细胞,显微镜观察重组病毒引起的细胞病变,RT-PCR方法验证PEDV S1基因的mRNA表达水平,SDS-PAGE、Western blotting方法验证重组PEDV S1蛋白的表达及其反应原性。结果显示,试验成功构建了重组穿梭质粒pFastBac HT A-PEDV-S1(pSL598),成功包装表达了PEDV S1的重组杆状病毒,重组杆状病毒能使sf9细胞出现细胞变大、胞内有空泡等典型病变,PEDV S1基因的mRNA获得表达,重组蛋白His-PEDV-S1在sf9细胞中得到表达,蛋白质大小为83 ku左右,主要存在于细胞沉淀中,表达的重组蛋白能与小鼠抗His抗体和猪抗PEDV阳性血清反应,说明该蛋白具有较好的反应原性。本研究为研制PEDV新流行毒株新型亚单位疫苗和防控该毒株的流行提供了材料。     

不同放牧环境下绵羊牧食行为的比较研究

为了研究同品种绵羊在不同放牧环境下的牧食行为差异,在典型草原区沙质草地和高平原草地两种放牧环境下,对四品种双杂交杂种绵羊的牧食行为进行了观察.结果表明:不同放牧环境下绵羊的采食时间和游走时间占放牧时间的80%左右,放牧环境对采食行为有显著的影响.绵羊在沙质草地采食和游走时间占总放牧时间的66.54%和15.63%,在高平原草地为77.49%和7.79%.不同放牧环境下卧息、站立等时间存在显著差异.     

Effects of CIDR-G and Melatonin Implants, and their Combination on the Efficacy of Oestrus Induction and Fertility of Kilis Goats

The objective of this study was to compare the efficiency of oestrus induction protocols on Kilis dairy goats kept on a goat farm situated close to Kilis, Turkey. Eighty goats were assigned randomly into four groups of 20 animals each in a factorial arrangement: (i) untreated control (CON), (ii) melatonin implant (MEL), (iii) CIDR-G (CIDR) and (iv) melatonin implant plus CIDR-G (MC). Experiments were performed in mid-anoestrus season under natural photoperiod environment. The differences among treatment groups in oestrus response were significant. Oestrus response was higher in the MC group than in other groups (p < 0.05). A significant difference was observed in the time interval from cessation of treatment to the onset of oestrus among treatments. The CIDR-G treatment reduced intervals from buck introduction to oestrus. The time to onset of oestrus in both the MC and CIDR groups was significantly shorter, compared with the MEL and CON groups (p < 0.05). The number of does kidding and fertility were not different among treatment groups (p > 0.05). Fecundity was similar among goats in all groups. Prolificacy and twining rates showed similar trends as fecundity rates, with no differences (p > 0.05) between treatments. The results of this study showed that oestrus in Kilis does can be effectively induced by using melatonin and CIDR combined treatment, and fertility will not be adversely affected. However, this treatment did not improve fecundity, prolificacy and twining rates.     

Late onset cerebellar cortical degeneration in a koala

A 10-year-old male koala started to fall from the tree while sleeping. Subsequently, the koala often fell down while walking and showed a gait abnormality, abnormal nystagmus and hypersalivation. At 12 years of age, the koala became ataxic and seemed blind. At 13 years of age, the koala exhibited signs of dysstasia and was euthanased. Necropsy revealed marked symmetrical atrophy of the cerebellum. Histopathologically, a severe loss of Purkinje and granule cells was evident in the cerebellum, while the molecular layer was more cellular than normal with cells resembling small neurons, which were positively stained with parvalbumin immunohistochemistry. Reactive Bergmann glial cells (astrocytes) were present adjacent to the depleted Purkinje cell zone. The very late onset and slow progression of the cerebellar cortical degeneration in this case is particularly interesting and appears to be the first report in the koala.     

Clinical trial of efficacy of ivermectin pour‐on against gastrointestinal parasitic nematodes in silvopasturing horses

The aim of this study was to assess, by a clinical trial, the efficacy of an ivermectin‐based pour‐on treatment against gastrointestinal parasitic nematodes in naturally infected horses using 2 groups of mature indigenous Pura Raza Galega grazing mares. Faecal and blood samples were collected individually over a 21 week period. Faeces were analysed by the coprological flotation, sedimentation and migration techniques. Changes in circulating blood cells were monitored over the study period. The administration of the ivermectin suppressed the eggelimination of ascarids and pinworms throughout the study and no strongyle‐eggs were observed in the treatment group between the 3rd and 10th weeks. The numbers of red cells increased significantly after the anthelmintic therapy, and a statistical reduction in circulating leucocytes was recorded. No side effects were observed. The pour‐on ivermectin formulation was highly successful against gastrointestinal nematodes and appears to be a useful therapeutic routine for large groups of horses.     

Interobserver Repeatability of Measurements on Computed Tomography Images of Lax Canine Hip Joints from Youth to Maturity

Objectives— To determine interobserver repeatability of measurements on computed tomography (CT) images of lax canine hip joints at different ages and in the presence of degenerative joint disease at maturity. Study Design— Longitudinal observational investigation. Animals— Sibling crossbreed hounds. Methods— Pelvic CT was performed at 20, 24, 32, 48, 68, and 104 weeks of age. Measures were performed on 3 contiguous two‐dimensional (2D) transverse CT images of both hips at each time point by 3 investigators. Center‐edge angle (CEA), horizontal toit externe angle (HTEA), ventral (VASA), dorsal (DASA), and horizontal (HASA) acetabular sector angles, acetabular index (AI), and percent femoral head coverage (CPC) were measured. Interobserver repeatability was quantified with the intraclass correlation coefficient (ICC). Satisfactory repeatability was considered when ICC≥0.75. Results— DASA, CEA, and CPC were repeatable in all age groups. HASA and HTEA were repeatable for all but 1 time point. At 20 weeks of age, all measures but AI were repeatable, and at 104 weeks of age, DASA, CEA, CPC, and HASA were repeatable. Measures were repeatable in hips with and without degenerative changes with the exceptions of AI and HASA in normal hips and VASA and HTEA in osteoarthritic hips. Conclusions— Most 2D CT measurements examined were repeatable regardless of age or joint disease. Clinical Relevance— Two‐dimensional CT measures may augment current techniques for assessing joint changes in lax canine hips.     

玉米浸泡和粉碎对绵羊日粮消化的影响

【目的】比较浸泡和粉碎2种不同加工方式的玉米粒对绵羊的自由采食和消化的影响。为提高绵羊对玉米颗粒的消化和饲养提供参考依据。【方法】选取6只3岁、体重为(55.0±3.8)kg的健康小尾寒羊公羊,随机分为3组,每组2只。按照3×3拉丁方设计,在3个试验期给各组绵羊分别饲喂组成相同(70%混合精料+30%粉碎玉米秸秆,其中玉米含量55%)、但玉米处理不同的日粮(1、2和3),即整粒玉米为对照组(日粮1)、粉碎玉米(日粮2)、浸泡60~72 h的整粒玉米(日粮3)。【结果】3种日粮的干物质自由采食量分别为(1 566.9±121.6)、(1 579.6±98.5)和(1 466.1±101.2)g/羊/d,日粮3比日粮1和2分别显著降低6.4%(P<0.05)和7.2%(P<0.05)。干物质表观消化率分别为(57.92±0.63)、(62.63±0.53)和(66.39±0.75)%,日粮3比日粮1和2分别显著增加14.6%(P<0.05)和6.0%(P<0.05)。干物质消化量分别为(907.5±59.4)、(989.3±92.5)和(953.4±78.5)g/羊/d,日粮3比日粮1和2分别显著增加5.0%(P<0.05)和减少3.6%(P<0.05)。但日粮3和日粮2比日粮1粗纤维消化率和消化量均无显著差异(P > 0.05)。【结论】日粮中使用浸泡玉米饲喂绵羊会降低绵羊的自由采食量,但同时会提高绵羊的表观消化率,表明浸泡玉米饲喂更有利于促进绵羊的消化。     

小麦生理型雄性不育系中反式烯脂酰-CoA还原酶基因(TaECR)的克隆及表达分析

超长链脂肪酸(VLCFAs)代谢在花药发育中发挥着重要的作用,而反式烯脂酰-CoA还原酶(trans-2,3-enoyl-CoA reductase,ECR)是催化超长链脂肪酸合成的脂肪酰-CoA延长酶之一.为进一步研究杀雄剂SQ-1诱导小麦雄性不育的机理,根据己报道二穗短柄草(Brachypodium distachyon)ECR基因,采用电子克隆获得序列并设计引物,从小麦(Triticum aestivum)中克隆ECR的开放阅读框cDNA序列,命名为TaECR,将该序列提交至GenBank,登录号为KC222053.序列分析表明,TaECR基因编码310个氨基酸,具有反式烯脂酰-CoA还原酶的经典结构域.表达分析表明,TaECR基因在小麦花药、颖片、叶和根中均有表达,其中在根中的表达量最底;与可育系相比,TaECR基因在生理型不育系三核期中表达急剧下调,在单核期和二核期表达趋势无显著变化,并与其蜡质积累量变化趋势基本一致,这表明TaECR基因调节的超长链脂肪合成途径可能参与了SQ-1诱导的败育过程.