鸽源冠状病毒PSH株纤突蛋白基因的遗传变异分析

对鸽源冠状病毒PSH株纤突蛋白基因进行了RT—PCR扩增、克隆和测序。结果表明，PSH株S基因由3504个核苷酸组成，编码1条由1167个氨基酸残基组成的多肽。S基因编码产物裂解后形成的S1和S2亚单位分别由541和626个氨基酸残基组成。PSH株S蛋白切割识别位点为精氨酸-精氨酸-苯丙氨酸-精氨酸-精氨酸（RRFRR），与多数鸡传染性支气管炎病毒（IBV）切割识别位点相似（RRF／SRR）。与GenBank中其他冠状病毒毒株S基因的推导氨基酸序列相比较，PSH株与IBV参考毒株的同源性为79．3％～99．6％，而与其他冠状病毒包括火鸡蓝冠病病毒和SARS病毒的同源性均小于37．8％。表明，鸽源冠状病毒PSH株属于第3抗原群冠状病毒，且与IBV亲缘关系较近。     

伪狂犬病病毒Fa株gp63（gI） 基因核苷酸序列测定及分析

对我国最早分离的伪犬病病毒（pseudorabies virus,PRV)Fa株糖蛋白gp63(gI)基因核苷酸序列及的氨基酸序列作了测定与分析，完整的gp63(gI)结构基因从起始密码子ATG到终止密码子TGA共有1050个核苷酸残基，编码由439个氨基酸残基构成的多肽链，4种核苷酸残基的构成比分别为：G35．9％，11.33%,T11.81%,C40.95%,G C含量达76．85％，PRV Fa株gp63基因核苷酸序列与Nice株的相比，两者同源性达98．13％，仅存在3个核苷酸残基的缺失变异，氨基酸推导序列分析表明，糖蛋白gp63具有典型膜蛋白特征，与Nice株相比，同源性为97．42％，gp63基因起始密码子由3个连续的ATG组成，ATG上游区域内无启动子调控区序列。     

四川草科IL-15 cDNA的克隆与序列分析

根据GenBank上登录的鸡白介素15（IL-15）基因序列,设计合成一对特异性引物,以ConA诱导的鸡脾淋巴细胞提取的总RNA为模板进行RT—PCR扩增,并克隆到pMD18-T载体测序。测序结果表明,四川草科鸡IL-15开放阅读框（ORF）由564个核苷酸组成,编码187个氨基酸,与GenBank中公布的鸡白介素15基因进行比较,核苷酸和氨基酸同源性为98．6％-99．5％。生物信息学分析表明,该基因编码的蛋白具有亲水性,有很强的抗原性,共有3个潜在的N-糖基化位点,可能存在3个蛋白激酶C磷酸化位点,存在2个酪蛋白激酶Ⅱ磷酸化位点。     

麻鸭α干扰素基因的克隆与序列分析

根据GenBank文献，应用Oligo6．0分析软件设计合成了用于扩增鸭Ⅰ型干扰素（α—IFN）基因的2对引物。以麻鸭肝脏提取的基因组DNA为模板，采用Nest—PCR方法扩增获得了约600bp片段，经T载体克隆和测序分析证实，是麻鸭Ⅰ型干扰素基因（SDIFN—α）。生物信息学分析表明，SDIFN—α的开放阅读框架（ORF）由576个核苷酸所组成，预测蛋白质相对分子质量为21640，编码191个氨基酸。其中前28个氨基酸可能是信号肽部分，切割位点在28号氨基酸A和29号氨基酸S之间，序列中无内含子。成熟的多肽中含8个半胱氨酸和2个糖基化位点，2个蛋白激酶C磷酸化位点（protein kinase C phosphorylation site）和2个酪蛋白激酶Ⅱ磷酸化位点（casein kinase Ⅱ phosphorylation site）。SDIFN—α与鸭α—IFN基因核苷酸同源性为99．3％。有4个碱基的差异；与北京鸭α—IFN基因的核苷酸同源性为99．1％，氨基酸同源性为98．96％；与鸡α—IFN的核苷酸同源性为71．8％。与鹅、狗、牛、马和人的α—IFN基因的核苷酸同源性分别为96．0％、45．8％、45．5％、44．6％和41．7％。遗传进化分析结果表明，IFN—α的这些同源性与其动物分类地位相一致。     

鸡IL-2受体α亚基成熟蛋白基因的克隆及其胞外段的原核表达

以鸡脾淋巴细胞总RNA为模板，采用RT—PCR方法克隆了鸡白细胞介素-2受体α亚基（ChIL-2Rα）编码区基因。将ChIL-2Rα胞外段基因克隆到pET-32a（＋）中，获得重组质粒pET32a—exChIL-2Rα，转化宿主菌E．coli Rosseta^TM（DE3）后，经IPTG诱导表达的融合蛋白大小约为34ku。序列分析发现，鸡IL-2Rα编码区基因与GenBank上已登录序列的核苷酸同源性为99．2％，氨基酸同源性为99．5％。ChIL-2Rα与其他哺乳动物IL-2Rα在核苷酸和氨基酸水平上的同源性分别为29．6％～54．5％和18．8％～28．0％。表明，禽类IL-2Rα与哺乳类的差异较大。     

鸡抗病毒Mx基因的克隆与序列分析

用干扰素诱导剂poly（I）／（C）诱导鸡胚成纤维细胞,提取细胞总RNA,采用RT—PCR方法扩增了北京白鸡Mx基因全长编码区序列。序列分析表明：该基因编码区长2118bp,编码705个氨基酸残基,其第631位为天冬酰胺,理论上推测具有抗病毒活性。通过与GenBank中已登录的7个品系鸡Mx基因进行核苷酸系统进化树分析,结果显示,北京白鸡Mx基因与WL—N品系鸡Mx基因的亲缘关系最近。北京白鸡Mx基因序列与其他动物Mx基因序列的比较结果显示,核苷酸同源性为49．5％～76．8％,氨基酸同源性为44．1％～61．6％。据此可以推断：克隆的Mx基因具有抗病毒活性的分子特征和特征性功能结构,不同种属动物Mx基因的同源性与其亲缘关系呈正相关。     

三穗麻鸭白细胞介素2基因的克隆与序列分析

根据GenBank发表的鸭白细胞介素2(IL-2)基因序列,设计合成一对特异性引物,从刀豆蛋白A(ConA)诱导的三穗麻鸭颈外周血淋巴细胞中提取总RNA,通过RT-PCR方法扩增三穗麻鸭IL-2基因并进行克隆与序列分析。测序结果表明,三穗麻鸭IL-2基因编码区序列全长为423bp,共编码140个氨基酸,预测的分子式为C695H1125N175O226S13。序列分析显示,三穗麻鸭与绿头鸭、番鸭、绍兴麻鸭的IL-2基因核苷酸同源性最高(为98.3%);与其它水禽IL-2蛋白氨基酸序列相比,在29(N/D)、32(K/T)、49(D/N)、58(T/K)、90(K/N)、105(M/T)、122(N/K)和129(Q/R)存在8处氨基酸位点变异,仅有L66、C68、E72和F1274个氨基酸是三穗麻鸭和人与其它动物IL-2均保守的位点。本研究对进一步研究三穗麻鸭IL-2的生物学功能以及开发疫苗免疫佐剂奠定了基础。     

新城疫病毒长春株F基因和HN基因的序列分析

从长春地区分离到一株新城疫病毒,经过对其进行生物学研究表明该毒株具有新城疫病毒弱毒株的一些特性,本试验通过ＲＴ－ＰＣＲ方法测定出该毒株Ｆ基因的核苷酸序列为１７５８ｂｐ,编码有５３３个氨基酸残基;ＨＮ基因核苷酸序列为１７３１ｂｐ,编码５７７个氨基酸残基,与国外发表的部分新城疫病毒强毒株和弱毒株之间相同序列进行比较。Ｆ基因核苷酸序列的同源性在８８．２％～９６．７％之间,氨基酸序列同源性在９０．１％～９     

鸡白细胞介素-2受体基因γ链的转录分析与表达

以脾单个核细胞总RNA为模板，对鸡白细胞介素-2受体基因γ链（chIL-2Rγ）进行了RT—PCR，获得了-1047bp的开放阅读框，编码由348个氨基酸残基组成的分子质量为37．8ku的蛋白多肽。预测的鸡IL-2Rγ多肽链中包含4个保守半胱氨酸残基、1个WSXWS基序和7个N连接的糖基化位点。鸡IL-2Rγ与其他动物IL-2Rγ在氨基酸水平上的同源性仅为21．49／6～38．2％。RT—PCR检测发现，鸡IL-2RγmRNA分布于大脑、小脑、脊髓、腔上囊、脾、胸腺、骨髓、盲肠扁桃体、腺胃、肌胃、空肠、卵黄囊憩室、回肠、盲肠、直肠、心脏、肾、肺、肝、骨骼肌和皮肤，而在十二指肠和睾丸中没有检测到其转录。构建了鸡IL-2Rγ胞外区的原核重组表达载体，进行了表达和鉴定。     

大围山微型鸡POU1F1基因编码区的克隆及序列分析

大围山微型鸡是我国目前报道的体形最小、体重最轻的地方优良品种,具有较高的屠宰率和饲料报酬。研究通过设计特定引物对大围山微型鸡POU1F1基因的编码区进行PCR分段扩增并测序。利用分子生物学软件对其基因序列及编码产物的结构、功能进行了生物信息学分析,并构建其系统发育关系。结果表明,大围山微型鸡POU1F1基因编码区全长984bp,与原鸡的POU1F1基因（NM〈sub〉2〈/sub〉04319）比对,在836位处发生一次碱基转换（C/T）,但未造成氨基酸改变;其编码产物由327个氨基酸残基组成,分子质量为38801.19Da,理论等电点为8.67;系统发育树结果表明,不同物种间在该基因编码区核苷酸序列和氨基酸序列上有较高的相似性,大围山微型鸡与原鸡POU1F1基因编码区核苷酸序列和氨基酸的相似性分别达到了99%和100%。大围山微型鸡POU1F1基因编码区的成功克隆,为进一步研究POU1F1基因的遗传特性和大围山微型鸡的矮小机理奠定了基础。     

白术、微米白术和白术多糖对断奶仔猪生长性能和肠道形态及微生态区系的影响

试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。     

Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia

Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.     

Feline intracranial neoplasia: retrospective review of 160 cases (1985-2001)

The purpose of this study was to determine the frequency of different tumor types within a large cohort of cats with intracranial neoplasia and to attempt to correlate signalment, tumor size and location, and survival time for each tumor. Medical records of 160 cats with confirmed intracranial neoplasia evaluated between 1985 and 2001 were reviewed. Parameters evaluated included age, sex, breed, FeLV/FIV status, clinical signs, duration of signs, number of tumors, tumor location(s), imaging results, treatment, survival times, and histopathologic diagnosis. Most of the cats were older (11.3 +/- 3.8 years). Primary tumors accounted for 70.6% of cases. Metastasis and direct extension of secondary tumors accounted for only 5.6 and 3.8% of cases, respectively. Twelve cats (7.5%) had 2 or more discrete tumors of the same type, whereas 16 cats (10.0%) had 2 different types of intracranial tumors. The most common tumor types were meningioma (n = 93, 58.1%), lymphoma (n = 23, 14.4%), pituitary tumors (n = 14, 8.8%), and gliomas (n = 12, 7.5%). The most common neurological signs were altered consciousness (n = 42, 26.2%), circling (n = 36, 22.5%), and seizures (n = 36, 22.5%). Cats without specific neurological signs were common (n = 34, 21.2%). The tumor was considered an incidental finding in 30 (18.8%) cats. In addition to expected relationships (eg, meninges and meningioma, pituitary and pituitary tumors), we found that lesion location was predictive of tumor type with diffuse cerebral or brainstem involvement predictive of lymphoma and third ventricle involvement predictive of meningioma.     

Y‐chromosomal variation of local goat breeds of Turkey close to the domestication centre

Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.     

A brief history of the prevention of infectious diseases by immunisations

Infectious diseases have always been a terrible scourge for humans. The appearance of these plagues, as they were called without distinction, was generally connected to various conditions: asters, climatic changes or religious reasons. The concept of contagious, and then infectious, diseases came slowly. Variolation, i.e. transmission of ‘virulent’ matter to induce a natural disease and the immunity against it, was brought from Constantinople to England by Lady Montague, in 1721. This ‘variolation’ technique was also often performed in veterinary medicine against diseases like sheep-pox or pleuropneumonia. As ‘vaccination’ is the term generally accepted for ‘immunisation’, variolation can be the word designating such a technique. The second period of the history of immunisation began, in 1880, with the studies of Pasteur and his collaborators. A great number of bacterial vaccines were developed: dead, live but attenuated or only parts of pathogens. The viruses were produced in animals, then in eggs and at last, in tissue cultures. Second generation vaccines appeared with genetic engineering: recombinant vaccines, vector vaccines, nucleic acids vaccines, and markers vaccines, among others. These novel technologies can permit the development of new ones and improve the quality of the vaccines already existing.     

Micronutrient Content of Certain Tropical Conventional and Unconventional Feed Resources of Southern India

The ash, silica and certain important micronutrients were estimated in conventional and unconventional feed and fodder resources available in Southern India. Commonly used dry roughages, such as paddy straw, ragi straw, maize kadbi/stalk, jowar kadbi/stalk, bajra stalk and wheat straw, were high in ash (9.9% +/- 0.77%) and silica (6.4% +/- 0.65%) and low in most of the other micronutrients, except iron, with paddy straw containing most silica (>9%). Cultivated non-leguminous (maize, jowar) and improved green crops (hybrid napier, guinea, green panic, NB-21, CO-1) were also high in ash (10.5% +/- 0.60% and 12.5% +/- 0.51%) but were moderate sources of P, Mg and Cu and good sources of Zn (98 +/- 13.8 ppm and 55 +/- 6.7 ppm). Leguminous green fodders (stylosanthus, lucerne, cow pea, soyabean) were excellent sources of Ca (1.9% +/- 0.16%), Mg (0.40% +/- 0.05%), Cu (30 +/- 5.2 ppm), Zn (121 +/- 14.7 ppm) and Fe (1234 +/- 166 ppm) and moderate sources of P. Mixed local grasses and weeds were high in silica (6.9% +/- 1.00%) but were good sources of Cu, Zn and Fe. Cereal grains (maize, wheat, rice, ragi) were low in ash (2.9% +/- 0.33%) and were relatively poor sources of Ca (0.22% +/- 0.03%), Mg (0.19% +/- 0.03%) and Cu (13 +/- 3.1 ppm). Pulses were low to medium sources of most minerals and good sources of Fe (1230 +/- 293 ppm). Oil seed cake/extractions (groundnut cake, cotton seed cake, soyabean meal, sunflower cake, safflower cake) and cereal by-products (rice polish, rice bran, wheat bran) were excellent sources of P (1.1% +/- 0.47% and 2.3% +/- 0.19%) and good sources of Zn (65 +/- 3.9 ppm and 66 +/- 10.7 ppm) and Fe (938 +/- 130 ppm and 662 +/- 126 ppm). Among the unconventional feeds screened, orange peel, sunflower heads, meat meal, rubber seed cake, spirulina algae and sea weeds contained plentiful Ca, Zn and Fe: tree leaves/top feeds (mulberry, erythrina, glyricidia, banana, subabul, groundnut haulms) were excellent sources of Ca (1.5% +/- 0.13%), Zn (120 +/- 22.9 ppm) and Fe (1033 +/- 133 ppm) but relatively poor sources of P. Soyabean husk, cocoa seed husk, rubber seed cake and meat meal were moderate to good sources of P (1.0% and 0.33%). The high Zn and Fe values of most feeds/fodders were probably due to soil contamination. This account of the micronutrient content of feed/fodder resources should help in strategic supplementation intended to alleviate local deficiencies.     

Bovine Mastitis in Selected Areas of Southern Ethiopia

A study on bovine mastitis, designed to determine the causal agents, prevalence of infection and impact of risk factors in three cattle breeds, was conducted in selected areas of southern Ethiopia. A total of 307 lactating and non-lactating cows, of which 162 were indigenous Zebu, 85 Jersey and 60 Holstein-Friesian, were examined by clinical examination and the California mastitis (CMT) test. Of these, 40.4% were positive by CMT and bacteriology for clinical or subclinical mastitis, with prevalence rates of 37.1% and 62.9%, respectively. Out of 1133 quarters examined, 212 (18.7%) were found to be infected, 83 (39.2%) clinically and 129 (60.8%) subclinically. The prevalence of mastitis was significantly higher in Holstein-Friesian than in indigenous Zebu, in non-lactating cows than in lactating cows, in the early lactation stage than in the mid-lactation stage, in cows with lesions and/or tick infestation on skin of udder and/or teats than in cows without this factor, and in the wet season than in the dry season. Mastitis increased with parity number (R = 0.9). Of 248 CMT and clinically positive udder quarter samples analysed microbiologically, 212 were culturally positive for known mastitis pathogens and 36 were negative. Of the 199 positive samples, Staphylococcus accounted for 39.2%, Streptococcus for 23.6%, coliforms for 14.1%, Micrococcus and Bacillus species for 8.0% each and Actinomyces or Arcanobacterium (Corynebacterium) for 7.0%. It was concluded that there was a high prevalence of clinical and subclinical mastitis, mainly caused by Staphylococcus aureus, Streptococcus agalactiae and Escherichia coli, in this study area.     

不同日粮氮水平对山羊氮代谢和微生物蛋白质合成的影响

本试验旨在探讨不同日粮氮水平对内蒙古白绒山羊氮代谢和微生物蛋白质合成(MCP)的影响,以达到提高氮利用率,减少环境污染和饲料资源的浪费。试验选用9只体况良好、体重为(43.83±2.95)kg,装有瘤胃瘘管的内蒙古白绒山羊,按体重随机分为3组,每组3只。日粮分为低氮7.5%、中氮10.5%、高氮13.5%3个氮水平。试验使用常规试验方法分析测定粪尿血液等生化指标,通过全收尿法和尿嘌呤衍生物法估测MCP。结果表明:随着氮水平增加,氨氮(NH3-N)浓度、氮摄入量、尿氮排出、尿中尿素氮(UUN)和MCP显著增加(P0.05),干物质采食量(DMI)显著降低(P0.01);沉积氮占总摄入氮的比例在中氮组最高,MCP在高氮组最高。综上所述,适当降低日粮氮水平可减少粪尿氮排放,提高反刍动物氮利用率。     

Microsporidial keratopathy in two dogs

A microsporidial keratopathy is described in two dogs. Both dogs presented with a unilateral stromal keratopathy characterized by multifocal coalescing opacities, and the diagnosis was made on histopathologic examination of keratectomy specimens. Transmission electron microscopy (TEM) on formalin‐fixed, paraffin‐embedded corneal tissue was performed in one dog, and the morphologic features were consistent with Nosema species infection. Both dogs were initially diagnosed and treated by superficial keratectomy. One dog received additional antifungal medication and underwent a penetrating keratoplasty following local recurrence two years later. No other systemic lesions attributable to the microsporidial infection were identified clinically. The clinical and diagnostic pathology findings, treatment, and follow‐up are discussed.