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1.
朊蛋白(prion protein,PRNP)基因编码朊蛋白,是引起疯牛病的主效基因。本研究利用PCR方法首次从杂交牛(大额牛×云南黄牛)基因组中扩增了PRNP基因,GenBank登录号为HQ875337。PCR产物直接双向测序表明,该序列包含杂交牛PRNP基因795 bp的开放阅读框(ORF),编码264个氨基酸前体蛋白。生物信息学分析结果发现,该蛋白包含1个信号肽、3个α螺旋、2个β折叠、6个八肽重复序列、1个疏水区域、1个二硫键和1个糖基磷脂酰肌醇锚定位点。与已报道的其他牛PRNP基因进行序列比对分析,核苷酸和氨基酸的同源性均在97%以上。  相似文献   

2.
奶牛朊病毒基因克隆与序列分析   总被引：8，自引：0，他引：8  
根据已报道正常牛朊蛋白(PrP^c)基因(PRNP)序列设计引物，采用PCR法扩增了6头荷斯坦奶牛的PRNP基因，将其克隆到T-Vector。序列测定及分析表明所克隆的奶牛PRNP基因片段为795bp，该基因内无内含子，包含了牛PRNP完整编码区序列，编码264个氨基酸的前体蛋白，推测其分子量约34ku。其中2头共同含有未曾报道的牛PRNP多态性位点M120I，无义突变G234A，但未引起酶切位点变异，未发现插入或缺失变异；与已报道牛PRNP序列(GenBank收录号为DI0613)相比，两者核苷酸序列同源性为99％，其编码的氨基酸同源性为99％。  相似文献   

3.
根据绵羊朊蛋白基因(prion protein nucleic acid,PrNP)序列,截去PrNP部分N端信号肽(150 bp)和C端GPI锚定位点(123 bp)形成PrNPT-08,设计特异性引物,以绵羊全血提取DNA为模板,扩增PrNPT-08序列。与表达载体pET30a(+)连接,转化入BL21(DE3)感受态细胞。用IPTG诱导表达,其产物经SDS-PAGE电泳、纯化、Western blotting验证。结果表明,所插入的克隆片段含有498个核苷酸,共编码166个氨基酸,序列对比分析表明,与GenBank中绵羊朊蛋白基因序列同源性为99.6%,氨基酸序列同源性为98.8%。PrNP T-08基因在大肠杆菌得到高效表达,表达产物为相对分子量为27 kDa的融合蛋白,并能被PrP单克隆抗体AH6所识别。该蛋白成功表达为研究朊蛋白生理生化功能和结构转变提供了基础生物学材料,同时为朊蛋白疾病诊断中所需单克隆抗体的制备提供基本的试验材料。  相似文献   

4.
为表达锡兰钩虫金属蛋白酶组织抑制剂(Ace-TIMP)重组蛋白,本实验根据GenBank中锡兰钩虫TIMP (ANCCEY-04405)基因序列设计引物扩增犬源锡兰钩虫Ace-TIMP基因,利用生物信息学软件对其序列鉴定;根据编码的氨基酸序列进行遗传进化关系分析;构建其重组表达质粒p ET-32a-Ace-TIMP-MP,转化大肠杆菌,并经诱导表达。结果显示,Ace-TIMP基因ORF为648 bp,编码215个氨基酸,包含16个氨基酸的信号肽,具有TIMP家族Cys-X-Cys特征性序列。进化树分析显示Ace-TIMP与犬钩虫TMP-2位于同一分支。经诱导表达与纯化,获得了分子质量约为42 ku的可溶性融合蛋白。本实验克隆了Ace-TIMP基因并利用原核表达系统表达了可溶性的重组蛋白,为Ace-TIMP生物学活性的研究和免疫潜能的评价奠定了基础。  相似文献   

5.
在感染家蚕质型多角体病毒(BmCPV)的家蚕中肠组织中发现一个差异表达的假定蛋白基因。利用cDNA末端快速扩增(RACE)技术克隆了该假定蛋白基因的全长cDNA。用生物信息学方法进行基因序列与结构分析表明:该基因全长cDNA序列为486bp,包含108bp的5′端非翻译区序列(5′-UTR)和153bp的3′端非翻译区序列(3′-UTR),开放阅读框(ORF)为225bp,编码74个氨基酸,蛋白分子质量为6.888kD,等电点为5.27;该基因由3个外显子和2个内含子组成,ORF位于第2外显子内,编码蛋白含二次跨膜结构,多肽链表现为疏水性,在多肽链上的第15～16氨基酸残基可能是信号肽的切割位点。RT-PCR结果显示该基因在家蚕5龄幼虫的丝腺、血液、脂肪体、生殖腺及中肠组织中均有表达;荧光定量PCR结果表明该基因在感染Bm-CPV的家蚕中肠组织中的表达水平为正常家蚕中肠组织的6.28倍。研究结果为进一步解析该基因的功能奠定了基础。  相似文献   

6.
本试验旨在克隆鉴定猪硒蛋白X(Sel X)基因,将其定点突变后进行原核表达,获得重组蛋白,并制备猪Sel X多克隆抗体,为以猪为模型Sel X功能研究奠定基础。利用c DNA末端快速克隆(3'-RACE)技术从猪肝脏总RNA扩增出含开放阅读框(ORF)至poly(A)共1 215 bp的Sel X基因c DNA片段,其348 bp的ORF编码区和对应的氨基酸残基与人相应序列分别有88%和91%序列同源性,猪Sel X基因提交NCBI Gen Bank数据库,序列号为EF113597。ORF编码氨基酸残基中硒代半胱氨酸(Sec)位于C-端第95个残基,其编码密码子TGA经定点突变为半胱氨酸(Cys)的TGT后,将其插入载体p ET30,转入大肠杆菌BL21(DE3)中,在0.5 mmol/L异丙基硫代-β-D-半乳糖苷(IPTG)诱导2 h获得融合表达产物,经His-tag亲和层析后,获得分子质量为18.0 ku的纯化蛋白。将纯化获得的Sel X基因突变体融合蛋白(Sel Xm)免疫兔子,得到效价高达1∶20 000的多克隆抗体,免疫印迹(Western-blot)结果显示该抗体能特异性识别纯化的Sel Xm和猪肝脏中相应Sel X。本试验成功克隆并鉴定了猪Sel X基因,并制备了其多克隆抗体。  相似文献   

7.
朊蛋白基因PRNP作为朊蛋白基因家族的一员,其编码的异常朊蛋白(prion)导致传染性海绵样脑病(TSEs)的发生。PRNP基因在定位、结构、表达和编码产物上与朊蛋白基因家族其他3个基因(PRND,PRNT和SPRN)存在很多相似之处,且该基因家族在不同种属之间十分保守,朊蛋白基因家族因此被称为"朊蛋白基因复合体"(prion gene complex)。已有资料表明,朊蛋白基因家族除了与TSEs的发生密切相关,其还对畜牧生产和兽医预防有着重要影响。论文介绍了朊蛋白基因家族的4个基因及其编码产物,而后依次阐述了该基因家族对畜牧生产的影响以及在兽医预防中的研究进展,以期为畜牧生产和兽医预防提供参考。  相似文献   

8.
朊蛋白基因家族包括4个基因:PRNP(PrP的编码基因),PRND(Doppel的编码基因),PRNT(Prt的编码基因)和SPRN(Shadoo的编码基因)。其中,PRNP,PRND和PRNT3个基因位于同一个55kb的区域内(PRNP-20kb-PRND-3kb-PRNT),而SPRN基因位于另一条染色体上。这4个基因被称为"朊蛋白基因复合体"(Prion gene complex),在不同种属之间相当保守。传染性海绵样脑病(TSEs)的发生不仅受到PRNP基因的调控,朊蛋白基因家族的其它3个基因在定位、结构、表达及其编码产物上与PRNP基因存在很多相似性,提示其它3个基因很可能作为TSEs研究的候选基因。文章从朊蛋白基因家族的结构特征、编码产物的结构及其相互关系、朊蛋白基因家族在TSEs中发挥的作用等三方面进行综述,以期为研究TSEs致病机制提供新的思路。  相似文献   

9.
本试验以鲤鱼TLR5M的EST序列为基础进行5'-RACE试验,获得了其cDNA的全长序列。结果表明,该序列共3182 bp,包含38 bp的5'端非编码区,486 bp的3'端非编码区,1个2658 bp的开放阅读框(ORF),共编码885个氨基酸。序列同源性比对结果表明,该序列与麦瑞加拉鲮鱼TLR5基因同源性高达84.46%。  相似文献   

10.
禽大肠杆菌外膜蛋白基因C(ompC)的序列分析   总被引：1，自引：0，他引：1  
根据 Gen Bank中人源大肠杆菌 K- 12外膜蛋白基因 C(omp C)的核苷酸序列设计引物 ,应用 PCR方法从禽大肠杆菌 O2 、O78株及它们的融合双价弱毒菌株 O2 ,78(Norr Chlr)中分别扩增得到 omp C基因 ,序列测定及分析比较发现 ,3个菌株的 om p C基因均由 170 2 nt组成 ,核苷酸序列完全相同 ,只有 1个大的开放性阅读框 (ORF) ,长 10 92 bp,编码由 36 3个氨基酸组成的前 Om p C蛋白 ,前 2 1个氨基酸残基组成信号肽 ,成熟的 Omp C蛋白由 342个氨基酸残基组成 ,Mr为 4 0 0 0 0。其氨基酸序列也完全相同。从基因水平上证明了禽大肠杆菌 O2 、O78株及融合双价弱毒菌株 O2 ,78(NorrChlr)存在相同的外膜蛋白 C抗原 ,从而为进一步研究 Omp C蛋白的免疫原性奠定了基础  相似文献   

11.
1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.  相似文献   

12.
Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.  相似文献   

13.
Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.  相似文献   

14.
The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.  相似文献   

15.
The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.  相似文献   

16.
Comparison of different tests to diagnose feline infectious peritonitis   总被引：1，自引：0，他引：1  
  相似文献   

17.
An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.  相似文献   

18.
Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein  相似文献   

19.
正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments in  相似文献   

20.
Tropical Animal Health and Production -  相似文献   

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