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1.
对鸡沙门氏菌诱导家蝇幼虫构建的抑制性消减文库(SSH)中筛选得到的家蝇双翅肽I(Musca domesticaDiptericin I,MdDptI)基因进行克隆、表达,并对表达产物的抑菌活性进行初步研究。以沙门氏菌诱导家蝇幼虫cDNA为模板,采用cDNA末端快速扩增技术(RACE),对MdDptI基因进行扩增,并对扩增产物进行测序和生物信息学分析,进一步去掉信号肽并构建重组表达质粒pET-28a-MdDptI,转化大肠杆菌BL21(DE3),IPTG诱导表达,对表达产物进行SDS-PAGE电泳分析。借助亲和纯化获得目的蛋白,并验证目的蛋白的生物活性。MdDptI基因全长为419 bp,包含一个300 bp的完整开放阅读框(ORF),编码99个氨基酸,其cDNA序列与GenBank中登录号为FJ794602.1的家蝇双翅肽基因同源性为95%。构建了家蝇MdDptI基因的成熟肽原核表达质粒pET-28a-MdDpt-I,并获得成功表达,表达产物约为12 ku,与预期结果一致。纯化后的目的蛋白表现出一定的抑菌活性。本试验获得了MdDptI基因的全长序列,构建了原核表达载体,并成功获得表达纯化。  相似文献   

2.
为了研究家蝇几丁质结合蛋白(Md-CBPⅠ)在家蝇防御体系中的相关活性,采用PCR技术,对从鸡源沙门氏菌诱导家蝇幼虫构建的抑制性消减文库(SSH)中筛选到的家蝇幼虫几丁质结合蛋白Ⅰ基因(Musca domestica chitin binding proteinⅠ,Md-CBPⅠ)进行扩增,并成功构建了重组表达质粒p ET-32a-Md-CBPⅠ,于大肠杆菌BL21(DE3)中得以高效表达,纯化并获得了MdCBPⅠ融合蛋白。进一步对该蛋白的亲和活性进行了研究,发现Md-CBPⅠ融合蛋白对几丁质以及纤维素均有一定的结合作用,且其对几丁质的结合作用相对较好。试验为家蝇几丁质结合蛋白生物学活性和免疫学活性的研究奠定了基础。  相似文献   

3.
家蝇溶菌酶1基因的克隆、序列分析及原核表达   总被引：1，自引：1，他引：0  
采用cDNA末端快速扩增技术（RACE）,对鸡致病性大肠杆菌诱导家蝇幼虫抑制性消减文库（SSH）中筛选得到家蝇溶菌酶1基因（（Musca domestica lysozyme-1,MdL-1）进行扩增,测序分析得到一个全长为537bp的cDNA片段,其开放阅读框（ORF）432bp,与Genbank中登录号为AY344589．1基因同源性为96％。构建重组表达质粒pET-32a-MdL-1,转化大肠杆菌BL21（DE3）,异丙基-β—D-硫代吡喃半乳糖苷（IPTG）诱导表达,十二烷基磺酸钠-聚丙烯酰胺凝胶电泳（SDS—PAGE）分析显示。表达产物大小约为34kD,与预期蛋白大小一致。结果表明,利用RACE技术克隆得到MdL-1全长基因并在大肠杆菌中获得了表达,为进一步研究该蛋白的生物学及免疫学活性奠定了基础。  相似文献   

4.
猪肺炎支原体诱导家蝇幼虫抑制性消减文库的构建   总被引：2，自引：0，他引：2  
采用抑制性消减杂交技术(suppression subtractive hybridization,SSH)构建猪肺炎支原体(Mycoplasma hyopneumonia,Mhp)诱导家蝇幼虫后产生差异表达基因的消减cDNA文库,并利用反向Northern杂交技术获得差异基因.结果表明,随机挑取的阳性克隆的大小均为200～750 bp,通过斑点杂交技术共筛选出186个差异基因片段,对其克隆、测序及同源性分析后鉴定出20种编码蛋白的基因片段和21个无同源序列.家蝇幼虫经猪肺炎支原体诱导后产生与抗病原体相关的基因及大量的未知基因.  相似文献   

5.
从脂多糖(LPS)诱导或非诱导的家蝇幼虫体内抽提总RNA,根据家蝇Cecropin基因(GenBank:DQ 232774)设计特异性引物,应用RT-PCR技术扩增出编码CecMd开放阅读框(ORF)的cDNA序列,将其克隆入pMD18-T载体,经PCR、双酶切和测序鉴定正确后,将CecMd亚克隆基因与线性化的pET32a(+)连接,构建重组表达载体pET32a(+)/CecMd,并对此基因及其推导氨基酸序列进行系统的生物信息学分析。结果表明从脂多糖(LPS)诱导的家蝇幼虫体内成功的扩增出家蝇抗菌肽Cecropin基因,命名为CecMd,但是从未诱导的虫体内未能获得此基因;CecMd开放阅读框的cDNA全长为192 bp,编码由63个氨基酸残基组成的多肽;此多肽最可能的裂解位点在氨基酸残基A23和G24之间,提示1~23氨基酸残基组成信号肽,24~63氨基酸残基构成成熟肽;CecMd的全长肽包含4个螺旋,成熟肽(不包括信号肽)含有2个螺旋,两者均不含二硫键;CecMd与果蝇Cecropins的同源性显著高于其他昆虫,达到81.0%以上;经PCR,限制酶切和DNA测序鉴定表明,成功构建了重组表达载体pET32a(+)/CecMd。重组表达载体pET32a(+)/CecMd的构建及其CecMd基因的生物信息学分析对其生物学功能研究和高效表达工程菌的构建具有重要意义。  相似文献   

6.
从脂多糖（LPS）诱导或非诱导的家蝇幼虫体内抽提总RNA,根据家蝇Cecropin基因（GenBank：DQ 232774）设计特异性引物,应用RT—PCR技术扩增出编码CecMd开放阅读框（ORF）的eDNA序列,将其克隆入pMD18-T载体,经PCR、双酶切和测序鉴定正确后,将CecMd亚克隆基因与线性化的pET32a（＋）连接,构建重组表达载体pET32a（＋）／CecMid,并对此基因及其推导氨基酸序列进行系统的生物信息学分析。结果表明从脂多糖（LPS）诱导的家蝇幼虫体内成功的扩增出家蝇抗菌肽Cecropin基因,命名为CecMd,但是从未诱导的虫体内未能获得此基因;CecMd开放阅读框的cDNA全长为192bp,编码由63个氨基酸残基组成的多肽;此多肽最可能的裂解位点在氨基酸残基A23和G24之间,提示1～23氨基酸残基组成信号肽,24～63氨基酸残基构成成熟肽;CecMd的全长肽包含4个螺旋,成熟肽（不包括信号肽）含有2个螺旋,两者均不合二硫键;CecMd与果蝇Cecropins的同源性显著高于其他昆虫,达到81．0％以上;经PCR,限制酶切和DNA测序鉴定表明,成功构建了重组表达载体pET32a（＋）／Cec Md 。重组表达载体pET32a（＋）／Cec Md的构建及其CecMd基因的生物信息学分析对其生物学功能研究和高效表达工程菌的构建具有重要意义。  相似文献   

7.
家蝇抗菌肽天蚕素基因的定点突变和高效表达质粒的构建   总被引：3，自引：0，他引：3  
运用反转录聚合酶链式反应 (RT PCR)技术从家蝇体内扩增出抗菌肽天蚕素 (cecropin)基因的开放阅读框(ORF) ,与pMD 18T载体重组 ,经限制性酶切片段分析和核苷酸序列分析 ,与GenBank中报道的序列一致。根据此ORF ,重新合成 1对引物 ,并在碳末端进行定点突变 ,加上Asn编码 ,使其末端酰氨化 ,再利用半嵌套式PCR扩增出家蝇cecropin基因的成熟肽 ,与双酶切的酵母表达载体pPICZαA连接 ,经PCR和双酶切鉴定 ,成功构建了分泌型表达质粒。  相似文献   

8.
采用RT-PCR技术从金黄地鼠(Mesocricetus auratus)脑组织获得朊蛋白基因(Prion protein nucleic acid,PRNP)开放阅读框(Open reading frame,ORF),截去其N端信号肽(66 bp)和C端GPI锚定位点(69 bp)形成朊蛋白编码区PRNPx;将编码区重组于融合表达质粒Pet-DsbA中,并在大肠杆菌BL21(DE3)plysS中经IPTG诱导表达,并经Western-blot验证。结果表明,金黄地鼠PRNP基因ORF区全长为765 bp,编码254个氨基酸的前体蛋白,核苷酸序列与已发表金黄地鼠序列(M14054)同源性为99.87%,其第116个氨基酸发生了同义突变由GCT变为GCC;朊蛋白在大肠杆菌得到高效表达,产物是相对分子质量为47 000的融合蛋白。  相似文献   

9.
采用牛多杀性巴氏杆菌针刺法诱导3日龄家蝇幼虫,提取诱导后的家蝇幼虫总RNA并分离纯化得到高质量的mRNA.运用抑制性消减杂交(Suppression subtractive hybridization,SSH)技术构建家蝇幼虫差异表达的cD-NA消减文库,并利用反向Northern杂交技术筛选差异表达基因.结果表明,随机挑取的阳性克隆片段大小均在200～750 bp,通过反向Northern杂交共筛选出183个差异表达基因,经BLAST比对分析后鉴定出大量与家蝇免疫防御功能相关的基因和一部分无同源性基因.  相似文献   

10.
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   

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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