牛瑟氏泰勒虫热休克蛋白基因的克隆与序列分析

从病牛血液中提取总RNA,根据GenBank上发表的牛瑟氏泰勒虫HSP70基因序列设计合成1对引物,通过RT—PCR技术扩增出牛瑟氏泰勒虫HSP70基因,并将该基因克隆到pMD18-TSimple载体上,经PCR鉴定和EcoR工、Sal工双酶切鉴定为阳性的重组质粒测定及分析结果表明,该片段长1966bp,编码620个氨基酸残基．同源性分析表明,该序列与牛瑟氏泰勒虫HSP70基因同源性为95．78％．     

牛瑟氏泰勒虫病致病机理的研究进展

牛瑟氏泰勒虫病是由蜱传染的一种血液原虫病。近年来,随着养牛业的发展,牛瑟氏泰勒虫病的发生呈上升趋势,尤其是引进牛和改良牛的发病率和致死率均较高,给养牛业带来了巨大的经济损失。本文对近年来牛瑟氏泰勒虫病的病原体、流行病学、病理学和致病作用等与此病的致病机理相关的方面的研究进展作一总结,以便广大兽医工作者对此病有更加深入的认识。     

牛瑟氏泰勒虫P33表面蛋白基因的克隆与序列分析

为分析吉林省流行的牛瑟氏泰勒虫基因序列，根据GenBank上发表的牛瑟氏泰勒虫P33表面蛋白基因序列设计合成一对引物，用PCR方法扩增出牛瑟氏泰勒虫的基因片段，并成功地将该基因纯化后克隆到pGEM-TEasy载体上，将经EcoRⅠ酶切鉴定和PCR鉴定为阳性的重组质粒进行测序。结果表明克隆的基因片段长度为868bp，编码283个氨基酸，有2个潜在的糖基化位点。核苷酸同源性分析表明，该基因片段与韩国株（AF521557）、日本株（AB016280）、俄罗斯株（AB016279）的核苷酸序列同源性分别为99．4％、88.0％、88．1％。     

Assessment of criteria for improvement in Theileria orientalis sergenti infection tolerance

We examined the relationships between calf productivity, anemia and Theileria orientalis sergenti infection from records of 109 Japanese shorthorn calves during a grazing period and we quantified the relative importance of the T. orientalis sergenti infection‐resistance criteria used. A decrease in average parasitemia (AvePara) and an increase in average packed cell volume (AvePCV) would cause a decrease in the number of drug treatments. An increase in AvePCV would decrease the number of drug treatments more efficiently than a decrease in AvePara. An increase in AvePCV would cause an increase in dairy gain, while a decrease in AvePara would cause a decrease in dairy gain. Therefore, an improvement in the capacity to control anemia development would improve T. orientalis sergenti infection resistance more efficiently than an improvement in the capacity to control parasitemia development.     

牛瑟氏泰勒虫P23表面蛋白基因表达条件的优化

将已构建并测序正确的含有牛瑟氏泰勒虫P23表面蛋白基因的pGEX-4T—P23转化菌用IPTG进行诱导表达,经SDS—PAGE电泳可检测到相对分子量为46．0ku的融合蛋白．根据SDS—PAGE确定融合蛋白的最佳表达条件,结果显示诱导时机和时间是影响表达的主要因素,诱导温度和IPTG浓度次之;确定最佳诱导时机为转接种后2．0h,最佳诱导温度34℃,最佳诱导时间6．0h,最适IPTG浓度0．08mmol／L．表达产物主要以包涵体存在,在优化条件下融合蛋白的表达量经Bandscan5．0软件分析约占菌体总蛋白的31．7％．     

牛瑟氏泰勒虫P23基因的克隆与生物信息学分析(英文)

[Objective] The aim of this study is to provide basis for developing genetic engineering vaccine and diagnostic kit for Theileria sergenti infection. [Objective] P23 gene of Theileria sergenti was amplified from its genomic DNA by PCR amplification, and cloned into the pGEM-Easy vector; then the sequencing result was analyzed with bioinformatics methods. [Result] Whole length of the P23 gene from Theileria sergenti is 684 bp containing a 672 bp open reading frame. The deduced amino acid sequence (223 amino acid residues) contains a signal peptide of 19 amino acid residues and two fragments of transmembrane domains, with relative molecular weight of the 25.886 kD and with the pI of 9.22. The homology between the yielded sequence and Chitose of Theileria sergenti P23 gene(TS-Chitose type, D84446), Ikeda of Theileria sergenti P23 gene(TS-Ikeda type, D84447) reached 99% and 90%, respectively. The sequence has been accessed in GenBank(EU573168). [Conclusion] The protein encoded by the P23 gene has better stability and immunogenicity, thus can be used as the antigen candidate for preparing genetic engineering vaccine for Theileria sergenti.     

以P33重组蛋白为诊断抗原建立牛瑟氏泰勒虫病乳胶凝集试验

本试验用P33重组蛋白建立了牛瑟氏泰勒虫病乳胶凝集试验。对81份被检血清的检测结果,阳性率为44.4%,明显高于血涂片镜检法的21.0%(P<0.01),而且在该病流行地区的不同牧场、不同性别和不同年龄牛的阳性率之间未见显著差异。试验表明,以P33重组蛋白作为诊断抗原具有特异性强、抗原易纯化和成本低等优点。     

奶牛瑟氏泰勒虫P33表面蛋白基因的克隆及序列分析

研究根据GenBank上发表的牛瑟氏泰勒虫P33表面蛋白的基因序列设计合成1对引物,用PCR方法扩增出了牛瑟氏泰勒虫的基因片段,将该基因纯化后连接到pMDl8-T栽体上,进行序列测定和分析,并用此方法对延边某奶牛场10头奶牛进行了检测.结果表明:10份样品中9份为阳性,所扩增的目的基因核苷酸长为868 bp,共编码283个氨基酸;该段基因片段与牛泰勒虫韩国株核苷酸序列同源性为99.4%,氨基酸同源性为99.3%.     

Clearance of Theileria sergenti-infected bovine red blood cells in severe combined immune deficiency mice

Clearance of Theileria sergenti-infected bovine red blood cells (Bo-RBCs) from the blood circulation of severe combined immune deficiency (SCID) mice was studied to help understand the mechanisms of anemia developing in cattle infected with T. sergenti. For the clearance test, Bo-RBC samples having 2%, 58%, and 76% parasitemia and, as a control, parasite-free Bo-RBCs were prepared in the Bo-RBC-SCID mouse model. The T. sergenti-infected Bo-RBCs and the uninfected control Bo-RBCs were separately labeled with two, green and red, fluorescent dyes, mixed together, and injected intravenously into SCID mice. The blood samples collected at various time points were observed under a fluorescent microscope, and the numbers of green and red fluorescing RBCs were counted differentially to determine the clearance rates of T. sergenti-infected and uninfected Bo-RBCs. This test clearly demonstrated that the Bo-RBC samples having higher parasitemias were cleared faster from the blood circulation of SCID mice. The results suggest that the intravascular clearance system in SCID mice may have a mechanism by which T. sergenti-parasitized and non-parasitized Bo-RBCs are recognized and cleared differentially.     

瑟氏泰勒虫病诊断技术的研究进展

瑟氏泰勒虫病是牛的1种血液原虫病．呈世界性分布，多发生于东亚地区，疫区内的发病率和致死率均较高，给畜牧业带来了巨大的经济损失．本文对瑟氏泰勒虫病诊断技术的研究进展进行了概述，以求为从事本病研究的科研工作者提供参考。