中国伊氏锥虫kDNA小环的克隆及kDNA探针的建立

本研究以质粒ｐＧＥＭ－７Ｚｆ（＋）为载体，对我国北方和南方疫区伊氏锥虫动基体株的ｋＤＮＡ小环进行了克隆，并以其中之ｐＴＫ０１１－Ｃ＿１为探针对不同地理区的动基体株和无动基体株的不同ＤＮＡ进行杂交，结果表明，我国北、南两大疫区动基体株的ｋＤＮＡ小环大小均约为１ｋｂ，且均属Ａ型，ｐＴＫ０１１·Ｃ＿１只与动基体株的ｋＤＮＡ及ｔＤＮＡ杂交，不与其ｎＤＮＡ杂交，也不与无动基体株的任何ＤＮＡ及黄牛白细胞ＤＮＡ杂交。说明具有特异性，可以用于诊断。ｔＤＮＡ的杂交信号与ｋＤＮＡ相当，诊断中可以代替ｋＮＤＡ作为检测对象。

CLONING OF kDNA MINICIRCLES AND DEVELOPMENT OF kDNA PROBE OF TRYPANOSOMA EVANSI IN CHINA

The kDNA minicircles of kinetoplatic strains of Trypanosoma evansi from the camelin Xinjiang Uygar Autonomous Region, Northwest China, and the horse in HubeiProvince, South China, were cloned in plasmid pGEM-7Zf( ),and one of tlie clonedkDNA minicircle pTKO11-C_1 from the camel was used to probe kDNAs,nDNAs andtDNAs of kinetoplastic and dyskinetoplastic strains from different geographical regions. The kDNA minicircles obtained from strains in Northwest and South China were allabout 1kb in size and belonged to type A according to the restriction endonucleaseanalysis.The probe pTK011-C_1 hybridized with kDNAs and tDNAs of kinetoplasticstrains,but not with their nDNAs,and also not with any kinds of DNAs fromdyskinetoplastic strains as well as bovine leucocyte DNA by Southern and Dot blothybridizations.This indicated that pTK011-C_1 was species specific and could be usedto diagnose animal T. evansi infection in China. The hybirdization strength of tDNA wasalmost the same to that of kDNA,thus,it could be used as testing target instead ofkDNA in diagnostic hybridization.