The Cloning Of 18S RRNA Gene Of Theileria. Sergenti And Establishment Of PCR Diagnosis Method Of Theileria. Sergenti

Theileriosis is a blood protozoal disease caused by Theileriidae, Theileria, Theileria sergenti. Recent years, Theileriosis result in economic losses seriously in animal husbandry with rising tendency, and paied the worldwide's attention. It is necessary to establish a kind of molecular bioogy diagnostic method which is fast, sensitive and specific to carry out early diagnosis and prevention for the Theileriosis.In this study two pairs of suitable PCR primers were designed according to 18S rRNA gene sequence of Theileria sergenti which were reported in GenBank. The amplification fragment were 1173bp and 1440bp, complete sequence was 1744bp. The results of the nucleotide sequence analysis and homology comparison suggest that cattle T. sergenti was closer to T. buffili(99%), but the distant were far to T. mutans(95%).In this study, the 18S rRNA gene was chose as target gene. And chose the specific primers to establishment PCR. the special test showed that there were no cross reaction between Theileria sergenti and other parasites, such as Neospora caninum, Toxoplasma gondii and Tthileria sp. the lowest DNA concentration of PCR could be detected was 5.3 fg/nL. The positive rate of PCR diagnosis method of 18S rRNA gene was 64.0%, and the positive rate of PCR diagnosis method of p33 gene was 58.0%.This study was offered a rationale of molecular taxonomy, genetics and diagnosis of T. S.