A GENETIC-ANALYSIS OF MIXED POPULATION IN THEILERIA-SERGENTI STOCKS AND ISOLATES USING ALLELE-SPECIFIC POLYMERASE CHAIN-REACTION

In order to differentiate parasite populations bearing two allelic for ms of p33/32, an immunodominant piroplasm surface protein of Theileria sergenti, two sets of oligonucleotide primers were designed to amplif y either of the two allele by the polymerase chain reaction (PCR). Eac h set of the primers differentially amplified either of Ikeda- or Chit ose-type p33/32 genes. By using this allele-specific PCR and restricti on enzyme digestion of amplified products, parasite populations within field isolates collected from different geographical regions in Japan were analyzed. Both of the allelic forms were detected in 13 samples out of 20 isolates and stocks by PCR. Either of Ikeda or Chitose type of p33/32 allele was detected in the other 7 samples. These results in dicated that the majority of T. sergenti-infected calves (11/15) in Ja pan harbored mixed parasite populations bearing at least two different alleles of p33/32.