Molecular evolution of Theileria parasites in Pacific area

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Bovine pirolasmosis caused by Theileria sergenti cause of economic loss in grazing cattle in Japan. We found parasite stocks and isolates consist of genetically and antigenically mixed populations.We have developed allele-specific polymerase chain reaction (PCR) using specific primers to differentiate parasite populations. From entire major piroplasm surface protein gene sequences of two T.sergenti Stocks (C and I) and one Warwick stock of T.buffeli (B), 3 sets of oligonucleotide primers were designed to amplify either of the 3 alleles by PCR.Amplified products by B-specific primers showed 2 different restriction enzyme patterns, thus B-type was further divided into the Bl-(T.buffeli type) and B2-types (parasites isolated from Japanese cattle but not from Australian cattle). By using this allele-spesific PCR,we found that in Japan the majority of bovines infected with benign Theileria parasites herbored mixed parasite population.For further analysis of parasite populations of T.sergent … More i/T.buffeli/T.orientalis, field isolates were collected from East Asian countries (Korea, China, Taiwan) where antigenically and genetically similar parasites to T.sergenti were distributed. Parasites were also collected from Australia, Thailand, USA and Italy. Parasite DNA was extracted from parasitized erythrocytes and tested by allele-specific PCR.All 5 isolates from China contained C-type parasites and one isolate was a mixture of I,C and B2-type parasites. The C-type parasites were detected in all l5 isolates from Taiwan and 4 of these also contained the B1-type. The I-type parasites were commonly found in Korean isolates and 28 out of 33 isolates were mixtures of I-and C-type parasite. Parasites isolated from Australian cattle showed mixed patterns of B1-type (T.buffeli) and C-type of T.sergenti. Theileria parasites isolated from Thailand were classified into C- type, and B1-type but unknown type (T.sp.) was also found. The Australian isolates and an Italian benign Theileria isolates were found to be a mixture of Bl and C-type of T.sergenti. In our preliminary experiments, apathogenic Theileria species collected from Thailand, China and USA seem to be unique and "yet-unidentified" Theileria parasite (T.sp.). The MPSP genes of these 3 T.sp.were amplified by the same specific primers. Nucleotide sequences of MPSP genes of these 3 T.sp.are quite similar but differ from that of T.sergenti/buffeli/orienta1is. Less