Molecular evolution of Theileria parasites in Pacific area

日本放牧牛中由蛇氏杆菌引起的牛轴缩菌病造成经济损失。我们发现寄生虫种群和分离株由遗传和抗原性混合的种群组成。我们利用特异引物开发了等位基因特异性聚合酶链反应（PCR）来区分寄生虫种群。从2个T.sergenti品系（C和I）和1个T.buffeli品系(B)的Warwick品系（Warwick品系）的全部主要螺质表面蛋白基因序列中，设计3组寡核苷酸引物，分别用PCR扩增这3个等位基因。b特异性引物扩增产物表现出2种不同的限制性内切酶模式，因此b型进一步分为Bl-(T)型。水牛型)和b2型（从日本牛中分离出来的寄生虫，但没有从澳大利亚牛中分离出来）。通过这种等位基因特异性PCR，我们发现在日本，大多数感染良性伊勒菌的牛都有混合寄生虫种群。更多i/T.buffeli/T. .在东亚国家（韩国、中国、台湾）收集到与血吸虫抗原和遗传相似的野外分离株。在澳大利亚、泰国、美国和意大利也采集到了寄生虫。从被寄生红细胞中提取寄生虫DNA，采用等位基因特异性PCR检测。5株分离物均为C型寄生虫，1株分离物为I型、C型和b2型混合寄生虫。台湾15株分离物均检出c型寄生虫，其中4株同时检出b1型寄生虫。韩国分离株中i型寄生虫较多，33株分离株中有28株是i型和c型寄生虫的混合物。从澳大利亚牛中分离的寄生虫表现为b1型（布氏t型）和c型瑟氏t型的混合模式。从泰国分离到的大肠杆菌属寄生虫可分为C型和b1型，但也发现了未知型（T.sp）。澳大利亚的分离株和意大利的一株良性泰氏菌分离株被发现是Bl型和c型瑟genti的混合物。在我们的初步实验中，从泰国、中国和美国采集的致病性希勒菌似乎是独特的，“尚未鉴定”的希勒菌寄生虫（T.sp.）。用相同的特异引物扩增了这3种tsp的MPSP基因。这3种t .sp的MPSP基因序列非常相似，但与T.sergenti/buffeli/ orientais的MPSP基因序列不同。少

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