Studies on the speciation in the genus Paragonimus in south-east Asia

本研究的目的是阐明卫氏肺吸虫三倍体的起源、卫氏肺吸虫亚洲种群的形成机制及其医学意义。1987年7月至9月，我们在中国和泰国进行了这方面的联合实地调查。本文简要报道了两年来在野外和实验室进行的联合研究结果。在4个省11个地点采集了长江溪蟹、福建马来溪蟹和达乌尔螯虾。成虫取自实验感染后蚴的动物，经鉴定为卫氏并殖吸虫。获得的吸虫为二倍体和三倍体类型。还发现了两个四倍体吸虫。中国东北地区的卫氏肺吸虫（三倍体）与中国东北地区的卫氏肺吸虫（三倍体）几乎相同， ...更多信息 日本的一种不仅具有寄主特异性，而且在电泳图谱上也有差异。中国大陆卫氏原螯虾（二倍体型）的电泳图谱表现为多态性，而日本种卫氏原螯虾的电泳图谱表现为单态性，日本种三倍体特有的等位基因出现频率较高，尤其是在中国东北地区的二倍体群体中。因此，从基因渐渗的角度看，中国东北的卫氏原蟹群的一个群体（二倍体型）可能与日本卫氏原蟹三倍体的祖先有一定的亲缘关系。beusekomae、Somanniathelphusa germaini和S.史密斯氏并殖吸虫自然感染囊蚴。根据形态学特征和成虫特征，将它们分别鉴定为异盘拟步行虫（P.heterotremus）、暹罗拟步行虫（P.siamensis）、曼谷拟步行虫（P.bangkokensis）和哈氏拟步行虫（P.harinasutai）。朱拉隆功大学提供了观察并殖吸虫标本的机会。虽然这些标本被鉴定为卫氏并殖吸虫（二倍体），但尚未对泰国卫氏并殖吸虫种群进行遗传学研究。少

The objective of these studies is to make clear the origin of the triploid type of P. westermani and the mechanism of the speciation in the P. westermani group in Asia, together with its medical importance. We performed joint field investigations on this subject in China and Thailand during the period of July-September, 1987. The results of the joint reserch works in the field as well as those done in the laboratory over the last two years are briefly reported here.In mainland China, Paragonimus metacercariae were isolated from freshwater crabs, Sinopotamon fukienense, S. yangtsekiense, Malayopotamon fukienense and crayfish, cambaroides dauricus collected in 11 iocalities of 4 Provinces. The adults were obtained from the experimentally infected animals with the metacercariae, and were identified as P. westermani. The flukes obtained were diploid and triploid types. Two tetraploid flukes were also discovered. P. westermani (triploid type) from north-eastern China was almost same as the … More Japanese one not noly in host-specificity but also in electrophoretic patterns. In P. westermani (diploid type) from mainland China, the electrophoretic patterns showed polymorphism while those of the Japanese one were monomorphic, and the specific alleles of the Japanese triploids were found, in high frequency, especially in the diploid populations from north-eastern China. Therefore, a certain population (diploid type) of P. westermani group from northeastern China seems to be related to the ancestor of the Japanese P. westermani triploids in terms of the gene introgression.In Thailand, 4 species of the freshwater crabs, Larnaudia larnaudii, L. beusekomae, Somanniathelphusa germaini and S. smithiana were proved to be naturally infected with Paragonimus metacercariae. They were identified as P. heterotremus, P. siamensis, P. bangkokensis and P. harinasutai, based on their morphological features as well as those of the adults, obtained experimentally. Opportunity was offered at Chulalongkorn University to observe the mounted specimens of Paragonimus. Although the specimens were identified as P. westermani (diploid), the genetic studies on Thai P. westermani population have not been done yet. Less