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

这些研究的目的是弄清三倍体卫氏并殖吸虫的起源和亚洲卫氏并殖吸虫种群的物种形成机制及其医学意义。1987年7-9月，我们在中国和泰国就这一问题进行了联合实地考察。本文简要介绍了两年来现场和实验室联合研究的结果。在大陆中国，从4个省11个地点采集的淡水蟹、福建华支睾吸虫和达乌尔小龙虾中分离到并殖吸虫囊虫。成虫是从实验感染囊虫的动物身上获得的，并被鉴定为卫氏并殖吸虫。获得的吸虫类型为二倍体和三倍体。还发现了两个四倍体吸虫。中国东北部的卫氏原虫(三倍体型)与…几乎相同更多的日本株不仅在宿主特异性上，而且在电泳谱上也是如此。来自中国大陆中国的卫氏并殖吸虫(二倍体型)和日本的卫氏并殖吸虫(P.westermani)的图谱呈单态，且日本三倍体的特异性等位基因频率较高，尤其是在东北中国的二倍体种群中。因此，中国东北部的某个种群(二倍体类型)似乎与日本三倍体卫氏并殖吸虫的祖先有基因导入的关系。在泰国，有4种淡水蟹被证实自然感染并殖吸虫囊虫病。根据它们的形态特征和实验获得的成虫的形态特征，将它们分别鉴定为异质拟青霉、暹罗拟青霉、邦果拟青霉和哈里纳苏泰拟青霉。朱拉隆功大学提供了观察安装的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)，但对泰国卫氏并殖吸虫种群的遗传学研究尚未完成。较少

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