Studies On Epidemiology And Molecular Phylogeny Of Paradeontacylix Sinensis

The disease of Paradeontacylix sinensis infect in Fugus leading to enormous economic losses.So we made a research on the harm and prevalence of the epidemic of P. sinensis from 2005 to 2007.Results showed that the disease of P.sinensis,a serious fish disease,plagued the aquiculture of cultured Fugu,and the most important stages of P. sinensis parasitized fugu were adults and eggs,especially the egges.The disease is once a year,and its prevalence time range was from May to middle September.The fastigium of this disease is between June and August.From the results of the infection rates,death rates and sediment of eggs in viscera and tissues,we can speculate that Fugu can acquire some immunity to resist p.sinensis.Sequencing partical segements of 18S rDNA,28S rDNA and whole ITS2- rDNA of P.sinensis,and their acception number is EU081899,EU368853 and EU082007 in Genbank respectively.Analysis of 18S rDNA and 28S rDNA show that there are high similarity between Schistosomatidae and Spirorchidae,and there are quite different from Sanguinicolidae.The evolutional distance between P.sinensis and five blood blukes of Paradeontacylix who parasitize the same host is further than them among the fives.So there was more high similarity between trematodes of Paradeontacylix which inhabit in the same host than those in different hosts.Analysis of ITS-2 rDNA between P.sinensis and other five Paradeontacylix species infected the same host,shows that P.sinensis is only 49.0%～54.2%comparability with the other fives.P.sinensis form a branch and other five species form another one in phylogenetic tree.Combine with the analysis of 28S rDNA and ITS-2 rDNA,we can presume that P.sinensis may be an absolute species of Paradeontacylix genus.To study genomic DNA between adults of P.sinensis and S. japonicum using randomly amplified polymorphic DNA(RAPD)markers.189 amplified fragments were generated by RAPD with 31 primers.And 22 primers of them can amplified 1～5 more or less similitude bands from genomic DNA polymorphisms in two adults of P.sinensis and S.japonicum.So the two blood flukes may have consanguineous phylogenetically relation.They may have close genetic background.