中华拟德氏吸虫分子系统发生初步研究

Primary Study on Molecular Phylogeny of Paradeontacylix sinensis Liu

对中华拟德氏吸虫核糖体基因进行扩增、克隆和测定，研究其系统发生．测得ITS-2rDNA和18srDNA部分序列分别为537bp和1819bp，GenBank上登录号分别为EU082007、EU081899．序列分析表明：中华拟德氏吸虫与寄生于琥珀鱼的5种拟德氏吸虫ITS-2rDNA序列相似性很低，为49．0％～54．2％，可初步判断中华拟德氏吸虫是拟德氏属的一个独立种；基于18SrDNA序列分别与海水未定名血居吸虫（AY157184）、淡水血居吸虫Plethorchis acanthus（AY222096）的亲缘最近，同源性高达99．4％和95．1％；与旋睾科吸虫Unicaecum sp．（AY604719）及5种裂体吸虫的同源性则分别为92．7％和91．5％～92．5％．可见血居科与旋睾科和裂体科吸虫的亲缘关系密切．

Studies ribosomal genes of Paradeontacylix sinensis by PCR amplification, cloning and sequencing. Partial sequences of ITS-2 rDNA and 18S rDNA were respectively 537 bp and 1 819 bp, and their Genebank numbers are respectively EU082007 and EU081899. The comparing of the ITS-2 rDNA sequences between P. sinensis and other five Paradeontacylix species infected amberjack shows that it only have the 49.0%～54.2% identity with them, so it may be an absolute specie of Paradeontacylix genus. While it shows the identities with marine Sanguinicolid sp. （AY157184）, Plethorchis acanthus （AY222096） from freshwater, Unicaecum sp. （AY604719） of Spirorchiidae, and five Schistosomatidae species are 99.4%, 95.1%, 92.7% and 91.5%～92.5%. It indicated that the genetic velationship among Sanguinicalidae, Spirorchiidae and Schistomatidae is very close.