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目的分析日本血吸虫和斯氏并殖吸虫的核糖体DNA第二内转录间隔区(rDNA-ITS2)基因的遗传变异。方法采集2种吸虫成虫标本,提取其基因组DNA,PCR特异性扩增rDNA-ITS2基因并测序;Clusterx软件进行多序列对比;MEGA4软件计算遗传距离,NJ法和MP法构建系统进化树;DNAsis软件对rDNA-ITS2序列片段进行模序分析。结果2种方法构建的遗传系统进化树基本结构相似,日本血吸虫与斯氏并殖吸虫间存在较远的遗传距离,但二吸虫ITS2序列间有42.7%的相似性。利用DNAsis软件在日本血吸虫和斯氏并殖吸虫的rDNA-ITS2序列中发现AP_2_CS6、bHLH_CS和CAP_site3种相同的转录因子。结论日本血吸虫和斯氏并殖吸虫虽然在rDNA-ITS2基因水平上存在明显种间差异,但在rDNA-ITS2序列、转录因子方面具有重要的相似性。
Objective To analyze the genetic variation of the second internal transcribed spacer (rDNA-ITS2) gene of S. japonicum and Paragonimus spp. Methods The genomic DNA was extracted from 2 species of adult worms and genomic DNA was extracted by PCR. The rDNA-ITS2 gene was amplified by PCR and sequenced. Clusterx software was used to compare multiple sequences. MEGA4 software was used to calculate the genetic distance. NJ and MP were used to construct the phylogenetic tree. Sequence analysis of rDNA-ITS2 sequence fragments. Results The phylogenetic tree constructed by the two methods had similar genetic structure. The genetic distance between Schistosoma japonicum and Paragonimus spp. Was far, but there was a similarity of 42.7% among the ITS2 sequences of the two flukes. The same transcription factors of AP_2_CS6, bHLH_CS and CAP_site were found in the rDNA-ITS2 sequences of Schistosoma japonicum and Paragonimus spp. Using DNAsis software. Conclusion Although there is a significant interspecific difference in the rDNA-ITS2 gene level between Schistosoma japonicum and Paragonimus spp., It has important similarity in rDNA-ITS2 sequences and transcription factors.