The second transcribed spacer rDNA sequence: an effective genetic marker for inter-species phylogenetic analysis of trematodes in the order Strigeata.
In the present study, the second nuclear internal transcribed spacer (ITS-2) rDNA of Schistosoma japonicum isolates in mainland China was amplified, sequenced, and assessed for inferring the intra- and inter-species phylogenetic relationships of trematodes in the order Strigeata. The fragment containing ITS-2 rDNA was obtained from 24 S. japonicum isolates from eight epidemic provinces in mainland China. The length polymorphisms were observed among these ITS-2 rDNA sequences, ranging from 343 to 346 bp, and the intra- and inter-population variations in ITS-2 sequence were 0.0-2.1% among S. japonicum isolates in China. Phylogenetic analyses using the maximum parsimony and maximum likelihood methods revealed that the ITS-2 rDNA sequence is not a suitable marker for studying inter- and intra-population variation in S. japonicum. However, phylogenetic analysis of trematodes in the order Strigeata indicated that the ITS-2 rDNA sequence provides an effective molecular marker for studying inter-species phylogenetic relationships among trematodes in this order.
State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, CAAS, Lanzhou, Gansu Province 730046, People's Republic of China.
G H
GH
Zhao
J
J
Li
X H
XH
Mo
X Y
XY
Li
R Q
RQ
Lin
F C
FC
Zou
Y B
YB
Weng
H Q
HQ
Song
X Q
XQ
Zhu
D000818:Animals; D002681:China; D018509:DNA, Helminth / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry* / Q000235:genetics*; D005260:Female; D005819:Genetic Markers; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D010802:Phylogeny; D011110:Polymorphism, Genetic; D012549:Schistosoma japonicum / Q000145:classification* / Q000235:genetics*; D012554:Schistosomiasis japonica / Q000469:parasitology; D017422:Sequence Analysis, DNA
D018509:DNA, Helminth; D021903:DNA, Ribosomal Spacer; D005819:Genetic Markers