Comparison of ancient and modern Clonorchis sinensis based on ITS1 and ITS2 sequences.
In 1975, an ancient corpse buried in 167 BC was found at Jiangling County, Hubei Province of China. The eggs of Clonorchis sinensis found in the gall bladder of the corpse were preserved well. In the present paper, we extracted the genomic DNA from the ancient eggs and modern eggs, respectively, and the internal transcribed spacer 1 and 2 (ITS1 and ITS2) at ribosomal RNA genes were studied. The results show that ITS2 sequences from the ancient sample were identical with those from modern samples, but in ITS1 differences in 15 nucleotide positions were found between the ancient and modern samples. The results demonstrated that it is possible to extract and sequence DNA from ancient parasite eggs. The ITS1 sequence obtained differed from all modern ones available to date. This might indicate sequence divergence through time, or might reflect a sequence polymorphism that may eventually be found also in modern samples.
Liu
Wen-Qi
WQ
Department of Parasitology, Tongji Medical College at Huazhong University of Science and Technology, P.O. Box 430030, Wuhan, China.
Liu
Juan
J
Zhang
Jun-Hua
JH
Long
Xiao-Chun
XC
Lei
Jia-Hui
JH
Li
Yong-Long
YL
D000818:Animals; D001483:Base Sequence; D002681:China; D003003:Clonorchiasis / Q000469:parasitology; D003004:Clonorchis sinensis / Q000145:classification / Q000235:genetics* / Q000254:growth & development / Q000302:isolation & purification*; D018509:DNA, Helminth / Q000032:analysis / Q000302:isolation & purification; D021903:DNA, Ribosomal Spacer / Q000032:analysis*; D005704:Gallbladder / Q000469:parasitology; D020459:Genes, rRNA; D049690:History, Ancient; D006801:Humans; D008969:Molecular Sequence Data; D009106:Mummies; D010063:Ovum; D017422:Sequence Analysis, DNA
D018509:DNA, Helminth; D021903:DNA, Ribosomal Spacer