title: Genetic variability of Echinococcus granulosus based on the mitochondrial 16S ribosomal RNA gene.
abstract: Echinococcus granulosus is the etiological agent of cystic echinococcosis, a major zoonotic disease of both humans and animals. In this study, we assessed genetic variability and genetic structure of E. granulosus in the Tibet plateau, using the complete mitochondrial 16 S ribosomal RNA gene for the first time. We collected and sequenced 62 isolates of E. granulosus from 3 populations in the Tibet plateau. A BLAST analysis indicated that 61 isolates belonged to E. granulosus sensu stricto (genotypes G1-G3), while one isolate belonged to E. canadensis (genotype G6). We detected 16 haplotypes with a haplotype network revealing a star-like expansion, with the most common haplotype occupying the center of the network. Haplotype diversity and nucleotide diversity were low, while negative values were observed for Tajima's D and Fu's Fs. AMOVA results and Fst values revealed that the three geographic populations were not genetically differentiated. Our results suggest that a population bottleneck or population expansion has occurred in the past, and that this explains the low genetic variability of E. granulosus in the Tibet Plateau.
authors.affiliation: Department of Parasitology, College of Veterinary Medicine, Sichuan Agricultural University , Ya'an , China .
authors.forename: Ning
authors.initials: N
authors.lastname: Wang
authors.forename: Jiahai
authors.initials: J
authors.lastname: Wang
authors.forename: Dandan
authors.initials: D
authors.lastname: Hu
authors.forename: Xiuqin
authors.initials: X
authors.lastname: Zhong
authors.forename: Zhongrong
authors.initials: Z
authors.lastname: Jiang
authors.forename: Aiguo
authors.initials: A
authors.lastname: Yang
authors.forename: Shijin
authors.initials: S
authors.lastname: Deng
authors.forename: Li
authors.initials: L
authors.lastname: Guo
authors.forename: Dawa
authors.initials: D
authors.lastname: Tsering
authors.forename: Shuxian
authors.initials: S
authors.lastname: Wang
authors.forename: Xiaobin
authors.initials: X
authors.lastname: Gu
authors.forename: Xuerong
authors.initials: X
authors.lastname: Peng
authors.forename: Guangyou
authors.initials: G
authors.lastname: Yang
mesh_terms: D000818:Animals; D001483:Base Sequence; D004443:Echinococcosis / Q000469:parasitology / Q000473:pathology; D048209:Echinococcus granulosus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D050259:Genes, Mitochondrial; D014644:Genetic Variation; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000032:analysis / Q000235:genetics*; D012756:Sheep
chemical_list: D012336:RNA, Ribosomal, 16S
keywords: Echinococcus granulosus; Tibet Plateau; genetic variability; mitochondrial 16 S ribosomal RNA gene