title: Genetic variation of the 8-kDa glycoprotein family from Echinococcus granulosus, Taenia multiceps and Taenia hydatigena.
abstract: BACKGROUND
  Echinococcosis, coenurosis and cysticercosis are debilitating diseases which prevail in China. Immunological diagnosis of metacestodosis is important in disease control. The 8-kDa glycoproteins from taeniid cestodes have successfully been used for diagnosis of human cysticercosis in immunological assays. The aim of the present study was to investigate genetic variations and phylogenetic relationships of the 8-kDa proteins for evaluating the possibility of utilizing these proteins as diagnostic antigens for other metacestode infections.
  
  
  METHODS
  The genes and complementary DNAs (cDNAs) encoding the 8-kDa proteins from Echinococcus (E.) granulosus, Taenia (T.) multiceps and T. hydatigena were amplified using PCR method. Their amplicons were cloned into the vector pMD18 and the positive clones were sequenced. Sequence data were analyzed with the SeqMan program, and sequence homology searches were performed using the BLAST program. Alignments were conducted using the ClustalX program, and the phylogenetic analyses were performed with the Protein Sequences Program and the Puzzle Program using the Neighbor-joining method.
  
  
  RESULTS
  Fifteen, 18 and 22 different genomic DNA sequences were identified as members of the 8-kDa protein gene family from E. granulosus, T. multiceps and T. hydatigena, respectively. Eight, four and six different cDNA clones respectively from E. granulosus, T. multiceps and T. hydatigena were characterized. Analysis of these sequences revealed 54 unique 8-kDa protein sequences. Phylogenetic trees demonstrated that the taeniid 8-kDa proteins are clustered into eight clades at least: Ts18, Ts14, TsRS1, TsRS2, T8kDa-1, T8kDa-2, T8kDa-3 and T8kDa-4.
  
  
  CONCLUSIONS
  We found that the gene family encoding for the taeniid 8-kDa antigens is comprised of many members with high diversity, which will provide molecular evidence for cross-reaction or specific reaction among metacestode infections and may contribute to the development of promising immunological methods for diagnosis of metacestodosis.
authors: State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Key Laboratory of Veterinary Public Health of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu 730046, China.
authors: Wan-Zhong
authors: WZ
authors: Jia
authors: Hong-Bin
authors: HB
authors: Yan
authors: Zhong-Zi
authors: ZZ
authors: Lou
authors: Xing-Wei
authors: XW
authors: Ni
authors: Hong-Xia
authors: HX
authors: Liu
authors: Hong-Min
authors: HM
authors: Li
authors: Ai-Jiang
authors: AJ
authors: Guo
authors: Bao-Quan
authors: BQ
authors: Fu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D018509:DNA, Helminth / Q000235:genetics; D048209:Echinococcus granulosus / Q000235:genetics / Q000378:metabolism*; D014644:Genetic Variation / Q000235:genetics*; D006023:Glycoproteins / Q000737:chemistry / Q000145:classification / Q000235:genetics*; D015801:Helminth Proteins / Q000737:chemistry / Q000145:classification / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid; D013621:Taenia / Q000235:genetics / Q000378:metabolism*
chemical_list: D018509:DNA, Helminth; D006023:Glycoproteins; D015801:Helminth Proteins