title: Genetic Diversity of Toxoplasma gondii Strains from Different Hosts and Geographical Regions by Sequence Analysis of GRA20 Gene.
abstract: Toxoplasma gondii is a eukaryotic parasite of the phylum Apicomplexa, which infects all warm-blood animals, including humans. In the present study, we examined sequence variation in dense granule 20 (GRA20) genes among T. gondii isolates collected from different hosts and geographical regions worldwide. The complete GRA20 genes were amplified from 16 T. gondii isolates using PCR, sequence were analyzed, and phylogenetic reconstruction was analyzed by maximum parsimony (MP) and maximum likelihood (ML) methods. The results showed that the complete GRA20 gene sequence was 1,586 bp in length among all the isolates used in this study, and the sequence variations in nucleotides were 0-7.9% among all strains. However, removing the type III strains (CTG, VEG), the sequence variations became very low, only 0-0.7%. These results indicated that the GRA20 sequence in type III was more divergence. Phylogenetic analysis of GRA20 sequences using MP and ML methods can differentiate 2 major clonal lineage types (type I and type III) into their respective clusters, indicating the GRA20 gene may represent a novel genetic marker for intraspecific phylogenetic analyses of T. gondii.
authors.affiliation: College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui Province 230036, PR China ; State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China.
authors.forename: Hong-Rui
authors.initials: HR
authors.lastname: Ning
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China.
authors.forename: Si-Yang
authors.initials: SY
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China.
authors.forename: Jin-Lei
authors.initials: JL
authors.lastname: Wang
authors.affiliation: College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui Province 230036, PR China.
authors.forename: Qian-Ming
authors.initials: QM
authors.lastname: Xu
authors.affiliation: College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui Province 230036, PR China ; State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China.
authors.forename: Xing-Quan
authors.initials: XQ
authors.lastname: Zhu
mesh_terms: D000818:Animals; D001483:Base Sequence; D001938:Brazil; D002681:China; D003670:Deer; D014644:Genetic Variation; D005838:Genotype; D006041:Goats; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D015800:Protozoan Proteins / Q000235:genetics* / Q000378:metabolism; D012756:Sheep; D013552:Swine; D014122:Toxoplasma / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification / Q000469:parasitology / Q000502:physiology; D014123:Toxoplasmosis / Q000469:parasitology*; D014124:Toxoplasmosis, Animal / Q000469:parasitology*; D014481:United States
chemical_list: D015800:Protozoan Proteins
keywords: Toxoplasma gondii; dense granule 20 (GRA20); phylogenetic analysis; sequence variation