Korean J Parasitol.  2015 Jun;53(3):345-348. 10.3347/kjp.2015.53.3.345.

Genetic Diversity of Toxoplasma gondii Strains from Different Hosts and Geographical Regions by Sequence Analysis of GRA20 Gene

• Ning HR
• Huang SY
• Wang JL
• Xu QM
• Zhu XQ

• KMID: 2381840
• DOI: http://doi.org/10.3347/kjp.2015.53.3.345

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.

Keyword

Toxoplasma gondii; sequence variation; dense granule 20 (GRA20); phylogenetic analysis

MeSH Terms

Animals
Base Sequence
Brazil
China
Deer
*Genetic Variation
Genotype
Goats
Humans
Molecular Sequence Data
Phylogeny
Protozoan Proteins/*genetics/metabolism
Sheep
Swine
Toxoplasma/classification/*genetics/isolation & purification/parasitology/physiology
Toxoplasmosis/*parasitology
Toxoplasmosis, Animal/*parasitology
United States
Protozoan Proteins