Korean J Parasitol.  2015 Jun;53(3):341-344. 10.3347/kjp.2015.53.3.341.

Sequence Diversity in MIC6 Gene among Toxoplasma gondii Isolates from Different Hosts and Geographical Locations

• Li ZY
• Song HQ
• Chen J
• Zhu XQ

• KMID: 2381839
• DOI: http://doi.org/10.3347/kjp.2015.53.3.341

Abstract

Toxoplasma gondii is an opportunistic protozoan parasite that can infect almost all warm-blooded animals including humans with a worldwide distribution. Micronemes play an important role in invasion process of T. gondii, associated with the attachment, motility, and host cell recognition. In this research, sequence diversity in microneme protein 6 (MIC6) gene among 16 T. gondii isolates from different hosts and geographical regions and 1 reference strain was examined. The results showed that the sequence of all the examined T. gondii strains was 1,050 bp in length, and their A + T content was between 45.7% and 46.1%. Sequence analysis presented 33 nucleotide mutation positions (0-1.1%), resulting in 23 amino acid substitutions (0-2.3%) aligned with T. gondii RH strain. Moreover, T. gondii strains representing the 3 classical genotypes (Type I, II, and III) were separated into different clusters based on the locus of MIC6 using phylogenetic analyses by Bayesian inference (BI), maximum parsimony (MP), and maximum likelihood (ML), but T. gondii strains belonging to ToxoDB #9 were separated into different clusters. Our results suggested that MIC6 gene is not a suitable marker for T. gondii population genetic studies.

Keyword

Toxoplasma gondii; toxoplamosis; MIC6; sequence diversity

MeSH Terms

Amino Acid Sequence
Animals
Base Sequence
Cats
Cell Adhesion Molecules/chemistry/*genetics/metabolism
Deer
*Genetic Variation
Genotype
Goats
Humans
Molecular Sequence Data
Phylogeny
Protozoan Proteins/chemistry/*genetics/metabolism
Sequence Alignment
Sheep
Swine
Toxoplasma/classification/*genetics/isolation & purification/physiology
Toxoplasmosis/*parasitology
Toxoplasmosis, Animal/*parasitology
Cell Adhesion Molecules
Protozoan Proteins