Original Article

Sequence Variation in Rhoptry Neck Protein 10 Gene among Toxoplasma gondii Isolates from Different Hosts and Geographical Locations


Background: Toxoplasma gondii, as a eukaryotic parasite of the phylum Apicomplexa, can infect almost all the warm-blooded animals and humans, causing toxoplasmosis. Rhoptry neck proteins (RONs) play a key role in the invasion process of T. gondii and are potential vaccine candidate molecules against toxoplasmosis.

Methods: The present study examined sequence variation in the rhoptry neck protein 10 (TgRON10) gene among 10 T. gondii isolates from different hosts and geographical locations from Lanzhou province during 2014, and compared with the corresponding sequences of strains ME49 and VEG obtained from the ToxoDB database, using polymerase chain reaction (PCR) amplification, sequence analysis, and phylogenetic reconstruction by Bayesian inference (BI) and maximum parsimony (MP).

Results: Analysis of all the 12 TgRON10 genomic and cDNA sequences revealed 7 exons and 6 introns in the TgRON10 gDNA. The complete genomic sequence of the TgRON10 gene ranged from 4759 bp to 4763 bp, and sequence variation was 0-0.6% among the 12 T. gondii isolates, indicating a low sequence variation in TgRON10 gene. Phylogenetic analysis of TgRON10 sequences showed that the cluster of the 12 T. gondii isolates was not completely consistent with their respective genotypes.

Conclusion: TgRON10 gene is not a suitable genetic marker for the differentiation of T. gondii isolates from different hosts and geographical locations, but may represent a potential vaccine candidate against toxoplasmosis, worth further studies.

Tenter AM, Heckeroth AR, Weiss LM. Toxoplasma gondii: from animals to humans. Int J Parasitol. 2000; 30(12-13):1217-58.

Montoya JG, Liesenfeld O. Toxoplasmosis. Lancet. 2004; 363(9425):1965-76.

Dubey JP. Toxoplasmosis of animals and humans. Parasit Vectors. 2010; 3(1):112.

Zhou P, Chen Z, Li HL, et al. Toxoplasma gondii infection in humans in China. Parasit Vectors. 2011; 4:165.

Hill D, Dubey JP. Toxoplasma gondii: transmission, diagnosis and prevention. Clin Microbiol Infect. 2002; 8(10):634-40.

Bradley PJ, Ward C, Cheng SJ, et al. Proteomic analysis of rhoptry organelles reveals many novel constituents for host-parasite interactions in Toxoplasma gondii. J Biol Chem. 2005; 280(40):34245-58.

Rashid I, Hedhli D, Moiré N, et al. Immunological responses induced by a DNA vaccine expressing RON4 and by immunogenic recombinant protein RON4 failed to protect mice against chronic toxoplasmosis. Vaccine. 2011; 29(48):8838-46.

Lamarque MH, Papoin J, Finizio AL, et al. Identification of a new rhoptry neck complex RON9/RON10 in the Apicomplexa parasite Toxoplasma gondii. PloS One. 2012; 7(3): e32457.

Zhou P, Zhang H, Lin RQ, et al. Genetic characterization of Toxoplasma gondii isolates from China. Parasitol Int. 2009; 58(2): 193-5.

Weiss LM, Dubey JP. Toxoplasmosis: A history of clinical observations. Int J Parasitol. 2009; 39(8): 895-901.

Su C, Shwab EK, Zhou P, Zhu XQ, Dubey JP. Moving towards an integrated approach to molecular detection and identification of Toxoplasma gondii. Parasitology. 2010; 137(1):1-11.

Huang SY, Cong W, Zhou P, et al. First report of genotyping of Toxoplasma gondii isolates from wild birds in China. J Parasitol. 2012; 98(3):681-2.

Thompson JD, Gibson TJ, Plewniak F, et al. The CLUSTAL_X windows interface: flexible strategies for multiple sequence alignment aided by quality analysis tools. Nucleic Acids Res. 1997; 25(24):4876-82.

Ronquist F, Huelsenbeck JP. MrBayes 3: Bayesian phylogenetic inference under mixed models. Bioinformatics. 2003; 19(12):1572-4.

Swofford DL. PAUP: Phylogenetic Analysis Using Parsimony (and Other Methods). Sunderland MA: Sinauer Associates; 2002.

Page RD. TreeView: an application to display phylogenetic trees on personal computers. Comput Appl Biosci. 1996; 12(4):357-8.

Wang PY, Lu P, Xu MJ, et al. Genetic diversity among Toxoplasma gondii isolates from different hosts and geographical locations revealed by analysis of ROP13 gene sequences. Afr J Biotechnol. 2012; 11(25): 6662-5.

Zhou Y, Lu P, Xu MJ, et al. Sequence variation in TgROP7 gene among Toxoplasma gondii isolates from different hosts and geographical regions. Afr J Biotechnol. 2012; 11(25): 6658-61.

Yan HK, Song HQ, Zhou Y, et al. Sequence variation in perforin-Like protein 1 gene among six Toxoplasma gondii strains. J Anim Vet Adv. 2011; 10(17): 2244-47.

Ren D, Zhou DH, Xu MJ, Zhou Y. Sequence variation in Toxoplasma gondii MIC13 gene among isolates from different hosts and geographical locations. Afr J Microbiol Res. 2012; 6(6): 1333-37.

Khan A, Taylor S, Ajioka JW, Rosenthal BM, Sibley LD. Selection at a single locus leads to widespread expansion of Toxoplasma gondii lineages that are virulent in mice. PLoS Genet. 2009; 5(3):e1000404.

IssueVol 12 No 3 (2017) QRcode
SectionOriginal Article(s)
Toxoplasma gondii Toxoplasmosis Rhoptry neck protein 10 (TgRON10) Sequence variation

Rights and permissions
Creative Commons License This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
How to Cite
ZHAO Y, ZHOU D, CHEN J, SUN X. Sequence Variation in Rhoptry Neck Protein 10 Gene among Toxoplasma gondii Isolates from Different Hosts and Geographical Locations. Iran J Parasitol. 2017;12(3):332-338.