Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 12 3 2017 09 17 332 338 Yu ZHAO College of Veterinary Medicine, Gansu Agricultural University, Lanzhou, China AND 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, China Donghui ZHOU 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, China Jia CHEN 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, China Xiaolin SUN College of Veterinary Medicine, Gansu Agricultural University, Lanzhou, China 2017 09 17 2017 09 17 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. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/1763 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/1763/753