Toxoplasma gondii is a medically and agriculturally important protozoan parasite
that can infect virtually all the mammalian and avian species. Previous studies showed that
the family of rhoptry proteins (ROPs) plays a key role in the invasion process of T. gondii, and
its several members can be potential marker for population genetic researches of Toxoplasma.
In order to estimate whether other member is also suitable as the novel genetic marker, the
variation of ROP41 gene among 11 T. gondii isolates from different hosts and geographical
locations and two reference strains was examined in this study. Our results showed that all
the examined sequence of TgROP41 gene was 1473 bp in length, and their A+T contents
were between 48.47% and 48.88%. Sequence analysis presented 14 nucleotide mutation
positions (0%-0.54%), leading to 5 amino acid substitutions (0%-0.61%) through alignment with
T. gondii ME49 strain (ToxoDB: TGME49_266100). Furthermore, phylogenetic analyses by
MP and BI methods based on deduced amino acid sequences of TgROP41 gene was only able
to distinguish the type I strain, but not able to separate the two classical genotypes (Type II
and III) into the respective clusters. These results indicated limited sequence diversity in the
TgROP41 gene.