Sequence variation in the Toxoplasma gondii ROP20 gene among strains from different hosts and geographical locations.
Toxoplasma gondii, an opportunistic protozoan parasite, infects almost all warm-blooded animals. In this study, we examined the sequence variation in rhoptry protein 20 (ROP20) genes among 18 T. gondii isolates collected from different hosts and geographical regions. Full length ROP20 genes were amplified and sequenced. The results showed that the genes were 1659 bp in length and contained only a single exon, and that the A+T content varied from 46.68 to 47.20% among the 18 strains. The results of sequence alignment indicated that there were 30 variable nucleotide positions (0-1.40%) in the 18 T. gondii strains containing 18 transitions and 11 transversions, representing 1.81% overall sequence variation. Phylogenetic analysis of the ROP20 sequences showed that ROP20 variation could differentiate between the clonal lineage genotypes I and ToxoDB #9, indicating that ROP20 exhibits a relatively marked degree of sequence diversity and might represent a novel genetic marker for intraspecies phylogenetic analyses of T. gondii.
College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui Province, China.
H R
HR
Ning
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, Gansu Province, China.
J L
JL
Wang
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, Gansu Province, China.
S Y
SY
Qin
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, Gansu Province, China.
S Y
SY
Huang
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, Gansu Province, China.
Z L
ZL
Lou
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, Gansu Province, China.
L Y
LY
Hu
College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui Province, China.
X Q
XQ
Zhu
D000595:Amino Acid Sequence; D000818:Animals; D005819:Genetic Markers; D014644:Genetic Variation; D008565:Membrane Proteins / Q000235:genetics; D010802:Phylogeny; D017346:Protein Serine-Threonine Kinases; D015800:Protozoan Proteins / Q000235:genetics*; D017422:Sequence Analysis, DNA / Q000145:classification; D014122:Toxoplasma / Q000235:genetics*
D005819:Genetic Markers; D008565:Membrane Proteins; D015800:Protozoan Proteins; D017346:Protein Serine-Threonine Kinases; C556793:ROP18 protein, Toxoplasma gondii