title: Nucleotide variation in the Toxoplasma gondii micronemal protein 8 gene.
abstract: Toxoplasma gondii is a successful opportunistic protozoan distributed worldwide, which can infect all vertebrates, leading to serious infection, blindness, and abortion. Micronemal (MIC) proteins are critically important for T. gondii infection, as they participate in various stages of the Toxoplasma life cycle, including invasion and attachment to host cells. MIC8 secretion relies on the concentration of intracellular calcium, and can mediate the invasion of T. gondii by interacting with soluble MIC3. To investigate genetic diversity of the MIC8 gene, 16 T. gondii strains from different hosts and geographical locations, and two reference isolates (ToxoDB: TGME49_245490 and TGVEG_245490) were examined in this study. The results showed that all the examined MIC8 genes are 2055 bp, with an A+T content ranging from 50.2 to 50.6%. Conversely, lower levels of variation were detected within their nucleotide and amino acid sequences. Phylogenetic analyses indicated that three classical genotypes of T. gondii and the ToxoDB#9 genotype did not group exclusively via Bayesian inference, maximum parsimony, neighbor joining, and/or maximum likelihood assays based on the nucleotide and amino acid sequences of the MIC8 gene. In summary, the T. gondii MIC8 gene is not a suitable marker for population genetic studies of this parasite.
authors.affiliation: College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang Province, China.|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.
authors.forename: Z Y
authors.initials: ZY
authors.lastname: Li
authors.affiliation: 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.
authors.forename: H Q
authors.initials: HQ
authors.lastname: Song
authors.affiliation: College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang Province, China.
authors.forename: C R
authors.initials: CR
authors.lastname: Wang
authors.affiliation: College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang Province, China.|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.
authors.forename: X Q
authors.initials: XQ
authors.lastname: Zhu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015815:Cell Adhesion Molecules / Q000235:genetics*; D014644:Genetic Variation; D005838:Genotype; D010802:Phylogeny; D015800:Protozoan Proteins / Q000235:genetics*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D014122:Toxoplasma / Q000235:genetics*
chemical_list: D015815:Cell Adhesion Molecules; D015800:Protozoan Proteins; C530346:microneme protein 8, Toxoplasma gondii