Submitted to: Journal of Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/25/2001
Publication Date: N/A
Citation: Interpretive Summary: Infection by the protozoan (single-celled) parasite, Toxoplasma gondii, are widely prevalent in humans and anmals. It causes mental retardation and loss of vision in congenitally-infected children and abortion in livestock. There is a single species of the parasite in the genus Toxoplasma, T. gondii. Scientists at the Beltsville Agricultural Research Center and the CDC, Atlanta, Georgia describe a new high resolution system for typing strains of T. gondii. These results will be of interest to biologists, parasitologists and geneticists.
Technical Abstract: High resolution typing of Toxoplasma gondii is essential to understand the effect of genetic differences among strains on the variation in disease manifestation and transmission patterns. Current typing methods discern 3 lineages with minimal within-lineage variation. Described here are 6 new variable loci. These loci, including a minisatellite and 5 microsatellites, were more polymorphic than allozymes, RFLPs, and sequence variation in introns. Most importantly, these loci revealed, for the first time, substantial within-lineage variation that was over 6-fold higher than that detected by other markers. Genotyping at these loci facilitates classification of isolates beyond the lineage level.