Population structure of Toxoplasma gondii: clonal expansion driven by infrequent recombination and selective sweeps.
Toxoplasma gondii is among the most successful parasites. It is capable of infecting all warm-blooded animals and causing opportunistic disease in humans. T. gondii has a striking clonal population structure consisting of three predominant lineages in North America and Europe. Clonality is associated with the recent emergence of a monomorphic version of Chr1a, which drove a selective genetic sweep within the past 10,000 years. Strains from South America diverged from those in North America some 1-2 mya; recently, however, the monomorphic Chr1a has extended into regions of South America, where it is also associated with clonality. The recent spread of a few dominant lineages has dramatically shaped the population structure of T. gondii and has resulted in most lineages sharing a highly pathogenic nature. Understanding the factors that have shaped the population structure of T. gondii has implications for the emergence and transmission of human pathogens.
Sibley
L David
LD
Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, 63130, USA. sibley@wustl.edu
Ajioka
James W
JW
D000818:Animals; D017125:Genes, Protozoan; D006801:Humans; D009656:North America; D010802:Phylogeny; D020641:Polymorphism, Single Nucleotide; D011995:Recombination, Genetic; D012641:Selection, Genetic; D013020:South America; D014122:Toxoplasma / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D014123:Toxoplasmosis / Q000469:parasitology / Q000635:transmission; D014774:Virulence / Q000235:genetics