New insights into clonality and panmixia in Plasmodium and toxoplasma.
Until the 1990s, Plasmodium and Toxoplasma were widely considered to be potentially panmictic species, because they both undergo a meiotic sexual cycle in their definitive hosts. We have proposed that both parasites are able of clonal (nonrecombining) propagation, at least in some cycles. Toxoplasma was soon shown to be a paradigmatic case of clonal population structure in North American and in European cycles. But the proposal provoked an outcry in the case of Plasmodium and still appears as doubtful to many scientists. However, the existence of Plasmodium nonrecombining lines has been fully confirmed, although the origin of these lines is debatable. We discuss the current state of knowledge concerning the population structure of both parasites in the light of the recent developments of pathogen clonal evolution proposed by us and of new hypotheses presented here.
Maladies Infectieuses et Vecteurs Ecologie, Génétique, Evolution et Contrôle, MIVEGEC (IRD 224-CNRS 5290-UM1-UM2), IRD Center, Montpellier, France. Electronic address: michel.tibayrenc@ird.fr.
Michel
M
Tibayrenc
Department of Ecology and Evolutionary Biology, University of California, Irvine, California, USA.
Francisco J
FJ
Ayala
D005075:Biological Evolution; D002999:Clone Cells; D005828:Genetics, Population; D010961:Plasmodium / Q000235:genetics / Q000502:physiology*; D012641:Selection, Genetic; D014122:Toxoplasma / Q000235:genetics / Q000502:physiology*
Evolution; Linkage disequilibrium; Malaria; Molecular epidemiology; Strain typing; Stratification; Toxoplasmosis