Are Eukaryotic Microorganisms Clonal or Sexual? A Population Genetics Vantage

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 88; no. 12; pp. 5129 - 5133
• Main Authors: Tibayrenc, Michel, Kjellberg, Finn, Arnaud, Jacques, Oury, Bruno, Brenière, S. Frédérique, Dardé, Marle-Laure, Ayala, Francisco J.
• Format: Journal Article
• Language: English
• Published: Washington, DC National Academy of Sciences of the United States of America 15-06-1991; National Acad Sciences
• Subjects: Animals; Biological and medical sciences; DNA Probes; DNA, Fungal - genetics; DNA, Protozoan - genetics; Eukaryota - physiology; Eukaryotic Cells - physiology; Fundamental and applied biological sciences. Psychology; Fungi; Fungi - physiology; Genetic loci; Genetics of eukaryotes. Biological and molecular evolution; Genetics, Population; Genotype; Genotypes; Leishmania; Leishmania - physiology; Linkage disequilibrium; Medical genetics; Natural selection; Nucleic Acid Hybridization; Parasitism; Plasmodium falciparum; Plasmodium falciparum - physiology; Polymorphism, Restriction Fragment Length; Population genetics; Population genetics, reproduction patterns; Protozoa; Reproduction, Asexual; Sexual reproduction; Thallophyta, bryophyta; Toxoplasma - physiology; Toxoplasma gondii; Trypanosoma cruzi - physiology; Vegetals; Fungi; Mating system; Plasmodium falciparum; Protozoa; Restriction fragment length polymorphism; Asexual reproduction; Sexual reproduction; Sporozoa; Population genetics; Thallophyta; Clone
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.88.12.5129

We argue that the mode of reproduction of microorganisms in nature can only be decided by population genetic information. The evidence available indicates that many parasitic protozoa and unicellular fungi have clonal rather than sexual population structures, which has major consequences for medical research and practice. Plasmodium falciparum, the agent of malaria, is a special case: the scarce evidence available is contradictory, some suggesting that uniparental lineages may exist in nature. This is puzzling (because P. falciparum is known to have a sexual stage) and poses a challenge that can be readily settled by ascertaining the frequency distribution of genotypes in natural populations.