Genetic diversity and population structure of Trypanosoma brucei: clonality versus sexuality

• Published in: Molecular and biochemical parasitology 1995-06, Vol.72 (1), p.89-101
• Main Authors: Mathieu-Daudé, F., Stevens, J., Welsh, J., Tibayrenc, M., McClelland, M.
• Format: Article
• Language: English
• Subjects: Africa; Animals; Animals, Domestic - parasitology; Arbitrarily primed PCR; Base Sequence; Cattle; chemotaxonomy; cladistic analysis; DNA Fingerprinting; DNA, Protozoan - genetics; genetic distance; Genetic diversity; genetic polymorphism; Genetic Variation; Genetics, Population; genomics; Humans; Isoenzymes - genetics; linkage disequilibrium; Molecular Sequence Data; Phylogeny; Polymerase Chain Reaction; Polymorphism, Genetic; population; Population genetics; population structure; Protozoa; Protozoan Proteins - genetics; Random amplified polymorphic DNA; Sex Characteristics; Species Specificity; taxonomic status; Trypanosoma - classification; Trypanosoma brucei; Trypanosoma brucei brucei; Trypanosoma brucei brucei - genetics; Trypanosoma brucei brucei - isolation & purification; Trypanosoma brucei brucei - physiology; Trypanosoma brucei gambiense; Trypanosoma brucei gambiense - genetics; Trypanosoma brucei gambiense - isolation & purification; Trypanosoma brucei gambiense - physiology; Trypanosoma brucei rhodesiense; Trypanosoma brucei rhodesiense - genetics; Trypanosoma brucei rhodesiense - isolation & purification; Trypanosoma brucei rhodesiense - physiology; Trypanosoma gambiense; Trypanosoma rhodesiense; Trypanosomiasis, African - parasitology; Trypanosomiasis, African - veterinary; Trypanosomiasis, Bovine - parasitology; Tsetse Flies - parasitology
• ISSN: 0166-6851; 1872-9428
• DOI: 10.1016/0166-6851(95)00083-D

Genomic fingerprinting by arbitrarily primed PCR was used to analyze the genetic variability among 59 Trypanosoma brucei stocks representing the three T. brucei subspecies isolated from various hosts and different countries in Africa. 14 oligonucleotide primers revealed 355 polymorphic binary characters which were used for phenetic and phylogenetic analysis and to perform recombination tests exploring the linkage disequilibrium in the sample. These was good concordance between arbitrarily primed PCR polymorphisms and isoenzyme data previously collected for many of the same strains [1]. However, the arbitrarily primed PCR typing was more discerning than multilocus enzyme electrophoresis typing. Phenetic and phylogenetic analysis using arbitrarily primed PCR markers did not confirm T. brucei brucei and T. brucei rhodesiense as separate subspecies, but T. brucei gambiense group I was monophyletic, confirming this group as suitable for the subspecies status. With this exception, there were no clear lineages among the sample, other than clustering of East African stocks and clustering of West African stocks. Some features of the phylogenetic analysis suggested that the population structure was not strictly clonal though recombination tests showed linkage disequilibrium, even in the absence of repeated genotypes. While genotypes appear stable enough for tracking in applied studies, sexuality will impact at the evolutionary time scale, and may be more frequent under some ecological conditions. The arbitrarily primed PCR approach should be an effective and simple approach to follow epidemics and to quantify the role of sexuality in T. brucei populations.