Discovery of Mating in the Major African Livestock Pathogen Trypanosoma congolense

• Published in: PloS one 2009-05, Vol.4 (5), p.e5564-e5564
• Main Authors: Morrison, Liam J, Tweedie, Alison, Black, Alana, Pinchbeck, Gina L, Christley, Robert M, Schoenefeld, Andreas, Hertz-Fowler, Christiane, MacLeod, Annette, Turner, C. Michael R, Tait, Andy
• Format: Article
• Language: English
• Subjects: Analysis; Animal reproduction; Animals; Biological activity; Biomedical research; Cattle; Cryptosporidium parvum; Drug resistance; Economic importance; Ecumenism; Epidemiology; Evolution; Genetic aspects; Genetic markers; genetic variation; Genetics; Genetics and Genomics/Population Genetics; Genetics, Population - methods; Genomes; Genomics; Genotype; Genotypes; Health aspects; Heterozygotes; Impact analysis; Infectious Diseases/Epidemiology and Control of Infectious Diseases; Infectious Diseases/Protozoal Infections; Life sciences; Livestock; Mating; Microbiology/Microbial Evolution and Genomics; Microbiology/Parasitology; microsatellite repeats; Microsatellite Repeats - genetics; Microsatellites; Muscidae; Nucleotide sequence; Parasites; Parasitology; Pathogens; Personal computers; Phylogenetics; Phylogeny; Plasmodium falciparum; Polymorphism, Genetic - genetics; Population genetics; Protozoa; Sexual Behavior, Animal - physiology; sexual reproduction; Theileria; Trypanosoma; Trypanosoma brucei; Trypanosoma congolense; Trypanosoma congolense - classification; Trypanosoma congolense - genetics; Trypanosoma congolense - physiology; Trypanosome; Well being
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0005564

The protozoan parasite, Trypanosoma congolense, is one of the most economically important pathogens of livestock in Africa and, through its impact on cattle health and productivity, has a significant effect on human health and well being. Despite the importance of this parasite our knowledge of some of the fundamental biological processes is limited. For example, it is unknown whether mating takes place. In this paper we have taken a population genetics based approach to address this question. The availability of genome sequence of the parasite allowed us to identify polymorphic microsatellite markers, which were used to genotype T. congolense isolates from livestock in a discrete geographical area of The Gambia. The data showed a high level of diversity with a large number of distinct genotypes, but a deficit in heterozygotes. Further analysis identified cryptic genetic subdivision into four sub-populations. In one of these, parasite genotypic diversity could only be explained by the occurrence of frequent mating in T. congolense. These data are completely inconsistent with previous suggestions that the parasite expands asexually in the absence of mating. The discovery of mating in this species of trypanosome has significant consequences for the spread of critical traits, such as drug resistance, as well as for fundamental aspects of the biology and epidemiology of this neglected but economically important pathogen.