TY - JOUR
T1 - Trypanosoma brucei gambiense Type 1 populations from human patients are clonal and display geographical genetic differentiation
AU - Morrison, Liam J
AU - Tait, Andy
AU - McCormack, Gillian
AU - Sweeney, Lindsay
AU - Black, Alana
AU - Truc, Philippe
AU - Likeufack, Anne C L
AU - Turner, C Michael
AU - MacLeod, Annette
PY - 2008
Y1 - 2008
N2 - We have rigorously tested the hypothesis that Trypanosoma brucei gambiense Type 1 is composed of genetically homogenous populations by examining the parasite population present in Human African Trypanosomiasis (HAT) patients from the Democratic Republic of Congo (DRC) and Cameroon (CAM). We amplified eight microsatellite markers by PCR directly from blood spots on FTA filters, thereby avoiding the significant parasite selection inherent in the traditional isolation techniques of rodent inoculation or in vitro culture. All microsatellite markers were polymorphic, although for four markers there was only polymorphism between the DRC and CAM populations, not within populations, suggesting very limited genetic exchange. Within the largest population from the DRC, Hardy-Weinberg equilibrium is not evident at any loci. This evidence suggests a clonal population. However, there was significant sub-structuring between the DRC and CAM samples (F(ST) = 0.32), indicating that Trypanosoma brucei gambiense Type 1 has genetically distinct clades. The data combine to indicate that genetic exchange plays a very limited role. The finding of distinct clades in different places suggests the possibility that samples from humans with clinical signs represent clonal expansions from an underlying population that requires identifying and characterising.
AB - We have rigorously tested the hypothesis that Trypanosoma brucei gambiense Type 1 is composed of genetically homogenous populations by examining the parasite population present in Human African Trypanosomiasis (HAT) patients from the Democratic Republic of Congo (DRC) and Cameroon (CAM). We amplified eight microsatellite markers by PCR directly from blood spots on FTA filters, thereby avoiding the significant parasite selection inherent in the traditional isolation techniques of rodent inoculation or in vitro culture. All microsatellite markers were polymorphic, although for four markers there was only polymorphism between the DRC and CAM populations, not within populations, suggesting very limited genetic exchange. Within the largest population from the DRC, Hardy-Weinberg equilibrium is not evident at any loci. This evidence suggests a clonal population. However, there was significant sub-structuring between the DRC and CAM samples (F(ST) = 0.32), indicating that Trypanosoma brucei gambiense Type 1 has genetically distinct clades. The data combine to indicate that genetic exchange plays a very limited role. The finding of distinct clades in different places suggests the possibility that samples from humans with clinical signs represent clonal expansions from an underlying population that requires identifying and characterising.
U2 - 10.1016/j.meegid.2008.08.005
DO - 10.1016/j.meegid.2008.08.005
M3 - Article
C2 - 18790085
SN - 1567-1348
VL - 8
SP - 847
EP - 854
JO - Infection, Genetics and Evolution
JF - Infection, Genetics and Evolution
IS - 6
ER -