Genetic Diversity and Population Structure of the Secondary Symbiont of Tsetse Flies, Sodalis glossinidius, in Sleeping Sickness Foci in Cameroon.
In: PLoS Neglected Tropical Diseases, Jg. 5 (2011-08-23), Heft 8, S. 1-9
Online
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Zugriff:
Background: Previous studies have shown substantial differences in Sodalis glossinidius and trypanosome infection rates between Glossina palpalis palpalis populations from two Cameroonian foci of human African trypanosomiasis (HAT), Bipindi and Campo. We hypothesized that the geographical isolation of the two foci may have induced independent evolution in the two areas, resulting in the diversification of symbiont genotypes. Methodology/Principal Findings: To test this hypothesis, we investigated the symbiont genetic structure using the allelic size variation at four specific microsatellite loci. Classical analysis of molecular variance (AMOVA) and differentiation statistics revealed that most of the genetic diversity was observed among individuals within populations and frequent haplotypes were shared between populations. The structure of genetic diversity varied at different geographical scales, with almost no differentiation within the Campo HAT focus and a low but significant differentiation between the Campo and Bipindi HAT foci. Conclusions/Significance: The data provided new information on the genetic diversity of the secondary symbiont population revealing mild structuring. Possible interactions between S. glossinidius subpopulations and Glossina species that could favor tsetse fly infections by a given trypanosome species should be further investigated. Author Summary: Human African trypanosomiasis remains a threat to the poorest people in Africa. The trypanosomes causing the disease are transmitted by tsetse flies. The drugs currently used are unsatisfactory: some are toxic and all are difficult to administer. Furthermore, drug resistance is increasing. Therefore, investigations for novel disease control strategies are urgently needed. Previous analyses showed the association between the presence of Glossina symbiont, Sodalis glossinidius, and the fly infection by trypanosomes in a south-western region in Cameroon: flies harbouring symbionts had a threefold higher probability of being infected by trypanosomes than flies devoid of symbionts. But the study also showed substantial differences in S. glossinidius and trypanosome infection rates between Glossina populations from two Cameroonian foci of sleeping sickness. We hypothesized that the geographical isolation of the two foci may have induced the independent evolution of each one, leading to the diversification of symbiont genotypes. Microsatellite markers were used and showed that genetic diversity structuring of S. glossinidius varies at different geographical scales with a low but significant differentiation between the Campo and Bipindi HAT foci. This encourages further work on interactions between S. glossinidius subpopulations and Glossina species that could favor tsetse fly infections by a given trypanosome species. [ABSTRACT FROM AUTHOR]
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Genetic Diversity and Population Structure of the Secondary Symbiont of Tsetse Flies, Sodalis glossinidius, in Sleeping Sickness Foci in Cameroon.
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Autor/in / Beteiligte Person: | Farikou, Oumarou ; Thevenon, Sophie ; Njiokou, Flobert ; Allal, François ; Cuny, Gérard ; Geiger, Anne |
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Zeitschrift: | PLoS Neglected Tropical Diseases, Jg. 5 (2011-08-23), Heft 8, S. 1-9 |
Veröffentlichung: | 2011 |
Medientyp: | academicJournal |
ISSN: | 1935-2727 (print) |
DOI: | 10.1371/journal.pntd.0001281 |
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