The cocoa pod borer (CPB) Conopomorpha cramerella (Snellen) (Lepidoptera: Gracillaridae) is one of the major constraints for cocoa production in South East Asia. In addition to cultural and chemical control methods, autocidal control tactics such as the Sterile Insect Technique (SIT) could be an efficient addition to the currently control strategy, however SIT implementation will depend on the population genetics of the targeted pest. The aim of the present work was to search for suitable microsatellite loci in the genome of CPB that is partially sequenced.
View Article and Find Full Text PDFAfrican trypanosomoses, whose pathogens are transmitted by tsetse flies, are a threat to animal and human health. Tsetse flies observed at the military base of the French Forces in Côte d'Ivoire (FFCI base) were probably involved in the infection and death of military working dogs. Entomological and parasitological surveys were carried out during the rainy and dry seasons using "Vavoua" traps to identify tsetse fly species, their distribution, favorable biotopes and food sources, as well as the trypanosomes they harbor.
View Article and Find Full Text PDFTsetse flies, the vectors of African trypanosomes are of key medical and economic importance and one of the constraints for the development of Africa. Tsetse fly control is one of the most effective and sustainable strategies used for controlling the disease. Knowledge about population structure and level of gene flow between neighbouring populations of the target vector is of high importance to develop appropriate strategies for implementing effective management programmes.
View Article and Find Full Text PDFDespite their role in Leishmania transmission, little is known about the organization of sand fly populations in their environment. Here, we used 11 previously described microsatellite markers to investigate the population genetic structure of Phlebotomus ariasi, the main vector of Leishmania infantum in the region of Montpellier (South of France). From May to October 2011, we captured 1,253 Ph.
View Article and Find Full Text PDFMicrosatellite loci still represent valuable resources for the study of the population biology of non-model organisms. Discovering or adapting new suitable microsatellite markers in species of interest still represents a useful task, especially so for non-model organisms as tsetse flies (genus Glossina), which remain a serious threat to the health of humans and animals in sub-Saharan Africa. In this paper, we present the development of new microsatellite loci for four species of Glossina: two from the Morsitans group, G.
View Article and Find Full Text PDFTrypanosoma brucei causes human African trypanosomiasis (HAT). Three subspecies were described: T. b.
View Article and Find Full Text PDFTsetse flies are vectors of parasites that cause diseases responsible for significant economic losses and health issues in sub-Saharan Africa, including sleeping sickness in humans and nagana in domestic animals. Efficient vector-control campaigns require good knowledge of the demographic parameters of the targeted populations. In the last decade, population genetics emerged as a convenient way to measure population densities and dispersal in tsetse flies.
View Article and Find Full Text PDFPopulation genetics is a convenient tool to study the population biology of non-model and hard to sample species. This is particularly true for parasites and vectors. Heterozygote deficits and/or linkage disequilibrium often occur in such studies and detecting the origin of those (Wahlund effect, reproductive system or amplification problems) is uneasy.
View Article and Find Full Text PDFTrypanosoma brucei gambiense (T. b. gambiense) is the major causative agent of human African trypanosomiasis (HAT).
View Article and Find Full Text PDFNull alleles and Wahlund effects are well known causes of heterozygote deficits in empirical population genetics studies as compared to Hardy-Weinberg genotypic expectations. Some authors have theoretically studied the relationship of Wright's FIS computed from subsamples displaying a Wahlund effect and FST before the Wahlund effect, as can occasionally be obtained from populations of long-lived organisms. In the 2 subsample case, a positive relationship between these 2 parameters across loci would represent a signature of Wahlund effects.
View Article and Find Full Text PDFBackground: Important control efforts have led to a significant reduction of the prevalence of human African trypanosomiasis (HAT) in Côte d'Ivoire, but the disease is still present in several foci. The existence of an animal reservoir of Trypanosoma brucei gambiense may explain disease persistence in these foci where animal breeding is an important source of income but where the prevalence of animal African trypanosomiasis (AAT) is unknown. The aim of this study was to identify the trypanosome species circulating in domestic animals in both Bonon and Sinfra HAT endemic foci.
View Article and Find Full Text PDFAntagonistic interactions between hosts and parasites are key structuring forces in natural populations. Demographic factors like extinction, migration and the effective population size shape host-parasite metapopulational dynamics. Therefore, to understand the evolution of host-parasite systems it is necessary to study the distribution of the genetic variation of both entities simultaneously.
View Article and Find Full Text PDFStudying isolation by distance can provide useful demographic information. To analyze isolation by distance from molecular data, one can use some kind of genetic distance or coalescent simulations. Molecular markers can often display technical caveats, such as PCR-based amplification failures (null alleles, allelic dropouts).
View Article and Find Full Text PDFOne key process of the life cycle of pathogens is their mode of reproduction. Indeed, this fundamental biological process conditions the multiplication and the transmission of genes and thus the propagation of diseases in the environment. Reproductive strategies of protozoan parasites have been a subject of debate for many years, principally due to the difficulty in making direct observations of sexual reproduction (i.
View Article and Find Full Text PDFProgress in malaria control has led to a significant reduction of the malaria burden. Interventions that interrupt transmission are now needed to achieve the elimination goal. Transmission-blocking vaccines (TBV) that aim to prevent mosquito infections represent promising tools and several vaccine candidates targeting different stages of the parasite's lifecycle are currently under development.
View Article and Find Full Text PDFEvolutionary theory predicts that the lack of recombination and chromosomal re-assortment in strictly asexual organisms results in homologous chromosomes irreversibly accumulating mutations and thus evolving independently of each other, a phenomenon termed the Meselson effect. We apply a population genomics approach to examine this effect in an important human pathogen, Trypanosoma brucei gambiense. We determine that T.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
November 2015
Tsetse flies are the cyclical vectors of deadly human and animal trypanosomes in sub-Saharan Africa. Tsetse control is a key component for the integrated management of both plagues, but local eradication successes have been limited to less than 2% of the infested area. This is attributed to either resurgence of residual populations that were omitted from the eradication campaign or reinvasion from neighboring infested areas.
View Article and Find Full Text PDFTrypanosomatidae are a dangerous family of Euglenobionta parasites that threaten the health and economy of millions of people around the world. More precisely describing the population biology and reproductive mode of such pests is not only a matter of pure science, but can also be useful for understanding parasite adaptation, as well as how parasitism, specialization (parasite specificity), and complex life cycles evolve over time. Studying this parasite's reproductive strategies and population structure can also contribute key information to the understanding of the epidemiology of associated diseases; it can also provide clues for elaborating control programs and predicting the probability of success for control campaigns (such as vaccines and drug therapies), along with emergence or re-emergence risks.
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