Winka Le Clec'h

Winka Le Clec'h
Texas Biomedical Research Institute · Department of Genetics

PhD
Staff Scientist - Texas Biomedical Research Institute

Publications

Publications (30)
Article
Full-text available
Schistosoma mansoni, a snail‐borne, blood fluke that infects humans, was introduced into the Americas from Africa during the Trans‐Atlantic slave trade. As this parasite shows strong specificity to the snail intermediate host, we expected that adaptation to S. American Biomphalaria spp. snails would result in population bottlenecks and strong signa...
Article
Aquatic snails, the intermediate hosts of schistosomes, harbor a diverse unexplored microbiome. We speculate that this may play a critical role in host–parasite interactions. We summarize our current knowledge of snail microbiomes and highlight future research priorities.
Article
Full-text available
Mass drug administration with praziquantel (PZQ) monotherapy is considered the mainstay for control and elimination of the parasites causing schistosomiasis in humans. This drug shows imperfect cure rates in the field, and parasites showing reduced PZQ response can be selected in the laboratory, but the extent of resistance in Schistosoma mansoni p...
Article
Full-text available
Both theory and experimental data from pathogens suggest that the production of transmission stages should be strongly associated with virulence, but the genetic bases of parasite transmission/virulence traits are poorly understood. The blood fluke Schistosoma mansoni shows extensive variation in numbers of cercariae larvae shed and in their virule...
Preprint
Full-text available
Schistosoma mansoni, a snail-vectored blood fluke that infects humans, was introduced into the Americas from Africa during the Trans-Atlantic slave trade. As this parasite shows strong specificity to the snail intermediate host, we expected that adaptation to S. American Biomphalaria spp. snails would result in population bottlenecks and strong sig...
Preprint
Full-text available
Mass treatment with praziquantel (PZQ) monotherapy is the mainstay for schistosome treatment. This drug shows imperfect cure rates in the field and parasites showing reduced response to PZQ can be selected in the laboratory, but the extent of resistance in Schistosoma mansoni populations is unknown. We examined the genetic basis of variation in PZQ...
Preprint
Full-text available
Both theory and experimental data from pathogens suggest that the production of transmission stages should be strongly associated with virulence, but the genetic bases of parasite transmission/virulence traits are poorly understood. The blood fluke Schistosoma mansoni shows extensive variation in numbers of cercariae larvae shed and in their virule...
Article
The microbiome - the microorganism community that is found on or within an organism's body - is increasingly recognized to shape many aspects of its host biology and is a key determinant of health and disease. Microbiomes modulate the capacity of insect disease vectors (mosquitoes, tsetse flies, sandflies) to transmit parasites and disease. We inve...
Preprint
Full-text available
The microbiome - the microorganism community that is found on or within an organism's body - is increasingly recognized to shape many aspects of its host biology and is a key determinant of health and disease. Microbiomes modulate the capacity of insect disease vectors (mosquitos, tsetse flies, sandflies) to transmit parasites and disease. We inves...
Article
Full-text available
Do mutations required for adaptation occur de novo, or are they segregating within populations as standing genetic variation? This question is key to understanding adaptive change in nature, and has important practical consequences for the evolution of drug resistance. We provide evidence that alleles conferring resistance to oxamniquine (OXA), an...
Article
Full-text available
Background: Parasite traits associated with transmission success, such as the number of infective stages released from the host, are expected to be optimized by natural selection. However, in the trematode parasite Schistosoma mansoni, a key transmission trait, i.e. the number of cercariae larvae shed from infected Biomphalaria spp. snails, varies...
Preprint
Full-text available
Background Parasite traits associated with transmission success, such as the number of infective stages released from the host, are expected to be optimized by natural selection. However, in the trematode parasite Schistosoma mansoni , a key transmission trait – the number of cercariae larvae shed from infected Biomphalaria spp . snails – varies si...
Article
Full-text available
Introgression among parasite species has the potential to transfer traits of biomedical importance across species boundaries. The parasitic blood fluke Schistosoma haematobium causes urogenital schistosomiasis in humans across sub-Saharan Africa. Hybridization with other schistosome species is assumed to occur commonly, because genetic crosses betw...
Preprint
Full-text available
Do mutations required for adaptation occur de novo , or are they segregating within populations as standing genetic variation? This question is key to understanding adaptive change in nature, and has important practical consequences for the evolution of drug resistance. We provide evidence that alleles conferring resistance to oxamniquine (OXA), an...
Preprint
Full-text available
The parasitic blood fluke Schistosoma haematobium causes urogenital schistosomiasis in humans and is a major cause of morbidity and mortality across sub-Saharan Africa. S. haematobium hybridizes with livestock schistosomes, including S. bovis , however the frequency, direction, age and genomic consequences of hybridization are unknown. We sequenced...
Article
Linkage mapping - utilizing experimental genetic crosses to examine cosegregation of phenotypic traits with genetic markers - is now 100 years old. Schistosome parasites are exquisitely well suited to linkage mapping approaches because genetic crosses can be conducted in the laboratory, thousands of progeny are produced, and elegant experimental wo...
Article
Full-text available
Adult schistosomes live in the blood vessels and cannot easily be sampled from humans, so archived miracidia larvae hatched from eggs expelled in feces or urine are commonly used for population genetic studies. Large collections of archived miracidia on FTA cards are now available through the S chistosomiasis C ollection a t the N atural History Mu...
Article
Full-text available
Vertical transmission mode is predicted to decrease the virulence of symbionts. However, Wolbachia, a widespread vertically transmitted endosymbiont, exhibits both negative and beneficial effects on arthropod fitness. This ‘Jekyll and Hyde’ behaviour, as well as its ability to live transiently outside host cells and to establish new infections via...
Article
Full-text available
Molecular surveillance provides a powerful approach to monitoring the resistance status of parasite populations in the field and for understanding resistance evolution. Oxamniquine (OXA) was used to treat Brazilian schistosomiasis patients (mid-1970s to mid-2000s) and several cases of parasite infections resistant to treatment were recorded. The ge...
Article
Full-text available
Background: Biomphalaria snails are the intermediate host of the blood fluke Schistosoma mansoni, which infect more than 67 million people in tropical areas. Phenoloxidase enzymes (POs), including tyrosinases, catecholases, and laccases, are known to play a role in the immune defenses of arthropods, but the PO activity present in Biomphalaria spp....
Article
Full-text available
Wolbachia is an intracellular α-proteobacterium which is transmitted vertically from mother to offspring but also frequently switches horizontally from one host to another. Our hypothesis is based on the role of immune cells and the organs that produce them, the hematopoietic organs (HOs), as primordial niches for the propagation of Wolbachia via h...
Article
Full-text available
In the terrestrial isopod species Porcellio dilatatus, unidirectional Cytoplasmic Incompatibility (CI) between two morphs (P. d. dilatatus and P. d. petiti) caused by a Wolbachia strain (wPet) infecting the morph P. d. petiti has been previously described by experiments initiated four decades ago. Here, we studied another Wolbachia that has been re...
Article
Full-text available
The alphaproteobacteria Wolbachia pipientis are among the most common and widespread symbionts in the animal world. Their vertical transmission mode is predicted to favour genotypes with low virulence. On the contrary, horizontal transfers of Wolbachia from one host to another have been shown to possibly increase the symbiont virulence. This situat...
Article
Full-text available
Maternally inherited Wolbachia (α-Proteobacteria) are widespread parasitic reproductive manipulators. A growing number of studies have described the presence of different Wolbachia strains within a same host. To date, no naturally occurring multiple infections have been recorded in terrestrial isopods. This is true for Armadillidium vulgare which i...
Article
Full-text available
The endosymbiont Wolbachia pipientis infects various hosts in which it navigates vertically from mothers to offspring. However, horizontal transfers of Wolbachia can occur between hosts. The virulence of the horizontally acquired Wolbachia can change in the new host as it has been illustrated by the case of the feminizing strain wVulC from the wood...
Article
Full-text available
The alpha-proteobacteria Wolbachia are the most widespread endosymbionts in arthropods and nematodes. Mainly maternally inherited, these so-called sex parasites have selected several strategies that increase their vertical dispersion in host populations. However, the lack of congruence between the Wolbachia and their host phylogenies suggests frequ...
Data
Behavioral film showing the symptoms encountered in P. d. dilatatus after the injection of the wVulC strain. Animals exhibited surfacing behavior, lack of mobility and several symptoms as seizures, leg tremors and paralysis. (MP4)
Article
Full-text available
Wolbachia are widespread endosymbionts found in a large variety of arthropods. While these bacteria are generally transmitted vertically and exhibit weak virulence in their native hosts, a growing number of studies suggests that horizontal transfers of Wolbachia to new host species also occur frequently in nature. In transfer situations, virulence...

About

30
Publications
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449
Citations
Introduction
I am an evolutionary and molecular biologist with a particular interest on studying host/symbiont interactions. My current research focuses on studying the human blood fluke schistosome, the most important of the helminth parasites infecting humans. I aim to decipher the genetic basis of multiple biomedically important traits in this parasite like drug resistance or transmission/virulence traits. I also developed new molecular tools to improve the molecular toolkits available for schistosome.
Additional affiliations
October 2018 - present
Texas Biomedical Research Institute
Position
  • Researcher
Description
  • Research topics: The genetic basis of several phenotypes of interest (virulence, transmission, drug resistance) in the human parasite Schistosoma mansoni
March 2013 - October 2018
Texas Biomedical Research Institute
Position
  • PostDoc Position
Description
  • Research topics: The genetic basis of virulence and transmission in the human parasite Schistosoma mansoni
October 2009 - December 2012
Université de Poitiers
Position
  • PhD Student
Description
  • Research topics: Horizontal transfers of Wolbachia in terrestrial isopods: immediate and evolutionary consequences for both hosts and symbionts
Education
October 2009 - December 2012
Université de Poitiers
Field of study
  • Evolutionary Biology and Molecular Biology
September 2007 - June 2009
Université de Poitiers
Field of study
  • Evolutionary Biology and Ecology
September 2005 - June 2007
Université de Poitiers
Field of study
  • Biology and Geology

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Projects

Projects (6)
Project
Since we discovered the gene and alleles involved in oxamniquine resistance from a lab genetic cross, we are analyzing data from natural population of schistosomes in order to identify resistance alleles and their frequencies. This work is critical for preventing resistance to future oxamniquiine derivatives.