Interested individuals must follow the "how to apply" link on the Geosciences E4 Doctoral Training Partnership web page: http://www.ed.ac.uk/e4-dtp/how-to-apply
Summary
What strategies have malaria parasites evolved to cope with the challenges of transmission by mosquito vectors?
Project background
Parasites live in the bodies of others – with whom they are engaged in a life-and-death struggle – yet, how parasites cope with the challenges of their lifestyle is remarkably poorly understood. Consequently, evolution continually erodes efforts to control parasites and infectious diseases remain responsible for considerable mortality and morbidity. Most disease research focuses on the processes that result in symptoms during infections and much progress in uncovering the interactions between parasites and their hosts has been made. However, for vector borne parasites, analogous studies of interactions between parasites and vectors have been neglected, despite the fact that vectors are responsible for spreading disease. Clearly, to fully understand the evolution of such parasites it is necessary to ask how parasites solve the challenges of living in hosts and in vectors.
The project will investigate how disease transmission is shaped by the ecological interactions parasites experience inside the vector. This is especially important because vector control programmes (e.g., large-scale insecticide use) are underway. The evolutionary responses of the vector to these control programs are being monitored (e.g., insecticide resistance in mosquitoes), but how this affects selection on, and the potential evolutionary responses of, the parasites are largely being ignored.
Parasite fitness is a product of both in-host survival and between-host transmission, but there are remarkably few instances where processes operating at these scales are integrated, especially for vector-borne diseases. This project will reveal the importance of within-vector ecology for transmission, and show how parasites can evolve in response to vector control. Trade-offs and constraints between parasite traits may reveal ways to target vector populations that are more difficult for parasites to overcome. Anticipating parasite evolution will inform monitoring strategies for current control programs as well as how to prevent unfavourable outcomes of future programs.
Research questions
The precise questions depend on the student's ideas and interests. Potential topics include:
Have malaria parasites evolved adaptive phenotypic plasticity to cope with the variable conditions they experience within vectors? e.g. the presence of competing strains of parasite, different ages of vector, transmission to a from the vector at variable times of day.
What genetically "hardwired strategies" help parasites exploit the vector's resources?
Are parasite strategies specialised to a particular vector species, or can parasites exploit multiple species equally well?
Methodology
This project will use malaria parasites of rodents and mosquitoes to integrate developments from different biological disciplines into an evolutionary framework. Malaria parasitesare ideal because they are among the best-understood eukaryotic parasites. Multiple distinct genotypes (plus fluorescent reporter lines) for the rodent malaria, Plasmodium chabaudi, and several species of the mosquito vector (Anopheles spp.) are available. With this system, well-controlled laboratory experiments that perturb the environments malaria parasites experience within mosquito vectors can easily be carried out. For example, manipulating parasite (genotype, presence/absence of competitors) and vector variables (genotype, insecticide resistant/sensitive, and age/reproductive/nutritional state) is straightforward. Infections will be established in lab mice and then transmitted to mosquitoes. The productivity and timing of each parasite developmental stage will be assayed and the mortality rate of vectors will be measured. The experiments will reveal the genetic and environmental drivers of parasite transmission to, and from, the vector.
Training
A comprehensive training programme will be provided comprising both specialist scientific training and generic transferable and professional skills.
Requirements
Students should have at least an upper 2:1 degree from a relevant biological discipline. Training will be provided in parasite and vector husbandry.
walling.bio.ed.ac.uk/
The School of Biological Sciences is committed to Equality & Diversity: https://www.ed.ac.uk/biology/equality-and-diversity
The “Institution Website” button on this page takes you to our Online Application checklist. Please complete each step and download the checklist which provides a list of funding options and guide to the application process.
Continue with Facebook
