School of Biological and Chemical Sciences

The evolution of immunity in species exposed to invading pathogens

Supervisor: Dr Rob Knell

Project description

Invasion of ecological systems by novel, imported pathogens is rapidly becoming recognised as a tremendous conservation issue globally, with high-profile examples such as white-nose syndrome in bats and chytrid disease in frogs causing tremendous damage to their host communities.

One response that we might expect from host species which are not immediately driven to extinction is the evolution of resistance to the pathogen, which will itself be mediated by selection for either immunity or tolerance to the pathogen in question or both. The outcome of this selection will be determined by the selection pressure from the pathogen, the degree of existing heritable variability in immunity, the cost of resistance and the biology of the pathogen, which will itself be evolving to avoid host immune responses.

This project will use laboratory evolution experiments with the Drosophila melanogaster ­ Metarhizium anisopliae system, coupled with mathematical modelling to answer a number of important questions about the evolution of resistance when a host species is exposed to a novel pathogen, with hypotheses to be tested including:

  1. Is tolerance or immunity more likely to evolve?
  2. Does the cost of resistance diminish over time as better-adapted and less costly gene combinations arise?
  3. To what extent does pathogen evolution negate the effects of host resistance?

Eligibility and applying

International students must provide evidence of proficient English language skills. See our entry requirements page for further information.

Potential candidates should contact Dr Knell by e-mail (r.knell@qmul.ac.uk) and submit their CV and a cover letter explaining their eligibility and interest in this project.

References

  • Staves PA, Knell RJ. 2010. Virulence and competitiveness: testing the relationship during inter- and intraspecific mixed infections. Evolution 64:2643­2652
  • Mazé-Guilmo E, Loot G, Páez DJ, Lefèvre T, Blanchet S. 2014. Heritable variation in host tolerance and resistance inferred from a wild host­parasite system. Proc. R. Soc. B 281:2013-2567
  • Fisher MC, Henk DA, Briggs CJ, Brownstein JS, Madoff LC, McCraw SL, Gurr SJ. 2013. Emerging fungal threats to animal, plant and ecosystem health. Nature 484:186­194.

See also