NERC GW4+ DTP PhD studentship: Evolution and ecology of virus host shifts

Main supervisor: Dr Ben Longdon, Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Penryn, Cornwall

Project description:

Virus host shifts where a virus jumps from one host species to another are a major source of emerging infectious diseases. For example, Ebola, HIV and SARS coronavirus have all jumped into humans from other species. Despite the importance of emerging viral diseases, we have a limited understanding about what determines the ability of a virus to infect some groups of hosts but not others, or how viruses will evolve in different hosts (Longdon et al. 2014). Understanding these processes is vital to predict when and where diseases will emerge in the future.

Viruses are disproportionally responsible for emerging infectious diseases, with RNA viruses that normally infect multiple host species considered the most likely to emerge. Additionally, host shifts appear to occur most often between closely related host species. However, evidence for these hypotheses largely come from correlational data (i.e. observations with no experimental manipulation). Therefore, they point us toward interesting areas for investigation, but cannot tease apart the complex processes explaining the observed patterns.

Experimental studies have highlighted some of the important host-virus interactions that result in successful host shifts (e.g. parvoviruses from cats to dogs (Parrish et al. 2008) but the majority of these studies have been limited to two host in vitro systems, i.e. using cell cultures. Host-virus interactions may differ in whole animals for many reasons, and using only two hosts prevents drawing general conclusions. Therefore, experimental studies using a wide breadth of host species that vary in their relatedness are essential to make broadly applicable conclusions. Work in our lab uses up to 50 species of Drosophila, and their naturally occurring RNA viruses (Longdon et al. 2011, 2015) to examine host shifts (video here www.goo.gl/sXBiv5 showing patterns of susceptibility across hosts). These flies have equivalent diversity to all mammals and are an established innate-immunity model. By using a large number of different host species we will be able to find general patterns that apply across host’s species with varying relatedness.

The project will explore how different environmental, ecological and evolutionary factors may limit the ability of a virus to infect different hosts. The project may be taken in several directions based on the interests of the candidate, including: • Examining how viral coinfection can affect the outcome of infection across different host species • Testing the relative importance and interplay of environmental and genetic factors in determining host susceptibility • Testing whether viruses with varying degrees of relatedness have similar abilities to infect different host species • Testing whether different routes of infection alter the likelihood of a successful host shift

This project is one of a number that are in competition for funding from the NERC Great Western Four+ Doctoral Training Partnership (GW4+ DTP). The GW4+ DTP consists of the Great Western Four alliance of the University of Bath, University of Bristol, Cardiff University and the University of Exeter plus six Research Organisation partners: British Antarctic Survey, British Geological Survey, Centre for Ecology and Hydrology, the Met Office, the Natural History Museum and Plymouth Marine Laboratory. For further details about the programme please see http://nercgw4plus.ac.uk/

See please http://www.exeter.ac.uk/studying/funding/award/?id=2264 for more details on how to apply.