.... ellie harrison ....
coevolution within the microbiome
I'm interested in the ecology and evolution of interactions within microbial communities. My work focuses in particular on interactions between bacteria and the many and various mobile genetic elements that inhabit them, such as conjugative plasmids (infectious loops of DNA) and phages (bacterial viruses).
These elements are extremely interesting for evolutionary biologists; Some elements are purely antagonistic, such as the lytic phages, viruses which infect bacteria and then kill them in order to reproduce. The lytic phage- bacteria interaction is characterised by rapid, antagonistic coevolution where phages cause selection for resistance in the bacteria which in turn selects for infectivity in the phage and so on and so forth. On the other hand elements such as plasmids and temperate phages (viruses which insert their own genome into that of the bacteria) can be beneficial to their hosts. They can carry genes encoding traits which can be helpful to the bacteria in particular environments, such as toxin resistance genes. However these elements are not purely benevolent, in order to persist they rely on host resources so, when the bacteria does not require the genes they carry, they too are essentially parasitic.
I'm interested in how any why these elements persist and how the evolution of this unseen diversity of elements can drive changes in the bacterial population which echo through communities.
Ellie harrison, P3 Fellow, University of Sheffield
Hall, Harrison, Lilley, Paterson, Spiers and Brockhurst (2015) Environmentally co-occurring mercury resistance plasmids are genetically and phenotypically diverse and confer variable context-dependent fitness effects, Environmental Microbiology