Research

I am interested in the role of biotic forces in evolution and ecology. My 'big question' is: 'how would the world be if animals and plants did not have microbial symbionts?' I also work to exploit our fundamental understanding of host-symbiont interactions to improve bee husbandry, reduce the impact of vector born diseases on livestock. and more widely mitigate the damage from pest insects. I additionally have some small policy-focussed projects on entomophagy and food security, assessing the potential for insects as sustainable food and feed.

The work of the lab group takes many approaches, including experimental analysis in insect hosts in the laboratory, molecular microbiology, comparative and evolutionary genomics, analysis of dynamics in natural populations, and mathematical modelling.

Our research is supported from a variety of UKRI (NERC, BBSRC), Charity (Moore Foundation) and other funding sources.

We work with partners from the UK (Nina Wedell, Exeter; Ailsa McLean Oxford), Japan (Daisuke Kageyama, NARO), USA (Jay Evans, USDA) and Africa (ICIPE Nairobi; IITA Benin)

The butterfly Hypolimnas bolina is host to a male-killing Wolbachia bacterium. Natural selection has favoured a suppressor gene (in green) that rescues males from this fate.

The role of sex ratio distorting microbes in host evolution and ecology

Many insects carry microbes that distort their host sex ratio, favouring the production and survival of female hosts. I work to establish:
a) How these microbes change the ecology of their host, in terms of mating system and the spread of sexually transmitted infections.
b) How they drive the evolution of their host, for instance the evolution of sex determining systems.
This work uses butterflies, lacewing, ladybird, Drosophila and Nasonia jewel wasp as model systems in the field and the laboratory.

Spiroplasma bacteria protect their fly host against attack by parasitic wasps. However, we demonstrated that protection was dependent on temperature, disappearing below 18 C.

Symbionts and disease risk

For many insects, symbionts represent a primary line of defence against natural enemies (parasitic wasps, nematodes, viruses).
We aim to understand
-the dynamics of protective symbionts
-the way in which they are affected by variation in the environment
-the way they interact with the 'classical' immune system.

Arsenophonus nasoniae, expressing GFP, targets the ovipositor of its parasitic wasp host to ensure onward transmission

Molecular basis of symbiosis

Whilst many regard microbes as pathogens that infect, replicate and then transmit on before they are cleared, microbes commonly also form persistent symbioses with their host. In some cases, the symbiosis is inherited - that is to say the microbe passes from a female host to her progeny. Unlike pathogens, microbial symbionts need systems to be retained in hosts through their life history and gain access to the host germ line. We use techniques of molecular microbiology and functional genetic manipulation of the host to understand the systems bacteria use to establish persistent symbiosis in insects and host responses.

Our model hosts systems for this work are: Nasonia wasps, Drosophila fruit flies and Galleria waxworms.
Our microbial models are the genus Arsenophonus and Spiroplasma.

Research grants

Insect cell culture systems to explore the symbiont-sex determination system interface.

BIOTECHNOLOGY & BIOLOGICAL SCIENCE RESEARCH COUNCIL

February 2024 - July 2025

Male-killing symbiosis across a predator-prey interaction: a genomic and experimental approach

NATURAL ENVIRONMENT RESEARCH COUNCIL

April 2023 - August 2024

Symbionts or genes? Integrating the evolutionary response to parasites across varying modalities of resistance.

NATURAL ENVIRONMENT RESEARCH COUNCIL

December 2021 - May 2025

Antisense inhibition to study Bodo saltans – Bodobacter symbiosis

GORDON AND BETTY MORE FOUNDATION (USA)

May 2020 - May 2024

WolAntiS: Antisense technologies for investigating Wolbachia biology

EUROPEAN COMMISSION

March 2019 - February 2021

The genetic basis of reproductive isolation through intragenomic conflict

NATURAL ENVIRONMENT RESEARCH COUNCIL

April 2019 - February 2023

The velocity of evolutionary responses of species to ecological change; testing adaptive limits in time and space in Lepidoptera

NATURAL ENVIRONMENT RESEARCH COUNCIL

May 2016 - February 2020

Evaluating the safety and nutritional quality of a novel insect based food product in Benin

BIOTECHNOLOGY & BIOLOGICAL SCIENCE RESEARCH COUNCIL

May 2017 - April 2019

How do sex ratio distorting symbionts affect the evolution of their host?

NATURAL ENVIRONMENT RESEARCH COUNCIL

September 2016 - September 2019