Project Reference: TRG27-IMR-JS1

Project title: Evolution of bacterial cell envelopes during host adaptation

Project outline

Every bacterium is surrounded by a protective cell envelope that determines its shape, enables growth and mediates interactions with its environment. A major component of this envelope, peptidoglycan, is one of the oldest and most conserved structures in biology and is the target of many antibiotics. Yet almost everything we know about bacterial cell walls comes from laboratory species such as Escherichia coli and Bacillus subtilis. Much less is known about how cell envelopes evolve when bacteria become adapted to living in association with animal hosts.

This project will investigate how bacterial cell envelopes have evolved during host adaptation using two remarkable organisms: Borrelia, a spirochaete with one of the most unusual peptidoglycan structures known, and Orientia, an obligate intracellular bacterium that has dramatically reduced its cell wall during evolution. These contrasting organisms provide a unique opportunity to discover how a fundamental cellular structure is remodelled as bacteria adapt to radically different lifestyles.

The student will combine bacterial cell biology, quantitative fluorescence microscopy, molecular biology and comparative genomics to visualise cell envelope organisation, investigate how peptidoglycan changes during transitions between host environments and identify the evolutionary innovations underlying these adaptations. They will also develop new imaging probes and computational image-analysis tools that will be broadly applicable to bacterial research.

This highly interdisciplinary project combines microbiology, cell biology, evolution and bioengineering to address fundamental questions about one of the defining structures of bacterial life. By comparing two evolutionarily distant bacteria with contrasting lifestyles, the project will uncover general principles governing the evolution of bacterial cell envelopes and generate new technologies that will benefit the wider microbiology community.

Principal Supervisor

Dr Jeanne Salje

Email address: jss53@cam.ac.uk

Department / Partner Institute: Cambridge Institute for Medical Research (CIMR)

Website: https://saljelab.com/

BBSRC strategic theme

Understanding the rules of life