Cellular noise and adaptive responses in E. coli
- Supervisors: Dr Christoph Engl (primary) and Dr Andrei Sapelkin (SPCS, secondary)
- Funding: China Scholarship Council (CSC)
- Deadline: 30th January 2022
Research environment
The School of Biological and Behavioural Sciences at Queen Mary is one of the UK’s elite research centres, according to the 2014 Research Excellence Framework (REF). We offer a multi-disciplinary research environment and have approximately 150 PhD students working on projects in the biological and psychological sciences. Our students have access to a variety of research facilities supported by experienced staff, as well as a range of student support services.
Research in the laboratory of Dr Engl aims to uncover how bacteria communicate with, adapt to, and shape their environment. We combine cellular, molecular, systems, ecology and state-of-the-art imaging techniques to address fundamental questions in bacterial cell physiology.
Training and development
Our PhD students become part of Queen Mary’s Doctoral College which provides training and development opportunities, advice on funding, and financial support for research. Our students also have access to a Researcher Development Programme designed to help recognise and develop key skills and attributes needed to effectively manage research, and to prepare and plan for the next stages of their career.
This is a multi-disciplinary project at the interface of biology and physics. The PhD student will receive training in genetics, molecular and cell biology of bacteria and fluorescence imaging as well as Raman spectroscopy.
Project description
Decision-making is an essential hallmark of life. At the cellular level, decision-making is controlled by regulating how much genetic information is converted into physiological output. This process (gene expression) enables cells to determine their fate and shape their surroundings. Gene expression can be surprisingly variable between cells (noise) potentially leading to divergent behaviour of individuals within a group of genetically identical cells; particularly relevant for survival of bacteria which are constantly exposed to fluctuating stressful environments. Gene expression noise may enable bet-hedging where some cells are pre-adapted to sudden environmental change increasing their survival compared to other un-adapted members of the group. This may increase population fitness in unpredictable environments through risk-spreading among individuals [1,2]. Yet to date it is still not clear whether gene expression noise indeed results in substantial physiological differences between cells. To address this, we will combine our expertise in single-cell bacteriology and Raman spectroscopy to study an environmental response of bacteria that maintains membrane integrity under stress. This membrane stress response exhibits high-levels of gene expression noise in absence of stress [3] suggestive of bet-hedging. Bet-hedging individuals whose membrane stress response is switched on a priori may be physiologically pre-adapted for a sudden and severe stress. We will analyse strains with varying levels of noise in the expression of the membrane stress response [3] under stress conditions applied with varying dynamics, magnitude and predictability. Per cell we will (i) correlate gene expression (measured via fluorescence imaging) with the specific physiological response (measured via Raman spectroscopy), (ii) assess if bet-hedging cells are pre-adapted to stress, and (iii) determine under which environmental conditions bet-hedging provides a benefit for individuals and/or the entire cell population. Outcomes will be correlated with cellular dynamics in dense populations to establish whether the recently developed approach [4] for analysis of dynamic systems can be used to provide a figure of merit for the overall system response.
Funding
This studentship is open to students applying for China Scholarship Council funding. Queen Mary University of London has partnered with the China Scholarship Council (CSC) to offer a joint scholarship programme to enable Chinese students to study for a PhD programme at Queen Mary. Under the scheme, Queen Mary will provide scholarships to cover all tuition fees, whilst the CSC will provide living expenses for 4 years and one return flight ticket to successful applicants.
Eligibility and applying
Applicants must:
- Be Chinese students with a strong academic background.
- Students must hold a PR Chinese passport.
- Applicants can either be resident in China at the time of application or studying overseas.
- Students with prior experience of studying overseas (including in the UK) are eligible to apply. Chinese QMUL graduates/Masters’ students are therefore eligible for the scheme.
Please refer to the CSC website for full details on eligibility and conditions on the scholarship.
Applications are invited from outstanding candidates with or expecting to receive a first or upper-second class honours degree and a masters degree in an area relevant to the project (Microbiology, Molecular and Cell Biology, Genetics, Biochemistry, Biophysics). Applicants should have laboratory experience in molecular biology. An interest in bacteriology is essential. Experience in handling bacteria and in (bio)physics (Raman spectroscopy) is desirable but not essential.
Applicants are required to provide evidence of their English language ability. Please see our English language requirements page for details.
The deadline for applications to Queen Mary is 30th January 2022. Applicants will need to complete an online application form by this date to be considered, including a CV, personal statement and qualifications. Shortlisted applicants will be invited for a formal interview by the project supervisor. Those who are successful in their application for our PhD programme will be issued with an offer letter which is conditional on securing a CSC scholarship (as well as any academic conditions still required to meet our entry requirements).
Once applicants have obtained their offer letter from Queen Mary they should then apply to CSC for the scholarship by the advertised deadline with the support of the project supervisor. For September 2022 entry, applicants must complete the CSC application on the CSC website between 10th March - 31st March 2022.
Only applicants who are successful in their application to CSC can be issued an unconditional offer and enrol on our PhD programme.
References
- Grimbergen et al. (2015) Microbial bet-hedging: the power of being different. Curr Opin Microbiol 25: 67-72.
- Engl (2019) Noise in bacterial gene expression. Biochem Soc Trans 47: 209–217.
- Engl et al. (2020) The route to transcription initiation determines the mode of transcriptional bursting in E. coli. Nat Commun 11: 2422.
- Kryuchkov et al. (2021) Mean-field model of melting in superheated crystals based on a single experimentally measurable order parameter. Sci Rep 11: 17963.