Optimising cell size for specialized functions: using a systems approach to understand the cell cycle during differentiation

The cell cycle is a highly conserved process, with the same major proteins controlling cell division in single-celled yeasts, plants and animals. The universality of the cell cycle underlines its evolutionary importance, but raises the question of how specialised cell divisions are produced. In multicellular organisms, one stem cell often gives rise to multiple specialised cell types with different sizes, meaning that different division rules must be followed in each lineage.
This project will use the root epidermis of Arabidopsis as a model system to address how changes in gene expression during the cell cycle can result in the production of different sized cells. The root epidermis is an important interface between the plant and its environment comprised of two distinct cell types that originate from the same stem cells; short root-hair cells that produce tube-like structures that improve water and nutrient uptake, and longer non-hair cells that play roles in transport. Although root hair growth occurs after cells have stopped dividing, differences in cell length are established much earlier and can affect the spacing between hairs as well as their development. We have previously published work showing how cell size is regulated in undifferentiated plant cells (Jones et al 201 Nat Comm 8:15060), but know little about how this mechanism changes as cells begin to differentiate or how it could be engineered to improve tissue function.
This project will use our newly developed cell-type-specific, cell-cycle markers to i) capture the dynamics of the cell cycle in the root epidermis using a state of the art light sheet microscope and ii) produce single cell transcriptomics data sets from hair and non-hair cells at different phases of the cell cycle using FACS and RNAseq. This information will be used to build a simple model of the cell cycle in differentiating cells and predict cell size under different conditions. Predictions will be tested by transiently mis-expressing genes in the opposite cell types and subjecting roots to environmental conditions that alter cell fate.
The project will carried out in the Murray Lab alongside a funded project focusing on the cell cycle in undifferentiated cells. You will take part in interdisciplinary group meetings with collaborators Dr Leah Band (University of Nottingham) and Prof. Claire Grierson (University of Bristol) and receive training in cutting edge imaging and next generation sequencing technology, allowing you to develop a highly desirable skill set.

The SWBio DTP follows a 4-year PhD model. In the first year, you will receive a range of directed training, tailored to support your PhD project. This includes a series of compulsory taught units (taught co-localised) and self-directed study that take up about one-third of your available time. In addition, you will experience two assessed laboratory rotations in year 1, each in separate disciplines but designed to provide focused training tailored to your PhD project. You will be able to use your experiences with the laboratory rotations to refine the PhD project on which you will concentrate on from August of the first year. The PhD thesis must be submitted within 4 years of starting the programme.

Academic criteria
Applicants for a studentship must have obtained, or be about to obtain, a First or Upper Second Class UK Honours degree, or the equivalent qualifications gained outside the UK, in an appropriate area of science or technology. Applicants with a Lower Second Class degree will be considered if they also have a Master’s degree or have significant relevant non-academic experience.

In addition, due to the strong mathematical component of the taught course in the first year and the quantitative emphasis in the projects, a minimum of a grade B in A-level Maths or an equivalent qualification or experience is required.

Equivalent qualifications/experience
•Physics A-level (grade B and above)
•Undertaking units as part of your degree that have a significant mathematical component*
*Significant mathematical component examples include; maths, statistics, bioinformatics.
Applicants are required to highlight their Maths background within their application and must upload supporting evidence.
If English is not your first language you will need to have achieved at least 6.5 in IELTS (and no less than 6.5 in any section) by the start of the programme.