Daniel St Johnston

Senior group leader

Research summary

Polarising epithelial cells and body axes

How do cells know ‘up’ from ‘down’? Most cells in the body perform different functions at opposite sides of the cell. This cell polarity is essential in development, for example: in determining the head-to-tail axis of many animals, for cell migration and for asymmetric stem-cell divisions. Furthermore, loss of polarity is a hallmark of tumour cells and is thought to contribute to tissue invasion and metastasis.

Our work focuses on epithelia, the sheets of polarised cells that form barriers between compartments and make up most of our organs and tissues. We study the factors that mark different sides of epithelial cells and how these organise the internal cell architecture, using the Drosophila intestine and the follicle cell epithelium as models.

Expand summary

We have recently discovered that the gut epithelium polarises by a fundamentally different mechanism from other fly epithelia, and is much more similar to mammalian epithelia. We are now identifying new polarity factors in the fly gut and are testing whether these play similar roles in mouse intestinal organoids.

We are also using live microscopy to visualise polarised secretion in epithelial cells, and quantitative super- resolution microscopy to examine the clustering and co-localisation of polarity proteins.

 

St Johnston Diagram special properties of epithelia

The special properties of epithelia: The drawing shows how epithelial cells stick together to form epithelial sheets, with their free apical surfaces facing towards the outside or the lumen of an epithelial tube or gland. The lateral junctions (yellow) create a barrier between cells so that fluids, solutes and pathogens cannot leak across the epithelium. Most cancers arise from epithelial tissues and are characterised by a loss of apical–basal polarity (red cells). 

 

 

Daniel St Johnston colour portrait

Selected publications

  • Doerflinger H et al. (2021) The Drosophila anterior-posterior axis is polarized by asymmetric myosin activation. Current Biology 32(2): 374-385.e4. DOI: 10.1016/j.cub.2021.11.024.

    December 1, 2021

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  • Nashchekin D et al. (2021) Symmetry breaking in the female germline cyst. Science 374 (6569): 874-879. DOI: 10.1126/science.abj3125.

    November 11, 2021

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  • Fic W et al. (2021) RhoGAP19D inhibits Cdc42 laterally to control epithelial cell shape and prevent invasion. J Cell Biol, 220 (4): e202009116. DOI: 10.1083/jcb.202009116.

    March 1, 2021

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  • Lovegrove H et al. (2019) The role of integrins in Drosophila egg chamber morphogenesis. Development 146: dev182774. DOI: 10.1242/dev.182774.

    December 9, 2019

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  • Erdmann RS et al. (2019) Labeling Strategies Matter for Super-Resolution Microscopy: A Comparison between HaloTags and SNAP-tags. Cell Chem Biol 26(4):584-592.e6. DOI: 10.1016/j.chembiol.2019.01.003.

    February 7, 2019

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  • Fic W et al. (2019) Drosophila IMP regulates Kuzbanian to control the timing of Notch signalling in the follicle cells. Development 146: dev168963. DOI: 10.1242/dev.168963.

    January 18, 2019

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  • Chen J et al. (2018) An alternative mode of epithelial polarity in the Drosophila midgut. PLoS Biol 16: e3000041. DOI: 10.1371/journal.pbio.3000041.

    October 19, 2018

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Biography

Prof Daniel St Johnston PhD FRS FMedSci
Wellcome Principal Research Fellow, Professor of Developmental Genetics, Member of the University Department of Genetics

Research group

  • Dr Edward Allgeyer

    Senior Research Associate

  • Jaime Canedo

    Research Assistant

  • Dr Jia Chen

    Research Associate

  • Dr Helene Doerflinger

    Research Associate/ Public Engagement Manager

  • Dr Xiaoming Fang

  • Xiao Li He

    Senior Research Laboratory Technician

  • Noah Jackaman

    MPhil Student

  • Florence Leroy

    Lab Administrator

  • Dr Dmitry Nashchekin

    Research Associate

  • John Overton

    Senior Research Lab Technician

  • Dr Jenny Richens

    Research Associate

  • Samarpita Sen

    PhD Student

  • Dr George Sirinakis

    Senior Research Associate

  • Dr Mihoko Tame

    Research Associate

  • Dr Joseph Jose Thottachery

    Research Associate

  • Xixi Zhu