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Dr Catherine J. Merrick

Dr Catherine J. Merrick

Senior University Lecturer

Division of Microbiology and Parasitology

My research focuses on the human malaria parasite, with the goal of improving our understanding of the parasite’s basic biology and the impact of this biology on virulence. I use molecular genetics and cell biology to study this important disease-causing organism.

208, Molteno Building,
Department of Pathology,
Tennis Court Road,
CB2 1QP.

Office Phone: 01223 333330


My first degree was in Natural Sciences at Cambridge, during which time I also participated in the Cold Spring Harbor undergraduate research program in the USA.  I then completed a PhD in Cell Biology at Cancer Research UK, before moving to the Harvard School of Public Health where I held a Charles H. Hood postdoctoral fellowship and began to study the epigenetic control of virulence genes in the malaria parasite.  During my postdoc I also conducted a field study at the MRC Institute in The Gambia, investigating clinical phenotypes and the expression of virulence genes in patients with malaria. 

Upon returning to the UK I worked briefly as a sub-editor at Nature, then joined the faculty at Keele University where I was a Lecturer and subsequently a Senior Lecturer until spring of 2018.  At Keele I established a research group within the Centre for Applied Entomology and Parasitology (CAEP), gained my Postgraduate Certificate in Teaching & Learning in Higher Education and became a Fellow of the Higher Education Academy.  I taught undergraduate and graduate courses in parasitology and other areas and was awarded a 'superb supervisor' teaching award by the SU.  I sat on the Council of the British Society for Parasitology from 2012 to 2018, serving as the Hon. Communications Secretary 2015-2018. 

In 2018 I moved to a Senior Lectureship at Cambridge, where my research group is currently funded by MRC and ERC consolidator grants. 

Merrick Lab photo 1

Research themes


Research Interests

My group studies the human malaria parasite Plasmodium falciparum.  Research interests are centred around DNA biology, particularly the molecular mechanisms underlying DNA replication and cell cycle control in Plasmodium, which replicates by an unusual method called schizogony.  I am also interested in mechanisms for silencing and promoting the recombination of a family of key virulence genes called var genes - particularly the role that G-quadruplex DNA structures may play in var gene controlVar genes encode the major parasite antigen expressed on infected red blood cells; they are found primarily at sub-telomeric loci and their variant expression is under epigenetic control.  In fact, we have discovered that G-quadruplexes and their helicases have more general roles in genome stability/evolution in the malaria parasite as well.  Finally, I have a long-standing interest in a group of NAD+-dependent deacetylase enzymes called sirtuins which regulate subtelomeric chromatin and virulence gene expression.  My postdoctoral work linked the Plasmodium falciparum sirtuins to particular patterns of var gene expression and to severe malaria in human patients.

 Merrick Lab photo 2

Merrick lab news and events

2019: Dr Merrick will be at the American Society for Tropical Medicine and Hygiene (ASTMH) meeting in November, teaching on the Parasitology pre-meeting course 'Imaging Parasites from Single Molecules to Whole Organism'.

A warm welcome to postdoc Holly Craven and MPhil student Louise DeThomasson, both joining the lab in autumn 2019.

Dr Merrick will be at the 30th annual Molecular Parasitology meeting (MPM) in the USA in mid-September, where she will act as a session chair and present research from the lab on a novel telomere-binding protein in Plasmodium.

Summer student Hunter Gage, from U. Madison Wisconsin, joins the lab throughout July and August on the SCORE undergraduate programme.

New grant: the Rosetrees Trust has awarded us a 2-year seedcorn grant to start in Sept 2019, investigating the antimalarial potential of G-quadruplex binding drugs. 

In May Dr Merrick will be teaching ~20 students from around the world on the intensive Wellcome Trust course in Malaria Experimental Genetics, held at the Sanger Institute. PDRA Dr Totanes will be acting as an assistant on the course.  

Our first Cambridge-based publication since the group's relocation is out now: an invited review: ‘Parasitic protozoa: unusual roles for G-quadruplexes in early-diverging eukaryotes’ in a special issue of Molecules, focussing on G-quadruplexes & microorganisms.

Merrick lab photo 5

2018: As part of the Cambridge Festival of Ideas in October, Drs Merrick and Dumetz participated in a debate held at the Law Faculty on whether humans have the right to exterminate parasites.  The audience was split almost evenly on the motion, but preserving parasites won by a 1-vote margin!

PDRA Dr Franck Dumetz has successfully applied to join Trinity Hall MCR with a postdoctoral research associateship.

Dr Merrick spoke about the lab's work on G-quadruplexes at the International Symposium on 'Biology of non-canonical nucleic acids: from humans to pathogens' in late September in Italy.

Dr Chun Kit Kwok (pictured here with Dr Merrick and PDRA Dr Dumetz) spent 2 weeks visiting the lab in August on a Royal Society Kan Tong Po fellowship.  This scheme encourages collaborative work between UK and Hong Kong universities: in this case, an ongoing project to investigate RNA secondary structures in P. falciparum.  The work forms part of our current MRC-funded project on G-quadruplex biology in malaria parasites.  Drs Kwok and Merrick recently published a review article in Trends in Biotechnology: G-quadruplexes: prediction, characterization, and biological application

Dr Merrick has been invited to join the editorial board of the journal Scientific Reports from July 2018.

Dr Merrick was an invited speaker at the recent Global Research Excellence Symposium at  the Centre for Medical Parasitology, Copenhagen (June 2018).  She discussed her work on Merrick Lab photo 4RecQ helicases in Plasmodium falciparum, which was published on July 2nd in Plos Genetics.  Pictured here outside the CMP with collaborators Thomas Otto (Glasgow University) and Antoine Claessens (Montpellier University), who is a first author on the Plos Genetics paper.

2017: Keele SU Student-Led Teaching Award for 'Superb Supervisor' goes to Dr Merrick

ERC Consolidator Grant awarded to Dr Merrick

Research Supervision

Please contact me by email if you are interested in PhD or postdoctoral work in my group.  If funded positions are available, they will be advertised here, otherwise I am happy to discuss possible projects for fellowship applications with qualified candidates. 

Current lab members:

  • Dr Jennifer McDonald, postdoc, from July 2018
  • Dr Francis Totanes, postdoc, from July 2018
  • Dr Franck Dumetz, postdoc, from Aug 2018
  • Dr Holly Craven, postdoc, from Oct 2019
  • Anders Jensen, technician, from July 2018
  • Louise DeThomasson, MPhil student, 2019-2020
  • Linda Onyeka Anagu, PhD student based at Keele University, 2015-2019
  • Christopher Cannon, undergraduate student, 2019-2020

Merrick lab photo 6

Lab members at Cambridge University, 2018

Previous lab members:

  • Technicians
  • Dr Lisa Rump, 2017-2018
  • PhD students
  • Dr Ashley J. Jordan, 2012-2016 (subsequently postdoc at Institut Laue-Langevin Grenoble).
  • Masters students (Keele, 2012-17)
  • 6 MSc students on programmes including MSc in Molecular Parasitology and Vector Biology, MSc in Scientific Research Training abroad, and ERASMUS.  3 students (Adriana Adolfi, Rinal Sahputra & Pamela Veneziano-Broccia) progressed to PhDs at LSTM, Manchester and Trieste.
  • 1 MPhil, Dr Katelyn Monsell - intercalated year in research during medical training at Keele Medical School.
  • Undergraduates
  • Cambridge:
  • 2018-19: Lydia Roberts (First class undergraduate degree 2019); Hunter Gage (summer student on the U. Madison SCORE programme)
  • Keele (2011-2017):
  • 20 undergraduate students, including 4 progressing to PhD/MSc degrees.

Merrick Lab photo 3

Lab members at Keele University

Key Publications

‘Parasitic protozoa: unusual roles for G-quadruplexes in early-diverging eukaryotes.’  (REVIEW)
Dumetz, F. & Merrick, C.J. Molecules, special issue on G-quadruplexes & microorganisms. doi: 10.3390/molecules24071339 (2019).

'RecQ helicases in the malaria parasite Plasmodium falciparum affect genome stability, gene expression patterns and DNA replication dynamics.’
Claessens, A., Harris, L.M., Stanojcic, S., Chappell, L., Stanton, A., Kuk, N., Veneziano-Broccia, P., Sterkers, Y., Rayner, J.C., Merrick, C.J. Plos Genetics (2018).

'Checks and Balances? DNA replication and the cell cycle in Plasmodium.' (REVIEW)
Matthews, H., Duffy C.W., Merrick, C.J. Invited review, Parasites & Vectors doi:10.1186/s13071-018-2800-1 (2018).

'ATAC-ing transcriptional mysteries in malaria parasites.’
Merrick, C.J. Preview article, Cell Host & Microbe doi:10.1016/j.chom.2018.03.016 (2018).

'G-quadruplex DNA motifs in the malaria parasite Plasmodium falciparum and their potential as novel antimalarial drug targets.'
Harris, L.M., Monsell, K., Noulin, F., Famodimu, M.T., Smargiasso, N., Damblon, C., Horrocks, P., Merrick, C.J.  Antimicrobial Agents & Chemotherapy

'Perspectives in Parasitology: Plasmodium falciparum.'
Merrick, C.J.  Emerging Topics in Life Sciences 'Perspectives in Parasitology' issue 1(6) 517-523 doi:10.1042/ETLS20170099 (2017).

'Single-molecule Analysis Reveals that DNA Replication Dynamics Vary Across the Course of Schizogony in the Malaria Parasite Plasmodium falciparum.'
Stanojcic, S., Kuk, N., Ullah, I., Sterkers, Y., Merrick, C.J.  Scientific Reports 7:4003 doi:10.1038/s41598-017-04407-z (2017).

'G-quadruplexes: prediction, characterization, and biological application.' (REVIEW)
Kwok, C.K. and Merrick, C.J.  Trends in Biotechnology (2017).

'Recombination events among virulence genes in malaria parasites are associated with G-quadruplex-forming DNA motifs.'
Stanton, A., Harris, L.M., Graham, G., Merrick, C.J.  BMC Genomics 17:859 doi:10.1186/s12864-016-3183-3 (2016).

'SEC-SANS: Size Exclusion Chromatography Combined In Situ With Small Angle Neutron Scattering.'
Jordan, A., Jacques, M., Merrick, C.J., Devos, J., Forsyth, V.T., Porcar, L., Martel, A.  Journal of Applied Crystallography 49 (2016).

'Transfection with thymidine kinase permits bromodeoxyuridine labelling of DNA replication in the human malaria parasite Plasmodium falciparum.'
Merrick, C.J. Malaria Journal 14:490. doi: 10.1186/s12936-015-1014-7 (2015).

'G-quadruplexes in pathogens: a common route to virulence control?' (REVIEW)
Harris, L.M. and Merrick, C.J. PLoS Pathogens 11(2):e1004562. doi: 10.1371/journal.ppat.1004562 (2015).

'Functional analysis of sirtuin genes in multiple Plasmodium falciparum strains.’
Merrick, C.J.,
Jiang, H. R., Skillman, K.M., Samarakoon, U., Moore, R.M., Dzikowski, R., Ferdig, M.T., Duraisingh M.T.  PlosOne 10(3):e0118865. doi: 10.1371/journal.pone.0118865 (2015).

'A quantitative analysis of Plasmodium falciparum transfection using DNA-loaded erythrocytes.'
Hasenkamp, S., Merrick, C.J., Horrocks, P.  Molecular and Biochemical Parasitology 187(2), 117-120 (2013).

‘Epigenetic dysregulation of virulence gene expression in severe Plasmodium falciparum malaria.’
Merrick, C.J.,
Huttenhower, C., Buckee, C.O., Amambua-Ngwa, A., Gomez-Escobar, N.,Walther, M., Conway, D.J., Duraisingh M.T.  Journal of Infectious Diseases, 205(10), 1593-1600 (2012).

‘Plasmodium Epigenetics: What do we really know?’ (REVIEW)
Merrick, C.J. and Duraisingh, M.T.  Eukaryot Cell, 9(8), 1150-8 (2010).

‘The effect of Plasmodium falciparum Sir2a histone deacetylase on clonal and longitudinal variation in expression of the var family of virulence genes.’
Merrick, C.J., Dzikowski, R., Imamura, H., Chuang, J., Deitsch, K., Duraisingh, M.T. Int. J.Parasitol. 40, 35-43 (2010).

Plasmodium falciparum Sir2: An unusual sirtuin with dual histone deacetylase and ADP-ribosyltransferase activity.’
Merrick, C.J. and Duraisingh, M.T.  Eukaryot Cell, 6(11), 2081-2091 (2007).

‘Heterochromatin-mediated control of virulence gene expression.’ (REVIEW)    
Merrick, C.J. and Duraisingh, M.T.  Mol Microbiol. 62(3), 612-20 (2006).

‘Functional Analysis of Avr9/Cf-9 Rapidly Elicited Genes Identifies a Protein Kinase, ACIK1, that is Essential for Full Cf-9-Dependent Disease Resistance in Tomato.’
Rowland, O., Ludwig, A.A., Merrick, C.J., Baillieul, F., Tracy, F., Durrant, W.E., Fitz-Laylin, L., Nekrasov, V., Yoshioka, H. and Jones, J.D.G.  Plant Cell 17(1), 295-310 (2005).

‘Visualisation of altered replication dynamics after DNA damage in human cells.’  
Merrick, C.J., Jackson, D. and Diffley, J.F.X.  J.Biol.Chem. 279, 20067-20075 (2004).


Online media _________________________________________________________________

'Rinse and repeat: can mosquito passage ‘reset’ malaria parasites?' Review of Spence et al. Plos Pathogens 2015.
Merrick, C.J. Bugbitten blog of Parasites & Vectors, Aug 2015

'Taking turns: how Plasmodium changes its spots.' Review of Zhang et al. Nature 2014.
Edwards-Smallbone, J. and Merrick, C.J. Bugbitten blog of Parasites & Vectors, Aug 2014.

'Throwing the switch: gametocytogenesis in malaria parasites.' Review of Kafsack et al. & Sinha at al. Nature 2014.
Horrocks, P. and Merrick, C.J. Bugbitten blog of Parasites & Vectors, Apr 2014.

'Malaria virulence genes: Complex control.’ Review of Volz et al. Cell Host & Microbe, 2012.
Merrick, C.J. British Society for Parasitology online journal club, Feb 2012.

 ‘Malaria: An old but pressing problem
Merrick, C.J.  SITN-Flash (Newsletter of the Harvard ‘Science In The News’ Network) World AIDS Day Special Issue on Infectious Diseases, Dec 1 2010.


Science Writing for the General Public ____________________________________________

‘A Scientist for all Seasons’ (A review of E.O Wilson’s ‘Biophilia’)
Merrick, C.J.   Slightly Foxed, Summer 2014 issue.

‘Adventures in achromatopsia’ (A review of Oliver Sacks’s ‘The Island of The Colourblind’)
Merrick, C.J.   Slightly Foxed, Spring 2013 issue.

‘Honest Jim and the double helix’ (A review of James Watson’s ‘The Double Helix’)
Merrick, C.J.   Slightly Foxed, Autumn 2011 issue.

‘Biophilia for beginners’ (A review of Charles Darwin’s ‘On the Origin of Species’)
Merrick, C.J.   Slightly Foxed, Spring 2011 issue.

‘Tuberculosis: Fighting the Great White Plague.’
Merrick, C.J.  Biological Sciences Review, 21(3), 2009.