
Dr Rachel McMullan
Senior Lecturer In Health Sciences
School of Life, Health & Chemical Sciences
Biography
Professional biography
I completed my PhD in Biosciences at The University of Birmingham in 2003, studying the role of Rho small GTPases in keratinocyte function. Following this I undertook a postdoc at the MRC Laboratory for Molecular Cell Biology investigating the function of Rho family small GTPases during neurotransmitter release in Caenorhabditis elegans.
In 2010 I became a Wellcome Trust Career Development Fellow at Imperial College using C. elegans to study the relationships between the nervous and immune systems the mediate responses to infection.
I joined the School of Life, Health and Chemical Sciences in 2015 as a lecturer.
1999 BSc Biochemistry and Molecular Cell Biology The University of Birmingham
2003 PhD Biosciences The University of Birmingham
Research interests
Disgust
The constant risk of infection by pathogens has driven the evolution of behavioural adaptations in free-living animals that helps them to reduce pathogen contact. Such pathogen avoidance behaviours are observed across Animalia, from invertebrates to mammals. In humans, the emotion that serves to keep us away from sources of infection is disgust. This pathogen avoidance theory of disgust (PAT) is supported by strong correlations between disgust elicitors and pathogen sources. Given the many parallels between human disgust and pathogen avoidance behaviours in other animals we can begin to understand disgust through experimental studies of pathogen avoidance in animals.
Twin studies have shown that disgust sensitivity is heritable implying the existence of ‘disgust genes’. The nematode worm Caenorhabditis elegans is routinely used as a genetic model to dissect complex behaviours. We and others have established C. elegans as a cost-effective invertebrate model of disgust that can be used to determine the function of specific genes in disgust. This model provides a platform for further investigations into the evolutionary role of disgust in host defence.
Unravelling the genetic basis of disgust-related behaviour could have numerous practical benefits. Disgust can be leveraged to improve health and influence social behaviours. It may lead to new therapeutic approaches to disgust-related pathologies such as contamination-based obsessive compulsive disorder (OCD), some phobias including blood- injection-injury phobia and arachnophobia and trypophobia.
The effect of organophosphate exposure on neuronal function and its role in mood disorders
In collaboration with Dr Gini Harrison (Psychology)
Previous research has reported a link between exposure to organophosphate (OP) pesticides, mood disorders and suicidal behaviour. The mechanism through which OP exposure may result in mood disorders is unclear. Some researchers have suggested that they may also cause changes to serotonergic and dopaminergic pathways, which are systems involved in mood and stress regulation. Using behavioural assays in C. elegans we are studying how the long-term, low level OP exposure that has been associated with mood disorders affects neuronal development and function.
Selected Publications
2018
Sarabian, C. Curtis, V. and McMullan, R. Evolution of pathogen and parasite avoidance behaviours
Philosophical Transactions of the Royal Society B: Biological Sciences, 373, Article 20170256(1751)
2014
Anderson A. and McMullan R. From head to tail it's a two way street for neuro-immune communication Worm 3(3) e959425
2013
Anderson A, Laurenson-Schafer H, Partridge F, Hodgkin J, McMullan R. 2013, Serotonergic Chemosensory Neurons Modify the C. elegans Immune Response by Regulating G-protein Signalling in Epithelial Cells, PLOS Pathogens Vol:9(12), e1003787
Anderson A, Kang S, McMullan R, 2013, A simple method for quantifying M. nematophilum clearance from the rectal opening of C. elegans, Worm Breeders Gazette, Vol:19 (4), Pages: 15-16
Anderson A, McMullan E, 2013, A modified leaving assay to study pathogen avoidance, Worm Breeders Gazette, Vol:19 (4), Pages: 13-14
2012
Anderson A, McMullan R, G-proteins: Fighting infection on two fronts, Worm, Vol:1, ISSN:2162-4046, Pages:196-201
McMullan R, Anderson A, Nurrish S, 2012, Behavioral and Immune Responses to Infection Require G alpha q- RhoA Signaling in C. elegans, PLOS Pathogens, Vol:8, ISSN:1553-7366, Pages:e1002530-e1002530
Teaching interests
Currently teaching on the following modules;
SK320 Infectious disease and public health
S350 Evaluating contemporary science
Impact and engagement
I am currently the engagement and enterprise lead for the School of Life Health and Chemical Sciences, a STEM ambassador and Nuffield placement provider.
I have been a competitor in "I'm a scientist get me out of here" (2015) and presented at a number of science festivals including the 2018 Northen Ireland Science Festival (Yuck, that's disgusting) and the 2016 Cheltenham Science Festival ("The Disgust Instinct" with Valerie Curtis (London School of Hygiene and Tropical Medicine)).
I run a range of primary school outreach activities including 'how clean are your hands?' and 'yuck, that's disgusting'.
Find out more about my recent talk at RSC Science and the Assembly 2017 here
In 2017 I organising the Royal Society Evolution of Pathogen and Parasite Avoidance meeting. You can listen to the presentations here.
Papers accompanying the meeting were published in a themed issue of Philosophical Transactions of the Royal Society B in 2018
External collaborations
Projects
Fleming Fund Grant Extension 2, to 31 Dec 2023
In October 2021 the Open University completed delivery of the second Global Learning Fleming Grant. It developed 25 online modules (OLCreate: Tackling antimicrobial resistance (open.edu)) and a toolkit (OLCreate: PUB_4849_1.0 Tackling antimicrobial resistance: the AMR surveillance toolkit (open.edu)). These are designed to promote greater understanding of AMR surveillance and the improvement and application of skills among AMR professionals, especially in Fleming Fund countries. The online modules and toolkit remain available on the Open University Open Learn platform beyond the end of the grant. Mott MacDonald and the Department of Health and Social Care asked OU to deliver this project's cost extention to provide monitoring data and associated analysis to monitor uptake of the modules and the toolkit. The data is to be disaggregated by module, pathway, AMR Toolkit and survey data. New contract Outputs: 1. Agree data reporting format with Mott MacDonald 2. Supply monitoring information and analysis throughout the contract period 3. Run quarterly data reports and carry out essential analysis as needed 4. Provide the data on a quarterly basis, by the 10th of the month following the end of the quarter. Simple table formats will suffice 5. Be prepared to have a brief phone call about the data each quarter in case of any queries 6. Take part in a review meeting in Q4 (Oct-Dec 2022) to discuss findings from the data and next steps
Fleming Fund Phase 2
Phase II of the Fleming Fund is further support to Fleming Fund countries to build-upon and advance the achievements of Phase I. Investing in similar areas, the programme focusses on four outcomes: 1. Production of quality AMR/U/C and burden data 2. Quality analyses of data 3. Sharing analyses and data with decision-makers 4. Promoting sustainable investment to counter AMR Phase II includes a programme of four grant streams: 1. Country Grants - To support implementation of quality assured national surveillance programmes for AMR/U/C and burden using a One Health approach and in line with Fleming Fund principles and National Action Plans; to provide coordination with other grant streams and with Government and other stakeholders; to work towards data and evidence use in policy and practice in human health, animal health and food production, food safety, and the environment; and to promote sustainability, primarily through resource mobilisation. 2. Fleming Fellowship Scheme Grants - To provide continual professional development and leadership opportunities for fellows to improve capabilities for production, analysis and use of data within the surveillance system. 3. Regional Grants – To provide technical assistance at a multi-country level to support and improve key technical functions for AMR surveillance systems in the production, analysis and use of data. 4. Strategic Alignment Grants – Grants that are used to take advantage of opportunities as they arise during the Phase II programme, under the principles of adaptive management.
Genetic analysis of post-developmental Rho GTPase signaling: identification and characterization of Rho signaling pathways required during the C. elegans immune response. (Transfer In)
Rho signaling has been extensively studied using biochemistry and cell-based assays that have demonstrated roles for Rho in many basic cell functions. These studies have told us a lot about the functions of Rho, however little about their importance in a whole animal. Rho signaling is essential during development making it difficult to study Rho’s role in adult animals. Analysis of adult Rho signaling pathways is important because aberrant signaling by these pathways has been implicated in human disease. In this study I aim to define the Rho pathways that act in adult animals. In particular I will identify those pathways that trigger changes in cell morphology as part of the C. elegans innate immune response. By identifying effectors important for this phenotype we will better understand Rho’s role in controlling cell morphology in adult animals. The innate immune system is evolutionarily conserved, for example, both Rho and MAPKinase function in the mammalian immune system and this is also true in C. elegans. In addition cross talk between Rho and MAPKinase pathways has been suggested to contribute to the action of oncogenic Ras. The molecular interactions that mediate this cross talk and Rho’s activation during the immune response remain poorly described and this phenotype provides a genetic model to dissect them. Defining these pathways and the relationships between them in C. elegans is likely to tell us more about how they are involved in innate immunity and misregulated in diseases such as cancer.
Publications
Journal Article
The effect of the COVID-19 pandemic on disgust sensitivity in a sample of UK adults (2022)
Evolution of pathogen and parasite avoidance behaviours (2018)
From head to tail it's a 2 way street for neuro-immune communication (2014)
G-proteins: fighting infection on two fronts. (2012)
Behavioral and immune responses to infection require Gαq - RhoA signaling in C. elegans. (2012)
The RHO-1 RhoGTPase modulates fertility and multiple behaviors in adult C. elegans. (2011)
The Gα12-RGS RhoGEF-RhoA signalling pathway regulates neurotransmitter release in C. elegans (2006)
Keratinocyte differentiation is regulated by the Rho and ROCK signaling pathway (2003)
Other
Work-based learning interventions for antimicrobial stewardship: a systematic review (2023)
Presentation / Conference
A putative C. elegans melatonin receptor is required for efficient pathogen clearance (2016)