A scientific breakthrough at the University of Exeter promises not only to accelerate testing for antimicrobial resistance (AMR) but also to provide an ethical alternative to the controversial use of rodents in research. Scientists have successfully created the world’s first genetically engineered wax moths, a development that could significantly reduce the reliance on mice and rats in infection studies.
The study, published in Nature Lab Animal, details how researchers have developed advanced genetic tools for the greater wax moth (Galleria mellonella), a small insect increasingly recognized as a cost-effective and ethically sustainable alternative to mammals. Dr. James Pearce from the University of Exeter emphasized the urgency of the situation: “With AMR posing one of the biggest threats to human health, we urgently need faster, ethical, and scalable ways to test new research. Engineered wax moths offer exactly that – a practical alternative that reduces mammalian use and accelerates knowledge discovery.”
Revolutionizing Infection Research
The greater wax moth presents unique advantages over other non-rodent model organisms. It can be reared at 37 degrees Celsius, the same as human body temperature, and its cellular responses to bacterial or fungal infections closely mirror those of mammals. However, its use as a model organism has been limited by the lack of genetic tools—until now.
Exeter researchers have adapted technologies originally developed for fruit fly research to create fluorescent transgenic and gene-edited moth lines. Professor James Wakefield explained, “By putting new genes into the wax moth genome, we’re able to make larvae that glow in a controlled way. This paves the way for ‘sensor moths’ that light up when infected or responding to antibiotics – offering a living, real-time window into disease.”
Implications for Animal Testing
Sensor moths have the potential to transform early-stage infection studies by enabling rapid antimicrobial screening and immune response analysis without the need for mice or rats. The larvae’s response to human pathogens, such as the superbug Staphylococcus aureus or the opportunistic fungus Candida albicans, provides a realistic yet ethical bridge between cell culture and animal testing.
Dr. Pearce continued, “Our methods make wax moths genetically tractable for the first time. The ability to insert, delete, or modify genes opens huge potential, from understanding innate immunity to developing real-time biosensors for infection.”
Each year, around 100,000 mice are used in the UK for infection biology research. If only 10 percent of those studies were replaced with moths, over 10,000 mice annually could be spared while still generating robust, human-relevant data.
Collaborative Efforts and Future Prospects
This research builds on over five years of investment from the National Centre for the Replacement, Refinement, and Reduction of Animals in Research, in collaboration with the Defence Science and Technology Laboratory and the University of Exeter’s advanced imaging and genomics facilities. The Exeter team has made all methods openly available through the Galleria Mellonella Research Centre, which they co-direct.
The Centre now supports more than 20 research groups worldwide with training, wax moths, and data resources, standardizing and accelerating the global adoption of this powerful model organism. The paper titled ‘PiggyBac mediated transgenesis and CRISPR/Cas9 knockout in the greater wax moth, Galleria mellonella’ is published in Nature Lab Animal.
Looking Ahead
The development of genetically engineered wax moths marks a significant step forward in the quest for ethical research methods. As the scientific community continues to explore and refine these techniques, the potential to reduce animal testing while enhancing research efficiency and accuracy grows ever more promising. The University of Exeter’s pioneering work sets a precedent for future research, highlighting the importance of innovation and collaboration in addressing global health challenges.
