Flies reveal crucial knowledge of medicines, diseases and the consequences of climate change

Among the insects that the researchers study are houseflies and fruit flies whose short life cycle makes them particularly suited for generational studies and studies with large populations.

- “Our laboratory facilities here are uniquely suited to our work. We have a number of excellent climate test cabinets that are central to our work, in which we can control temperature, humidity and light in very exact detail, and we have a number of machines where we can test the cold and heat resistance of the flies. We have a flywheel where we can suspend a fly and study how far it can fly in a day, and we have molecular-biology equipment that lets us study the DNA and the microbiome of the flies. Altogether, this gives us some very unique opportunities for studying the flies’ behavior and evolution in a wide variety of contexts and for a wide variety of purposes” Simon Bahrndorff explains.  

In addition to the advanced laboratory facilities, Torsten Nygård Kristensen also emphasizes the unique collaboration across the department as adding value to the researchers’ work:

Fruit flies help improve treatment of mental illnesses

One of the projects currently taking place in the labs in Aalborg may in the future become an important stepping stone for optimized treatment of people with mental illnesses. Torsten Nygård Kristensen explains:

- “We have recently initiated a project in which we are going to use fruit flies as a model for human mental illnesses. Humans and fruit flies are actually very much alike genetically – 75% of all known genes that have been identified as connected to mental illnesses in humans are present in fruit flies as well. This means that we can work with those genes in the flies – either duplicate the genes or knock them out so they don’t function – and see how this affects the flies’ behavior. This enables us to study whether having a specific type of gene makes our flies react in a certain way to a specific type of medicine” Torsten Nygård Kristensen says. Through these experiments, the researchers get results that may aid the development of personalized medicine for mental illnesses including schizophrenia and ADHD.

“We hope that the identification of the genes that cause positive – or negative – reactions from specific medicines will be useful for the future development of targeted medicine. Since it can be used as a pointer towards how human patients will react to these medicines, it may serve to improve their treatment – and their lives – markedly” he adds.

Mapping dissemination of diseases through houseflies

Another major project that the researchers at Aalborg University are currently working on is applying knowledge on stress biology – including how organisms react to being subjected to a variety of bacteria – on identifying the role of houseflies in the dissemination of Campylobacter bacteria in chicken farms.

- “If we consider a bacteria such as Campylobacter, which is fairly infamous from being found in chicken meat, it has turned out that the housefly plays a major role in the dissemination of this bacteria from A to B – for instance into chicken farms. We have been out in the field to gather flies at different locations in Denmark, and have subsequently looked at questions like, how does the fly move from A to B, and are there patterns to how they travel? In essence, we have looked at the genealogical tree of the flies to determine which farms or areas they stem from” Simon Bahrndorff explains and adds:

- “Recently, we have also started looking at the microbiome of the flies to map exactly what kinds of bacteria are present in them. We use this to study how the microbiome affects the flies’ ability to carry – and spread – bacteria. In this work, we are performing bacterial transfers among flies by extracting the colon of one group of flies, dissolve them in a suspension of sugar and feed it to another group of flies. If it turns out that we can make a healthy fly sick or vice versa, we will have a model system that will let us test a wide variety of things concerning the dissemination and potential control of these bacteria. We will also be able to identify the microbiomes of flies that are not affected by the bacteria – and even those that, when transferred, enable a sick fly to fight the bacteria and get better.”

In a Danish context, this knowledge can be used to map – and, most importantly, limit – the dissemination of Campylobacter bacteria from one chicken farm to another, but the researchers are also currently working with an Ethiopian PhD student who is using the techniques to map out the spread of diseases such as chlamydia in Ethiopia.

- “Being able to look at these things was unthinkable just 20 years ago, but now we can go out in the field, catch a fly, study its DNA and at the same time map out all the bacteria on and get an idea of where it comes from and what role it might have in the dissemination of this or that disease. It is quite fascinating, and the potential applications of this knowledge, and the technology itself, are quite extensive” Simon Bahrndorff says.

Insects revealing the effects of climate change

The researchers’ close study of the stress biology of insects has also brought them into one of the current major issues: How nature – and the Earth as a whole – will react to the climate changes we are currently seeing. Through collaboration with a variety of partners, the researchers have gained access to insects from the Arctic. This gives them a unique opportunity to study how these insects react and adapt when subjected to either higher temperatures than they are used to or more extreme or frequent temperature fluctuations – and get an indication of how the climate changes may influence the location of the natural habitats of these insects.

- “This knowledge can be applied in a range of practical contexts. Consider for instance the dissemination of diseases through mosquitos. In that specific case, it is important to know whether we will be subject to a variety of new diseases in the future because mosquitos move further north due to a warmer climate. And of course the Artic is subject to some very major changes at the moment, that may have a huge impact on a wide range of species, large and small alike” Simon Bahrndorff explains and finishes: