‘One of science’s most important species’: how the humble fruit fly changed 4 fields of research

The common fruit fly (Drosophila melanogaster), aptly called the vinegar fly, is a frequent visitor to ripe fruit in homes around the world, often laying eggs in rotting flesh undetected. We’ve probably all eaten different body parts of fruit flies – with no known consequences.

But the fruit fly is not just an annoying house guest.

Actually, Drosophila melanogaster has been one of the most important forms of science for more than a century.

If it weren’t for these flies, some of the most important scientific discoveries would never have been made.

The origin of the fruit fly

This species originated in the forests of south-central Africa, where it relied heavily on marula fruits. These fruits were – and still are – part of the human diet in this area as well, which leads to fruit flies establishing a relationship with human communities and habitats.

Over time, this friendship would lead to fruit flies first spreading across Africa, then to Asia, Europe and – centuries ago – North and Central America and Australia.

It is important to differentiate Drosophila melanogaster and its close relatives from the larger and more colorful “true” fruit flies, several of which are found in Australia.

Also called tephritid flies, they attack fruit before it rots. Millions of dollars have been spent (in the end to no avail) to try to keep them out of parts of Victoria and South Australia.

Drosophila Flies are abundant in some areas, with clouds appearing on piles of rotting fruit in wineries, stone fruit orchards and banana plantations at harvest time. However, these cases are rare and the fly is not considered a rare pest.

It is naturally suitable for science

While many non-destructive insects receive little scientific attention, house flies are an exception.

Some of the things that make fruit flies a member of popular research are natural. They are small, easy to eat, have a fast life cycle and can produce hundreds of offspring.

However, today’s findings Drosophila melanogaster researchers also owe much to decades of genetic engineering development.

These allow us to create almost any gene we desire. For example, we can change the sequence of the vinegar fly gene so that the protein it encodes becomes fluorescent. We can even take genes from other things and study their effect on fruit flies.

Taken together, these facts help explain why the fruit fly has played a major role in four areas of research in particular.

1. Understanding genetics

The fruit fly has a long history of use in genetic research and education.

It was in Drosophila melanogaster that the genes were found to be integrated into the chromosomes, in crosses between red-eyed and white-eyed mutant flies. Although this research was done more than a century ago, such crosses are still a powerful way to show the principles of inheritance.

The fruit fly also remains a powerhouse for biological discovery. Its genome was sequenced in the 1990s. This was done in part as an experimental test to synthesize human genes, but also to allow genetic comparisons across animals.

Many vinegar genes show clear associations with specific human genes, including approximately 65% ​​of genes associated with human disease. This allows research on processes from embryonic development and disease progression to education and aging to be carried out in the vinegar fly.

2. Understanding tissue damage

Animals vary greatly in their ability to regenerate damaged structures. For example, if you cut flatworms in half, both parts can regenerate the whole body.

Although impressive, these do not provide a good example for the moderate – but still important – ability of humans to heal wounds. Fruit flies, which like humans are made up of many complex cells, have been instrumental in mastering the molecular interactions that allow cells to migrate and link together to repair tissue damage.

Perhaps surprisingly given their short lifespan (no more than a few months even under the right conditions), fruit flies are also a popular model for cancer research.

They provide an alternative to traditional cell-based methods for evaluating the effectiveness of chemotherapeutic drugs, which will not reflect problems with how the tumor interacts with surrounding cells, and most popular when evaluating the effectiveness of chemotherapeutic treatments.

3. Understanding disease control

In addition to providing tools and understanding of biology applicable to medicine and biology, Drosophila melanogaster directly contributed to disease control.

In particular, Wolbachia bacteria isolated from this strain are used to prevent the transmission of dengue and other mosquito-borne human diseases.

The pressure of Wolbachia living in the cells of fruit flies and transmitted from mother to offspring was transferred by microinjection to Aedes mosquitoes.

The Wolbachia bacteria interact with viruses by preventing the accumulation of the virus in the mosquito’s salivary gland.

This work has already prevented many cases of dengue infection in northern Australia and many countries overseas.

4. Understanding evolution

Finally, fruit flies provide useful experimental methods for investigating evolution, especially in the context of endangered species conservation.

This work established the importance of maintaining genetic diversity in endangered species to maintain their ability to evolve and prevent the effects of disease and climate change. The number of fruit flies in the field is now being monitored to see if this species is adapting to the hot and dry conditions we are experiencing.

So this summer, take a close look at your fruit bowl and see if you can spot a small brownish yellow bug flying around.

Then remember all the ways Drosophila melanogaster it has contributed to our well-being. You might like it instead of reaching for that canister of fly spray.