Mental Floss

15 Fascinating Facts About Fruit Flies

Jordan Rosenfeld|
John Tann via Wikimedia Commons // CC BY 2.0
John Tann via Wikimedia Commons // CC BY 2.0 | John Tann via Wikimedia Commons // CC BY 2.0

The common fruit fly, Drosophila melanogaster, may seem like nothing more than a nuisance when your fruit gets too ripe, but medical research owes a great deal to this tiny little menace. Here are 15 fascinating facts about our fruit-loving buddies:

1. THEY LIVE AND DIE QUICKLY.

The fruit fly has a very rapid life cycle. Just one fertile mating pair can produce hundreds of genetically identical offspring within 10 to 12 days, so long as the temperature is at 25°C or higher.

2. YOU CAN THANK THE FRUIT FLY FOR MANY MAJOR MEDICAL BREAKTHROUGHS.

Because of these comparatively short life spans, fruit flies make for ideal lab subjects: Researchers can easily study genetic evolution over generations. By comparison, what scientists have learned about fruit flies in 30 years of study would have taken 200 years in mice. So for more than a century, fruit flies have been the stars of genetic research.

3. FRUIT FLIES HELPED SCIENTISTS DISCOVER GENETIC BASICS.

Thomas Hunt Morgan was one of the first to systematically study fruit flies at the turn of the century. Morgan was the first to confirm the chromosomal theory of inheritance—in essence, that genes are located on chromosomes “like beads on a string,” and that some genes are even linked, or inherited together. This work won Morgan the Nobel Prize in Physiology or Medicine in 1933.

4. THOUGH THEY'RE SMALL, FRUIT FLIES HAVE MANY GENES …

To put in context just how many genes fruit flies have, humans have 24,000 genes. Fruit flies, which are only a couple of millimeters long, have 14,000.

5. … WHICH COULD STILL TEACH US A LOT.

Scientists successfully sequenced the entire fruit fly genome in 2000. According to the Human Genome Project, “During the last century, fruit flies have yielded a wealth of information about how genes work. They have been used to discover the rules of inheritance and to study how a single cell, the fertilized egg, becomes a whole animal.”

6. HUMANS AND FRUIT FLIES ARE GENETICALLY SIMILAR.

A whopping 75 percent of the genes that cause diseases in humans are also found in the fruit fly. But don’t worry, you’re unlikely to reprise the horror flick The Fly anytime soon.

7. THAT'S WHY FRUIT FLIES CAN MODEL HUMAN DISEASE.

Because they have many of the same genes as humans, researchers can use fruit flies to simulate diseases that plague humans. For example, flies eating a lot of sugar also exhibit symptoms of type 2 diabetes. Researchers can also genetically modify fruit flies to study a variety of other conditions.

8. HOW DO THEY KEEP THEM FROM FLYING AWAY?

Researchers make fruit flies woozy with carbon dioxide before they let them out of their test tubes for study; otherwise, they’d wing off.

9. FRUIT FLY CHROMOSOMES RESEMBLE BARCODES.

Drosophila have polytene chromosomes, or barcode-like banding patterns of light and dark. This makes it easy for scientists to assess genetic rearrangements and deletions.

10. THE FEMALES STAY BUSY.

A female fruit fly lays 30 to 50 eggs per day throughout her lifetime at room temperature. When it’s cold, she may produce far fewer eggs.

11. SMALL INSECT, BIG BRAIN.

The brain of the adult fruit fly has more than 100,000 neurons that form discreet circuits and “mediate complex behaviors, including circadian rhythms, sleep, learning and memory, courtship, feeding, aggression, grooming, and flight navigation,” according to one study.

12. THEY DON'T JUST HELP MEDICINE: FRUIT FLIES ALSO MAKE YOUR BEER TASTE BETTER.

Fruit flies are masters of discernment when it comes to the yeasty flavors of beer. An experiment at Stanford found that fruit flies were attracted to beers with fruitier base yeasts, which tend to be the beers humans prefer as well.

13. FLIES SELF-MEDICATE WITH ALCOHOL TOO.

Sexually rejected male fruit flies also drown their sorrows. As reported in a study in the journal Science, the reward circuitry of fruit flies' brains, as in humans, gets a pleasurable boost from drinking alcohol. What's more, they may turn to it for reasons similar to humans: to make them feel better. A study done at the University of California, San Francisco found that the male fruit flies who had been rejected by females drank four times as much alcohol as the mated flies.

14. FRUIT FLIES GET THE BEST DRUGS.

Drosophila’s versatility is often used as a model to test the effects of new drugs on the biochemical pathways that are conserved within both fruit flies and humans.

15. RESEARCHERS HAVE DISCOVERED A NEW HEALING MECHANISM, THANKS TO FRUIT FLIES.

Using fruit flies as test subjects, researcher Vicki Losick recently discovered that in wounds, cells enlarge by polyploidization—or the multiplication of chromosomes—to compensate for cells that are lost. This suggests that cellular damage caused by wounds either leads to cell proliferation or cell growth, depending on context, changing our understanding of how the body reacts to injury.