Secrets of a Drosophila Researcher: Things You Might Not Know About Working with Fruit Flies

After my semester of avoiding a transformation into a were-rat, I applied to a Drosophila melanogaster genetics lab. I liked it so much I stayed for two summers and two full school years, until I graduated. Here are some secrets about Drosophila research that everybody who works in a fly lab knows.



1.  You sometimes see flies in your sleep. Yep, it’s true. So many Drosophila researchers who I have spoken with occasionally see them in their sleep. A fellow lab tech called them “fly nightmares”. I wouldn’t say they were exactly nightmares.  For me, they were more like dreams where you find yourself counting red or white-eyed flies in your field of view. Just like you spend a lot of time doing when you’re actually in the lab.



2.  You have to learn how to distinguish between virgin and non-virgin flies. No, they don’t wear little scarlet letter A’s on their thoraxes. Virgin flies are young female flies who are lighter in color than the other older flies and may really only younger by a number of hours. Every morning when I came into lab and every afternoon before leaving, I would “virgin”, meaning I went through the vials with the type of female flies I wanted and look for the young females and save them to mate with the males I also selected.  Why do we care about virgin flies?  Once female adult flies emerge from their pupae cases, they have a certain number of hours before they will start mating with their brothers or other males in their vial. If you cross a non-virgin female with the desirable males in a new vial, the non-virgin female will produce some offspring that are NOT from the desirable males, which can really mess up your results!


3.  Fly experiments require patience and a lot of organization. Organizing my data and keeping track of everything was definitely one of the most challenging parts of working in the fly lab for me.


The life cycle of the fly at room temperature is about 10 days.


Here is a sample experiment timeline:

  • Mate approximately 4 virgin females from strain 1 and 9 males from strain 2 on day 0, per vial.  Depending on your experiment, you might need about 10 vials, so 40 virgins and around 90 males.  They then lay eggs all over the inside of the vials after they mate.
  • On day 7, remove the parents so you don’t confuse them with the offspring when they start to emerge.
  • On approximately day 10, adult offspring begin to emerge from their pupae cases.
  • From these adult offspring, start to collect virgin females each day for the next mating step in the process. Stop collecting before day 20.
  • Start the process all over again with the next generation.

So if your experiment requires 3 different generations to produce the fly you want to study, it may take you 30-45 days… and that’s an underestimate!


4.  Flies do get everywhere. There are occasional stray flies that can be found wandering around the lab.  They do land on you occasionally, but they aren’t annoying like houseflies or crazy giant biting flies on the “Joy-sey” Shore.  Drosophila most resemble the tiny tiny fruit flies you see buzzing around the onions at Wegmans.  Drosophila are totally harmless.  You just get used to it.  They do get in your hair and occasionally travel home with you from the lab.  Your roommates may strongly dislike that you work in a fly lab.  Every once in a while, I’d hear “BETHANY! A FLY AGAIN!” from the other side of my apartment and I knew I had a stowaway.


My reaction: At least they don’t bite.


In my next post, I will be writing about the science behind working with Drosophila and what makes them totally unique, so come back soon to read it!
Post-it Note Clipart by Teachers Resource Force 


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