Experiment

On Day 1 we conducted hands on experiments to go through the whole process of breeding fruit flies (drosophila). In summary, these are the things that we did:



1. Make fly food
We were told that the ingredients for making the fly food were mainly agar powder, milo powder, mashed bananas, vinegar and yeast. For our very first try, we first poured vinegar into a cup, then added milo powder and agar powder and stirred until the mixture curdled up and was adequately moist for the fruit flies to feed on. The food was also to be the medium in which the flies lay their eggs.



2. Anesthetize the flies
In order to investigate heredity (the passing down of genetic information) in fruit flies, we had to seperate them into males and females. But to do that, we had to anesthetize the flies in order to analyze their physical characteristics. We dipped a cotton bud into a vial of FlyNap, knocked the containers containing the flies on the table to prevent the flies from escaping, and removed the cotton wool enclosing the vials just a fraction in order to insert the cotton bud. All the flies were "knocked out" in just a matter of minutes.





credits of https://www2.carolina.com/webapp/wcs/stores/servlet/CarolinaBio/images/medium/173010_d_gen.jpg



3. Sex the flies
To sex the flies means to seperate them into them males and females. We first tipped the unconscious flies onto a piece of paper,moving them around carefully using a brush to avoid kiling them, and, analyzing them one by one under a microscope, seperated the males from the females. Using our knowledge of the physical features of the males and females, we were able to do so. The males had sex combs on their legs while the females did not. The males had rounder, shorter and darker abdomens than the females. Also, the males were comparatively smaller than the females.



taken from http://www.berkeley.edu/



4. The breeding itself
We put one identified male and female fruit fly into another seperate container containing the previously prepared fly food. We then capped the container with a plastic lid and poked holes in it to enable the fruit flies to breathe. Then all we had to do was to wait for the fruit flies to wake up from the effects of the anesthetic and breed.