The study of Genetics could have not been possible without the use of common fruit fly, Drosophila melanogaster. Scientists have depended on the use ofthis organism because it has a very short generation time of at least 10 days at 25oC with the ability to yield large amount of breeding data in a very short time. Furthermore, scientists prefer Drosophila melanogaster because it is easy to feed them due to a variety of foods they eat and also they are generally easy to handle while in the laboratory. They are therefore less costly in maintaining while a study is taking place.
For the experiments to follow, structural recognition of adult organism especially sexual differences will be very important. Head, thorax, abdomen and the mouthparts especially the unique proboscis, the feather like antennae (aristae) and the compound eyes that are attached to ommatidia which are special facets to hold the eyes in place (singular ommatidium) will be studied.
Drosophila melanogaster’s eggs are approximately 0.5 millimeters (mm) in length having special filament that help them to float in soft foods that they are usually laid. Their larvae survive by barrowing into the food and continue eating to grow and shed their outer protective cuticle through two molting stages called instars to finally achieve 4.5 mm in length. Upon completion of the second molting, the larvae moves from the food and form dark cocoon where they spend about four days at 25oC to finally reach their adult stage.
The new adult is usually pale in color and difficult to distinguish between the male and female. Their wings are usually crumpled but expand to full size and adult coloration is visible after a few hours. Sex maturity takes about six hours after hatching. Female fruit flies remain virgins for these six hours but mate freely thereafter. Therefore, while conducting the experiment it is important to separate the flies before or after birth so that planned mating can occur in the course of the experiment. Females that have stayed with males for more than six hours are excluded from the experiment because they may have probably mated with the males in the container.
This study was aimed at determining the mode of inheritance of a specific mutant phenotype. We observed that our mutant flies exhibited a mutant characteristic in eye color. Specifically, the mutant flies displayed a white-eyed phenotype as compared to the wild type flies which had a red-eyed phenotype.
In our flies, we had anaesthetized them so we were able to examine them under a microscope. We used flynap, to anaesthetize the files, which alloed the files to sleep for a little time so we can view them.
In order to observe the flies, we had to first anaesthetize them so they were able to be examined under a microscope. To anaesthetize the flies we used FlyNap which allowed the flies to sleep for an appropriate amount of time while viewing them. To effectively use FlyNap, we obtained the dedicated FlyNap vials and transferred the flies we wanted to examine to these vials. In order to transfer the flies without allowing any specimen to escape, we opened our vial of flies and immediately placed the FlyNap vial over the opening. By placing the FlyNap vial on top of the fly vial, most of the flies crawled up into the FlyNap vial. For any flies left in the original fly vial, we had to invert the vials and gently tap on the original fly vial to transfer the rest of the flies. After all of the flies had been transferred, we took the FlyNap vial off of the original fly vial and immediately covered the opening of the FlyNap vial with a foam plug. Once the foam plug was firmly in place, we used a small brush to dip into the FlyNap and carefully inserted the brush into the FlyNap vial. After a few minutes the flies became anaesthetized and were able to be observed.