Science Buddies: "Ask an Expert"

I am a highschool student conducting a research project on calorie limitation and its effects on the lifespan of drosophila. Through my research, I have found that the normal diet of drosophila is rotting fruit - therefore, sugar and the yeast that ferments it. As far as calorie limitation goes, I plan to limit the drosophila to half of its normal sugar intake, and the normal amount of yeast, and vice versa. In addition to those two experimental groups, I plan to have two control groups - one group with the normal diet and a second group with no food at all. The two control groups will serve as my baseline, based on which I may make comparisons and draw conclusions. Because I am testing the effect on the amounts of food and what is the limited factor, I am testing each drosophila separately (in separate test tubes). To do this, I need to know quantitative amounts of sugar and yeast per drosphila. The trouble I am having is HOW MUCH sugar and yeast is in the normal diet, and without those numbers, I don't know how much to limit them in my experimental groups. Any suggestions on qualitative amounts of yeast and sugar ?

Hi!
I did a quick google search and I came up with a few articles that may not be exactly what you're looking for but they might help to give you a rough idea of the amt. of sugar and yeast drosophila consume-
http://www.pubmedcentral.nih.gov/articl ... id=1140681
http://biology.plosjournals.org/perlser ... 30223&ct=1 --> look in materials and methods, life span experiments section
Hope this helps, good luck with your project!

Hi,

This is a great project because it's one of the "hot" research topics right now! I just have one suggestion regarding your controls. Maybe I misunderstood what you wrote, but if you have one control group receiving no food at all, then won't those flies just die since they have nothing to eat? Instead of having no food at all, perhaps you could have a group receiving half the sugar and half the yeast.

Have fun with your project!
Grace

Thats one of my controls too, the group that i'm not feeding at all is too see how long they will last without food. But i AM having a group with half the sugar and standard yeast, and vice versa as well.

From the site of the first reply, I found this:
The standard restricted diet had equivalent amounts of yeast and sugar (65 grams each) and an estimated caloric content of 521, while the yeast-restricted (65 g yeast/150 g sugar) and sugar-restricted (65 g sugar/150 g yeast) diets each had just over 860 calories. The control diet for the flies had equivalent amounts of sugar and yeast (150 grams), amounting to an estimated 1,203 calories.


Is that for every ONE drosophila?

Hi!
I believe that is for one fruit fly..at the following site, I found a graph showing the amount of calories-
http://www.pubmedcentral.nih.gov/articl ... id=1140680
Hope this helps, good luck!

Hi
you must be aware that the fruit flies are canibalist. and they can eat the dead body of other flies. and their life cycle had been found out. that means you don't need the second control.
kamran