Day 1: Introduction and WAY too much information

If you're here because you're my AP Biology teacher, I hope this meets your standards. If you're here because you read my real blog, you might want to go back there. And if you just loooooove fruit flies? I highly recommend you seek psychiatric help.


Classification: Drosophila melanogaster
In Drosophila melanogaster wing type is controlled by an autosomal or non-sex-linked gene. Flies having the dominant gene for normal wings (V) would have either a VV or a Vv genotype. Flies with normal wings have fully developed wings and are able to fly. Those having no dominant (V) gene would have vestigial wings and would have a vv genotype. Flies with vestigial wings have nothing more than vestiges or degenerated elements of wings and are unable to fly. However, they can still jump and run quite well. The inheritance of these traits follows the simple rules for alleles having a dominant - recessive relationship with the sex of the fly having no influence.

Eye color is controlled by a sex-linked gene. More specifically, this gene is X-linked in Drosophila melanogaster. Male flies with red eyes having the dominant gene for red eyes will have an XWY genotype. Female flies with red eyes having the dominant gene will either have an XWXW or XWXw genotype. Male flies with white eyes (the recessive trait) will have an X wY genotype. Female flies with white eyes will have an XwXw genotype. Remember that in Drosophila melanogaster males are heterogametic and females are homogametic. Eye color in Drosophila melanogaster is actually controlled by multiple alleles, however, we are only examining the most dominant (red) and most recessive (white) alleles in the allele dominance heirarchy. Because the genes for eye color are X - linked, the sex of the fly has a definite bearing on the frequency of the red and white phenotypes in males and females. Remember to use the W (red) and w (white) symbols as superscripts on your X symbols in order to account for this fact.

These flies were used by Thomas Hunt Morgan to study inheritance.
The fruit fly culture is completely self-contained and needs no cleaning or special care.

Larvae will continually pupate from eggs laid by the adults in the culture. It is important to keep at least 25-50 adult flies in the culture. These adult flies will be busy laying more eggs and ensuring that you will have a successful and constant supply of flies. It is best to keep the fruit fly culture at room temperature (around 70° F). The higher the temperature, the higher the bacterial growth. But, you may want to raise or lower the temperature to control the lifespan of your culture. Optimum reproductive rate occurs at temperatures of approximately 80� F. At around 60� F, reproductive rate slows, thus allowing longer feeding time and longer use from a single culture. 

1:1 ratio is necessary for food media.