Valeria

Allen Tijerina
BIOL 3413 102 - Introduction to Genetics
Texas A&M International University
Drosophila Melanogaster Report
Dr. Michael R. Kidd
Fall 2009

Genetic Crosses & Mutations in Drosophila Melanogaster
Drosophila Melanogaster is a small fruit fly that is commonly found in rotted fruits. It comes from the family Drosophilidae and this species is frequently used forlaboratory purposes such as Genetics, Evolution, and Physiology studies. Drosophila was first study by the biologist Thomas Hunt Morgan in the 1900’s. Morgan was the first to discover sex-linkage, epistasis, chromosome genetics, development, behavior, and evolution (Pierce, 2008, p.84). Due to this discovery all the geneticists from now a day’s use this small fly to make their experiments. This is one ofthe most amazing and few organisms whose entire genome is known and many genes have been identified. One of the advantages of the D. Melanogaster is that it will complete an entire generation in about 10 days at room temperature and so several generations can be study in a few weeks (Pierce, 2008, p. 84).
One of Mendel’s law is the Law of dominance which consist when mating occurs between twoanimals or plant differing in some character, the offspring frequently exhibit the character of one parent only, in which case that character is said to be “dominance” (W.E. Castle, 1903). Mendel’s second Law is known as Independent Assortment which consists of alleles at different loci separate independently of one another (Pierce, 2008, p. 49). Another of Mendel’s law is the Law of Segregationwhich consists of individual diploid organisms that possesses two alleles for any particular characteristic.
The objective for this experiment was to mate the D. Melanogaster and gain an understanding of the life cycle of the fly, an insect which exhibits complete metamorphosis. Another is to construct crosses of caught and known wild- type and mutated flies. Also to examine how geneticinformation is transmitted from one generation to another, that is transmitted trough gene transmission, and to test Mendel’s hypothesis of the 9:3:3:1 ratio of inheritance. Finally, learning techniques to manipulate flies, sex them, and keep constant journal notes. In hypothesis the Mendel’s Laws are as followed because of the change in ratios.
As mention before the flies are the most commonly usedanimal for laboratory purposes because of their rapid growth and their easy morphology identification. First of all, two plastic vials need it to start the experiment. The professor is going to provide the media and yeast for the class so both of those ingredients are placed at the bottom of the plastic vials starting with the media then following with two or three grains of yeast and add water untilthe media is wet but not soaked in water. From there get the virgin females flies and just double check they are females using a microscope and getting a second opinion of your fellow classmate, but before that the Fly Nap is need it so the flies can be transferred from one plastic vial to the next. Using the Fly Nap is a very easy and fast procedure. It is performed by introducing the cotton swabin the bottle, once it’s soaked with the fly nap liquid it is placed inside of the vial without completely taking off the sponge cap. Then the vial is placed parallel to the table to avoid the flies sticking to the bottom of the vial. Fly Nap will anesthetize the D. Melanogaster in 30 minutes. After certain amount of time they are ready to be moved or studied under the microscope. If by anychange the liquid is released or spilled some steps are need it to be taken. Ventilate area of spill, eliminate all sources of ignition, and remove all non-essential personnel from area, clean-up personnel should wear proper protective equipment and clothing, and finally absorb material with suitable absorbent and containerize for disposal. The laboratory procedure was the removed of parental (F1),...