Even primitive organisms display principles of genetics.

The common Fruit Fly ( Drosophila melanogaster) is the most widely used animal for genetic studies.

A single female may lay as many as 500 eggs

Their small size makes them easy to store, yet they are large enough for rapid notation of phenotypes.

This fly is easily cultured and it takes only two weeks for a new generation at 21 0 C.

The Fruit Fly has been the subject of genetic studies since 1909 with Thomas Hunt Morgan.

Transparent plastic vials are used as culture vessels

We will use an instant medium formula for our experiments. Equal volumes of water and medium along with 5 grains of yeast are mixed in a vial.

Known mutations and locations of fruit fly mutant genes

Ebony body is a recessive mutation

This is the normal dominant wild type fruit fly

The parental cross will be homozygous ebony body flies (ee) with homozygous wild type flies (++)

There are four stages in the life cycle of a fruit fly.

Two days after emerging, a female can start laying eggs.

It is extremely important that all adult flies be removed from a culture 8 to 12 hours before it is used for the selection of virgin females.

FlyNap will be used to anesthetize the fruit flies.

Lay the culture vial on its side while anesthetizing the flies.

Dip the wand into the FlyNap solution and rub off extra solution on the lip of the bottle.

Stick the anesthetic tip of the wand into the vial, just below the plug. Keep the vial on its side until all the flies are anesthetized.

Immediately spill the flies onto a white card or piece of paper. You have up to 50 minutes to do your examination.

Place flies in a row on the paper. Move them with a fine brush. Separate different kinds and sexes. Place discarded flies into the morgue.

Dividing flies by type and sex

A Fruit Fly morgue

Sexing Flies Males have a dark end to the abdomen and the abdomen is more rounded.

Male – Female fly characteristics

Ventral posterior view of female and male fruit flies

Mating and Counting Vials are labeled with characteristics of each parent. 6 virgins and 6 males are placed in a culture vial.

7 to 10 days after a cross is started, remove the parents from the culture.

Review of Anesthetizing Fruit Flies  Anesthetizing Fruit Flies Anesthetizing Fruit Flies